Stock boost gauge/boost leak question

[bigbro6785]

I have a 97 GST Spyder which I have only had for a few weeks (I have an intake/K&N filter, and Apex-i catback). I have never driven a gst before, but to me the car does not feel as fast as it should (my LS Integra pulls alot harder). My guess is a boost leak. My question is....When i drive the car at WOT, the stock boost gauge only goes up 3/4 of the way, and once it gets to about 5k rpm it drops down to a little above half. Once again im new to dsm's so im not sure if this is normal or not. Could this be boost leak? Is there something else I should get checked? Any input will be appreciated. Thanks

 

[OverBoostinGST]

Its most likely a boost leak bro, if not check your spark plugs and make sure there arent burnt out or gapped improperly

 

[P90]

well the stock turbo the t-25 starts to die off around those rpms it doesn't pull all the way to redline...but yes check for boost leaks too

 

[marq97gsx]

I have a 97 GST Spyder which I have only had for a few weeks (I have an intake/K&N filter, and Apex-i catback). I have never driven a gst before, but to me the car does not feel as fast as it should (my LS Integra pulls alot harder). My guess is a boost leak. My question is....When i drive the car at WOT, the stock boost gauge only goes up 3/4 of the way, and once it gets to about 5k rpm it drops down to a little above half. Once again im new to dsm's so im not sure if this is normal or not. Could this be boost leak? Is there something else I should get checked? Any input will be appreciated. Thanks

The t25 turbo does not "die out" at 5k rpm. I ran that turbo for about a year on my last car (95gst) before switching to a evo3gt16g. It does sound like a very bad boost leak. What do you mean by 3/4 of the way? Do you have a manual boost controller? If not what reading exactly are you getting on your boost gauge? (psi) If so, what do you have your boost controller set at? With your airflow upgrades, you should be smoking a craptegra easily. Your clutch slipping???

1. Do a boost leak test
2. Check your plugs (.30 gap), and not corroded

 

[Bo0O0ostedDSM]

In case you don't already know, I want to mention that the stock boost gauge is not very accurate, so don't rely on it too much. In your case, I suppose its ok to get a rough idea, but for any more than that... for get about it. As formentioned, the T25 can't hold boost to redline so the boost pressure will naturally start to drop off a little bit. The T25 is a very small turbo, and has often been described as "a fast N/A". Yes, you probably have a boost leak somewhere... fix it and things will improve. However, don't expect too much more pull out of that stock turbo... unfortuantely, it just doesn't happen.

 

[Bo0O0ostedDSM]

The t25 turbo does not "die out" at 5k rpm. I ran that turbo for about a year on my last car (95gst) before switching to a evo3gt16g. It does sound like a very bad boost leak. What do you mean by 3/4 of the way? Do you have a manual boost controller? If not what reading exactly are you getting on your boost gauge? (psi) If so, what do you have your boost controller set at? With your airflow upgrades, you should be smoking a craptegra easily. Your clutch slipping???

1. Do a boost leak test
2. Check your plugs (.30 gap), and not corroded

Read his post more carefully and also check out his vehicle profile. From what he has written/posted, he has no MBC and he only has the stock boost gauge; there are no psi markings on the (stock) boost gauge. Also, bolting on an big exhaust and air filter help, but only to a certain extent. Those are the most elementry supporting mods to make more power later... they really don't provide big power gains in themselves.

 

[bigbro6785]

I wasnt expecting big gains out of those upgrades, I was just expecting a little more out of the car. I know the stock turbo doesnt keep power all the way to redline, but from what i read it is good up to a little above 6k. I will do a boost leak test this week to try to locate the problem. Thanks for the info.

 

[MrBoxx]

To do a proper boost leak test, however, you're going to need an aftermarket boost gauge to read off how much pressure is actually making it to the manifold. As mentioned, the stock boost gauge is more for entertainment purposes than as an actual monitoring device.