Well in my never ending search to make more power, I stopped by the muffler shop and told them to put my car up on the lift and remove the 1 resonator in my exhaust. The resonator is beefy and we all were expecting a 2.75 bottle neck in the 3" system. Ummmm negative....it was a 2.25" bottleneck as we couldn't fit a 2.25" pipe inside of it (the pipe OD was more like 2.30-2.35"). Took it out and the car is louder but not by much. Idle is noticable louder and if you rev it, it is louder. However while cruising and driving it's barely louder maybe 2-3 decibels more. Still WAAAAAAAY quieter than my old Blitz exhaust. So all you guys with 400+ hp on the Evo2 exhaust....I'd bet you still have 10-20 hp waiting to be tapped in Siegel was shocked when I told him the news.
When I removed my resonator, I didn't really notice much of a difference. I was only going from the 2.25" diameter to 2.5" diameter, not as drastic of a change as you, but I didn't notice the exhaust getting any louder. I did notice that when I start the car in the winter, the exhaust has a tinny kind of sound to it, until the car warms up.
he's guessing that guys making 400 hp+ could possibly gain 10-20 whp if they remove this resonator. notice how he said "I'd bet"
I thought about deleting mine, just swapping in a flex piece but at 280 whp I don't think it'll make much difference
really...who makes a 2.8" downpipe to mount to this? I thought the idea was that it mounts right up to the stock 2.5" doughnut gasket.
Well I'm no where near a point where my greddy evo2 is robbing HP from me. Once I get there, I'll swap out the exhaust system for a catless and full 3". Until then, I'm loving the sound and don't miss the obnoxious loudness of other turbo backs.
It's not that much louder. I will say that the turbo is now spooling like a banshee. It's spooling a good 200 rpms faster than before and I still have multiple issues to straighten out.
QFT Your best bet is a good ol' boy muffler shop with lots of chevelles and grand nationals and whatnot sitting around
Midas on Roswell Rd just south of Abernathy. The only reason I don't have exhaust leeks right now. They took care of the 3"downpipe to 2.5"midpipe change and used a flex pipe so the exhaust wouldn't shake itself apart again. Need a little flex! Cost me about $60. Runs like a champ. The guy who did it does custom work for Harleys and muscle cars he new his shit. I forgot his name but I can get it for you.
Some of the 3" exhausts come with a flex joint right there after the downpipe -- apparently to prevent unnecessary vibration on the turbo studs or something...dunno.
He had a tapering flex pipe from 3-2.5. He sawed off a piece of the mid pipe infront of the resonator and welded it on used a 3" flange to the downp. It also allowed for some flex so that the generic mid and stromung axleback had a little bit more clearance to hang naturally. The clearance was weird becuase all the exhaust parts were from differen't manufacturers. It brought the whole set up together. Overall I am very happy with the work. He also let me stand right there and watch which I like when anyone is working on my car. Cool guy!
Actually there IS a need for it UNLESS you've got Cusco/Group N engine mounts AND kartboy/Group N exhaust hangers. Even then a flex joint is worth it. What will happen over time is all the movement of the engine/trans assy vs the movement of the exhaust system will break the uppipe. I've been there and done that many times.