Drag Racing Online

Ed. Note: Wady Hamam or Pro Mod Wad as he is known in the business is NOS's main nitrous Guru. He has been involved in nitrous oxide injection almost from its inception especially with the Pro Mod division.. He is originally from the Buffalo, New York area and has been involved in all types of racing from flat track motorcycles to fuel dragsters. In his wasted youth he even raced a fuel funny car powered by a blown and injected small block Ford! He and his brother campaigned a front motored Top Fuel dragster and lost a race against Don Garlits at the now closed Niagara Falls Dragway. His advice about nitrous problems is highly sought after but he is hard to get to. He has agreed to answer one question every couple of weeks for Drag Racing Online readers. Email your questions to: promodwad@racingnetsource.com, and he will answer the question he finds most intriguing.

Dear Pro Mod Wad:

I have a 598 c.i. big block Ford in an '92 'Stang street stuff. I switched to a Fogger set-up last year. I had problems with it being lean. The guy that sold me the new Y kit told me to start out using a 70 Holley jet with about 7 lbs. of fuel pressure flowing.

OK, I did this, but I was still too lean. 14 pistons later, I use a 90 Holley jet at 7 lbs. and I am doing good now.

I have a B.G. 400 pump that flows good numbers. I have the nitrous and the fuel jet the same as last year, 36, 36. I listen to the guys at the track running off set jetting and 5.5 to 6 lbs. of fuel pressure.

I can't help myself, but what in the hell is going on with my set-up? The motor is doing good with the setting now, but if I try to change the flow I just know that it will be time to chase pistons again.

On the motor, it like 98 jets and 34 on the timing. On nitrous, it like 22 on the timing with 350 hp.

Jim

Hi Jim,

There are many answers to your question, but let me see if I can give you a few sensible ones. First, for some reason, Fords do not like a lot of timing on or off of nitrous, so part of your problems with being lean is timing. That is why when you flowed through larger jet you solved your problems.

Second, when using nitrous, the piston tops should be thick enough to handle the cylinder pressures and heat generated by the accelerated burn in the engine, so lean condition and possible incorrect pistons could be part of your dilemma.

My suggestion would be, if you feel you do not have a piston problem, to get some more timing out of that bullet. Probably 16 or 18 degrees total when on the 350 HP system. You will also find with less timing that you can put the fuel pressure back to that 5.5 of 6 PSI that you hear about.

I am pretty certain you are going to see more power out of your engine when you get the timing out. You will also be able to set your fuel pressure through a 70-72 jet and be very safe in your tune-ups.

Hope this helps you, Jim, and please let me know how you are making out with your program.