First run in stock 85 GN

[camaro75racer]

Ok, made my first pass today in my completely stock 85 GN. Ran consistant 9.99's at 69mph. Is this average for these cars? Also it peaks to about 10psi and will only hold at 9psi for a second and starts to drop off from there. Is this normal? Any input appreciated. Thanks guys.

 

[85 TR]

no thats not normal you should check all you vac lines going to the wastegate and your wasegate silanoid

 

[camaro75racer]

ok, thanks. should it just hold the boost as long as im on the throttle? im really new to these turbo cars so i dont know what the norm is. thanks again

 

[BRAD_PADGETT]

I have an 85 GN and the stock boost should be around 13psi. If you have the stock bar light boost gauge you have no idea what your actual boost is. The stock bar light boost gauge is worthless and should not be used to change anything on the motor. I added a VDO boost gage and tach(Stock bar light tach is worthless as well!). I can compare real VDO gauges to the stock lights and the stock gauges are off by more than 30%. Brad

 

[camaro75racer]

I have a VDO boost gauge (good up to 30psi) but no tach yet. And mine never gets over 10psi. When it gets that high it's just for a split second. in the 1/8 mile by about 3/4 track i was back down to 2-3psi. Ill start checking all my lines as soon as i get a chance.

 

[cool 84]

I would check for an exhaust restriction like a plugged cat. If boost spikes up and then falls off to 2psi, this definately sounds like a restriction. With a convertor on my car, it went to 18psi and fell to 8 by the end of the run.

 

[camaro75racer]

ok cool84, thats a good possibility because it does still have the converter. Ill chop it off and have a piece of pipe put in place as soon as possible.

 

[BRAD_PADGETT]

I agree with COOL84 concerning the cat. I ran into the same situation where bad turbo seals leaked oil into the intake and eventually plugged up the cat to the point I got no boost at all. I now run with a test pipe and keep my new cat in the trunk. Also check for exhaust leaks on the headers which can cause the same problem as well. Brad

 

[edchapman]

I agree about the boost but 9.99@69 is pretty close to
what my bone stock 84 runs. The best was 71.5 during
the 15.4 run.

bye, Ed
http://edchapman.tripod.com/cars.html -- runner up B-5 GS nats 2004 -- 03 GSX stock
84 T-Type WH1 15.4@89 stock, 87 T 14.1@97 stock, 87 GN stock 399/400 points