Not pulling enough boost
- Thread starter phicho
- Start date
Is the car stock? Also what are you using to determine the boost level? The dash boost gauge is not normally accurate and most people install an aftermarket boost gauge. I think stock boost is around 14 lbs.
Car is stock. Using aftermarket gauge that was installed when I purchased. My car has digital inst panel. Inst panel has 2 indicator lites for boost. Top light comes on when turbo spools, but bottom lite rarely comes on. Any help here is appricated. I am new to the GN world. I have always been a fan, and just recently had the chance to pick up an 84 GN.
RegalT-type85
New Member
- Joined
- Jan 23, 2010
Welcome
The 14lb boost level is when everything is working right,93 octane and it's your lucky day. Most HA only see about 12lbs max stock. Did your GN come with an adjustable If it's adjustable your wastegate rod will have a nut and threading on it.
What are you goals/plans for this GN?
The 14lb boost level is when everything is working right,93 octane and it's your lucky day. Most HA only see about 12lbs max stock. Did your GN come with an adjustable If it's adjustable your wastegate rod will have a nut and threading on it.
What are you goals/plans for this GN?
With everything being perfect on your car, the only thing that would keep it from making boost would be the wastegate remaining open.
If the wastegate is working properly then you have a really good size exhaust leak before the turbo (you'd hear it for sure) or you can't produced enough pressure in the intake manifold (intake leak) or the turbo needs to be rebuilt.
Those seem to be the clear causes for such low boost.
the turbo is new, i did have a good leak that i fixed and now im getting around 5 pounds. it sounds like i have a vacuum leak will that cause low boost? im new to the turbo world so your help is greatfully needed. i also have a aftermarket gauge that is plummed in to a vacuum line sould it be in the port on the front of the intake?
BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
I had a similiar problem and it was a vacuum leak on the MAP line. The most common place for the after market boost gauge is on the front of the intake. I have my boost gauge hooked up to the fuel pressure vacuum line and it reads the same on the gauge as on the powerlogger. Good luck. Brad
Take a look at this diagram.
http://www.engraver1.com/help/intake2ETC.gif
It's the plug number seven on the intake view.
http://www.engraver1.com/help/intake2ETC.gif
It's the plug number seven on the intake view.
I plan to keep it stock, nice street rod with some zip. How do you tell if the turbo needs rebuilt? Is it better to rebuild turbo or replace with new or reman? What is the pro and con of going to a performance turbo? I am new to the ha/turbo world. I really appreciate the feed back. I think this site is awsome.
BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
Another cause of low boost is a plugged up CAT. A bad turbo will not boost, throws oil, or has side to side shaft play among other problems. The only off the shelf turbo options are rebuild your stocker or upgrade to a TA33C. This is a larger compressor in the stock housing with ~700 cfm vs the stock ~390 cfm. Should be around 30-40 HP increase. Brad
BRAD_PADGETT
Well-Known Member
- Joined
- Jan 22, 2004
No boost? Did you drop a bolt down the passenger side exhaust manifold? Don't ask how I figured out this problem. Brad
The easiest way to check the turbo is to remove the throttle body off the turbo. The compressor wheel should spin easily, the shaft attached to the compressor wheel should not much play in it (in or out, up, down, sideways, etc...). If there's any play, just post up what's happening and we'll tell you how serious it is. Also there should not be any missing pieces on the compressor wheel or obvious wear.
The cheapest thing to do if there is a problem is take off the turbo and send it to be rebuilt. More expensive is to buy another newly remanufactured one. Even more expensive is to send the turbo off and have it converted to a TA33C (This is the performance turbo for hot air cars).
The cheapest thing to do if there is a problem is take off the turbo and send it to be rebuilt. More expensive is to buy another newly remanufactured one. Even more expensive is to send the turbo off and have it converted to a TA33C (This is the performance turbo for hot air cars).
Good one Brad, I didn't think of that (of course it's been a while since I've had one:biggrin
im going to move it to that plug 7. i was thinking maybe the cat so i plan to remove it tonite. i did check the turbo out it looks new inside. the guy i bought the car from said it has a bigger turbo and injectors but i dont know how to tell. it had a spun rod bearing so i got a 109 motor and now im trying to work out the bugs. thanks for your help!!!! john
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