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NoDOHC · 01-23-2011, 10:21 PM

What do you consider good for AFR?

You should be shooting for 13.0 to 13.5:1 on Gasoline. If you run much rich of that, you are wasting fuel and leaving power on the table.

What are you running for ignition timing?

You should not need 550 cc/min injectors. If you do, you either have a fuel pressure problem, have hit on some amazing porting that flows exceptionally well, or are running excessively rich.

I was at 63% Duty Cycle with 216 WHp on 460 cc/min injectors. Unless you are making 250+ WHp, the 460cc/min are plenty.

Lets get a feeling for torque, if you floor the throttle in first gear with the engine at 2500-3000 RPM - will the tires spin? If you floor it at 7,000 RPM, will the tires spin? Where does it feel like it pulls the hardest? My 6-port made peak torque about 7500 rpm. If you are running excessively rich there, you are probably killing your sweet spot.

I would expect that engine to be capable of spinning all season 205/60 R15s on a throttle transition between 6,000 RPM and 7,500 RPM.

Ignition Timing should be around 30 degrees BTDC Above 3,500 RPM.

01-23-2011, 10:21 PM	#45
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	What do you consider good for AFR? You should be shooting for 13.0 to 13.5:1 on Gasoline. If you run much rich of that, you are wasting fuel and leaving power on the table. What are you running for ignition timing? You should not need 550 cc/min injectors. If you do, you either have a fuel pressure problem, have hit on some amazing porting that flows exceptionally well, or are running excessively rich. I was at 63% Duty Cycle with 216 WHp on 460 cc/min injectors. Unless you are making 250+ WHp, the 460cc/min are plenty. Lets get a feeling for torque, if you floor the throttle in first gear with the engine at 2500-3000 RPM - will the tires spin? If you floor it at 7,000 RPM, will the tires spin? Where does it feel like it pulls the hardest? My 6-port made peak torque about 7500 rpm. If you are running excessively rich there, you are probably killing your sweet spot. I would expect that engine to be capable of spinning all season 205/60 R15s on a throttle transition between 6,000 RPM and 7,500 RPM. Ignition Timing should be around 30 degrees BTDC Above 3,500 RPM. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic) Last edited by NoDOHC; 01-23-2011 at 10:29 PM.