performance/boost questions

JayLashua

Member
Joined
Jun 28, 2001
Concerning this lovely '87 GN...

First off, the boost.. I reconnected the wastegate lines, Y tube, etc.. wastegate (adjustable) is as short as possible. I cannot seem to get more than 13 psi out of this.. the wastegate duty cycle is 88%, with 95% 3rd gear, 85% 4th gear scaling.. Im using a (original) JL 93 chip for 868 injectors with, ofcourse, 868 injectors.

No knock.. just.. little boost.. Now I am a little confused, I saw one pic of a TE62 on gnttype where the wastegate hole was hogged out.. I was also looking at some other large turbos which had normal sized wastegate hole.. So I am assuming that my TE62 is perfectly stock, will the stock wastegate puck seal it, or do I just need a good downpipe like a houston, etc?

now... next topic..

It has the stock intercooler.. bowling green custom up pipe (its fairly large), Stock downpipe, stock passenger header (Driver side is a KB? with a small leak, I can probably get someone to weld it up for $0 though.. While this may seem stupid, the hotair I had went through many worse exhaust leaks than this header is giving me, and it built 16, 17, 18 psi boost on a '87 turbo just fine..

LASTLY: It has the stock converter..
HOWEVER: It did built 7-8 psi on the brake just fine (within a matter of seconds) subsequently lighting up the tires.. would a 3200 stall converter increase spool up even while the motor is revving up anyhow?

Id like to get this car all tuned up and running as good as it can with the turbo I got on here.. I am thinking of getting the racetronix kit which includes hotwire and walbro 340? seems like a good deal, I am not rich so that is probably all I can really afford for the moment ;p

advice away!

PS:

I just changed headgaskets because the car was pblowing bubbled in my overflow jug and forming puddles under my exhaust pipes.. doing everything properly, i am still seeing many small bubbles int he damn jug.. and some (not as much) vapor from the exhaust.. the cat is hollowed out by the way.. or so it appears anyhow.. what gives?
 
I am not great at wastegate diagnosing, but a stock elbow and a 62 turbo are a bad match. The first thing I would buy if I were in your shoes would be a THDP. You would probably see much better spoolup and boost control.

Try a set of GM coolant tabs for you coolant leak. p/n 3634621. They cost 3 bucks and may help your problem.

When you took the old gaskets off it should have shown you where the leak was occuring, if in fact it was a bad gasket. Did you find this evidence? Also bubbles in the jug does not automatically mean a HG problem. Take off the radiator cap and run the engine and see if you see bubbles
 
First things first...

Do the fuel pump. A MUST before going any farther! If you have the stocker in there, that can be part of your problem.
 
Originally posted by blackbuick87
I am not great at wastegate diagnosing, but a stock elbow and a 62 turbo are a bad match. The first thing I would buy if I were in your shoes would be a THDP. You would probably see much better spoolup and boost control.


I agree! I have a TE60 and the stock puck would have never sealed the waste gate hole in this turbo. A THDP would be your best performance investment at this point.

The stock fuel pump needs to be retired asap! Get the Walbro 340 and hotwire kit and be done with it. Racetronix is a great vendor for the Walbro kit.
 
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