Okay, i completed my installation of the GM S/C for my 99 z24. but i have a couple of questions.... If i have an underdrive crank pulley on along with the stock 2.8" pulley on the charger, about how much boost should i be seeing? I have this setup, and i'm not seeing any boost whatsoever. When it's under full throttle i'm seeing on my boost gauge 0 Boost and 0 Vaccum. Where do most of you have your Boost gauge hooked up to? Also, you know the little nipple directly under the supercheger right where the head and the charger meet....what exactly does that do? Okay, that's enough questions....I hope someone can help me out with the boost problem.
NEW SIG COMING SOON FOR 07'!!!
if you underdrive your crank pulley the 2.8 pulley isnt a true 2.8 cause you are spinning it slower resulting in less boost....
i have my boost signal pulled off of the line that goes to the fpr
Well, I did have the boost gauge reading from the FPR nipple too, but it's now reading from the throttle body (i didn't do that....) my friend said you can read boost from the throttle body also, how, i don't know and still don't understand, but i'm going to put it back to the FPR nipple. That's what i was thinking also about the whole underdrive pulley thingy, i think i'll see if i could get a machine shop around here to make the blower pulley smaller. Thanks!
NEW SIG COMING SOON FOR 07'!!!
With your supercharger (roots type) you can not get a boost reading from the throttle body. Stop listening to your friend.
- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.
^^^ yeah he is right. how are you supposed to read boost before the air even gets boosted. hook up that boost gauge to the fpr and your problem should be solved. well not all your problems, get rid of that underdrive pullie asap, put the stock on back on or get a lightened stock size one.
turbo doesnt matter , or a vortec style doesnt matter
pretty much the way it goes , you have to read boost after the device doing the boost
That nipple at the bottom near the head connects to another nipple near where the TB bolts up to the blower. Not sure exactly what it does but it's there for a reason so you'd best get that fixed up.
14.330 @ 96.37mph
Hey fellaz, I know that the Throttle Body can't read boost but the reason my friend thought it would work is because he has a twin turbo mustang, and he has his boost gauge off his throttle body, but where would i put the FPR vaccum line at if i take it of the FPR vaccum nipple on the blower? Can i just cap the nipple on the FPR off?
NEW SIG COMING SOON FOR 07'!!!
just get some vaccum tubing from the autoparts store, run it from the s/c to the FPR (sorta a pain to get it on there down by the s/c nipple), buy a "T FITTING". run one line to the boost guage.
i zip tied the lines on the nipple, didnt want them falling off. also i found that windshield washer tubing works great for vaccum lines.
