Stock Turbo Limits

[Great'98]

Hello. Just joined DSM tuners.com and I must say it's a cool site with tons of great info! I've probably been through the entire site a couple times now. Anyway, I'm starting to consider upgrades on my '98 Eclipse GST but want a "streetable" daily driver that can hang with the many stock sports cars out on the road (BMW M3's, Mustang Gt's and other domestic V8's, supercharged Integra's etc...

As of now I am running completely stock except for a 2.5 "Thermal" cat back exhaust as well as new upper intercooler piping, 1st Gen. BOV and intake.

I know the stock turbo sucks. For the time being I'd like to up the boost of the stock turbo with a manual boost controller (with gauge) to 15psi.

I would like to know the following:

1. How much Hp will I really pick up? I was told by the guys at Extreme Motorsports that in general you will get an additional 10hp per 1psi of added boost. So if I go to 15psi would I really pick up 30hp assuming the stock turbo runs at about 12psi?

2. Will the stock ECU, injectors and full pump handle the additional boost without having to do any tuning?

3. How much difference would a downpipe & high-flow cat upgrade make at this point? Is it worth the expense till I consider a bigger turbo?

I would like to eventually run a larger turbo (Forced Performance Big28) however I don't know if I'm ready to replace fuel pump, injectors, clutch and having to add an AFC and EGT and do the whole "tuning" thing.

4. Could I run a FPBig28 SAFELY without doing all the additional support mods? Would I be able to run the Big28 at low boost 15-17psi with the stock stuff? Would I see a gain beyond that of the stock turbo running at 15psi?

5. And finally, I live in Wisconsin with COLD winters. Will any mods to boost ect... hamper the cars reliability in the winter?

Thanks for the help!

 

[L2RTSiAWD]

1. 1psi-7-10HP on a T-25 not likely the turbo is so small going to 15psi will get little more power but will still run out of steam at higher RPM's.

2. Yes up to 15psi but no more.

3. A big difference. Highly recommended.

4. If you replace the turbo you must do all supporting mods Bottom line.
If your not ready to replace those Items your not ready for a big turbo r going fast. Any turbo upgrade requires at least a fuel pump. But without and AFC,EGT,INJ and logger you will never reach your potential.

5. No the colder temps will actually make the car faster!!

Later,

 

[larryd]

advice from a fellow GST owner who wanted the same as you.. follow the guide to upgrades step by step because it makes sense.. dont just slap the turbo on and expect to go faster.. btw you can find lots of info on my site in my signature in regards to the T25 and power it made on the dyno.. not much but it was neat.. also look into the Forced Perf Big 28?? you would love this turbo