4 Cylinder Short Track 1/5 mile Asphalt Track

4

4CylinderDriva

Guest
To put it simple I previously drove 4 cylinders for a couple of friends/family. I was very successful racking up numerous wins and 2 championships in 4 years. I went on to college and get my degree and I am returning back to racing. My friends and family helped me get my car up and running but it just seems like there has been a lot of tensions and talking behind one anothers back. I don't want to cause drama and feel I am no longer accepted so I am doing things on my own this year.
With that being said I am not the most knowledgeable with certain things in the car such as springs. I have no idea what to do with springs. I know the RR is stiff as possible, I know the camber we use, the tow we use.. Just the springs and any other tips and tricks I don't know. Any suggestions on how I can get the right spring weight in the car, or how I can find what numbers work?
The track is a 1/4 mile (1/5 mile actually) and you are constantly turning. You never go straight.

Thanks again for reading
 
In general, the softer the spring is at a wheel the more grip you can get at that wheel. HOWEVER, it is easily possible to have too much grip at a wheel - you need to control that wheel (bouncing due to track surface) and you need balance among all four wheels. Controlling a wheel requires a stiffer spring. Balance means that as the car's weight transfers while turning you still get as much overall grip among all four tires as possible (and it also tends to keep the car handling consistently throughout the whole race). Also, if a tire gets too much grip it can overheat, which will cause it to lose most of its grip. It can be a complicated system - especially when you also need to factor in changing track conditions as well as what "feel" you need in order to drive with confidence (a.k.a. being willing and able to push the car to its best potential).

A relatively stiff RR will tend to cause more loading on the LF - this can compensate for the LF wanting to unload during turns, due to body roll taking load off the left side of the car and transferring it to the right side (during left turns). Since your car is FWD, and assuming that the engine power is transferred reasonably equally through the transmission and CV joints to both front wheels, trying to reduce LF unloading would be beneficial. But if you get too stiff on rear springs then the car's back end can get too loose.

Other things that effect how your springs work: type of track surface (dirt or paved) and its condition (smooth or rough), the banking angle in the turns, shock absorbers operating parameters, tires used (street vs. racing), and especially what the rules allow. Rules can limit spring choices (as well as shock choices), and set minimum chassis heights. Note that, for most standard linear rate springs, if you cut any coils off you make it stiffer.

How can you get the right spring weight in the car, or how you can find what numbers work?
First, realize that while it is easy to set the car onto a set of scales and weigh it out - those are static condition numbers. They can make a good starting point, but they do not tell you what happens to the car while it is moving on the track. What's going on while the car is moving is the most important. If you can afford to take your car to a shop with a 4-Post or 7-Post chassis testing rig (like the pros use) then you can start to get a handle on what happens as your car moves... otherwise, most of us run test laps and experiment - and we pay most attention to what the stop watch tells us.

I'd start with my car basically stock (original factory springs installed at all wheels), or if you already have prior successful knowledge then install those springs (you might need to ask somebody whom you trust). I'd also make or install something to measure wheel travel at each wheel. Try to drive carefully onto the track (without bouncing the car much) so that your wheel travel measurements don't get thrown off by bouncing through the pits and onto the track. (Also exit the track carefully for the same reasons.) Make sure to write down what those spring rates are, as well as what tire pressures you use and any tire stagger that you have.

Run some laps to get a feel for what the car is doing, and get some lap times. If it is a paved track, take tire temperatures across all tires (if it's a dirt track, measure tire pressures). Check what your wheel travels are. Write all of this down!

Change your RR spring only to a stiffer one. Reset your tire pressures to where you started / allow the tires to cool off. Reset your wheel travel measurers, carefully go back onto the track, run the same number of test laps, and record all of the same stuff that you did before. Now you have some things you can compare.

As long as you have time, and as long as the track conditions haven't changed a lot (surface got hotter due to the sun, or dirt is drying out) then change another spring and do it again... and again... and again... This builds your database so you get a good idea of how different springs effect your car. By the way, things that cause your car to get slower are still good data - but don't get fooled by changing track conditions.

You can test on race days, but it's more difficult with everybody else doing stuff too. Do try to get data from feature races - since those are the races that pay, those are the races that you want to focus your adjustments on.
 
gone said:
In general, the softer the spring is at a wheel the more grip you can get at that wheel. HOWEVER, it is easily possible to have too much grip at a wheel - you need to control that wheel (bouncing due to track surface) and you need balance among all four wheels. Controlling a wheel requires a stiffer spring. Balance means that as the car's weight transfers while turning you still get as much overall grip among all four tires as possible (and it also tends to keep the car handling consistently throughout the whole race). Also, if a tire gets too much grip it can overheat, which will cause it to lose most of its grip. It can be a complicated system - especially when you also need to factor in changing track conditions as well as what "feel" you need in order to drive with confidence (a.k.a. being willing and able to push the car to its best potential).

A relatively stiff RR will tend to cause more loading on the LF - this can compensate for the LF wanting to unload during turns, due to body roll taking load off the left side of the car and transferring it to the right side (during left turns). Since your car is FWD, and assuming that the engine power is transferred reasonably equally through the transmission and CV joints to both front wheels, trying to reduce LF unloading would be beneficial. But if you get too stiff on rear springs then the car's back end can get too loose.

