Fuel Injection...

My dad wants to know how this is gonna screw with the races. everybody is going to get the same fuel mileage now. Skinner mentioned they can change maps, but do they get to chose from 5 built in maps,or can they make their own?
 
There are always things that can be changed regarding fuel injection that can add a little bit of horsepower, but will hurt fuel mileage. I'm sure NASCAR will restrict a lot of it. But the few things that will probably be up to the teams is where a team may or may not lose a little bit in fuel mileage.
 
I think the process of changing over from carburation to Fuel Injection should be very interesting. Racing carburators have been developed/tuned over the years to become very efficent especially at full throttle/power their biggest weakness is under partialy throttle/power conditions, which is exactly where the computer controlled fuel injection systems really shine. The different fuel curves will vary from manufactaurs because of the mechanical variations between engines, there will probably also be variations among teams/drivers of the same brand. Of course calibrations will have to be developed for the variety of tracks the NASCAR races on ( the calibration for a Super Speedway will not be the optimum for a road course )
The biggest advantage of FI over carburation is with the fuel injection system being a closed-loop learning system it should be able to learn and adjust fuel trims in real time (something that cannot be accomplished with a carburator) A/F ratio will be monitored by the control module using input from the O2 sensors, air temp sensor, coolant temp sensor, barometric sensor and throttle position sensor and the A/F ratio will be correct at all times under all conditions. Also, as the engine's needs change (due to weather conditions and track conditions) the system should adjust for those changes. It should also make for a much cleaner/easier to drive engine during part throttle ( pit road speed and under caution ) and short tracks/road courses where throttle application smoothness is very dependent on traction.
I really doubt that it will have a effect on the racing, unless........someone finds a way to cheat it.
Should be interesting.
 
I like the change to EFI. NASCAR has always been about racing what Detroit sells, so it make sense. It wont be too long before they are racing dual overhead cam 6 cylinder engines, perhaps in 7 or 8 years.

Teams will have a field day with the throttle body and intake manifolds, which leaves them plenty of room to play. Perhaps they will be allowed some playing room as far as injector location and angle. I expect teams will come up with lots of innovations that Detroit can actually use.

When EFI arrives, I hope it forces NASCAR to get rid of the cable drive fuel pump and go back to a motor driven pump with an electronic shut off. I have my doubts that the mechanical pump will provide consistant pressure at all times. Besides those concerns, an electric pump is cheaper and more reliable.
 
I think the process of changing over from carburation to Fuel Injection should be very interesting. Racing carburators have been developed/tuned over the years to become very efficent especially at full throttle/power their biggest weakness is under partialy throttle/power conditions, which is exactly where the computer controlled fuel injection systems really shine. The different fuel curves will vary from manufactaurs because of the mechanical variations between engines, there will probably also be variations among teams/drivers of the same brand. Of course calibrations will have to be developed for the variety of tracks the NASCAR races on ( the calibration for a Super Speedway will not be the optimum for a road course )
The biggest advantage of FI over carburation is with the fuel injection system being a closed-loop learning system it should be able to learn and adjust fuel trims in real time (something that cannot be accomplished with a carburator) A/F ratio will be monitored by the control module using input from the O2 sensors, air temp sensor, coolant temp sensor, barometric sensor and throttle position sensor and the A/F ratio will be correct at all times under all conditions. Also, as the engine's needs change (due to weather conditions and track conditions) the system should adjust for those changes. It should also make for a much cleaner/easier to drive engine during part throttle ( pit road speed and under caution ) and short tracks/road courses where throttle application smoothness is very dependent on traction.
I really doubt that it will have a effect on the racing, unless........someone finds a way to cheat it.
Should be interesting.

I doubt they will be using extensive sensors on Cup cars, especially since NAS is talking about sticking with a restrictor plate for SSpeedways. (I would guess between the throttle body and intake, but it's possible to bolt it on to the front of the throttle body). Staying away from O2 sensorsand other tuning tools and sticking with just fuel and air flow sensors would require more know how when fine tuning the engine. Reading plugs would remain an artform, and optimizing the TB and intake would be crucial to performance at a range of RPM's. I expect more than a few burnt pistons before this is settled.
 
