i have test pipes and JIC y-pipe with stock muffler. Everytime i change gears (release gas pedal) i have some kind of long blow-off-valve sound coming from the y-pipe or test pipes (sounds like i have FI). I think it started having this sound after i installed my test pipes...what's wrong?? i've checked around and there shouldn't be any leaking

thx

 

i have the exact same sound...weird...i have test pipes and evo2 exhaust.....then some sort of backfiring or mad shaking noise when the revs jump...especially around 100mph.

 

i got the same sound too.
i think itz coming from the testpipe.
should be normal since nothing is leaking.
anyone can confirm this?

 

it's the test pipes - I have the Helix ones with a stock exhaust and I get that exact sound... regardless of whatever exhaust mods you have, if you have the test pipes, you will have raspiness when you let off the throttle and when you are a specific RPMs (mine is raspy b/w 2200-3000 RPMs)...

the price for performance is as so...

 

I have the same sound.. and I'm stock except for the exhaust resonator being cut out. Kind of hisses in between shifts.

 

you might be running a little rich, which is causing a slight backfiring from exhaust. Same thing happened to me with my supra when i ran a full 3" exhaust with no cats, until I got it tuned.

 

the raspiness sounds actually stoped after few houndreds of km on the exhaust.
dono why

 

There is a thread on this "Raspy buzzing noise...." (157 replies).

 

yeh we should all know about the raspy buzzing noise of the test-pipes. But the hises from shifting is weird

 

I also have the JIC Y-pipe, stock midpipe and stock muffler. Only difference is I have RT cats versus test pipes. The hissing that happens off-throttle I think could be caused by the difference in diameter between the larger JIC Y-pipe and the smaller stock mid-pipe. This larger into smaller connection is not likely the best setup, but I went with it because I love the sound on the stock exhaust. Also, the hissing is not the same noise as the "raspiness" that everyone has posted about endlessly.

 

your right~ i did have a leak before between the jic y-pipe and midpipe but then i used a better gasket and checked...there is no leaks...i'm thinking if the hissing is coming from the flex joints on the y-pipe