I installed my saleen supercharger. I didn't get there gauge pod as it was very obvious on top of dash. They don't sell the gauges seperately so I went with a set of auto meter gauges. I am having a hard time with the mechanical boast/vac gauge. when i tap into the fuel vac or blow off vac. It read vac only unless i am on the gas (hard) then boost happens (5psi). Right when i let off the gas it shots down to vac. I thought if I hold the gas at 3500rpm i should get some sort of boost reading. Am i wrong? I only get boost under WOT. I have contacted Saleen and they will only help if I had they gauges. They don't know how or where to tap a mechanical line in. I find that hard to believe so now I am turning to you guys.

 

Sounds to me like you are attempting to get a reading off of the car while it is sitting still. If you try to build boost without a load on the engine it is nearly impossible, especially with that type of supercharger and the minimal amount of boost it produces at maximum. If you have not done so already put the car in 3rd or 4th gear and at about 3500 rpm mash the throttle down and the boost should climb as you expect. If this is not the case then I would most likely be inclined to believe that your choice of locations for vacuum/boost retrieval is less than adequate. Boost is a variable thing and can show very different numbers depending on where in the intake system you plum the sensor. Hope this helps.
Derek

Edit: I forgot to mention, when you are putting your car in the higher gear make sure you are moving at the appropriate speed to do this, don't just put it there from a dead stop.

 

Contact Jim III at JDM, 732-780-0770, www.teamjdm.com. They have been running the Saleen blower for a while (in the mid 11s, too), and know these things pretty well. Tell him don_w gave you the contact info.

 

It should read vacuum most of the time unless your are at WOT or hard part thottlle. I guess I'm not sure what you are asking, unless you felt boost would be there all the time and that would be incorrect. It should jump into boost pretty quick once the loud pedal goes down, however at 5 psi it'll be a little less responsive than lets say my Lightning with close to 20 psi. With the amount of boost I run it's very responsive. I hope I've helped you out. If not I'll try again, but it sounds correct.

Thanks Mike