The NASCAR fuel injection system has eight injectors – one per cylinder – located in the intake manifold and a Electronic Control Module with 8-10 electronic sensors. The throttle body is manufactured by Holley, current vendor for NASCAR carburetors, the restrictor plate for plate tracks will be located between the throttle body and intake manifold, while the airbox and air intake remain the same as currently being used. The system is similar to the one supplied by McLaren for the IndyCar Series in the past, although it is NASCAR-specific.
 
8 to 10 sensors..

water temp
manifold pressure
throttle position
O2 left
O2 right

That's 5, where to they pull the other 3-5 from??
 
The NASCAR fuel injection system has eight injectors – one per cylinder – located in the intake manifold and a Electronic Control Module with 8-10 electronic sensors. The throttle body is manufactured by Holley, current vendor for NASCAR carburetors, the restrictor plate for plate tracks will be located between the throttle body and intake manifold, while the airbox and air intake remain the same as currently being used. The system is similar to the one supplied by McLaren for the IndyCar Series in the past, although it is NASCAR-specific.

Thanks for the surprising info. All those sensors sure takes a lot of human talent out of the equation. Lap top and usb cable qualifies you as a pro. I know that's an over statement, but software will rule the day.
 
Water Temp
Manifold pressure
Throttle position
4 O2 sensors, sensors coupled in paired cylinders.
Combined ambient temp/ humidity sensor/ Barometric sensor
Fuel pressure sensor
RPM/Timing sensor
 
Thanks for the surprising info. All those sensors sure takes a lot of human talent out of the equation. Lap top and usb cable qualifies you as a pro. I know that's an over statement, but software will rule the day.

Thats why NASCAR went to McLaren Electronics for the ECUs they have experiance in racing applications with limitations. McLaren/NASCAR limits tuning through software codeing and parameter adjustments. Further tuning or "hacking" of the units is prevented by codeing. McLaren Electronics officials GUARANTEE that any attempts to alter the system will be easy to track and have made the system simple for NASCAR to police..........hopefully ;)
 
I doubt they will be using extensive sensors on Cup cars, especially since NAS is talking about sticking with a restrictor plate for SSpeedways. (I would guess between the throttle body and intake, but it's possible to bolt it on to the front of the throttle body). Staying away from O2 sensorsand other tuning tools and sticking with just fuel and air flow sensors would require more know how when fine tuning the engine. Reading plugs would remain an artform, and optimizing the TB and intake would be crucial to performance at a range of RPM's. I expect more than a few burnt pistons before this is settled.

This has been the best thread I have seen for quite some time. Thank you.

I do have to ask a question. If NASCAR dictates the mapping for the computers, why would they still use plates on the SS's?
 
Water Temp, fuel pressure sensor and RPM/Timing sensor are nothing new, but I'm sure they will be utilized differently.

The throttle position sensor is necessary because it replaces the mechanical linkage.


The Manifold pressure sensor allows them to simulate the accelerator pumps on carburators.

The Barometric sensor adjust the engine tune to compensate for altitude. I doubt it makes it into the final spec.

I hope they dump the O2 sensors, since they are post combustion and allows the engine to adjust it's tuning on the fly. Why not go to direct injection and take all the skill out of tuning an engine?
 
Water Temp, fuel pressure sensor and RPM/Timing sensor are nothing new, but I'm sure they will be utilized differently.

The throttle position sensor is necessary because it replaces the mechanical linkage.


The Manifold pressure sensor allows them to simulate the accelerator pumps on carburators.

The Barometric sensor adjust the engine tune to compensate for altitude. I doubt it makes it into the final spec.

I hope they dump the O2 sensors, since they are post combustion and allows the engine to adjust it's tuning on the fly. Why not go to direct injection and take all the skill out of tuning an engine?
hell we may be switching to mechanical injection as soon as august on our drag car. Being told that we could pick up 2 tenths on ET over the carburetor.