Other things that effect how your springs work: type of track surface (dirt or paved) and its condition (smooth or rough), the banking angle in the turns, shock absorbers operating parameters, tires used (street vs. racing), and especially what the rules allow. Rules can limit spring choices (as well as shock choices), and set minimum chassis heights. Note that, for most standard linear rate springs, if you cut any coils off you make it stiffer.

How can you get the right spring weight in the car, or how you can find what numbers work?
First, realize that while it is easy to set the car onto a set of scales and weigh it out - those are static condition numbers. They can make a good starting point, but they do not tell you what happens to the car while it is moving on the track. What's going on while the car is moving is the most important. If you can afford to take your car to a shop with a 4-Post or 7-Post chassis testing rig (like the pros use) then you can start to get a handle on what happens as your car moves... otherwise, most of us run test laps and experiment - and we pay most attention to what the stop watch tells us.

I'd start with my car basically stock (original factory springs installed at all wheels), or if you already have prior successful knowledge then install those springs (you might need to ask somebody whom you trust). I'd also make or install something to measure wheel travel at each wheel. Try to drive carefully onto the track (without bouncing the car much) so that your wheel travel measurements don't get thrown off by bouncing through the pits and onto the track. (Also exit the track carefully for the same reasons.) Make sure to write down what those spring rates are, as well as what tire pressures you use and any tire stagger that you have.

Run some laps to get a feel for what the car is doing, and get some lap times. If it is a paved track, take tire temperatures across all tires (if it's a dirt track, measure tire pressures). Check what your wheel travels are. Write all of this down!

Change your RR spring only to a stiffer one. Reset your tire pressures to where you started / allow the tires to cool off. Reset your wheel travel measurers, carefully go back onto the track, run the same number of test laps, and record all of the same stuff that you did before. Now you have some things you can compare.

As long as you have time, and as long as the track conditions haven't changed a lot (surface got hotter due to the sun, or dirt is drying out) then change another spring and do it again... and again... and again... This builds your database so you get a good idea of how different springs effect your car. By the way, things that cause your car to get slower are still good data - but don't get fooled by changing track conditions.

You can test on race days, but it's more difficult with everybody else doing stuff too. Do try to get data from feature races - since those are the races that pay, those are the races that you want to focus your adjustments on.
Click to expand...
Thank you a lot for this. It is a paved oval and there is no bumps whatsoever very smooth pavement. I plan on taking tire temperatures and going up for practice prior to season starting soon. I have the springs that were always successful for me in the past in, and I'm going to start there. I have a question about getting the car loose. I'm not sure if it's because of the track being so small or what it is but nobody ever seems to be loose. I've never once in all my years there have been loose in the FWD car. (The NASCAR MOD I've been loose in before)
When you stated above ""instrument to measure Wheel travel" can you give me a reference on this as I have no idea how I would even do that.
Do you feel that camber in the rear would help at all? Our cars used to have a ton of rear tow and would drive at a 20 degree angle going straight.
There is also a 4 inch ride height rule at my local track but no left side weight % on the car. Should I try to max left side weights out to anything as long as im legal on ride heights? Thanks for all this insight. You even taking the time out of your day means a lot to me.
 
1/5 mile that runs Mods and is circular. Is this Mahoning Valley?
 
About "loose": it can feel different to different drivers. People watching can usually tell - the rear end of the car tends to swing out towards the wall (and then might whip back-and-forth if it's bad). Generally if you're not loose the back tires follow in the same tracks that the front tires make. Depending on the car, driver, and track a little looseness is faster - it keeps the back tires from getting excessive grip that slows down lap times.

To me, "loose" feels different in a FWD car vs. a RWD car. It has to do with which wheels power the car. Typically on a RWD car the engine is overpowering the grip that the rear tires can get - they might not lose enough grip to spin the tires, but the driver can feel that the power is making the car go sideways instead of straight. (Again, depending on the car / driver / track interaction that could be good or bad.) For a FWD car, "loose" feels to me that the front end wants to dart into the turn - causing the rear end to swing out. It might not be as much of a problem, since in a FWD car the rear tires aren't propelling the car so you're only creating some extra drag instead of also losing forward propulsion. You're trying to fight against two types of speed-sapping drag: friction caused by the rear tires sliding sideways instead of following the front tires exactly, and friction caused by the rear tires digging into the track (some call this "track bound", and in low horsepower classes it can even bog the motor if it is really bad). There's a very fine line here - I prefer to be a little loose since sliding friction is usually less than bound-up friction.

I don't know Mahoning Valley, but if you're in a constant turning circle then you are probably playing with that fine line through all of the lap. You might ask somebody in the grandstands to film your laps, and you can see if your rear end is hanging out towards the wall (which would be looseness) or not. Again, this could be good... I just would prefer to minimize it so I minimize the sideways drag.

To measure wheel travel, what we used to rig up was a rod that was parallel to the shock absorber. We mounted a pointer (piece of stiff wire) near the bottom of the shock's shaft (where the pointer won't interfere with the shock's normal travel), and we placed two grommets on the rod, so that the pointer was between the grommets. We set the device to "zero" with the car standing still, and pushing the grommets against the pointer. As the suspension moves (as the car travels) the shock will compress and expand, and the pointer will move those grommets apart. When you stop the car, you can measure the distance between the grommets to get an idea of the wheel's travel. This is not an exact measurement, but if you do it consistently you can get relative data that can help you decide what works better for your car (or not). You have to be careful not to hit any abnormally large bumps (such as getting onto or off of the track) because those will move the grommets and give you an exaggerated reading. It might take some experimenting to build these tools and make them work consistently (I think that some racing vendors might sell something like this). By the way, there are procedures easily found on the Internet about how to measure your total wheel travels while sitting in the garage, but realize those are maximum possible numbers that you will probably not see on the track. I prefer numbers due to movement on the track, even if they are not exact. Also realize that if you change shock absorbers they can effect your wheel travel and these measurements.

