Hey everyone this is my first post and was hoping I could get some information! I had my car dyno tuned yesterday at DK Goodrich's place in Frankfort Kentucky. It is a 1991 CRX Si with a b16a2 swap and turbonetics t3/t4 turbo on it. The power graph on the dyno was very rocky when it should have been smooth and the car was only making 220WHP. My boost gauge said it was on 12lbs of boost but his computer said it was under only 4lbs of boost. The guy I bought the car off of said the motor was completely built and all the parts he said were there have been there so far. My main problem is whenever the car was hitting Vtec it fell flat on its face, the power graph on the dyno became very rocky and wasnt a smooth curve like he said it should have been. He told me that the first place to look would be the turbo and that it probably needed rebuilt. Would anyone recommend me going ahead and having it rebuilt? My turbo manifold is also complete ****...its a crappy log manifold and my down pipe is beat to hell and has a massive dent in it so all that stuff needs replaced and im sure didn't help the power graph at all.

 

Can you post pictures of the Dyno and your setup

 

you just dont get a turbo rebuilt for no reason... you need to examine it and see if it has any oil leakage or excess shaft play or if the wheels are hitting the housings...

numerous things can cause issues like this.. tune, injectors, bad fuel, bad injector(s), boost leak, timing, etc.

without a complete setup list and the dyno graph we cannot help you

 

Negative, didn't get any pictures of the dyno
Skunk 2 intake manifold
SKunk 2 cam gears
ctr cams
680cc Precision injectors
t3t40b turbonetics turbo
3in downpipe
38mm tial wastegate
built skunk 2 head
Thats about all i can think of right now

 

without the graph we cant help you because we cant see what the motor is and isnt doing
ask your tuner if he has the graph still

 

The only shaft play in the turbo is a very very very tiny amount of up and down movement, and no leakage any where that I can see. Only thing that worries me is the oil return line is completely black, I'll try to have the dyno graphs in the next couple days

 

When you say dyno tuned did they actually tune the car? What are you using to tune the car?

I have seen plenty of "built" motors pushing turbos end up being 165k mile oem time bombs. You need to get a parts list from the dude.

I would address the boost gauge discrepancy and would change cap, rotor, wires, plugs.

 

im pretty sure he's on a stock bottom end

 

compression test, leak down test........now!!

 

Already did a compression test...came back 180 across all 4 cylinders.
Found the parts list he had posted,
Weisco pistons 9:1 compression
Eagle H beams
acl bearings
arp head studs
Quaff LSD tranny
and all the other things I mentioned earlier

 

and yes the car was actually dyno tuned, it was on ectune before but when I brought it back to him yesterday he tuned it using Neptune.

 

Are you using stock valve springs?

It could be valve float. Seen it happen before.

 

Nope the valve springs are not stock. Built skunk 2 head. Any ideas on what would be causing the boost gauge to read 12psi and the data logger to read 4psi? Bad map sensor or bad gauge?

 

Leak in the line?

 

Possibly...the car Doesn't have any boost or vaccum leaks that I know of but I'm still learning a lot about it! The gauge is mechanical and runs into the BOV line.

 

Why into the bov? Try running it straight to the intake manifold

 

So should there be two seperate lines going into the intake manifold for the BOV and boost gauge? They're both on the same one right now

 

That's how I would have it

 

boost gauge isnt so picky but try another source

 

Could also be a bad gauge or sensor for the logger. Either way it needs to be resolved.

 

Sounds like user error, I'd go back to Gran Turismo.

(He's my roomate, had to.)

 

Installed completely new auto meter boost gauge...new wiring new vacuum hoses new everything and ran it into a different vacuum line on the intake manifold. Still says 12psi of boost so had to have been a electrical error. Still no dyno graphs though.