is this normal

so i started practicing to powershift to increase my track times and im noticing that when i power shift my car is back firing im wondering if this is normal or not

im not tapping the rev limiter so thats not the problem

all depends what kind of exhoust you got. If its a free flowing no cats, Ya ull probly get backfiring, Specialy if you rev it high. High for like a 5.0 is like 4500 or more. But it could be ur timming. Check that. Super simple

chrisverneuil wrote:all depends what kind of exhoust you got. If its a free flowing no cats, Ya ull probly get backfiring, Specialy if you rev it high. High for like a 5.0 is like 4500 or more. But it could be ur timming. Check that. Super simple

High for a modular 5.0 is 4500 rpm?

well i have a 06 gt with slp loudmouths

Backfire is likely on the exhaust side. Too rich or too lean air/fuel, clogged fuel filter or other cause in fuel pressure drop. Is this the stock tune? did you put a cold air intake on the car? or is it just the SLP loudmouths?

BCP wrote:

chrisverneuil wrote:all depends what kind of exhoust you got. If its a free flowing no cats, Ya ull probly get backfiring, Specialy if you rev it high. High for like a 5.0 is like 4500 or more. But it could be ur timming. Check that. Super simple

High for a modular 5.0 is 4500 rpm?

lol
i shift mine at higher than that when i raced it


and since u have SLPs the backfire is that

If you do not have cats on the vehicle then yes its normal. If you do have cats, then its as other have said can be anything that changes the A/F ratio, either by tune, or by parts. Normally when upgrading exhaust past the cats there is no adverse affects, as far as backfiring. Most Unburnt fuel will be handled by the ignited cats.

We would need more info to pinpoint why your settup is backfiring.

Is the backfire between shifts? When RPM is dropping fast? Or at other times?

RTW0223 wrote:

BCP wrote:

chrisverneuil wrote:all depends what kind of exhoust you got. If its a free flowing no cats, Ya ull probly get backfiring, Specialy if you rev it high. High for like a 5.0 is like 4500 or more. But it could be ur timming. Check that. Super simple

High for a modular 5.0 is 4500 rpm?

lol
i shift mine at higher than that when i raced it


and since u have SLPs the backfire is that

4500 On a push rod engine, Depending on the type ya it is and the year:) You have to remember push rod engine has much more crap internally to go wrong during high RPM than OHC. Overhead cam is a totally different story.

chrisverneuil wrote:

RTW0223 wrote:

BCP wrote:

chrisverneuil wrote:all depends what kind of exhoust you got. If its a free flowing no cats, Ya ull probly get backfiring, Specialy if you rev it high. High for like a 5.0 is like 4500 or more. But it could be ur timming. Check that. Super simple

High for a modular 5.0 is 4500 rpm?

lol
i shift mine at higher than that when i raced it


and since u have SLPs the backfire is that

4500 On a push rod engine, Depending on the type ya it is and the year:) You have to remember push rod engine has much more crap internally to go wrong during high RPM than OHC. Overhead cam is a totally different story.

Well considering he posted it in the "modular" section and his SN ha s"S197" in it, one would gather he wasnt referring to a 5.0 pushrod engine. FWIW, 4500 is not "high RPM" on those either.

Lolz maybe not for 5.0:) but idk i dont have a 5.0. But id be a lill afraid to rev it high if i did. Id make sure id have a high rpm cam and the right valve train to do it. Becouse floating the valvs could be atomic

chrisverneuil wrote:Lolz maybe not for 5.0:) but idk i dont have a 5.0. But id be a lill afraid to rev it high if i did. Id make sure id have a high rpm cam and the right valve train to do it. Becouse floating the valvs could be atomic

Well maybe you should learn a bit about a 5 liter before commenting on them?

FWIW, i shifted my stock long block 302 with 115,000+ miles at 6300 RPM...
F cam, GT 40 intake. Stock heads, stock valve springs, stock lifters, stock headers, etc. Not only did it live, but it ran well, and continued doing so until i pulled the engine and put it in another car, then it continued to run well in that car.

I shifted my 310 ci 5.0 at 7600 with pretty mild parts.

I shift my current engine north of 7000 as well.

I would hope you would ensure you have a cam, etc, that makes power in the upper RPM range, otherwise you'd be wasting your time by over revving the engine.

7000, Shiz I got a dam rotary and I shift at 7k but it's designed to rev that high... The first part of my post I was dead on. It's the second half where kinda got screwy. But I'm also not wrong nor right also. Info is valid just not exactly what I was talking about

chrisverneuil wrote:7000, Shiz I got a dam rotary and I shift at 7k but it's designed to rev that high... The first part of my post I was dead on. It's the second half where kinda got screwy. But I'm also not wrong nor right also. Info is valid just not exactly what I was talking about

Cant really compare the RPM range of a rotary to a pushrod V8 though.

I'd agree with the rest of your comment.

http://en.wikipedia.org/wiki/Wankel_engine well my engine is balanced stock to 9000 RPM and with small mods is capable of 12K 13K rpm and more

chrisverneuil wrote:http://en.wikipedia.org/wiki/Wankel_engine well my engine is balanced stock to 9000 RPM and with small mods is capable of 12K 13K rpm and more

So, like I said....