About rear camber: many race cars benefit from rear camber - usually setting the camber so that the tire is pretty much perpendicular to the track during the turns will give you the most tire patch contact with the track, and therefore (hopefully) the best grip. Since at your track you're pretty much in a constant turn, rear camber could be a really good idea (rear camber can fight against traction on straights, but if your straights are really short or nonexistent then you don't have to worry about it). HOWEVER, other things come into play too - particularly how your tires distort under load, which is usually due to their construction and air pressures. You can use some trigonometry to calculate theoretical tire camber based upon the track's banking angle, but unless your track banking is perfectly uniform (at least where your driving line is) and you are always able to use the same driving line (which is doubtful while dealing with traffic) I would only use a calculated number as a starting point. Possibly better would be to start out with cambers a degree or two more than the stock settings, and experiment from there (or ask somebody you trust). Let your tire temperature measurements tell you when you've found the best compromise setting - the temps will be closest to even across the tire.

About "tow": I think you mean "toe" as short for "toe-in" or "toe-out"? Toe helps the car feel more (or less) stable while it is moving, and it helps more on the front than the back. We prefer 0 toe (wheels completely parallel to the frame, while moving) because any other measurement creates some drag. 0 toe also requires a driver who doesn't mind that it can cause the car to feel a little twitchy - if you don't like that then add some toe-out. Toe-in on the front usually makes a RWD car feel unstable, but it can help a FWD car turn. A FWD car can use extra static toe-out because the mechanical effect of powering the wheels tends to pull the wheels in (cause toe-in) so you set some extra toe-out to compensate (in our case, we tried to set enough toe-out so when the motor pulls the toe back in we ended up near 0).

In my experience, rear toe should be set to get as close to 0 as you can since anything else there only creates drag and has little effect on stability. HOWEVER, if you are required to use stock wheel spindles or other stock suspension parts that deflect under racing conditions, you might play with toe settings to offset those deflections. This would be a fine tuning exercise that I wouldn't bother with until after I thought I had everything else really good in my suspension. The only way to know how much toe to use on each axle is to pay attention to how the driver "feels" and what the stopwatch says.

About left side weight %: this effects weight transfer in the turns. You want enough to help load the right side tires (but not overload them) while not unloading the left side tires too much, as the car body leans in the turns. On pavement you can more easily overload the right side tires due to weight transfer than you can on dirt tracks, so I prefer to mount my weights as low and to the left side of the car as I can. Low because height acts like a lever arm that multiplies the effect of weight transfer, and too much lever allows a larger and more sudden weight transfer that can overload your right side tires (especially the RF). How much? It's another driver feel thing, and it's also affected by the condition of your tires and how they distort in the turns. Usually other people have already figured out what works best at your track, and the track rules end up getting set to limit it, so I'd start with a left side weight % that matches what the rules allow. Then I might experiment by moving my weights inboard a little (but still low) and see how that effects the car. You might also experiment with a little extra weight (50 pounds or less) because sometimes being a little overweight at the scales actually yields better lap times due to better grip around the track (plus you're less likely to be found underweight). Your "feel" and the stopwatch will tell.

About ride heights: generally on a smooth paved track you want to be at the minimum that the rules allow. This is more an aero advantage than a weight transfer function. By the way, if you decide to work on aero effects and this track has you in a constant turn, I'd massage my aero to be most effective when the car is at the angle that it is on the track - which might make it look a little lopsided - but car body side-to-side symmetry is mostly only effective on straights. You can get ideas by looking at the bodies of Late Model dirt cars.
 
gone said:
About "loose": it can feel different to different drivers. People watching can usually tell - the rear end of the car tends to swing out towards the wall (and then might whip back-and-forth if it's bad). Generally if you're not loose the back tires follow in the same tracks that the front tires make. Depending on the car, driver, and track a little looseness is faster - it keeps the back tires from getting excessive grip that slows down lap times.

To me, "loose" feels different in a FWD car vs. a RWD car. It has to do with which wheels power the car. Typically on a RWD car the engine is overpowering the grip that the rear tires can get - they might not lose enough grip to spin the tires, but the driver can feel that the power is making the car go sideways instead of straight. (Again, depending on the car / driver / track interaction that could be good or bad.) For a FWD car, "loose" feels to me that the front end wants to dart into the turn - causing the rear end to swing out. It might not be as much of a problem, since in a FWD car the rear tires aren't propelling the car so you're only creating some extra drag instead of also losing forward propulsion. You're trying to fight against two types of speed-sapping drag: friction caused by the rear tires sliding sideways instead of following the front tires exactly, and friction caused by the rear tires digging into the track (some call this "track bound", and in low horsepower classes it can even bog the motor if it is really bad). There's a very fine line here - I prefer to be a little loose since sliding friction is usually less than bound-up friction.

I don't know Mahoning Valley, but if you're in a constant turning circle then you are probably playing with that fine line through all of the lap. You might ask somebody in the grandstands to film your laps, and you can see if your rear end is hanging out towards the wall (which would be looseness) or not. Again, this could be good... I just would prefer to minimize it so I minimize the sideways drag.

