I just bought the strup test pipes the other days and installed them in my guarge. When I went for a test drive I noticed a vibration noise coming from underneith the car under acceleration over 2,000RPM. I put the car back in the guarge and lifted it up and made sure everything was nice and tight and all the heat shilds were tight (just in case) and noting was wrong. It sounds like crap. Like a honda with a gutted cat almost. Is this normal... If it is these are going up for sale ASAP. Anyone else have this problem. it also happens when im just reving the car at a stop, on the back pressure it makes a gurggle noise. Any suggestions?

 

Test pipes drastically change the sound of the car, and the gurggling noise is normal even with some high flow cats.

 

so the really loud vibration type noise under exceleration is normal then?

 

I'm sorry to say I think what you are describing is normal.

Hence all the talk about "raspy", "bb's in a can" type noises with test pipes.

I have seen some speculation that is is caused by exhaust resonance fron the engines firing order when there is not enough back pressure from the cats.

Sorry.

 

I'd recheck any clearances between the pipes and the chassis. If it's less than 1/2", there's probably pipe to chassis contact when the motor is under load. Remember that the engine does twist in it's mounts quite a bit, even under light acceleration.

 

cool

 

Not that it's the solution to your problem, but a Stillen Engine damper may help (at least a bit):

http://stillen.com/product_detail.aspx?sku=307355

 

I have some clips of my G with test pipes, I'll try and see about hosting them but yeah even the vibration is pretty normal.

 

cool thanks for all the info. im gonna be taking them off tomorrow and selling them. David