backfiring

[Camaro Dom]

ok. summers almost here and my camaro is still the wanna be sports car it was when i bought it. I'm getting a full header back system (!cat) in about 2 weeks and i wanna put some balls on this beast. Turbocharged: someday... but for now i could afford a nitrous kit.
Ok, so basically, i'm gonna do comp and leak down tests to see if the engine can handle the power, full out tune up and the whole nine yards. I got a shaved intake w/ the ghetto air silencer delete.
So, with my car being an auto, how do i not blow the intake off the motor like kristen and 12second did? i understand the CONCEPT of fuel puddling but not any idea how that would happen or how to avoid it.
I'll be starting with probably a 75 wet shot if everything checks out. I just wanna know that i'm being safe about this. Is there anythign else i need to look at/ prep up? Engine internals are all factory.

[Shodown]

Re: backfiring

As far as I know, James (12secondv6) never backfired his nitrous, he straight up blew popped a piston. Kristen and I backfired our systems.

To prevent backfires, use a WOT switch (most kits come with them) and a window switch set at 3000-6000 rpms and you should be fine. To safeguard your car even more, you could get a progressive controller as well, but they are another $125-$200.

[ssms5411]

Re: backfiring

Yes, A WOT switch and window switch is your best bet.

[BobDoLe]

Re: backfiring

considering the concept that you want to spray only during WOT, here's something to think about:

some people on here are going to tell you that the only way to go fast is to spray through the shifts (with an A4).
while you're at WOT, your stock PCM is going to cut back the throttle for the shifts - meaning you will not actually be at WOT while you're putting the pedal to the floor.

here's the proof - screenshot of fireball27's (stock tune with 87 octane) 99 A4 Camaro during a WOT shift. he kept his foot mashing the gas pedal to the floor, but you're seeing the throttle position cut back to 45% and injector pulse width dropping back to 10.5msec .... with the motor going at over 5000rpm. just before the shift at the same RPM, injectors were pushing pretty hard at 17.6msec pulse width.


a TPS switch (not the mechanical one that sits behind the gas pedal) should see this electronic lifting of the gas pedal and shut the nitrous off accordingly.

[97rs4life]

Re: backfiring

considering the concept that you want to spray only during WOT, here's something to think about:

some people on here are going to tell you that the only way to go fast is to spray through the shifts (with an A4).
while you're at WOT, your stock PCM is going to cut back the throttle for the shifts - meaning you will not actually be at WOT while you're putting the pedal to the floor.

here's the proof - screenshot of fireball27's (stock tune with 87 octane) 99 A4 Camaro during a WOT shift. he kept his foot mashing the gas pedal to the floor, but you're seeing the throttle position cut back to 45% and injector pulse width dropping back to 10.5msec .... with the motor going at over 5000rpm. just before the shift at the same RPM, injectors were pushing pretty hard at 17.6msec pulse width.
http://hattiecarnegie.org/meatspot/camaro/wot.99.jpg (huge screenshot)

a TPS switch (not the mechanical one that sits behind the gas pedal) should see this electronic lifting of the gas pedal and shut the nitrous off accordingly.

hmm, I wouldn't say that as here is proof of my 97 shifting through the gears and it didn't drop the TPS during the shifts. This was a WOT run against a lt1 from a light to 80mph. Check into the tuning and see if there is something in TM or the trans settings causing that to happen. Or maybe it is something with the newer 99+ cars and the electronic TB. I know for a fact that my 97 spraying through the shifts does not have that drop in TPS each shift.

[BobDoLe]

Re: backfiring

hmm, I wouldn't say that as here is proof of my 97 shifting through the gears and it didn't drop the TPS during the shifts. This was a WOT run against a lt1 from a light to 80mph. Check into the tuning and see if there is something in TM or the trans settings causing that to happen. Or maybe it is something with the newer 99+ cars and the electronic TB. I know for a fact that my 97 spraying through the shifts does not have that drop in TPS each shift.

you have torque management removed, right?
torque management is what cuts back on the throttle.
on my 2001, i removed torque management and it no logger cut back the throttle.

on the other hand, my 99 A4 SS, it also doesn't show the throttle lifting on the stock tune - it does not have electronic throttle control.

[97rs4life]

Re: backfiring

yes all TM is removed now, I also have another log before I did any tranny tuning or engine tuning at the track and it didn't drop the TPS at all either. So TM doesn't affect that at least on 97 cars

[BobDoLe]

Re: backfiring

given that the pulse width remained constant in your other log without the tuning, it is probably safe to say:

cars without electronic throttle control WOT shifts are WOT shifts.

on 98+ v6 camaros, your electronic throttle is going to close up on you during WOT shifts unless you remove torque management.

[97rs4life]

Re: backfiring

yea I will have to log my brothers 99 here soon and check that out, just got the credits for his. Pretty sure it deals with that elect. tb though

[Sean_99_3.8]

Re: backfiring

i have a 99 and between shifts i can feel the car slow for a sec then shift it probably keeps the trans together. has any one had better ET with torque management removed?

[97rs4life]

Re: backfiring

one of the first things to get done when people tune a car is to remove the TM. It is there for ride comfort from the factory. If you have HPtuners Sean, get rid of it. If you don't, see me at the michigan fbody gathering on June 16th and I can help ya out if you want to pay the credits. ;)

[bah]

Re: backfiring

on 98+ v6 camaros, your electronic throttle is going to close up on you during WOT shifts unless you remove torque management.

correction, 99+