I have a t3/t4 .50 a/r on my car now, but I think the specs are wrong for what my engine can produce. The engine was rebuilt with 9-1 compression, and everything else needed to run a turbo setup, hondata, rc550's, etc... wont waste time listing. However the turbo will not boost over 12 psi with an 18 psi external wastegate, AND it takes till almost redline to get that. I found every boost leak on the car, some I/C piping holes, a torn TB gasket, a leak at the BOV and havent gained a single psi. I am looking for a good power making turbo that will match this smaller, lower compression engine. Looking for about 250-300whp max. Any specs would help alot.
If this turbo sounds right. Then why wont it boost over 12 psi. The motor still has the factory vacuum setup with pcv system.

Modified by QwkD16 at 6:44 PM 5/10/2006


Modified by QwkD16 at 7:37 PM 5/10/2006

 

Any ideas please!!! Help!

 

best overall turbo for that power level if you got the money would be a GT28RS. nothing beats fast spooling action of ball-bearing turbos. good up to 350hp.

 

What do gt28rs turbos cost, roughly?
Does the turbo I have sound to big for my engine? I have seen basically the same setup hit 20+ psi on this forum.

 

What trim is the turbo?

Sounds like there's another problem if it won't go over 12psi. Any leaks bewteen the head and the turbo manifold or turbo manifold and turbo?

Are you sure you've found all of the boost leaks?

I know the GT30s run around 1200, so I'm going to guess the GT28s are around 900-1200.

 

Not sure what the trim is because I got this turbo used from a friend the had it rebuilt. It is a turbonetics knock-off, I think, becasue the rebuilder said his turbonetics parts are what he used.
I dont hear any exhaust leaks anywhere, with the motor under load or just revving it. I am stumped! This has been an on-going thing for a few months.

 

Is the compressor housing really shiny?

It's starting to sound like an SSAC or XSPOWER turbo. If it's one of those then that's most likely your problem.

What kind of external wastegate do you have?

 

No, the compressor isnt shiny, but the BOV the came with this kit (used kit) is a XSPOWER and the wastegate is tial. I have a turbosmart MBC also. But why would the make of the turbo be the reason it isnt boosting past 12 psi? It has been rebuilt.

 

people always wanna blame the ebay stuff. but forreal though, check your wastegate. try different springs, etc. maybe the springs in there aren't really 18psi springs.good luck

 

Im almost possitive the spring is 18 psi, even still, the lowest double spring combination is 16 psi (15.954) but 12 is all it will do.

 

Try disconnecting the wastegate and put a nipple on whatever vacuum source you're using to feed it. Then see if it'll bost past 12psi. If disconnecting the wastegate doesn't do it then you probably have a boost leak or a shitty turbo.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nota-eg &raquo;</TD></TR><TR><TD CLASS="quote">Try disconnecting the wastegate and put a nipple on whatever vacuum source you're using to feed it. Then see if it'll bost past 12psi. If disconnecting the wastegate doesn't do it then you probably have a boost leak or a shitty turbo.</TD></TR></TABLE>

yea thats what i was gonna say. be careful though, with no wg connected it will boost up as far as the turbo can.

 

I took my turbo to my local builder, and we are goin to try to lower my hotside a/r from.63 to .48, which will make my turbo a t3/t4 t04e .50/.48. Then i'll see what happens from there.

 

i have seen an ebay 60-1 on a fully built h22 at 20psi only making 300 whp. those ebay turbos suck!