LOW BOOST!!!...... 97 GST

[Louis Gibson]

Hello fellow DSM’ers. I’ve been searching around on DSMTuners but haven’t been able to get a good answer to the problems I’m dealing with.

I own a 1997 Eclipse GST with 106k miles on it. It has an aftermarket front mount IC, new greddy BOV and charge piping, and a pair of ram horn headers that go to an HKS exhaust.

Since I got the car I’ve had to rebuild the turbo charger because the oil seal on the turbine side was shot.

With that being said, ever since I got the car it’s been dirt slow. I got gapped by a freaking 07 Nissan Altima SR. I raced my friend in his IDENTICAL 97 GST and also gapped me.
This has obviously gotten me concerned, so I’ve been doing some research based upon the symptoms my car has.

Symptoms: car builds little to no boost in 1st gear ( has almost no torque at all). If it does build boost, it hits MAYBE 5 Psi but then drops down to 2-3 psi. 2nd to 3rd gear will spike up to 10 psi and then drop to about 6-8 psi ( which is low for a 2G eclipse), and will gradually continue to drop as I climb RPMS. 4th and 5th gear, however, spool up to 10 psi and then hold a solid 8 lbs all the way to the top of the rev range.

Now I’ve obviously checked tons of different threads on dsmtuners and other DSM forum websites on wether the symptoms are caused from a boost leak, a bad waste gate, and bad turbo.

What gets me confused is that the turbo has NO problem at all spooling up like the little tiawan wind whistle it is. 3rd, 4th, or 5th spool up almost instantly with no problem at all it seems. So that gets me to think that it’s not a boost leak??

And when my wastegate (which needs replaced) stops working, the turbo has NO problem shoving 15 lbs into my eclipse’s throat (I hit fuel cut right after 10 ).

The car seems to also SOMETIMES have a rough idle...

Anyways, I was not able to find a DEFINITIVE answer so that’s why I’m here. The symptoms are confusing the crap out of me...

All help is greatly appreciated

 

[Vegas Smith]

Whew, where to start. It sounds like you're running a ChinaBay 16g with a giant boost leak. Your'e also saying the wastegate doesn't work and you'e also saying you're hitting fuel cut? It sounds like you need to do a legitimate boost leak test, buy a legitimate turbo and most likely get a fuel pump to support everything. Your response should not be that you don't think it's a boost leak. Every performance problem with a dsm starts with a boost leak test.

 

[Louis Gibson]

The slang term for the turbo was just to be funny. It has the stock Garrett t-25 that comes with the eclipse...

Whew, where to start. It sounds like you're running a ChinaBay 16g with a giant boost leak. Your'e also saying the wastegate doesn't work and you'e also saying you're hitting fuel cut? It sounds like you need to do a legitimate boost leak test, buy a legitimate turbo and most likely get a fuel pump to support everything. Your response should not be that you don't think it's a boost leak. Every performance problem with a dsm starts with a boost leak test.

 

[Vegas Smith]

The slang term for the turbo was just to be funny. It has the stock Garrett t-25 that comes with the eclipse...

Ahh, ok. A lot of new members come on here running Chinabay turbos that are on the way out. What fuel mods do you have?

 

[Louis Gibson]

Ahh, ok. A lot of new members come on here running Chinabay turbos that are on the way out. What fuel mods do you have?

Gotcha. So far I have no fuel mods... and from what I know, nothing has been done to the car other than the mods listed above.... I should still be running on stock specs...

 

[Evolving_sti]

You said it has a "new greddy bov". Did you yourself recently change it? If you didnt have this issue then it started doing this after the bov install, I would look there.. I had a greddy on my evo and when it was installed it was leaking bad. New gasket fixed it right up. Is your bov recirc or VTA? You didn't mention any ecu mods so I'm assuming its recirc.

 

[Kryndon]

Your wastegate stopped working how? Did the rod break or come apart? If so, the internal flapper inside the hot side will be free which means the turbine will be slowed down causing almost no boost regardless of gear or load. I had a stock wastegate go bad on me and the car drove like a naturally aspirated piece of shit. So how exactly did your WG go bad?

Also, did the rebuild kit come with a new O-ring for the compressor housing side? Are you sure you installed it properly?

 

[Louis Gibson]

You said it has a "new greddy bov". Did you yourself recently change it? If you didnt have this issue then it started doing this after the bov install, I would look there.. I had a greddy on my evo and when it was installed it was leaking bad. New gasket fixed it right up. Is your bov recirc or VTA? You didn't mention any ecu mods so I'm assuming its recirc.

Greddy BOV came I stalled on the car. However I’ll go ahead and give that a look.... and yes, it’s recirculated

 

[Louis Gibson]

What I mean by wastegate not working, is that the actuator itself seems to fluctuate. Sometimes it opens and then sometimes it won’t open at all which causes high boost which then causes the ECU to hit fuel cut. This only happens From 3rd-5th gear. 1st and second never seem to come close to even being able to generate enough boost, but the latter gears do, and too often the boost isn’t being limited.

Your wastegate stopped working how? Did the rod break or come apart? If so, the internal flapper inside the hot side will be free which means the turbine will be slowed down causing almost no boost regardless of gear or load. I had a stock wastegate go bad on me and the car drove like a naturally aspirated piece of sh**. So how exactly did your WG go bad?

Also, did the rebuild kit come with a new O-ring for the compressor housing side? Are you sure you installed it properly?

 

[Louis Gibson]

also (forgot to mention) I did install a new o-ring on compressor side! Infact I almost forgot to put it on. All seals and retaining clips have been reinstalled and turbo hasn’t given me any problems as far as having trouble spooling up at 2500 rpms in 4th and 5th gear

Your wastegate stopped working how? Did the rod break or come apart? If so, the internal flapper inside the hot side will be free which means the turbine will be slowed down causing almost no boost regardless of gear or load. I had a stock wastegate go bad on me and the car drove like a naturally aspirated piece of sh**. So how exactly did your WG go bad?

Also, did the rebuild kit come with a new O-ring for the compressor housing side? Are you sure you installed it properly?