Evo III options

[eclipsemustang]

Im looking at the MHI Evo III for my car and i was wondering how important people thikn it is to do the porting or the 34mm wastegate, because im looking at getting it from ExtremePsi and i cannot find the options to do any of these things?

 

[JusMX141]

Porting an EvoIII housing isn't very necessary in my opinion. If you compare a ported EvoIII exhaust housing to an unported one, there isn't much difference....not as much as between, say, a ported and unported Small 16G 7cm2 housing.

The wastegate mod would depend on how much boost you plan on running.

 

[daren_p]

For the porting, most do it but the difference either way isn't going to be much. People have gone equally fast on both ported & non ported. Personally I wouldn't pay the extra to have a vendor do it, I'd do it myself. It's easy to do even for a first timer, lots of threads on here about how to do it. As for porting the evoIII properly to prevent boost creep, vendors don't normally offer this, thats something you would have to do yourself (or pay alot more & have someone do the specific areas that require attention). As for the flapper mod, really depends on what amount of boost you want to run & how free flowing your exhaust is. If your running 3" from turbo back without a CAT, your more likely to have creep issues vs someone with some restriction (such as a high flow CAT). If you plan on running low boost, the flapper mod is probably a good idea (& will require additional porting to make sure you don't creep) but if your plannin on running higher boost (20+ psi) then a larger flapper isn't a good idea as they tend to blow open under higher boost levels.

 

[DSMsOwnYourV8]

Dsmparts.com sells the turbo and they can port it for you for $87. I would port it but that's just me.

 

[eclipsemustang]

well i plan on running about 17 psi for a while but eventually down the line i want to run above 20, so would i still be better off not going with the larger flapper? are the odds high that i'll get boost creep? i do havea 3 inch DP but only 2.5 exhaust

 

[DSMsOwnYourV8]

I'd go with the bigger flapper, you can never really tell if you're going to get boost creep or not. I got boost creep with a 3" exhaust and I had a ported turbo. If you do get it, the options are a 34mm flapper or an external wastegate - run over $200 new.

 

[eclipsemustang]

so what happens when i get to the point where i want to turn up the boost past 20 psi is there some kind of middle ground here?