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,

Hi, I would like to ask a question. I have a 706 c.i. engine with a fogger. What pressure fuel should I run when using 2 systems, fogger and spray bar. I have two regulators and the fogger is set at 8 lbs. What pressure should the spray bar be set at?

—BULLTRI

BULLTRI,

To answer your question, fuel pressures can vary from engine to engine. Heads, cam and manifold configuration usually dictate what pressures you can run. Generally when using fogger and spray bar systems, the foggers are set at 6 1/2-6 3/4 psi, while the bars are at 7 3/4- 8 psi. The jetting patterns in the foggers can be staggered with fuel and N20 to get all plug readings reasonably close on both sides of the engine, when both systems are being used. How you jet the bars depends on whether you use split style bars or front feed only. Some racers use a .110 N20 jet / .98 fuel jet pattern in the bars and do all fine tuning with nozzles. This should help you.

Thanks for writing.

— Pro Mod Wad

Dear Pro Mod Wad,

The IHRA legal Pro Mod nitrous car appears to be running at a bit of a power deficit to the blown cars. If we could throw the rule book out, what would you do to get these cars to run a tenth faster (i.e. consistent low 6.30s from the current 6.40s)?

— Speedsquad

Salutations Speedy,

First off let me say we really don’t need to throw the rule book out. If you were following IHRA Pro Mod this season you are aware that the parity in Pro Mod is better than ever. True, the blown cars hold the records in the class but in 11 IHRA events this year the score for wins is N20: 8 — blower: 3! Also in at least four of the 11 events, it was a blower vs. N20 final. The deal is that during the season there are a few races and tracks where the blown cars do have the advantage due to weather and track conditions. The fact that blown cars are on full torque and power right from the starting line and nitrous cars must bring on two or three stages in the run means that the N20 guys better be on their clutch settings or they will blow that run.

At the IHRA finals in Shreveport in October, Tommy Mauney was the number one qualifier with a 6.30 and won the event with a 6.32 against a blown car’s 6.34. Tommy’s worst run for the weekend was 6.33 and several N20 cars were in the 30’s all weekend and the rest in low 40’s. A weight reduction may be coming for the nitrous cars this season. So stand back baby this is gonna get good.

Thanx for the email.

— Pro Mod Wad