I recently switched from a Powerdyne supercharger (making about 5PSI of non-intercooled boost w/my ported heads) to an ATI Procharger D1 (pullied for 6PSI, but making about 8PSI of intercooled boost). I have not yet made any computer changes, and on a recent track and dyno run the car seems to be running out of fuel. Do you think my 30lb injectors are maxed, or is there something in the computer that I might be able to modify to compensate? I tried playing with the PE/RPM tables, but to no avail. If it's relevant, my MAF is maxing (ie 471g/s ~4000 RPM vs. 6000 previously w/the Powerdyne).

Thanks in advance...

PAUL D.

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Paul D.

1994 Z-28 A4
Formerly Powerdyne 6# (Now ATI D-1) + NX 75 shot
G2 LT1 Ported/Polished Racing Manifold/Big Valve(2.00/1.56)Heads, CC 512/512 220/230 ls112, CC ProMagnum 1.6 RR
PCM by Ed Wright then more w/LT1-Edit, ACCEL 300+ Ignition & Coil,
G2 Wires, Borla, SLP Jet-coated Headers, G2 52mm TB, G2 MAF
3.73, G2 High Stall Converter, TG shift-kit, Built Trans
G2 Engine Brace, G2 Sub-Frame & X-Brace, G2 Control-Arms
WolfCraft 6-pt Roll-Bar
BF Goodrich 275/40/17 Front 315/35/17 Rear
ACT Aluminum/Titanium 17X9 & 17X11 Rims
11.13 @ 127.4 1.70 60ft.
480+ rwhp 470+rwt

1967 Camaro RS/SS
502ci w/Holley 177ci Blower + NX

1972 Dodge Challenger
446ci + NOS

 

Generically you will need to add more fuel (get on the dyno), since your now making more power.

You may also need to pull more timing, generic rule seems to be 2º for ever pound boost if I recall correctly, if your not seeing knock though then you can probably thank the intercooler for the assist.

Your going to have to work around that MAF issue.

Good luck!

[This message has been edited by Dr.Mudge (edited August 17, 2002).]

 

Looks like the pulsewidths are about 33ms and the Duty Cycle is ~128%. I assume this means that the injectors are more than maxed out and I need to upgrade? Or... is there a specific way within the PCM to compensate?

 

I did think about that later on, and with what other people make on 8PSI then I'd say hell yes you need injectors. I ran 30# on my NA stock bottom (much less power than you!, ~490 crank), I'd go with 42#, even I considered 36# (for my car).

With a blower you want to have larger than minimum injectors for sure. Every once in awhile the 42# show on eBay.

[This message has been edited by Dr.Mudge (edited August 17, 2002).]

 

Yeah.. you need bigger injectors or an FMU. You also need to Power Enrich the heck out of it everywhere above where the MAF maxes out. You will run leaner and leaner the more you go if you don't. Need to see if its knocking also.. might need to back off some timing. Really to go log a run to see what its doing at the dyno or track. A blower car running lean is a time bomb.

 

You have to get bigger injectors so you might as well keep the fmu out of the picture (you really can't tune with one anyway).

Hal

 

Paul,
Just curious how much boost your seeing at 4000 when you max out the maf?

Thanks
Travis