Greddy EVO I - Rust thru @ muffler flange

[Fletch]

The Greddy EVO I has only seen 2 entire winters (granted there is a lot of snow, ice and salt) and I just heard and found an exhaust leak @ the resonator section to muffler flange. I think it should have lasted a little longer, but I have heard similar stories from other platforms with the EVOI in my area.

My plan, don't laugh, is to take it to a local muffler shop and have them cut the flange out and weld in a piece of pipe.

When the rest of it rusts out, I think I'll have them fab some kind of custom 3" cat back set-up. Maybe keep the greddy muffler because it is the only stainless part. Good or bad plan for those with custom exhaust???

[PhreakdOut]

Removing the flange before the resonator is OK. It's a hard joint and should not cause any additional problems. Removing the flange joint just before the muffler would not be good. This would promote torsional cracking at the head of the muffler thus accelerating the fatigue of the system.

Sorry to hear about the Greddy rusting out so soon. Even for South Bend, this should have lasted longer.

[Fletch]

Hmmm, my exhaust system is already pretty rigid because the custom y-pipe flex joint is too far downstream which used to make the top of the downstream O2 sensor bang into floorpan in reverse or under hard acceleration. That problem stopped, probably because of all stress on the rest of the exhaust joints, thus accelerating the rust problem in the rear flange.

Perhaps a flex joint could replace the rear flange?

[PhreakdOut]

Oops, my bad. I thought the joint between the center pipe and the muffler had spring bolts and a semi-spherical graphite gasket. I don't have the drawings for the Gen 1 or 1.5 system, but the current is shows hard connections from the converter back. I believe this to be true on your model as well. In general, any connection without spring bolts can be replaced with a welded joint. Toyota adds the flanges for serviceability.

As for the Y-Pipe flex, this is critical to the system life. Toyota tries to locate the flex section underneath the centerline of the crankshaft. (Between the manifolds) Locating it fore or aft of this point increases stress on the flex. Additionally, it's best to maintain the same diameter and length of flex. Shorter or smaller diameter flexes are more ridged. Thus movement is transmitted downstream. Too large or too long can promote a resonance.

Since your system is basicly scrap metal, none of this matters right now. However, I'd make corrections before going to a high dollar custom or stainless steel system.

Feel free to PM me any questions and I'd be glad to help.

[TadS]

I had one of the hangers rust of my Apexi system. I just welded it back on. I think it's the Indiana road salt, that stuff will eat anything.

[Fletch]

Took it to Quality Muffler & Brake, same place that put my y-pipe on, and he said he could probably fix it with a new gasket. I had him cut the flange out and weld a 2.5" piece in place of it.

Besides fixing the leak, when he welded it up, he positioned the Greddy closer to the floorpan so it doesn't hang down so low to the ground like many of the Greddys seem to do.

It was a good cheap fix, $20 cash.

[Midias]

yea don't worry about the flange I don't.\

Look ma no flange