Current GM Q-jet Rules

[Mark Yacavone]

Originally Posted by oldskool

OK, thanks !

That brings up more questions. Since this info is not mentioned in the Class Racer Info guide, exactly when did this new rule go into effect ?

Is the rule only mentioned in an official NHRA rule book, or is there another source I can find online, if I know the correct link ?

It's not a new rule, by any stretch. Been this way for 20 years...Probably more

[oldskool]

Originally Posted by Mark Yacavone

It's not a new rule, by any stretch. Been this way for 20 years...Probably more

OK, just going by what I read in the Class Racer Info guide. If I'm reading it correctly, there is no mention of the fact that any Q-jet that is within the legal venturi size is OK.

So, another question: Does an Edelbrock Q-jet have any advantage over a GM Q-jet ? Or, can the good Q-jet builders get the same power potential from either, just as easily ?

[J.R. Haddad]

I think that would be a question for the good quadjet builders. J.R.

[Dwight Southerland]

Originally Posted by oldskool

OK, just going by what I read in the Class Racer Info guide. If I'm reading it correctly, there is no mention of the fact that any Q-jet that is within the legal venturi size is OK.

The tech sheet info on Class Racer Info is obtained from the NHRA Tech Sheets. Neither do the NHRA Tech Sheets or rule book specifically describe the situation you are questioning. There is a statement under the Carburetor paragraph of the Stock Cars section of the rule book that states "Replacement carburetors permitted provided they are same model, type,throttle bore, and venturi size." The provision for using Qjet carbs apparently falls under that statement.

[older racer]

hello, question? does the inlet have to be the same location? on any carbs? just curious. thanks

[Mark Yacavone]

Originally Posted by older racer

hello, question? does the inlet have to be the same location? on any carbs? just curious. thanks

No

[oldskool]

"Replacement carburetors permitted provided they are same model, type,throttle bore, and venturi size."

OK. I reckin the words "same model, type" just mean they have to be a Q-jet type carb, and not necessarily a Chevy Model, or Buick model, or whatever car brand you race, or one specific Edelbrock number.

I suppose it only matters how the tech guys interpret the rule. It makes sense to me, since I don't see any big advantage to a particular Q-jet. But then there are lots of very similar parts, from different year cars, that would not provide an advantage, but are not legal.

Don't know if more of these similar, but different year parts will become legal, as parts for the older cars become more scarce, or not. ?

[J.R. Haddad]

OLDSKOOL, you are overthinking this topic. ANY q-jet as long as it
measures correctly. PERIOD. J.R.

[Bob Mulry]

When Edelbrock was a Major Sponsor with the Q-Jet replacement carbs, NHRA changed the rule to allow Edelbrock to sell more carbs......

The B-O-P guys could by an Edelbrock carb to replace the front inlet style....

The phrase "stock inlet location required" was removed from rule book…….

Show me the money and I'll show you a rule change.....

In Stock AFTERMARKET disc brakes, aluminum seats, intakes, heads and radiators, transmissions, 6" clutches, 2 year seat belts and on & on & on......