Lupo222

Well, I hooked up my boost gauge this morning...kinda just ran it through the hood and in my car through the window so I could monitor it on a test drive. Right now, I have the stop bolt completely off the S/C. I'm going to let the car cool off and reinstall it further out as it was on my last adjustment.

Vacuum's good...stays right around -13 to -10. When I get on it hard, it looks like it MIGHT be getting 1 psi but nothing near the 5-6psi it should be getting. I bought some vacuum hose to replace all the vacuum lines in hope of a leak, but the vacuum's good, so there goes that idea.

My belt is the recommended size but I guess I could try a size smaller in hopes that I have an UD pulley somewhere that is causing slippage on the S/C pulley (but again, I doubt that).

The boost actuator works...I put my finger over the nipple and the plunger stayed up until I let it go.

I'm so lost right now....does anyone have any advice or ideas??

moochman4life

Hey fella. Is it a boost/vacuum gauge, or do you have seperate boost and vac gauges? Couldn't really tell from the post.

Also, the 13-10 vac reading you're getting...is that at idle (neutral), or in gear? In neutral (I have a 5-speed), mine reads about 21...but if I'm cruising around, it would be about 10. Checking with people, that seems to be normal.

Last question: where do you have the hose plugged up? The line above the injectors, port-side? Yes, I said port-side, Marine.

Oh, and did you use anything to "seal" the hose to the back of the gauge? Like teflon tape, or something?

When I rigged my own boost, and then, boost/vac gauges, I had all kinds of sealing issues on the back on the gauge, itself.

dmhines

With factory cams the vacuum should be -20 at idle ... anything less and there is a leak. Not sure about the Hot Rod Cams though.

The first step in the Saleen instructions is to replace any under-drive pulleys with stock pulleys. You won't be spinning the S/C fast enough with UD pulleys.

What boost/vacuum numbers you get with the stop bolt in like my picture?

Lupo222

Ok, its reading -12 at idle...If I rev it up, it will goto 0 and then at the peak, right as it winds down, it will go to -16 and then right back to -12. I guess maybe I have a vacuum leak somewhere...

The gauge is coming off the fuel sensor on the drivers side (port side from the drivers seat, starboard from the front of the car hehe)

I do have teflon sealing the gauge so I don't think that is the problem...

I do have a boost/vac mech. gauge. And I know its not the gauge malfunctioning...this thing does NOT have the power of a twinscrew s/c!!!!

Lupo222

Ok, re-installed the stop bolt out further like your vehicle hines....

The vacuum now reads -15 and when it winds down, it spikes around -21, but at idle in neutral, its right at -15...still no boost though...

PSUSkier

You must be pulling air in elsewhere... When you say it spikes at -21, what do you do to get it there? Rev it and let off? Coast in gear?

moochman4life

There you go.

Hey, are you trying to get a boost reading in neutral?...or under driving conditions? I won't generate boost in idle, but will peak under load (9.5psi in gear).

dmhines

Is the diaphram pulling the actuator arm FULL UP at idle? And it drops to stop bolt when you you turn off the engine?

After you installed the bolt ... are you testing this by revving engine in nuetral or driving on street? You will need some load to get good boost reading so you need to be on the street driving.

Lupo222

Well, i just found a small hose clamp and installed it on the boost actuator vacuum, thinking maybe it was loose and loosing suction. I started it and it again idled at -15psi, but when I revved it in neutral, I saw 5psi of boost but only when I was right at the rev limiter, pushing it to the limit. I have an aluminum flywheel so it gets there quick though.

I'm going to take it for a test drive right now to see what I get. Fingers crossed....

Lupo222

Test Drive: unsuccessful. Vacuum was good...-20 when I let off the gas under a load. However, the boost went up to maybe .5-1psi when I floored it.

I think I'm going to move off of this boost actuator and start attacking the pulley system. Maybe I have an UD pulley on there I didn't know about? Maybe my belt FEELS tight but isn't tight enough? I do have one size smaller...I might try that.

Unfortunately, the guy before me installed the UD pulleys so I have no idea which one is a UD pulley!! Everything he bought is Steeda so which pulley does Steeda replace??

This is getting frustrating lol

Edit: just spoke to Saleen and they said my cams could be the culprit? Something about the timing blowing all teh boost out the exhaust (cams and LTs)...

I am now going to replace the belt...they said the belt should be ridiculous hard to get on and the one I put on actually fit pretty easy...fingers crossed...