I bought my blower off a guy who had a 91 305 TPI Slp performance package (headers,catback, runners,chip)Camaro. Everything else was stock. The blower was producing 10lbs at 5500RPMs on his car.

I have a similar setup to him but I have 1.6full roller rockers, you can also see my mods below. Point is, I'm only getting a maximum of 5lbs of boost. Is my engine that much more efficient than his was or is it something else?

How can I have half the boost he did???

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91 Formula
305 TPI 5speed
1LE/G92/WS6

Paxton SN92 polished kit, Ford SVO 24#injectors, Crane AFPR,SLP airfoil, ported/polished plenum, March alt. pulley,Crane Gold 1.6rrs,MSD coil,MSD6AL (5400rpm limit),Holley 9mm wires,Ac delco R43ts plugs,stock chip,Bosch O2sensor,SLP 1 5/8" headers,SLP catback,shortened shifter,3:73s w/Auburn posi,180* t-stat,JET 195* fan switch, Macewen white face gauges, Autometer gauges, Zoom hi-performance clutch.

[This message has been edited by theformula (edited March 25, 2001).]

 

theformula,

O.K., I'm no expert by any means, but from what i can see, first is you are not turning as many rpm's, you have a ported plenum, and 1.6:1 rockers, with these thing's you will have better efficiency (not allowing for backpressure to build in the intake), so your boost will be lower, how much, i can't say. Also there might be a slight variance in the accuracy of the boost gauges.

Willie could probably help you alot more with this, cause he's already been through this problem.

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MÅN¡ÅÇ ©
88 IROC 5.7L,edelbrock TES,random tech cat,borla exhaust,chip,sfc,accel wires,airfoil,k&n's,ETC..
and NOW supercharged!!!
http://maniac.megamania.com

 

theformula,
I have about the same mods with a Paxton s/n2000 with the modified impeller.
Check my sig.
and I get 10psi of boost at 5400 rpm.
Are you sure that your boost gage is working correctly.
Do you have the correct pulleys.


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Louis
Convertable
92 Z28 305tpi Auto
1/4 at 13.23 @ 106.1mph w/Paxton 10psi, Ram air mod,Water methanol inj.,52mm T/B,ASM Large tube runners, ported upper & lower intakes,AFPR,23# injectors,1.6 roller rockers,slp tri-y headers,3in. cat,3in. gale banks cat back system,3.42 gears,17x9 camaro SS wheels, 285x40x17 tires,and much more.
http://www.lbsz28blown.cz28.com

 

hey man. I have the correct pullies. I dont remember the exact measurements but i could take them.

 

OK heres a basic thing to remember...if your heads flow more air then you will have lower inherant pressure. Just cause the gauge says 20 PSI does not mean that your heads are flowing that much, the better result is that your heads are "backed" up allowing the 'charger pressure to rise, but that pressure is not making it into the heads.
The more you port the better the flow, now you can get a bigger gear and try again till you start to get "clogged" heads or just step up 1-2 ratios and be happy that your engine is running much more effeicently and is able to use the pressure wisely.