Garage Storage Organization and Garage Cabinets

turbovanman · 11-22-2005, 12:09 PM

Hey guys, helping out a friend, has a turbo Omni and using the stock computer for boost control. There is no nipple on the comp, so is it ok to use a manifold vacuum source? Taking the turbo off to drill it for a fitting is out of the question.

Jeremy97sc2 · 11-22-2005, 12:27 PM

I would imagine as long as the source is on the intake manifold, aft of the throttle body it would be fine.

I know many people (not here) recommend taking a boost source reference at the manifold rather than the compressor actually, especially if you have long charge routes. You can actually lose boost if you run it off the compressor as the wastegate will see x boost before the throttle body does, but thats only in cases of long charge routes.

Darkapollo · 11-22-2005, 01:04 PM

i always use a manifold vacc source. to me, its a more relyable source of boost.

Jeremy97sc2 · 11-22-2005, 01:13 PM

Dana is that you?!

OmniGuy123 · 11-22-2005, 03:42 PM

I agree that manifold vac is fine. That is what I use on my omni with no issues. The advantage to the manifold vac is that it will be a more stable and reliable signal as previously mentioned. However for the grainger setup it will take a little longer for the signal to reach the WG. I doubt that would be perceptable though.

It actually would not be too bad to pull the compressor cover off and drill/tap it. There are just the six 13mm bolts back there. I clocked the hybrid in my omni quite easily with the turbo on the car.

Taking the vac source would be the quickest and easiest way to go though.

turbovanman · 11-22-2005, 04:17 PM

Thanks guys!

flynboxx · **boost**

Quote:

Originally Posted by cordes

I agree that manifold vac is fine. That is what I use on my omni with no issues. The advantage to the manifold vac is that it will be a more stable and reliable signal as previously mentioned. However for the grainger setup it will take a little longer for the signal to reach the WG. I doubt that would be perceptable though.

It actually would not be too bad to pull the compressor cover off and drill/tap it. There are just the six 13mm bolts back there. I clocked the hybrid in my omni quite easily with the turbo on the car.

Taking the vac source would be the quickest and easiest way to go though.

When i run manifold vacuum to the turbo i only get 5 lbs boost,here is my setup all of these run to manifold.map/fuel regulator/heater/boost gauge/turbo/ my vacuum lines were taken out so i had to redo them is this ok? i must be missing something.

turbovanman · 11-23-2005, 12:08 AM

Quote:

Originally Posted by flynboxx

When i run manifold vacuum to the turbo i only get 5 lbs boost,here is my setup all of these run to manifold.map/fuel regulator/heater/boost gauge/turbo/ my vacuum lines were taken out so i had to redo them is this ok? i must be missing something.

If you run the wastegate straight to manifold vacuum, as you did, roughly 4-6 psi is correct. This is a cheap and easy way of limiting your boost,

lol!

oldgregg · 11-23-2005, 12:24 PM

Quote:

Originally Posted by turbovanman

Hey guys, helping out a friend, has a turbo Omni and using the stock computer for boost control. There is no nipple on the comp, so is it ok to use a manifold vacuum source? Taking the turbo off to drill it for a fitting is out of the question.

I can't believe you had to ask that!

turbovanman · 11-23-2005, 12:26 PM

Quote:

Originally Posted by ButchN

I can't believe you had to ask that!

Why? all the factory systems use the compressor nipple for the stock boost control? didn't know if it would make a difference using manifold vacuum. Fair question,

puppet · 11-23-2005, 02:29 PM

My stock vacuum schematic shows the compressor nipple feeding the cruise control. AFAIK, all ECU controlled boost comes off the solenoid to the wastegate ... and the solenoid get's it's reference directly from manifold pressure/vac.