NoRiceInside

ive always noticed my car pops when i shift or at any other time when the engine is on the decel. its annoying and even embarassing.

reason i bring it up now, a year after having my car, is my friend just installed a LM on his 98 TA and it sounds so smooth with no popping or any kind of weird bumbling. i love it and wonder why LT1s pop?

razor02097

just turn off the jake brake

NoRiceInside

LenT1

I don't know.

I do know that my car used to pop real bad all the time but now that it runs like crap it dont pop even after a 6000 neutral rpg rev and let it fall back down. I think it might have to do with how rich or lean the car is running?

Lees94Formula

I see in your sig you have a 3" bullet muffler. Thats the cause. Lt1's always pop when you put on a low-restriction muffler, even more if the cat is removed.

Severous01

you need back pressure...that's it.

razor02097

don't be embarassed about a motor that "pops" under deceleration... its just the car's way of engine braking and yes as above the more backpressure you have the less the popping the more the car will decelerate and the more restriction you will have in the exhaust.

NoRiceInside

hmm...i thought it had to do with stock manifolds and stock 2.75" tubing...the popping almost sounds like too much backpressure. i had a flowmaster 80 series before and it did it even worse.

CamaroUK

My car was fine (completely stock) until I unbolted the stock muffler and ran a straight pipe out the back, it popped upon deceleration and really went bang if I blipped the throttle at the right moment. Peronally I loved it, and gave a few people a suprise.

I have since put a proper cat back on, and it has put a stop to it, although I recognise the car trying to pop under the same conditions but it kind of just makes a quiet "put" sound instead.

As far as I know the condition is brought on by fuel igniting in the manifold, maybe the pcm goes crazy when the tps reads shut and the rpms are high, so it overfuels in an effort to compensate? Maybe someone can shed some light here?

wrd1972

I have a lot less of this decell poping since I loosened my rockers some. They used to be 1/2 PZL and now they are 1/4.

Definitely made a difference to the point it is practically gone.

NoRiceInside

lol. i thought it was supposed to be 1/4 past zero.

well i have had several of my friends say it sounds like a backfire. thats the point where it gets embarassing. badass trans am but "runs like crap" as they said. eh, **** em, they drive slow imports.

1racerdude

No cats, leak to draw in air under decell,running a tad rich.
Ya don't need back pressure either.

NoRiceInside

huh. this is gonna mix things up. i resealed my intake to fix the infamous oil leak and now the popping is gone.

i guess the manifold wasnt torqued down enough so thats why it sprung an oil leak, but i guess it also sprung a vacuum leak, causing excessive popping from being too LEAN, not rich.

Cerwin Vega Fan

Good to hear you got the problem fixed.

NoRiceInside

chris! what up brah. havent talked to you in forever. whatchu been doin to the z?