I am just curious. I would think there is a possibility of an extreme lean condition if your boosting and hit fuel cut due to traction control. I guess it depends on how the fuel cut operates... like does it completely cut fuel so there is no fuel at all, meaning no possibility of a burn...

do any of you FI guys bang around the traction control fuel cut with no problems?

thanks

 

It's not a problem, don't worry about it. I hit it all the time when I punch it and forget to turn off the TCS. AFAIK, TCS just reduces the throttle, it does not cut fuel.

 

Yep.......i've hit it too.......not a concern

 

jesse: good call, i was not thinking about fly by wire.

i hope your right, cause that would be kick ***! perhaps someone datalogging TPS could go try and do a burnout with TCS on?

-charles

 

So all that stuff from ATI about this was BS? I thought they recommeded turning it (TCS) off so as not to hit it?

 

hehehe.......yeah, well they also recommended not using the gas pedal with this kit.

 

I wouldn't be so sure about that. If it was just "reducing" the throttle it would be A LOT more smooth then it is. Much like when cars hit speed goveners in them.

There is much more going on then just reducing throttle. Maybe later this week I can confirm what is going on. But the rev-limiter I have felt in the 350Z is pretty much the same as other cars I have driven that I know for a FACT cut fuel.

Some cars cut fuel in a pattern to slow the motor down. Some limit fuel, either way BOTH are bad, cause say the injecotor cuts off. There is still some fuel vapor in the intake runner that is going to make it's way in on the next cycle.

Heck since the Mid 80's cars have been using fuel cuts to control Revlimiters.
The only cars that are pretty mild on the revlimiters are running ignition ONLY cuts. But there is no way to tell just by the sound or the feel. You would have to confirm it with somone that has fully researched it.

EA

PS: "Good old fashion" 5.0 Mustangs from 87-93 used a fuel cut for a revlimiter. At 6250 it would pull out 1/2 of the fuel. Then a few hundered RPM later it would pull all fuel. So yes it is very common for the OEM to do this. Since to doesn't really cause any issues on N/A cars.

 

SVTkid,

From what has been posted on this site, the TCS system on the Z uses the drive-by-wire throttle to reduce throttle input under slip conditions in coordination with the ABS and Electronic Brake Distribution.

phunk is not asking about rev limiter.

D

 

Ditto what articfury said. We're talking about two separate things here. Yes rev limiter cuts fuel, TCS limits throttle.

 

I realize that. TCS is what I am talking about. ATI (and if I remember correctly, Mike from AA) recommended turning it off in FI cars.

So you are saying that this is NOT necessary?

 

Seems the TCS hads its fingers in everthing, fuel, throttle, brakes..

To quote the service manual...


"TCS Function
The wheel spin occurrence of the drive wheels is detected by the ABS actuator and electric unit using the
wheel speed signals from all four wheels, so when wheel spin occurs, the amount of wheel spin is
reduced by controlling the hydraulic brakes on the right and left rear wheels, cutting the fuel to the engine,
and partially closing the throttle valve to reduce the engine torque. The throttle opening is also controlled
to obtain the optimum engine torque."

 

 

I don't know about this. It just seems like such a poor engineering idea to cut fuel under any conditions. If the same amount of air is coming in and you cut fuel, you are going to run lean no matter what. Lean of course equals detonation, which is bad for any car.

Regis' quote from the manual only states that the car pulls throttle and fuel together. This is just like taking your foot off the gas. If you read it as written, it might seem different. I still believe that the ECU does not pull fuel and leave the throttle open.

 

agreed........cutting the fuel does not translate into leaning out the AFR.....they could be saying that they've caused the injector to close entirely