Can't get the boost level down.

[1967 GeeTO]

I purchased my 87 "T" in January with 25,000 miles. Since then I have installed the Terry Houston style 3" downpipe from ATR. The car came with an adjustable wastegate. I have lengthened the rod as far as it will go, but cannot get the boost below 16 pounds. The car is definately not putting out as much power as before so I know lengthening the rod is having some effect, but the boost level will not budge. What gives? I am trying to turn the boost down because I am getting two to three yellow lights on my knock guage, but that is an issue for another day. Thanks in advance for any help as I am obviously new to these cars. Sam Williford

 

[Slow91z]

If you want to lower the boost more you should probably port the wastegate hole in the exhaust housing...Do a search it has ben discussed many times.

 

[Red Regal T]

Vacuum line connected on the turbo?

 

[Reaper]

could have an HD Wastegate?

 

[1967 GeeTO]

Thanks for the input guys!!!

Red Regal T: I installed the new "Y" hose kit. Is that what you are talking about? I'll be sure it's on tight.

Grim Reaper: The car is basically stock except for exhaust and K&N. I doubt the prior owners would have installed one, but don't know how to tell if it is a heavy duty wastegate.

Slow91Z: Thanks for the input. I've gotten into a local TR club and will check with some of them regarding your advice. We are supposed to have a meeting in the next couple of weeks.

 

[Slow91z]

Remember if you decide you HAVE to port it, and nothing else is wrong, be careful if you port it to much or you will loose the ability to turn it up a bunch later.

I just thought of something, you should also check the orfice hole in the Y cord...Their are different sizes, GM sold different replacement sizes and some people didn't get the right one...My car used to overboost badly, and I drilled (actually I used a fork to ream it) the orfice out to full size...it works much better now, but you have to remember if you do this it will limit your ability to raise the boost later.

John's Performance <-----This is a link to Johns performance, if you scroll down the page there are screw in replacement orfices...If I ever have a problem getting my boost high enough, I'm going to buy one of those to fix my reamed out tube.

 

[Reaper]

i am not sure how ot ID an HD wastegate but others may...


you would be perdy hard pressed to get less then 18 psi out of an HD wastegate, but i would imagine that with a near stock set up you could get 16 psi out of it.


also the actuator may just be bad. you can test it with a vaccum pump (mighty vac).
.

Dathan

 

[Nick Micale]

Originally posted by Grim Reaper
[B..........also the actuator may just be bad. you can test it with a vaccum pump (mighty vac). Dathan [/B]

Actually you need pressure, not vacuum, to check a W/G actuator. There is a version of the Mityvac that will also do pressure.

 

[Reaper]

Originally posted by Nick Micale
Actually you need pressure, not vacuum, to check a W/G actuator. There is a version of the Mityvac that will also do pressure.

yea thats what i meant.... damn my dyslexic mind!