boost spiking to 20 psi

TeamRedLine23 · #1 03-10-2006, 05:28 PM

I just got a 1997 gs-t for $4100. the car is in show room condition. not one scratch or ding. carbon fiber hood, boost and air/fuel gauge, and a manual boost controller, 3'' turbo back with a cat. and a hks ssqv with recirculation kit. anyways, the boost is set at 15 psi when I punch the throttle the boost spikes to 18-20 psi then comes back down to 15 psi. the car has the stock t25 turbo. Is 15 psi to much for the stock turbo? Im not to sure. thanks

Blackcrow64 · #2 03-10-2006, 05:35 PM

Run the balls off that t25, it won't hurt it.

Black99GST · #3 03-10-2006, 06:09 PM

i've heard 18 is the most... pretty much toping out the t25...

EDIT: But i wouldnt chace it, 15psi is good for me as of now... on this turbo

TeamRedLine23 · #4 03-10-2006, 06:31 PM

I want to turn the boost down but i don't know how. I could probably figure it out but the intake pipe is in the way so i can really see it. I looks like I can adjust it with a wrench. but when the boost kicks in I can hear the turbo so loud pretty much over the exhaust. making that high pitch sound.

Blackcrow64 · #5 03-10-2006, 06:38 PM

Your gonna need to install a manual boost controller so you can adjust your boost.

TeamRedLine23 · #6 03-10-2006, 06:57 PM

it has a manual boost controller

Thor06 · #7 03-10-2006, 07:00 PM

He has one, it said in his first post.

IIRC, the t25 efficiency is just about maxed out at 15 psi and after that, you will start to knock due to the extra pressure. I would turn it down to like 12 and see where it spikes at. Also, boost spiking is a result of wg creep right? How do you fix that?

Blackcrow64 · #8 03-10-2006, 07:10 PM

Quote:

Originally Posted by Thor06

He has one, it said in his first post.

Opps, my bad. When he said it looked like he could adjust it with a wrench I thought he meant something on the turbo. lol

Quote:

Originally Posted by Thor06

Also, boost spiking is a result of wg creep right? How do you fix that?

Bigger wastegate should fix it up nicely. Another thing that contributes to boost creep is an exhaust that is too restrictive, although that isn't the problem in this case.

It is also possible that the internal wastegate isn't operating properly and opens too slow.

scottsee · #9 03-10-2006, 07:47 PM

not bad for $4100.

Thor06 · #10 03-10-2006, 07:58 PM

Porting the o2 housing helps too right? I wouldnt get a manifold mount wg unless you are going to be running a bigger turbo. I'd just port the bitch a bit and see what happens.

TeamRedLine23 · #11 03-10-2006, 08:04 PM

I will post pictures when it stops raining and I washing the car.

TeamRedLine23 · #12 03-10-2006, 10:52 PM

how do I test the wastegate to see if it is working properly? If there is a way. How do I turn the boost down with a manual boost controller? Is it as easy as twisting the knob?

Blackcrow64 · #13 03-10-2006, 10:56 PM

Yes, just twist the knob to and test it... To check the wastegate, I'm not really sure how you would go about it. I guess just pull the turbo off and see if it give you any problem to move the wastegate flapper manually? lol

firemedic2143 · #14 03-15-2006, 09:37 PM

ok I was wondering what was the max boost allowable for a 1997 eclipse GS-T spyder with a stock turbo, i am installing a manual boost controller and dont want to blow my engine.

ez1286 · #15 03-15-2006, 09:43 PM

Quote:

Originally Posted by firemedic2143

ok I was wondering what was the max boost allowable for a 1997 eclipse GS-T spyder with a stock turbo, i am installing a manual boost controller and dont want to blow my engine.

Safely you can run about 42psi if you have balls you can set it to about 55psi.

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