OK, NOW I have all the facts.

Yes, I am using a donut in my Perrin downpipe with no flex. I am NOT using stock bolts, I found my stock bolts and they wont work anymore because I also have a Megan Racing O2 housing and the stock bolts apparently had a different thread pattern and the installer had to use other bolts without springs. Thats why I am not using the stock bolts and springs. The thread in my stock bolts were #$%@ up, when trying to install them.


Apparently everything being so thight and because of the vibration it gets loose. And now?

 

I have a 05 EVO and put on a RSR stainless downpipe and Greddy EVO2 catback and have zero leaks and it was near perfect fitment.

Dan

 

are you sure? I thought no true 3 inch downpipe fits 05 evo yet. Is RSR 3 inch?

 

Yea, I called up Jeff at 500whp and he said it is the only one that fits and its definitely 3inch. It installed with no problems what so ever.

Dan

 

Helix fits the 05's and is 3 inch, so does RSR, so does Ultimate Racing, so does Invidia as I recall

If it is loosening up, either it's not starting off tight enough in the first place, or perhaps you need some sort of thread lock on it (though I have never had to use it on the dp, and cannot imagine why/how it is working it's way loose if it is being torqued to spec in the first place)

 

05' with Megan DP and perfect fitment. Dunno why some people report problems.