legal qjet

Jeff Lee · 01-07-2010, 01:16 PM

Quote:

Originally Posted by Billy Nees

And there you have another perfect example of NHRA selectively applying their rules! Intentionally or not.

I would use the argument about the Holley allowance on the Q-Jet, AVS, AFB, or whatever you run. My understanding is all NHRA cares about is venturi and throttle blade size with no porting or polishing. Fuel inlet location or angle is no longer an issue on a q-jet. Guess you still have to run the choke plate.
I'm sure you've seen more than one Holley 4bbl in tech with no concerns about thinned boosters.

Tony Curcio · 01-07-2010, 07:41 PM

To clarify the question- most Q-Jets have a booster as well as a ring around the booster. The only exception is a Pontiac Ram Air carburetor from one year only (1971). That particular throttle body is sought after by collectors, and the last I heard, cores were selling at about $1,000.

The removal of this ring adds about 50 cfm to the flow, probably a lot more than changing booster sizes or angles in a Holley. The use of the Ram Air throttle body would have clearly been illegal before the rule change that allowed any carb with the same throttle blade and venturi diameter. It is less clear now, as the rule book addresses only the throttle blade and venturi sizes.

Danny- when did you have this conversation with an NHRA tech man- recently?

Danny Ashley · 01-07-2010, 10:08 PM

Tony:
If memory serves me correctly, It was at the 2007 U.S. Nationals. I had always believed, as you, that because the venturi measured 1.093 and the throttle blades were 1.375 & 2.250 that these Q-Jets were legal for any engine that required these specifications. I don't think the ruling has changed, but if anyone is serious about running one of these, then you should contact your division director. Not all single boosters came on the Ram Air and H-O engines. The most common number is 7041263 that came on the low performance 400 & 455. 7041267 & 7041268 were on H-O's and 7041270 & 7041273 were the Ram Air's. The 263's can be bought for a lot less than the others. Danny

01-07-2010, 07:41 PM	#2
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: legal qjet To clarify the question- most Q-Jets have a booster as well as a ring around the booster. The only exception is a Pontiac Ram Air carburetor from one year only (1971). That particular throttle body is sought after by collectors, and the last I heard, cores were selling at about $1,000. The removal of this ring adds about 50 cfm to the flow, probably a lot more than changing booster sizes or angles in a Holley. The use of the Ram Air throttle body would have clearly been illegal before the rule change that allowed any carb with the same throttle blade and venturi diameter. It is less clear now, as the rule book addresses only the throttle blade and venturi sizes. Danny- when did you have this conversation with an NHRA tech man- recently? __________________ Tony Curcio 1860 STK Last edited by Tony Curcio; 01-07-2010 at 07:47 PM.

01-07-2010, 10:08 PM	#3
Danny Ashley Member Join Date: Nov 2001 Location: Marion,In. Posts: 267 Likes: 60 Liked 110 Times in 29 Posts	Re: legal qjet Tony: If memory serves me correctly, It was at the 2007 U.S. Nationals. I had always believed, as you, that because the venturi measured 1.093 and the throttle blades were 1.375 & 2.250 that these Q-Jets were legal for any engine that required these specifications. I don't think the ruling has changed, but if anyone is serious about running one of these, then you should contact your division director. Not all single boosters came on the Ram Air and H-O engines. The most common number is 7041263 that came on the low performance 400 & 455. 7041267 & 7041268 were on H-O's and 7041270 & 7041273 were the Ram Air's. The 263's can be bought for a lot less than the others. Danny

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