Thought of a new way to waste money. I couldn't find this weird combo in the search. Run a 100 cell cat for the ladies and an o2 dump for the fellas.

Aiming for 650whp max on ID1700s/FP Red size turbo, 2.4. Would this combo still be restrictive? How much worse than a testpipe? I kinda like the idea of a car that's tame off boost but wild when you get on it.

 

The new GESI UHP cats will do that no problem. I run a GESI UHP cat on my Evo 10. One thing to note is that going from test pipe to the GESI cat did not change the volume whatsoever. If it's loud now, it still will be.

 

Thank you, that's great feedback. I now see that there are some Evo X examples running a similar combo. For me it's not just noise but also a nod to the environment since it's cleaner when cruising around this way. Seems like a dump isn't even necessary to compensate for the decreased exhaust flow, but I just want to try it.

Edit: I wonder if GESI (300 but bigger) or Mil.Spec (100 but smaller) flows better. You said GESI so I trust your advice.

 

Is the GESI cat better flowing than a Milspec 100 cell? I'm assuming that their price reflects better emissions control (more precious metal inside), but just wondering about performance as well.

 

I tried 100 cell, and 200 cell cat. Both didn't clean ****. The stank didn't go away until moving to the GESI G-sport cat, which I found by looking into what the twin turbo LAMBO guys use. It isn't cheap compared to the other cats, but honestly the 100 / 200 cell cats didn't seem to work anyhow.
How do you ALSO know the GESI cats actually work? They have an EPA CERTIFICATION CODE embedded in the side. This makes them legal in all states except CA.

https://www.evolutionm.net/forums/pr...l#post11896934

 

I saw posts saying they swap out the GESIs for test pipes when they go to the track to avoid issues of overheating/melting/damaging. I wonder if an o2 dump can help the GESI endure longer track sessions.

The idea is to combine normal off-boost street driving with uncompromised track driving. Same parts, same tune.

 

Not sure if that was me, but I do swap out my GESI for a test pipe at the track. To reduce heat stress and backpressure during long runs at WOT. I don't know if it would have a problem or not, I suspect it would be fine actually.