stock turbo spool and A/F ratio - 3000GT/Stealth International Message Center

FernyVR4 · 10-26-2006, 06:17 AM

I recently bought a '95 VR-4 off of one of the forum members and I must say that for what I paid, I got a great deal.
Since I live somewhat close to DJAuggie, I had him take a look at my car to see how it stacks up. He said everything was great except for 2 main things. My stock 9b's reach 14psi at around 3700-3800RPM, which I was told is very slow for the stock turbos. I'd like to know what kind of spool others are getting on their stock setups, and what could be causing all the boost lag.
The other problem we noticed is that, when we plugged in the hybrid datalogger, I was getting A/F ratios of ~.84-86 on throttle. I'm told this is very lean. Any idea what could be causing this as well?

Any input would be greatly appreciated!

~Andrew

(p.s. yes, I did use the search function, and no, I couldn't find anything relevant)

edit: I guess those #'s are from the O2 sensors, or something, my bad

BjornRune · 10-26-2006, 07:49 AM

Surely Shawn suggested you pressure test the intake? If you have a leak that would explain the slow spool up. About being lean, just to clarify, were you in boost when you recorded those O2 values?

FernyVR4 · 10-26-2006, 07:54 AM

Quote:

Originally Posted by BjornRune

Surely Shawn suggested you pressure test the intake? If you have a leak that would explain the slow spool up. About being lean, just to clarify, were you in boost when you recorded those O2 values?

yes, he did, I just was wondering whether there were any other alternative possibilities before I spend $40 on a pressure tester.
yes, those O2 values were recorded during boost

BIG_BALLER · 10-26-2006, 08:28 AM

well, your lean soo it could be a VAC leak between your MAF and your turbos. I made a pressure tester today that I would let you use but my setup is MUCH diffrent

.

FastOldGuy · 10-26-2006, 09:01 AM

Quote:

Originally Posted by FernyVR4

yes, he did, I just was wondering whether there were any other alternative possibilities before I spend $40 on a pressure tester.
yes, those O2 values were recorded during boost

Yeah spend $10 and make a pressure tester your self.

http://www.supercar-engineering.com/...T/IntPresTest/

ou need to pressure test your car.

FernyVR4 · 10-26-2006, 10:03 AM

well, something did come with the car, its PVC pipe, around 4" in diameter, and has a pressure hose connection and pressure gauge on one end and is open at the other, but a) I don't have a compressor other than the one I use to fill my tires, and b) I don't know what to unclamp and where to insert it, the intake is oval, isn't it?

cbehnken · 10-26-2006, 10:14 AM

You pull the intake oval out to use that pressure tester.

Your turbos are very slow for whatever reason. If I hit the gas in 5th at about 1800 RPM I can hit 15 PSI by the time I hit 2000-2200 RPM and one of my turbos is larger than stock.

BIG_BALLER · 10-26-2006, 10:18 AM

^ do you see knock when you do that in 5th gear ?

cbehnken · 10-26-2006, 10:19 AM

Quote:

Originally Posted by BIG_BALLER

^ do you see knock when you do that in 5th gear ?

no, why would I? I'm not even going full throttle, but it doesn't knock at WOT in 5th either(not that I would lug it like that normally)

FernyVR4 · 10-26-2006, 04:45 PM

Quote:

Originally Posted by cbehnken

You pull the intake oval out to use that pressure tester.

Your turbos are very slow for whatever reason. If I hit the gas in 5th at about 1800 RPM I can hit 15 PSI by the time I hit 2000-2200 RPM and one of my turbos is larger than stock.

how do you fit a circular pressure tester into an oval hole?
or am I mistaken and when you take the intake off, the hole is circular?

10-26-2006, 08:28 AM	#4 (permalink)
BIG_BALLER I'm a Troll Join Date: Jul 2003 Location: Albany,NY Drives: MODS SUCK DICK Trader Rating: (25)	Re: stock turbo spool and A/F ratio well, your lean soo it could be a VAC leak between your MAF and your turbos. I made a pressure tester today that I would let you use but my setup is MUCH diffrent .

10-26-2006, 10:03 AM	#6 (permalink)
FernyVR4 Bom Chicka Wah Wah Join Date: Sep 2005 Location: New Windsor, NY Drives: '95 VR-4 Trader Rating: (0)	Re: stock turbo spool and A/F ratio well, something did come with the car, its PVC pipe, around 4" in diameter, and has a pressure hose connection and pressure gauge on one end and is open at the other, but a) I don't have a compressor other than the one I use to fill my tires, and b) I don't know what to unclamp and where to insert it, the intake is oval, isn't it? Last edited by FernyVR4 : 10-26-2006 at 04:44 PM.

10-26-2006, 10:14 AM	#7 (permalink)
cbehnken Forest Gump Join Date: Nov 2004 Location: Cape Girardeau Mo Drives: 1992 Stealth TT Trader Rating: (42)	Re: stock turbo spool and A/F ratio You pull the intake oval out to use that pressure tester. Your turbos are very slow for whatever reason. If I hit the gas in 5th at about 1800 RPM I can hit 15 PSI by the time I hit 2000-2200 RPM and one of my turbos is larger than stock. __________________ Power: DSM 13G/DR650 Combo, DSM 450 cc bluetops, SAFC I, K&N, Ebay Downpipe, ATR Dual Catback, no cats, DN Y-Pipe, HKS SSQV, HKS EVC 5 at 14.5PSI, Walbro 255 with AN Bulkhead 8.07 @ 85.55 1/8th mile 1.84 60FT Suspension: KYB GR-2 - Tein S-Techs, Crossdrilled/slotted rotors, AWS Delete Drivetrain: RPS Street Max, M.W. 300m O/S, Seattle F&R Poly Mounts Etc: Roller Bearing Short Shifter Smokinvr-4 Corner box, 10" Rockford Fosgate Punch sub, Eclipse Headunit Leatherseats.com Charcoal/Dove Grey Interior, 99 front end/lights/wing/sideskirts/doorcaps Maintenance New VSS, all 60K stuff, new 1st,2nd, 3rd syncro, trans seals, oil pump, rod and main bearings. Mobile 1 10w40, Redline MTL in trans, 85w90 Coastal GL5 in transfer case and rear

10-26-2006, 10:18 AM	#8 (permalink)
BIG_BALLER I'm a Troll Join Date: Jul 2003 Location: Albany,NY Drives: MODS SUCK DICK Trader Rating: (25)	Re: stock turbo spool and A/F ratio ^ do you see knock when you do that in 5th gear ?

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