To measure wheel travel, what we used to rig up was a rod that was parallel to the shock absorber. We mounted a pointer (piece of stiff wire) near the bottom of the shock's shaft (where the pointer won't interfere with the shock's normal travel), and we placed two grommets on the rod, so that the pointer was between the grommets. We set the device to "zero" with the car standing still, and pushing the grommets against the pointer. As the suspension moves (as the car travels) the shock will compress and expand, and the pointer will move those grommets apart. When you stop the car, you can measure the distance between the grommets to get an idea of the wheel's travel. This is not an exact measurement, but if you do it consistently you can get relative data that can help you decide what works better for your car (or not). You have to be careful not to hit any abnormally large bumps (such as getting onto or off of the track) because those will move the grommets and give you an exaggerated reading. It might take some experimenting to build these tools and make them work consistently (I think that some racing vendors might sell something like this). By the way, there are procedures easily found on the Internet about how to measure your total wheel travels while sitting in the garage, but realize those are maximum possible numbers that you will probably not see on the track. I prefer numbers due to movement on the track, even if they are not exact. Also realize that if you change shock absorbers they can effect your wheel travel and these measurements.

About rear camber: many race cars benefit from rear camber - usually setting the camber so that the tire is pretty much perpendicular to the track during the turns will give you the most tire patch contact with the track, and therefore (hopefully) the best grip. Since at your track you're pretty much in a constant turn, rear camber could be a really good idea (rear camber can fight against traction on straights, but if your straights are really short or nonexistent then you don't have to worry about it). HOWEVER, other things come into play too - particularly how your tires distort under load, which is usually due to their construction and air pressures. You can use some trigonometry to calculate theoretical tire camber based upon the track's banking angle, but unless your track banking is perfectly uniform (at least where your driving line is) and you are always able to use the same driving line (which is doubtful while dealing with traffic) I would only use a calculated number as a starting point. Possibly better would be to start out with cambers a degree or two more than the stock settings, and experiment from there (or ask somebody you trust). Let your tire temperature measurements tell you when you've found the best compromise setting - the temps will be closest to even across the tire.

About "tow": I think you mean "toe" as short for "toe-in" or "toe-out"? Toe helps the car feel more (or less) stable while it is moving, and it helps more on the front than the back. We prefer 0 toe (wheels completely parallel to the frame, while moving) because any other measurement creates some drag. 0 toe also requires a driver who doesn't mind that it can cause the car to feel a little twitchy - if you don't like that then add some toe-out. Toe-in on the front usually makes a RWD car feel unstable, but it can help a FWD car turn. A FWD car can use extra static toe-out because the mechanical effect of powering the wheels tends to pull the wheels in (cause toe-in) so you set some extra toe-out to compensate (in our case, we tried to set enough toe-out so when the motor pulls the toe back in we ended up near 0).

In my experience, rear toe should be set to get as close to 0 as you can since anything else there only creates drag and has little effect on stability. HOWEVER, if you are required to use stock wheel spindles or other stock suspension parts that deflect under racing conditions, you might play with toe settings to offset those deflections. This would be a fine tuning exercise that I wouldn't bother with until after I thought I had everything else really good in my suspension. The only way to know how much toe to use on each axle is to pay attention to how the driver "feels" and what the stopwatch says.

About left side weight %: this effects weight transfer in the turns. You want enough to help load the right side tires (but not overload them) while not unloading the left side tires too much, as the car body leans in the turns. On pavement you can more easily overload the right side tires due to weight transfer than you can on dirt tracks, so I prefer to mount my weights as low and to the left side of the car as I can. Low because height acts like a lever arm that multiplies the effect of weight transfer, and too much lever allows a larger and more sudden weight transfer that can overload your right side tires (especially the RF). How much? It's another driver feel thing, and it's also affected by the condition of your tires and how they distort in the turns. Usually other people have already figured out what works best at your track, and the track rules end up getting set to limit it, so I'd start with a left side weight % that matches what the rules allow. Then I might experiment by moving my weights inboard a little (but still low) and see how that effects the car. You might also experiment with a little extra weight (50 pounds or less) because sometimes being a little overweight at the scales actually yields better lap times due to better grip around the track (plus you're less likely to be found underweight). Your "feel" and the stopwatch will tell.

About ride heights: generally on a smooth paved track you want to be at the minimum that the rules allow. This is more an aero advantage than a weight transfer function. By the way, if you decide to work on aero effects and this track has you in a constant turn, I'd massage my aero to be most effective when the car is at the angle that it is on the track - which might make it look a little lopsided - but car body side-to-side symmetry is mostly only effective on straights. You can get ideas by looking at the bodies of Late Model dirt cars.
Click to expand...
Here's some footage of the track
 
gone said:
About "loose": it can feel different to different drivers. People watching can usually tell - the rear end of the car tends to swing out towards the wall (and then might whip back-and-forth if it's bad). Generally if you're not loose the back tires follow in the same tracks that the front tires make. Depending on the car, driver, and track a little looseness is faster - it keeps the back tires from getting excessive grip that slows down lap times.

