2.4L LD9
GM M45 Supercharger
2.8" stock pulley
Is the vacuum supposed to be -20 or something like that at idle? Does this mean I have a vacuum leak?
I re-did my gauge tubing (electronic sensor in the engine bay) and it didn't change anything, unless my gauge tubing is ballooning in areas or something like that (it's kinda soft tubing)..
I just want to figure out why I'm reading such low boost numbers, thought it's supposed to be 4-6 PSI.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
And 2-3 PSI is 4-6 in. Hg. I thought the GM supercharger shot for 4-6
PSI, does it not?
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Wish j-body had edit buttons. So since the vacuum reading is fine, what would cause the 2 PSI boost at WOT?
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
we do have edit buttons, go premium
My car may run 18s, but I can do your taxes in 10 seconds flat.
JBO lube - they would never have enough in stock and we'd never see RodimusPrime again
Machzel08 (Teh Jew) wrote:we do have edit buttons, go premium
How does that help him?
I'd triple check for a vacuum leak, you should get 5psi with the 2.4 blower. Is your gauge working properly? What happens when you turn the car off, I'm assuming it's mechanical? It should centre back at 0.
" To study and not think is a waste. To think and not study is dangerous. "
it's an electrical. the boost sensor is in the engine bay with wires going into the gauge in the interior. with the car off (in acc mode in order for the gauge to be on but not the car) the gauge reads 0. when i turn the car on it ranges from negative 8-10 PSI (around 20 in. Hg. vacuum). here's a video of what happens from a roll of 5MPH and laying it out (after the outside of car video):
watch the boost gauge
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
What do you have it T'd into? Maybe you've got too much on it...
You supercharged an Alero, that's awesome!
Try a mechanical boost gauge, see if you have the same results.
JuggaloZeke wrote:What do you have it T'd into? Maybe you've got too much on it...
The fuel pressure regulator line on the boost side. I replaced its tubing with the tubing that came with my gauge (clear plastic-like) from the FPR to the boost side of the intake manifold, and the plastic T is near the middle of that hose. No kinks in the hose, no part of it squished. I'd check with a mechanical gauge if I had one.
I'm just thinking that maybe the connections are leaking, the hose itself is leaking somewhere, or its bulging under pressure since it seems to be quite a soft hose. If those were true, would it still read the vacuum at idle correctly as it does? It's just the positive boost it's not getting right (I hope, and my supercharger is fine)
@Admiral Jedi: Haha
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Would the tube that comes from the PCV baffle to the timing chain cover being off have anything to do with anything? I wouldn't think so.. but I didn't put it on all the way at all and it fell off. So I re hooked up the hoses right and clamped them good. (Can't test it yet, my engine bay ate a screwdriver underneath the serpentine so I need to find a way to get that mofo out first)
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Nope, no change in boost or vacuum readings. Since the vacuum reading is correct, it leads me to assume that under boost is when the gauge's lines are bulged/leaking, does that make sense? Or can anyone else put forth insight as to what could be the culprit of this?
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
So what is the better boost gauge to go with? Mechanical or electrical?
Regards,
Well I thought electrical since you don't need to route the tubing into the interior, only as far as you need to go in the engine bay to reach the sensor, so as to reduce the possibility of kinks/misreadings, but I get a misreading with my electrical, more my fault than anything probably.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
That's basically what I'm doing, the FPR line goes onto nto the supercharger on one of those nozzles. I guess I could try it with the T as close as possible to the supercharger, but... what would happen if I disconnected the line from the s/c to the FPR and ran a direct hose from the s/c to the gauge's sensor (to test if my current T setup is leaking)? Would the car run like crap without the boost line going to the FPR?
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Re-did the FPR/boost gauge tubing and tee, still no change, 2 PSI max.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
you try a real gauge yet ?
this tinted a/f & boost gauge combo cost me $75, not real eager to drop more money on another one.
would not going fully "wide-open" on the throttle body's butterfly plate cause the bypass valve to not close all the way thus leaking boost? because using my hand i can move the throttle control pulley/thing all the way 90 degrees, but i had someone push the pedal down all the way and it doesn't turn fully 90 degrees, its off by like 10 degrees
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
.. do you have an underdrive crank pulley?
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
No.
WOW. I just took off my aftermarket Tenzo pedal cover, and removed the floor mat, and now my throttle plate opens fully (as I observed with another person pumping the pedal. Got out on the road and HOLY CRAP, 4 PSI and this thing SCREAMS. It's like once it hits 3 PSI it finds another gear and surges to the redline, scary power to me. Wow. Gauge reads correctly, pedal wasn't going all the way down so the bypass valve wasn't closing all the way, but now when this thing pressurizes damn you feel it.
Thanks for everyone's help, though none of it was the answer.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Isnt the Stock Output 6psi and your only getting 4psi?
it's really hot out, its supposed to be 4.5 PSI acc to resources
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