Direct injection would have so many costs implications....
 
hell we may be switching to mechanical injection as soon as august on our drag car. Being told that we could pick up 2 tenths on ET over the carburetor.

Direct injection would have so many costs implications....

I was just making a point about taking all of the skill out of tuning an engine. Direct injection eliminates even more from the equation, but it's not a mainstream technology yet.

I'm thinking that some of these sensors are there for testing purposes only. With O2 sensors, you wouldn't need to check plugs to see if the engine is tuned perfectly. Just read the O2 sensor outputs, and you know exactly what is going on during combustion. Using post combustion sensors takes most of the skill out of fuel delivery and throttle control adjustments. They are the main reason cars now go 100,000 before we even think of tuning them. Then it's as simple as changing plugs and checking injector resistance. I have some big questions about implementation of EFI, most of all will NASCAR allow these engines to tune themselves on the fly, like todays cars do.

Yet another edit. I checked the link to your race team. Nice. You obviously know how much easier it is to get a perfect tune with EFI when compared to carbs.
 
1. IAT- intake air temp
2.ECT- engine coolant temp
3. TPS- throttle position? and does not activate the throttle,merely sees where the driver is pushing mechanical linkage.
4. MAP- manifold absolute pressure,basically a vacuum sensor to sense engine load.
5.MAF- mass air flow,senses how much air is flowing into engine, in the past street cars have had either MAP or MAF but not both until the 90"s when they would use MAP to confirm what MAF was seeing.
DREF (GM) or PIP (Ford)- basically RPM
6.CKP- crankshaft position sensor, this will effect base timing and advance curves
7.CMP. camshaft position sensor,primarily used for sequential injection and missfire detection (on all production cars sold in the U S since 1996)
8.O2 sensors-oxygen content in the exhaust manifolds,Rich or lean.If anything only 2 just left and right banks. if they use them at all. O2 sensors on production cars are there for catalyst efficency and some have more normally after the CAT to help verify CAT efficenicy.
9. VSS-vehicle speed sensor but I doubt they would use this.
 
3. TPS- throttle position? and does not activate the throttle,merely sees where the driver is pushing mechanical linkage.

I didn't state it clearly, but the direct fuel flow control function of carburator linkage isn't present in an EFI system. On a carburator, the linkage activates the accelarator pump(s) and butterflys, then the increased vacuum feeds more fuel into the engine. Since EFI doesn't use vacuum fuel feed control, the TPS tells the ECU to up the fuel supply by changing frequency and duration of injector function.

That said, many of todays cars have no mechanical linkage connected to the gas pedal, it's just a pedal position sensor and some wires. That's how all those Toyota's were able to go crazy before "failsafe" logic was mandated by the Government. Just as scary, many steering wheels have no mechanical connection to the wheels. Sensors and wires to the ECU is all you get. The ECU controls an electric motor to control steering.
 
Thats why NASCAR went to McLaren Electronics for the ECUs they have experiance in racing applications with limitations. McLaren/NASCAR limits tuning through software codeing and parameter adjustments. Further tuning or "hacking" of the units is prevented by codeing. McLaren Electronics officials GUARANTEE that any attempts to alter the system will be easy to track and have made the system simple for NASCAR to police..........hopefully ;)

I just hope that access to post combustion sensors isn't allowed for tuning purposes. (O2 or exhaust manifold temp for example)
 
I doubt any TPP will be used. TPS along with MAP and or MAF will be used to control injector pulse width.
I"m also wondering if they will also use 2 cylinder head temp sensors.
 
I doubt any TPP will be used. TPS along with MAP and or MAF will be used to control injector pulse width.
I"m also wondering if they will also use 2 cylinder head temp sensors.

No, they'll still use linkage, but you understand what I was saying about the linkage function. I doubt you'll see cylinder temp on the final build. I don't know of any function they have other than hooking it to an idiot light. I guess they could indicate a lean condition, but you wouldn't know which cylinder. Aren't they more of a safety/emissions sensor?
 
