Some interesting reading on the fuel injection progress...> http://www.jayski.com/teams/fuel-injection.htm
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.
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.
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.
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.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....
3. TPS- throttle position? and does not activate the throttle,merely sees where the driver is pushing mechanical linkage.
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 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.
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?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?
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.
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.