To me, "loose" feels different in a FWD car vs. a RWD car. It has to do with which wheels power the car. Typically on a RWD car the engine is overpowering the grip that the rear tires can get - they might not lose enough grip to spin the tires, but the driver can feel that the power is making the car go sideways instead of straight. (Again, depending on the car / driver / track interaction that could be good or bad.) For a FWD car, "loose" feels to me that the front end wants to dart into the turn - causing the rear end to swing out. It might not be as much of a problem, since in a FWD car the rear tires aren't propelling the car so you're only creating some extra drag instead of also losing forward propulsion. You're trying to fight against two types of speed-sapping drag: friction caused by the rear tires sliding sideways instead of following the front tires exactly, and friction caused by the rear tires digging into the track (some call this "track bound", and in low horsepower classes it can even bog the motor if it is really bad). There's a very fine line here - I prefer to be a little loose since sliding friction is usually less than bound-up friction.

I don't know Mahoning Valley, but if you're in a constant turning circle then you are probably playing with that fine line through all of the lap. You might ask somebody in the grandstands to film your laps, and you can see if your rear end is hanging out towards the wall (which would be looseness) or not. Again, this could be good... I just would prefer to minimize it so I minimize the sideways drag.

To measure wheel travel, what we used to rig up was a rod that was parallel to the shock absorber. We mounted a pointer (piece of stiff wire) near the bottom of the shock's shaft (where the pointer won't interfere with the shock's normal travel), and we placed two grommets on the rod, so that the pointer was between the grommets. We set the device to "zero" with the car standing still, and pushing the grommets against the pointer. As the suspension moves (as the car travels) the shock will compress and expand, and the pointer will move those grommets apart. When you stop the car, you can measure the distance between the grommets to get an idea of the wheel's travel. This is not an exact measurement, but if you do it consistently you can get relative data that can help you decide what works better for your car (or not). You have to be careful not to hit any abnormally large bumps (such as getting onto or off of the track) because those will move the grommets and give you an exaggerated reading. It might take some experimenting to build these tools and make them work consistently (I think that some racing vendors might sell something like this). By the way, there are procedures easily found on the Internet about how to measure your total wheel travels while sitting in the garage, but realize those are maximum possible numbers that you will probably not see on the track. I prefer numbers due to movement on the track, even if they are not exact. Also realize that if you change shock absorbers they can effect your wheel travel and these measurements.

About rear camber: many race cars benefit from rear camber - usually setting the camber so that the tire is pretty much perpendicular to the track during the turns will give you the most tire patch contact with the track, and therefore (hopefully) the best grip. Since at your track you're pretty much in a constant turn, rear camber could be a really good idea (rear camber can fight against traction on straights, but if your straights are really short or nonexistent then you don't have to worry about it). HOWEVER, other things come into play too - particularly how your tires distort under load, which is usually due to their construction and air pressures. You can use some trigonometry to calculate theoretical tire camber based upon the track's banking angle, but unless your track banking is perfectly uniform (at least where your driving line is) and you are always able to use the same driving line (which is doubtful while dealing with traffic) I would only use a calculated number as a starting point. Possibly better would be to start out with cambers a degree or two more than the stock settings, and experiment from there (or ask somebody you trust). Let your tire temperature measurements tell you when you've found the best compromise setting - the temps will be closest to even across the tire.

About "tow": I think you mean "toe" as short for "toe-in" or "toe-out"? Toe helps the car feel more (or less) stable while it is moving, and it helps more on the front than the back. We prefer 0 toe (wheels completely parallel to the frame, while moving) because any other measurement creates some drag. 0 toe also requires a driver who doesn't mind that it can cause the car to feel a little twitchy - if you don't like that then add some toe-out. Toe-in on the front usually makes a RWD car feel unstable, but it can help a FWD car turn. A FWD car can use extra static toe-out because the mechanical effect of powering the wheels tends to pull the wheels in (cause toe-in) so you set some extra toe-out to compensate (in our case, we tried to set enough toe-out so when the motor pulls the toe back in we ended up near 0).

In my experience, rear toe should be set to get as close to 0 as you can since anything else there only creates drag and has little effect on stability. HOWEVER, if you are required to use stock wheel spindles or other stock suspension parts that deflect under racing conditions, you might play with toe settings to offset those deflections. This would be a fine tuning exercise that I wouldn't bother with until after I thought I had everything else really good in my suspension. The only way to know how much toe to use on each axle is to pay attention to how the driver "feels" and what the stopwatch says.

About left side weight %: this effects weight transfer in the turns. You want enough to help load the right side tires (but not overload them) while not unloading the left side tires too much, as the car body leans in the turns. On pavement you can more easily overload the right side tires due to weight transfer than you can on dirt tracks, so I prefer to mount my weights as low and to the left side of the car as I can. Low because height acts like a lever arm that multiplies the effect of weight transfer, and too much lever allows a larger and more sudden weight transfer that can overload your right side tires (especially the RF). How much? It's another driver feel thing, and it's also affected by the condition of your tires and how they distort in the turns. Usually other people have already figured out what works best at your track, and the track rules end up getting set to limit it, so I'd start with a left side weight % that matches what the rules allow. Then I might experiment by moving my weights inboard a little (but still low) and see how that effects the car. You might also experiment with a little extra weight (50 pounds or less) because sometimes being a little overweight at the scales actually yields better lap times due to better grip around the track (plus you're less likely to be found underweight). Your "feel" and the stopwatch will tell.