No, they'll still use linkage, but you understand what I was saying about the linkage function. I doubt you'll see cylinder temp on the final build. I don't know of any function they have other than hooking it to an idiot light. I guess they could indicate a lean condition, but you wouldn't know which cylinder. Aren't they more of a safety/emissions sensor?
Since they mentioned a water temp sensor, I doubt they'd get to use a cylinder head sensor. But with NASCAR, you never know. As far as I'm aware of, the basic system shouldn't need more than a TPS and MAP, correct?

This isn't the system we're going to (it's EFI, we're looking at MFI), but the manual says an IAT (or barometer sensor), TPS, water temp, and 02 is all that's needed to function at stoich. If you don't want to run at stoich, take away the 02 sensor.

IF it's going to be a similar box to what IRL runs, I wonder if cup will now have a fuel map selection knob on the dash?
 
Since they mentioned a water temp sensor, I doubt they'd get to use a cylinder head sensor. But with NASCAR, you never know. As far as I'm aware of, the basic system shouldn't need more than a TPS and MAP, correct?

This isn't the system we're going to (it's EFI, we're looking at MFI), but the manual says an IAT (or barometer sensor), TPS, water temp, and 02 is all that's needed to function at stoich. If you don't want to run at stoich, take away the 02 sensor.

IF it's going to be a similar box to what IRL runs, I wonder if cup will now have a fuel map selection knob on the dash?

Great info mag. It seems the coolant temp sensor has to do with cold idle. These cars idle very high and don't use thermostats, so I doubt a coolant sensor is needed. I see why the O2 sensor is recommended, but it doesn't seem to be necessary.

I hope it is a very 'dumb' FI system so the ECU isn't doing most of the tuning. I'm thinking a MAP, MAF and TPS is all that's needed. Today, tuners have to guess at race time air temp and read plugs to get a good tune. With a full-on system, the ECU would be constantly adjusting for changing conditions, and that kills off a key area of competition between teams. I don't enjoy Indy because the driver ends up being little more than a chaufer for the engineers. tires are hot, ease off. turn a knob and save fuel. Letting a computer tune the engine just takes away from the human talent nascar teams rely on to win. Watching Keselowski use his clutch to save gas was great stuff. It sure beats watching a guy turn a knob based on precise calculations done on computers by a bunch of egg heads sitting in a trailer.
 
Since they mentioned a water temp sensor, I doubt they'd get to use a cylinder head sensor. But with NASCAR, you never know. As far as I'm aware of, the basic system shouldn't need more than a TPS and MAP, correct?

A very basic EFI system could get away with just using;
Throttle position sensor, for throttle input.

A Crank position sensor, the EFI control unit needs it to know When to fire the injectors.

A Coolant temperature sensor, it could be done without one but engine temperature would have to be controlled within a very small window or poor performance and driveability would result.

That would be a very simplistic model capable of extremely limited data feedback and real time tuning.
I have'nt seen NASCARs final system , but I have seen the system on test mule engines and they where using a full range of sensors. My understanding at this time is that some of the sensors currently being used are for testing purposes only and will not be on the final product.
 
A very basic EFI system could get away with just using;
Throttle position sensor, for throttle input.

A Crank position sensor, the EFI control unit needs it to know When to fire the injectors.

A Coolant temperature sensor, it could be done without one but engine temperature would have to be controlled within a very small window or poor performance and driveability would result.

That would be a very simplistic model capable of extremely limited data feedback and real time tuning.
I have'nt seen NASCARs final system , but I have seen the system on test mule engines and they where using a full range of sensors. My understanding at this time is that some of the sensors currently being used are for testing purposes only and will not be on the final product.

The crank position sensor is part of electronic ignition. Lots of EFI systems used distributors for timing. NASCAR still specifies distributors mounted in the stock location using the stock firing order. I haven't heard any plans to change this.

I could live with a coolant sensor, but todays cup cars run fine without the ability to adjust for temp on the fly. If the engine starts running hot, power drops off. An EFI system with no coolant sensor would leave this aspect of racing unchanged.

