just installed the stainless steel greddy evo II /w test pipes and I get a throaty rasp at 3500-4000 rpm, anyone know a fix for this? I took it to a muffler shop and they sad to ask greddy if it was a factory defect. It's mainly coming from the y pipes. anyone else have a greddy that might have the same problem?

Thanks

 

its from your testpipes

 

agreed.....my evo II is perfect but once the test pipes go on it gets raspy. When I look at the angle of the flanges where they attach between the y-pipe and test pipe....they never match. I have had 3 manufacturers now and they all have the same problem. You almost need thick gaskets that deform when they are tightened to compensate for uneven flange angles. The rasp is the resonance of the exhaust gases leaking through the metal gasket and vibrating. PIA!!

 

would changing the test pipes clear it up? If so which ones should I get?

 

If you get HFC, the sound will be less raspy (if any at all) depending on which ones you go with. I recommend Helix DNA Hi Flows, Crawfords, and the Ultimate Racing Cats.

Ravi

 

Before installing Kinetix plenum, I had rasp with Crawford HFC. More air coming through might have solved the anwanted sound...

 

I have had Mines, Xerd, and Labree resonated......and they all had rasp. None of them had flanges that match up to a stock y-pipe. The stock y-pipe flange actually has a bit of an angle to it.