About ride heights: generally on a smooth paved track you want to be at the minimum that the rules allow. This is more an aero advantage than a weight transfer function. By the way, if you decide to work on aero effects and this track has you in a constant turn, I'd massage my aero to be most effective when the car is at the angle that it is on the track - which might make it look a little lopsided - but car body side-to-side symmetry is mostly only effective on straights. You can get ideas by looking at the bodies of Late Model dirt cars.
Click to expand...
We used to have the rear toe out so far that the cars would be traveling so sideways down the straight line. It worked damn good too for that track. Soon everyone was doing it and they said we weren't allowed to do it anymore. Something I've never done was take tire temps. I never knew how it worked and how to utilize the information gained from it. I was asking questions recently and found out how you can change the camber and take the guessing work out of it to find the perfect tire temps (or close to perfect as possible) I have 2 gopro's as well so I'm going to be keeping track of wheel movement as well and see how it goes with adjustments to the car.
As for looseness I don't really think the cars can get loose there. Someone provided a video above and its just constant pushing. I'd love to loosen this up and be on the edge. I heard somewhere about putting washers in the rear hub of the car would help. Is this more of like a stagger thing so your wheel is out farther? Do you think this would help
 
Watching that video, I see some looseness in most of the cars - easiest to see as they exit turn 4 (and somewhat as they enter and exit turns 1 - 2). It's not a lot, but even the leader is doing it. Look for wiggles in the back end. Note that, for a FWD car, if the front end is tight then it could cause the rear to wag (look loose) but don't try to correct that problem the same way that the RWD cars do. The FWD car's front tires have to do almost all of the work (propel, steer, and most of the braking) so it is easy to overheat them and end up with a push due to the front tires losing grip (without the rear tires overpowering them).

There are a number of articles available online about taking tire temperatures. The two main things to get best results are: do it as soon as possible after the car comes off the track, and have the same person doing it while using the same equipment and doing it using the same pattern and tire order. Might want to do the RF first, followed by the RR and then the LF and LR, and always starting with the edge closest to the wall, then the middle, and then the other edge. By the way, avoid driving through any water while coming off the track or your temperatures could be thrown off.

What you are looking for (tire temps): fairly even temperatures across the tread of each tire. Edges that are significantly hotter than the middle and / or the opposite edge indicate camber problems (the tire is riding more on the hottest area, instead of evenly across the whole tire). Hottest in the center indicates too much air pressure (which could be worsened by pressure build-up during the race). You may not be able to get temps perfectly even, but the goal is to avoid hot narrow strips.

You also want to compare overall tire temperatures among all four tires. Right sides will be hotter than left sides due to loading in the turns, and driving tires will be hotter than coasting tires. Some folks try to get both right sides to average nearly the same temperature (and left sides close to equal of each other, although that is usually more difficult). Generally, the closer all four tires are to being the same temperature the better overall grip you're getting - BUT driving style and available horsepower might produce better results without running the tire temps all the same. It's another area for experimenting.

Sliding the tires - particularly if the car is loose or if the driver likes to throw it sideways - can give you tire temperatures that mislead your interpretation of what's going on. We liked to have a teammate in the grandstands who took video, or at least paid attention to how well (or not) the rear tires followed the front tires. He could tell us if we were sliding around enough to skew our tire temp readings. As an example: if a tire keeps sliding out toward the fence, temps along its outside edge (edge towards the fence) will be hotter - the same thing you might see if you have too much camber on that tire - and you might think the camber is at fault when actually it's a load transfer problem. Sometimes it can be hard to tell, or hard to find the best adjustment... so you might try lessening the camber on that tire anyway - if the car still looks like it is sliding and that tire still has a hot outside edge then probably you're not going to fix this with camber settings.

Another thing about tire temperatures: you want to get each tire as close as you can to its best gripping temperature without exceeding it. Too hot, and the tire overheats and quickly loses most of its grip. Not hot enough, the tire doesn't make all of the grip that it could but it still makes more grip than if it gets overheated. What is the best temperature? If you run racing tires then somebody from that company should be able to give you a number (or narrow range), or other racers may know. Typically the temperature is around 200 degrees F. Street tires are usually happier at a lower temperature, but you usually have to find that temperature yourself (or find out from another racer who knows). Unfortunately, if you overheat a tire for a short time (such as by sliding it) you may not see the result during your temperature measurements because the tire cooled down before you could measure it. Some drivers can feel a tire losing grip, and they might not know exactly why (it could be caused by several things) but at least they know that corner of the suspension could be improved.

About using washers on the rear hub: this would be a wheelbase alteration - not stagger. Stagger is the difference in circumference (height) between the tires on the same axle. Measure stagger with your pressures set to what you intend to start the race with. For oval tracks that run counter-clockwise (which most are, and yours is) you want the taller tire on the right side. Stagger is more effective on the driving axle, so unlike a RWD car you might like more stagger on the front than the rear. Careful, though - front stagger also affects your steering.