I don't think they could do without a MAF sensor or a precise RPM/speed circuit and still get acceptable fuel mixture through all the various loads these engines go through. TPS and crank position wouldn't give much info about engine load.

It will be interesting to see how much old school tuning talent nascar will leave in the equation.
 
The crank position sensor is part of electronic ignition. Lots of EFI systems used distributors for timing. NASCAR still specifies distributors mounted in the stock location using the stock firing order. I haven't heard any plans to change this.

That's debatable- I don't know if NASCAR uses crank trigger or distributor trigger. We're switching this week, over to a crank trigger. We're at 42 degrees of timing and it starts mixing up the cylinders every now and then.

Doesn't have the catastrophic result that mixing them on a nitro motor does, but it seems to recover itself. We aren't sure if it's the distributor or MSD box, so we're switching to crank trigger.
 
A distributor wont necessarily change timing if there are no primary ignition components inside it.
Example A 98 Chevy pickup 5.7L has a distributor but the only components inside it are a cam position sensor to tell the PCM or ECU when cyl #1 is at TDC compression stroke the cmp is used for sequential firing of the injectors and for misfire detection to set a DTC for whatever cylinder is misfiring.
The crank sensor can only detect when #1 comes by and signal the PCM to start telling the ICM when to fire the coil it can't detect if it is on intake or exhaust stroke.
You can turn that distributor all you want and never change the base timing, about all you can do by turning it is to either get it so far out of sync it wont even run or at minim turn on the check engine light with a code for CKP and CMP out of sync. now if you take a hammer and big punch and actually knock the CKP around will you change base timing.
As far as IAT that is exactly what it is, measures ambient air temp entering the engine and has nothing to do with baro.
Barometric pressure is normally measured by either MAP as soon as it is powered up and on some by MAF.
30 + years in the industry has sent me for a boatload of schooling.
 
Just watched Race hub, and if you believe the info, it's a direct injection and full electronic fuel injection system to go with it. The presently mandated distributor will be gone, I'm dissapointed that it's going to full computer control and adjustment. Looks like NASCAR will now be monitoring sofware installed on the ECU.
 
No way in frozen hell it's direct injection. Audi was the first direct injection for racing, and they're still working on that design, 5 or 6 years later. Even then, that's diesel. Besides, direct injection requires dual overhead camshafts for proper injection angle- with the rockers, there's no room for the injectors.

It might have been confused with Direct PORT Injection, which would make a ton more sense.

With no distributor, I'm guessing they're also going the way of coil-on-plug. On that will be fun. I think even the ROLEX cars run distributors...Indycars are COP i believe, but they're alot shorter races, granted more RPM. To maybe same # of fires per race. Those would be a "replace every session" item. Main issue being vibration, distributor coil is on firewall, COP coil is on the valve cover.
 
I'm sure you are right, Magnethead. After reading up on the fuel pressures involved with direct injection, it's obvious that Geisler misstated when he said 'injected directly into each cylinder'.

My main concern wasn't how the fuel was supplied, it was more about the new ignition system which really hasn't been talked about until now. It seems tuning is now down to intake design and software. Hopefully, the system will limit the ECU's ability to adjust on the fly. From what Hub showed, the 8 coils are on the valve covers.
 
EFI Test Concludes at Degga

Intereting stuff from todays EFI test at Degga:
http://www.nascar.com/news/111020/fuel-injection-testing-talladega-rpemberton/index.html

DAYTONA BEACH, Fla. -- After a similar session at Charlotte Motor Speedway on Monday, Sprint Cup Series teams again tested electronic fuel injection on Thursday at Talladega Superspeedway.


Ten cars turned laps, including two teams from Roush Fenway Racing and Richard Childress Racing, and one team each from Hendrick Motorsports, Earnhardt-Ganassi Racing, Stewart-Haas Racing, Michael Waltrip Racing, Penske Racing and Joe Gibbs Racing. Plans call for the full implementation of EFI in the Cup Series beginning with the 2012 season.
 
