Dear Members,

I am looking to mod my Evo GSR and I have a question about how much of a restriction keeping the stock downpipe/catalytic converter (don't want to deal with emissions issues) while modding some of the other parts. I came across an article where they used the following parts to take a stock Evo (254 whp) to 391 whp using the following mods:
1. Garrett GT3071R Turbo
2. 800cc injectors
3.Front Mount Intercooler
4.UICP
5.Intake
6. Intake Fan Shield
7. Widemouth Downpipe
8. Exhaust
9. Walbro 255lph Fuel Pump
10.Dyno Tune

My question is, if I were to follow the same setup except I left the stock downpipe/cat in place, how much of a power loss would I be losing? They were able to get 391whp with this setup. What would I get if I left those two parts stock? Would it still be worth upgrading or would I just be better off with a aftermarket intake, exhaust, and tune ONLY?


Thanks

 

You can easily do 400whp on E85 with stock downpipe and OEM cat.

The OEM cat will produce a good amount of backpressure so E85 will be very helpful over 91 octane.

Years and years ago I tuned a Evo 10 with a CBRD BBX turbo (about the same as a GT3076R) to 400whp on a mustang dyno on E85 with 100% oem stock exhaust from turbo back *and* oem intake.

With some of the newer GTX variant turbos, you could probably easily surpass that.

A good recipe for what you want could look something like this:

- GTX3076R Gen 2
- upgraded FMIC
- Upgraded upper ic pipe
- Drop in 65mm fuel pump
- ID1300cc injectors
- 3 port boost controller
- Tune

 

100% agreed perfectly stated