Is there any way for my boost gauge to read lower than the actual boost. I have the hrc stage 2 with fmic, s16g, clipped turbine wheel, ported head, infinite angle valve job, je 8.8:1 pistons, crower rods, thermal r&d exhaust and no cat. My boost gauge says I am only running 4 psi, but the car dynoed at 211whp. I have got a lot of replies that say you cannot hit 211hp at only 4psi, but I beat a lot of cars I know are fast,ie Z-28, mustang cobra, 5.0's, etc. I have only had the car to the track once w/ the turbo on and ran a 9.4 (1/8th mile) with a crappy 60ft time, but I finished at 84 mph, so I know it is fast. Any input would be helpful, thanks.

when the car is off does the gauge sit at 0?
if it does it could be a couple of things, pinched vacuum line, not a strong enough vacuum/boost signal (what do you have the vacuum line hooked up to?) or it could be a faulty gauge.

the gauge is hooked into the tri-fitting on the intake manifold. it sits at 0 when the car is off and my vacuum readings stay around 18hg at idle. don't see line pinced anywhere, but could it be where the fitting goes into the gauge is pinched too tight?

If you wanna be sure, do a pressure test on your intake system. Pressurize your system to say 10psi, then see if the gauge also reads 10psi. This will also help you look for vacuum/boost leaks too. :thumbsup

>If you wanna be sure, do a pressure test on your intake
>system. Pressurize your system to say 10psi, then see if the
>gauge also reads 10psi. This will also help you look for
>vacuum/boost leaks too. :thumbsup

I know i need a intake mani gasket but can u tell me how to pressure check the whole system exactly ?



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Make a cap out of PVC piping and put a valve stem in the closed end. Just go to Home Depot or some home store and look thru their selection. You'll need to find pieces to build a sealed cap and a drill to drill out the end and put the valve stem in. Use the coupler that normally holds your intake pipe to the turbo to hold the cap to the turbo. Hook up an air compressor to the valve stem and you'll push air into your whole intake system.

sorry guys that will not work. If I understand your thread, you want him to cap off the inlet of the turbo and apply pressure. Doing this will accomplish nothing more than blowing oil out of any weak point on your engine..ie dipstick, oil fill, weak seals etc. You see, no matter where the crank is in its revolution, atleast four intake valves are atleast partially open (2 intake valves on each cyl) which will allow the air to leak into the combustion chamber which will allow the air to somewhat bypass the rings and pressurise the crankcase. It will also escape through any ope exhaust valves...rendering you test worthless. The best way to check your gage would be simply to check it against a known good one. Hook another gage to the same point you have your current one hooked to and see what it reads. Doesn't have to be a high dollar boost gage, just a $20 vac/pressure gage from cratsman. Hope this helps...not trying to direspect...just trying to inform.

umm...it works just fine. Ive done it on several cars.

that wasnt some off-the-wall suggestion, its an old school tried-and-true DSM way of checking for boost leaks.

Not buying it. How do you keep the pressure from blowng by the rings and also dumping out any minimally open exhaust valves? If you pressurise at the turbo inlet..the air will go through the turbo, the intercooler, the intake..and then the intake valves that are open depending on where it is at in the stroke...leading to losses via the piston rings. While this may be ok simply to check for boost leaks..it is not an accurate way to check a boost gage as there will be enough leakage to keep you from obtaining an accurate reading. I agree it is an effective way to crudely check for intake leaks...but he's looking a minimal diff in pressure..not a large difference.

Ummmm, no. The air will not leak away that quickly. If you pressurize the system to say 10psi and it leaks faster than you can check the boost gauge, you have bigger problems than a bad boost gauge.

True, the pressure will slowly leak out thru the open valves, but it still give you plenty of time to see if the boost gauge also reaches the same psi as you are pushing in, as well as listen/look for any leaks.

Thanks for the replies. I think I will try using another boost gauge and if it is still the same I will try pressurizing the intake and see what that tells me.