Spacing your wheel out (placing washers on the wheel lugs, between the hub and the wheel) changes your track width. First, be careful that you don't space a wheel out so far that when the lug nut is tight there aren't at least a couple of threads poking through the lug nut - if not, you might not be able to get the wheel tight enough. You might need longer wheel studs. (If you change wheel studs you might also go up to the next available stud diameter, if you can drill out the hub to accept them and if the rules allow, because spacing a wheel out puts more load on the wheel studs - racing can break stock wheel studs.) Generally, on pavement, widening your track width makes the car more stable - it tends to slow down the rate of weight transfer while turning, so right side tires don't get overloaded as easily. (By the way, on dirt you want to narrow your track width, to make the right side tires dig into the surface.) Your rules might limit how much wheel spacing you can do, but probably whatever that limit is will be the best setting you can get. You can space out both wheels, or just one - but which one? Another experiment. We liked to space out left wheels (on pavement) because that allowed us to control weight transfer better.
 
gone said:
Watching that video, I see some looseness in most of the cars - easiest to see as they exit turn 4 (and somewhat as they enter and exit turns 1 - 2). It's not a lot, but even the leader is doing it. Look for wiggles in the back end. Note that, for a FWD car, if the front end is tight then it could cause the rear to wag (look loose) but don't try to correct that problem the same way that the RWD cars do. The FWD car's front tires have to do almost all of the work (propel, steer, and most of the braking) so it is easy to overheat them and end up with a push due to the front tires losing grip (without the rear tires overpowering them).

There are a number of articles available online about taking tire temperatures. The two main things to get best results are: do it as soon as possible after the car comes off the track, and have the same person doing it while using the same equipment and doing it using the same pattern and tire order. Might want to do the RF first, followed by the RR and then the LF and LR, and always starting with the edge closest to the wall, then the middle, and then the other edge. By the way, avoid driving through any water while coming off the track or your temperatures could be thrown off.

What you are looking for (tire temps): fairly even temperatures across the tread of each tire. Edges that are significantly hotter than the middle and / or the opposite edge indicate camber problems (the tire is riding more on the hottest area, instead of evenly across the whole tire). Hottest in the center indicates too much air pressure (which could be worsened by pressure build-up during the race). You may not be able to get temps perfectly even, but the goal is to avoid hot narrow strips.

You also want to compare overall tire temperatures among all four tires. Right sides will be hotter than left sides due to loading in the turns, and driving tires will be hotter than coasting tires. Some folks try to get both right sides to average nearly the same temperature (and left sides close to equal of each other, although that is usually more difficult). Generally, the closer all four tires are to being the same temperature the better overall grip you're getting - BUT driving style and available horsepower might produce better results without running the tire temps all the same. It's another area for experimenting.

Sliding the tires - particularly if the car is loose or if the driver likes to throw it sideways - can give you tire temperatures that mislead your interpretation of what's going on. We liked to have a teammate in the grandstands who took video, or at least paid attention to how well (or not) the rear tires followed the front tires. He could tell us if we were sliding around enough to skew our tire temp readings. As an example: if a tire keeps sliding out toward the fence, temps along its outside edge (edge towards the fence) will be hotter - the same thing you might see if you have too much camber on that tire - and you might think the camber is at fault when actually it's a load transfer problem. Sometimes it can be hard to tell, or hard to find the best adjustment... so you might try lessening the camber on that tire anyway - if the car still looks like it is sliding and that tire still has a hot outside edge then probably you're not going to fix this with camber settings.

Another thing about tire temperatures: you want to get each tire as close as you can to its best gripping temperature without exceeding it. Too hot, and the tire overheats and quickly loses most of its grip. Not hot enough, the tire doesn't make all of the grip that it could but it still makes more grip than if it gets overheated. What is the best temperature? If you run racing tires then somebody from that company should be able to give you a number (or narrow range), or other racers may know. Typically the temperature is around 200 degrees F. Street tires are usually happier at a lower temperature, but you usually have to find that temperature yourself (or find out from another racer who knows). Unfortunately, if you overheat a tire for a short time (such as by sliding it) you may not see the result during your temperature measurements because the tire cooled down before you could measure it. Some drivers can feel a tire losing grip, and they might not know exactly why (it could be caused by several things) but at least they know that corner of the suspension could be improved.

About using washers on the rear hub: this would be a wheelbase alteration - not stagger. Stagger is the difference in circumference (height) between the tires on the same axle. Measure stagger with your pressures set to what you intend to start the race with. For oval tracks that run counter-clockwise (which most are, and yours is) you want the taller tire on the right side. Stagger is more effective on the driving axle, so unlike a RWD car you might like more stagger on the front than the rear. Careful, though - front stagger also affects your steering.

Spacing your wheel out (placing washers on the wheel lugs, between the hub and the wheel) changes your track width. First, be careful that you don't space a wheel out so far that when the lug nut is tight there aren't at least a couple of threads poking through the lug nut - if not, you might not be able to get the wheel tight enough. You might need longer wheel studs. (If you change wheel studs you might also go up to the next available stud diameter, if you can drill out the hub to accept them and if the rules allow, because spacing a wheel out puts more load on the wheel studs - racing can break stock wheel studs.) Generally, on pavement, widening your track width makes the car more stable - it tends to slow down the rate of weight transfer while turning, so right side tires don't get overloaded as easily. (By the way, on dirt you want to narrow your track width, to make the right side tires dig into the surface.) Your rules might limit how much wheel spacing you can do, but probably whatever that limit is will be the best setting you can get. You can space out both wheels, or just one - but which one? Another experiment. We liked to space out left wheels (on pavement) because that allowed us to control weight transfer better.
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Thank you for your insight. Going to be checking tire temperatures now after each session, as for toe. Will that have anything to do with front end temperature?
 
Yes, toe can contribute to tire temperature. Unless the toe is set perfectly at zero, tires can be sliding somewhat because they are not pointing exactly in the same direction as the car is trying to move. That can be a good thing, though - it can help heat the tire towards its best gripping temperature.

