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[roadtrip_69]

Hello everyone, I'm a new DSM owner. I've always been interested in having one and the opportunity finally struck. As my profile I believe states, I have a 99 Eclipse gst spyder. I love it so far. Have done the recommended maintenance, changed my timing belt(set timing it was retarded apparently), balance belt, water pump. New plugs and wires(the old plugs were gapped to .042!!! and was causing the car to cut out a lot) As a quick boost to the power so to speak, I installed a aftermarket boost gauge and MBC. Its a cheap ebay one, but i have the exact same one on my Probe GT and it works great with it. But on the Eclipse It doesn't seem to have much effect. The max boost i can get out of it is 13psi. I think I've seen it spike to 14 maybe once with the MBC completely closed(should have made it spike to high hell right?) I've adjusted the MBC all the way out and in. Double checked the connections. I have it hooked straight from the compressor housing to the wastegate.(like on my probe) And disregarded the factory vacuum lines from the factory boost controller, though kept it connected via the electrical connection. Plugged the hole in the intake. No matter what i do I cant seem to get anything better than 13 psi. While I know the little T25 isn't capable of TOO TOO much more. I would like to get the 15-16 everyone else says is possible. Until I get around to purchasing the 16g. (also plan on upgrading the air intake, and the exhaust within the next couple months before venturing into replacing the turbo.)Also I have read on these forums the stock BOV sucks. But I should at least be spiking higher, even if the BOV is leaking so that i cant sustain the boost? I'm looking into getting the 1g BOV when i can. The car runs otherwise pretty well. I suspect the CAT might be a little clogged. Top end power(speed)over 100 really seems less than i was expecting(My probe with its sohc 2.2 pulls hard all the way to redline in 5th gear, through its got a 3 inch exhaust from the turbo back, and ram air). So anyway question is what could be causing the lack of boost. In my Probe with its little IHI hybrid I can set it up to 20 plus, while its extremely inefficient above 16-17 it still at least spikes to it. When Ive played with it to make it do so. Ive checked for exhaust leaks. And haven't found any. I'm holding a steady 18 psi vacuum at idle. Anyone have any ideas? Could the BOV really be leaking THAT much that i cant even spike above 13? Wouldn't i hear it losing air, or would it just be venting it back into the intake?

 

[architechnik]

Have you checked your entire system for leaks? If you're taking pressure readings at the manifold, as you should, and the mbc is reacting off of the pressure directly from the j-pipe then you could be losing a lot of air throughout the rest of the system but still pulling as hard as the turbo is capable.

The other possibility is that the wastegate is stuck open. You could also have a burnt out turbo. Is there any shaft play or anything that would denote premature failure - ie cracks in the housing, bent fins on either side, "folded" exhaust side (lumpy inside)?

 

[delta448]

First, update your profile.

Second, if you can't get more than 13psi with the WG actuator vac line disconnected you either have an issue with your wastegate flapper sealing, a boost leak or your engine is outbreathing the turbo. If you have cams and an exhaust you likely won't ever see more than 13-15psi on a T-25.

 

[roadtrip_69]

Well, I havent been able to check shaft play. As i dont have the tools to do so with me. Right now. But there isn't any smoke coming out the tail pipe so the seals are still good. And the turbo itself is rather quiet actually in comparison to the one on my Probe. So it cant have too much play at least not enough to hit the sides of the housing. It spools fast, and holds 13 without a problem. Just wont get above it. Even in spiking. And my cams are stock. As is the exhaust right now. Though i am going to get a test pipe and cat back in a couple weeks.

 

[roadtrip_69]

I checked the turbo for play and amazingly it has absolutely none, turns VERY smoothly. By the looks of it, it has been replaced before. Still has a GARRETT tag on it. In newer shape. So it doesnt appear to be a problem with the turbo itself. I bought a 1g bov and plan to install that this week sometime. Maybe that could make a difference? I also seem to be getting compressor surge once in a while too.. which is a new issue....

 

[delta448]

Did you check the WG too?
You should not be getting any surge with a T25 if your BOV/CBV is working correctly.

 

[rarson]

I think it's the stock plastic crap BOV. They've been known to leak at even less boost.

 

[vancitydsm]

the stock recirculating valve will not let u boost anything over 14ish from what i remember on my car.. i pulled the WG line all together, it spooled MUCH faster but max boost only went up 1 pound if that. You need a crushed 1 g or something.

 

[rarson]

I wouldn't pull off the wastegate actuator. By doing so, you're just spinning the turbo up and making it heat up the air even more, and getting nothing from it (probably losing power).

Also, I wouldn't crush the 1g valve. It works fine with the factory spring pressure. What you need to do is mod the fast actuation port. There's a VFAQ on this (notice there is no VFAQ for crushing).

 

[the_mork]

Check your boost gage for leaks, I couldn't figure out why my MBC wasn't letting me raise boost and then I realized it was just that my boost gage was blowing it out the back no issue though it ended up only a few psi higher than it was registering and I was running pretty conservative settings.