This is my first post. I am interested in FI and how it works. I am no expert on the subject. I was wondering if the teams would rather return to the carb? I had to join to find anything on FI and NASCAR? I think I found my answer. I apologize for the poor sentence structure and concepts I use for my abstract. No one trained me on FI and my friend said good luck trying to figure this stuff out. I'd like to know if I am on the right path with all these sensors? Please correct me if the abstract is incorrect or it's all out of step? Thanks for your patients.

1. IAT - This is a cold morning, the wind blows on the sensor, or is still and circles the sensor in the room temp of the garage. Everything in the garage is at room temp. So when the key is turned on, a morning map tells the stepper motor to rise the throttle plate or open it a crack for said choke setting.
2. ECT - Same signal is this balanced temp of the room temp and now that water is at a room temp sending in a signal to match the temp that matches a balance of numbers is the IAT, and each has a number to it as an input signal.
3. TPS - This is a demand input. I demand WOT and I send in that one number of many. Look at me like a room light and it's a dimmer switch. See my many wattages moving up to 100w? So this makes me a many-signal-sending-sensor: means analog is the concept to the abstract. When I am at closed throttle, this is one signal being sent in of many. Still, the abstract has to first send in an analog into the black box.
4. MAP - This is where if I WOT and create the most vacuum, this tiny ear drum is being move away from the penultimate number. On lift, this drum or silicone wafer is being sent in the other direction as in no it's not. It is still being pulled in the same direction and that means rich on lift. Rich on WOT. When that car is sitting in the garage, not only room temp is there, but the atmospheric is at 0, or no pressure on the sensor, therefore, not running, the sensor is set at 14.7 psi. That is what is pressing on that wafer. This is now the penultimate number to remember or, man, if you tell anyone about this, especially nazzzzzzzzz
5. MAF - This is glow plug theory. Same kind of intake was moving past my glowing, cool me down, ah, your throttle is open this much. What is the difference I calc a vacuum or a point of open/close is the air moving until the valve closes on the penultimate in the chamber.
6. CKP - This sensor creates a magnetic field or a certain wave used for computing. The output is a square wave and acts like an ocean wave coming to shore. However, conceptually, the wave begins at 0 and this comes to a height and that height remains as a 1 in computer speak, and when the wave crests and flattens out back to 0, all this time, the speed of the crank dictated how long/short that square wave was in computer speak or binary numbers.
7. CPM - This too is an A/C current maker like the crank sensor. This is where we have key off, the cam sent in a signal, the black box has saved it in RAM (volatile data that is erasable), we turn the key off on another cylinder, the spark knows who to fire off, you never felt that engine start so quick.
8. 02 - This holds the penultimate number steady. We climb a mountain we lose oxygen, the 02 sniffs too wet a charge. It runs this calc all the time hitting it's 'target number,' [closed loop] or the ideal zero is minimum emissions.This then reverts back to the penultimate number. neutralizes the gases, i.e., in ideal conditions. So the 02 keeps aiming for that in an emissions kind of way. You cannot tune a closed loop engine. Open loop is a different story. The 02 sensor has a range of .01v to .90v and never over a volt. So that ping is up at .90v, and if I'm correct, the opposite happens as in, the higher the number you think rich, but it's lean as in AFR numbers. This is an analog signal as in many ranges that can be measured from tenths of volts to under a single volt.
9. VSS - This is an RPM limiter. Say you have a 2 or-3-piece crankshaft on your dually. The harmonics are going to spin way, way too, too fast so you hit that speed limit, that's all she wrote.

This is a very complicated but really simple at the same time. There is more to explain but it's going to be difficult to send it under the radar and how to cheat with the genericough-cough processing. I can't flat out tell you how to do it. You have to figure it out on your own how many ways it can be done. All I am is the messenger of reading between the nodes, flip-flops, and binary buffoonery.


Some where in a place long ago, I have the horrible memories and the smell of burnt wire insulation engrained in my brain. But, I always seem to wake up before the fire starts while trying to troubleshoot that damn intermittent loss of ground signal @ WOT.
 
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