Note that I said "can be sliding" - you can take advantage of toe to do some steering for you (since toe puts the tire tread at an angle to the track surface). In that case the tire could better track during turns, and only slide significantly along the straights. If your track has you always turning, the sliding may not scrub off speed like it could on a track with long straights. But even on a track with long straights, toe could be beneficial if you gain more speed in the turns than you lose on the straights. Another compromise, and it takes some experimenting to decide what setting works best for you.

By the way, although traditionally toe is set by angling both wheels on the same axle, you don't have to do it that way. You can set one wheel straight ahead and only add toe to the other wheel. We liked to set our RF straight and add toe to the LF. For several reasons: unless your car has a lot of Ackermann already built in, toeing the LF out acted like Ackermann (the LF steers in a slightly tighter radius than the RF does, during left turns). Second, weight shift during turning unloads the LF which in turn doesn't keep it as hot, so toe added to the LF helped keep heat in that tire. Third, since on a FWD car both wheels tend to get pulled in (toe-in) that was the direction we wanted the RF to go in the turns but opposite the direction we wanted the LF to go in.

We preferred to set zero toe on both rear wheels, since we felt that generated less drag back there. On a FWD car the rear axle is mostly just keeping the rear of the car tracking behind the front of the car, and contributing some braking. In a RWD car the back axle is also propelling, so any drag at the rear tires can usually be easily overcome by engine power. Some people say they can get some rear steer effect via toe settings on the rear axle, but traditionally you do that by mounting that axle at an angle. If you decide to experiment with rear steer, be careful because a little goes a long way. Dirt cars (especially high horsepower classes) utilize rear steer a lot, but pavement tracks are very sensitive to it.
 
gone said:
Yes, toe can contribute to tire temperature. Unless the toe is set perfectly at zero, tires can be sliding somewhat because they are not pointing exactly in the same direction as the car is trying to move. That can be a good thing, though - it can help heat the tire towards its best gripping temperature.

Note that I said "can be sliding" - you can take advantage of toe to do some steering for you (since toe puts the tire tread at an angle to the track surface). In that case the tire could better track during turns, and only slide significantly along the straights. If your track has you always turning, the sliding may not scrub off speed like it could on a track with long straights. But even on a track with long straights, toe could be beneficial if you gain more speed in the turns than you lose on the straights. Another compromise, and it takes some experimenting to decide what setting works best for you.

By the way, although traditionally toe is set by angling both wheels on the same axle, you don't have to do it that way. You can set one wheel straight ahead and only add toe to the other wheel. We liked to set our RF straight and add toe to the LF. For several reasons: unless your car has a lot of Ackermann already built in, toeing the LF out acted like Ackermann (the LF steers in a slightly tighter radius than the RF does, during left turns). Second, weight shift during turning unloads the LF which in turn doesn't keep it as hot, so toe added to the LF helped keep heat in that tire. Third, since on a FWD car both wheels tend to get pulled in (toe-in) that was the direction we wanted the RF to go in the turns but opposite the direction we wanted the LF to go in.

We preferred to set zero toe on both rear wheels, since we felt that generated less drag back there. On a FWD car the rear axle is mostly just keeping the rear of the car tracking behind the front of the car, and contributing some braking. In a RWD car the back axle is also propelling, so any drag at the rear tires can usually be easily overcome by engine power. Some people say they can get some rear steer effect via toe settings on the rear axle, but traditionally you do that by mounting that axle at an angle. If you decide to experiment with rear steer, be careful because a little goes a long way. Dirt cars (especially high horsepower classes) utilize rear steer a lot, but pavement tracks are very sensitive to it.
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Thank you again for your insight. Means a lot more than you realize. I was curious on if in your opinion aerodynamics would help on such a small track like the one I'm racing on. Not very fast speeds (4 cylinder) constant turning.
 
Aerodynamics always plays some effect, but probably not much on small tracks with low horsepower cars. You might make the driver's "feel" better, but you might not see any advantage on the stopwatch. If your rules allow a rear spoiler or a Gurney flap on your trunk or rear edge of the roof you might get car's rear end to follow the front end a little better. Careful, though - it is easy to build a rear spoiler that hurts speed by causing too much drag.

Assuming that your rules allow aero modifications, first I'd try to figure out where on the car's body there is enough air to work with. Traditionally guys would glue short strands of yarn on the body, run some laps, and get people to pay attention to how the yarn moves. For your situation, you might find enough air movement at the rear of your roof... you might also find surprisingly little air pressure at the back edge of your trunk. Another way is to spray your car with water, run some laps, and see where it dried - wherever water is still sitting indicates little air pressure.

On your nose, you might want to smooth it up as much as you can, including minimizing grille area (if races are short you might not need the whole stock grille opening, but make sure you don't overheat... and you might need to open up your grille on hot race nights). If rules allow, you might find that you can get more air into your air cleaner by ducting from the base of your windshield (instead of using the grille) and that can be better aerodynamically. If rules allow, and if your class time trials, some guys will block off their grilles entirely while qualifying.

You can also gain good aerodynamics by smoothing the underside of your car. Rules might not allow belly pans, but they might let you smooth or get rid of anything that sticks out into the air. Pavement cars usually run a windshield so interior panels may not help, but you still might add deflectors on your A pillars to help keep turbulent air out of your interior. If rules allow you might remove your rear window so that air can exit your interior (but check that it doesn't mess up air onto your rear spoiler - you might need some interior panels to get that back). Finally, straight (slab) sides tend to do better aerodynamically, but again rules might not allow it.
 
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