hey guys i was wondering if anyone knows why my t3/t4 50trim garrett is spooling at 6000rpm instead of earliar. i have a 38mm tial wastegate that has a 7 1/2 spring rate. the tuner tuned my car at 6 1/2 psi because he said that's the safe boost for a stock SOHC. my question is why is my car spooling to late, also my redline is at 7200 so that only gives me about 1000 before i have to shift. people told me it might be a leak or my wastgate. but the tuner said it probably my turbo is too big for my motor, so i don't know if he's bulls*** me or what but i need answers to why it spools too late... thanks guys

 

first thing i would do is pull the wastegate off and make sure you have the fire ring installed. when looking at the valve you shouldnt be able to see anythign behind it, if you can see behind the WG valve then the fire ring isnt there.

 

also check for boost leaks. You can pressurize the intake side of the turbo and spray soapy water on all your couplings and see if there are any bubbles. I'm assuming its a stage 3 wheel in your turbo? with either a .48 or .63 a/r ?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GTEC913 &raquo;</TD></TR><TR><TD CLASS="quote"> i have a 38mm tial wastegate that has a 7 1/2 spring rate. the tuner tuned my car at 6 1/2 psi </TD></TR></TABLE>

how did he tune at 6.5lb if you have a 7.5lb spring? he is either lying or you have a crazy boost leak. you sure it's a 7.5lb spring. the turbo is a little big for that motor, but the exhaust side a/r will play a bigger part of the spool up. when you say spooling at 6000rpm, when is full boost?

 

The wastegate has the tial (small green) spring and the website says its 7.252 Also i was told that when you get a spring for the wastegate and it is for example a 7psi spring that means you can only boost 7psi or higher, NOTHING LOWER RIGHT? correct me if i'm wrong. cuz i specifically told the tuner what spring rate i had but he still tuned it at 6 1/2 psi!!!

 

ya that's y i asked. you can tune lower in the psi range but cannot boost less than 7.5lbs without having a crazy boost leak.

 

either a boost leak or its because you have a stock motor... i had that exact same turbo on my 95 integra that was almost fully built and it spooled at 4000rpms

 

so the only way i can check for boost leak is by spraying the pipes with soapy water or is there another way i can check?

 

you can do the normal check of a couplers not ripped, pipes sitting properly, bov not leaking/venting under boost(requires hand pump with gauge). normally if you cant pull the pipes apart by hand pulling reeaallyy hard you shouldn't have a boost leak. make sure fire ring is there between the wastegate bottom and the mounting spot, looks like an O, but in metal.

 

thanks guys ill let you know what happens!!!!!

 

I have the same turbo and I start spooling by 4400-4600 rpm. Like the other said it might be a boost leak.

 

what kind of exhaust system are you running right now?

 

i have a qtp electric cut-out w/ a greddy exhaust system 2 1/2. the ETC is connected to the downpipe and i ran the car w/ the ETC open at all times.

 

if its spooling late it as to be an exhaust leak, not a post compressor leak. check to make sure the head to manifold gasket isnt leaking and the manifold to turbo isnt leaking. also check the WG like someone stated. i usually start the car cold and moe my hand around all the flanges to feel for a leak before the stuff gets too hot.

a 50 trim is not a very big turbo and def. shouldnt be spooling that late. also where do you have the vacuum source tapped for the wastegate? if its tapped off the turbo then it will most definatley run less then wastegate sping pressure because the gate is still opening at 7.5 psi but there is pressure drop through the intercooler so it wil lose a pound or so by he time it hits the manifold.

 

check the vac line goin to the blow off valve. mine was so small the valve was kinda staying open during boost. i replaced with a bigger one and its working good now.

 

and lets be clear, a 50 trim stage 3 w/ a 63 cover is not big for any honda engine.

 

yeah my car is acting funny too. It was hittin full boost at 5200-5300, now its hittin from like 5700-6000, and I checked my couplers and they were all fine.