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Tony Curcio · 03-23-2013, 04:47 PM

I have two experiences with the "big" two barrel.

In 2004 we compared Q-Jet vs 2 bbl on our 255-350 that was set up for IHRA pure stock at the time. It was a stick shift, with the mandated stock valve spring pressure and stock duration cam. The 2 bbl slowed it about .55 and it was further under the index, by about .15. We didn't need a rev limiter for either combo, it couldn't spin high enough to hurt itself.

Two years later, same car with a modern NHRA stocker engine and an automatic. This time the Q-Jet was further under the index by about .30 or more. As the difference between H/SA and M/SA is .70, this must mean it slowed 1.00 that day, although in my mind it was worse.

The 2 bbl was going through the traps at 5700, the 4 bbl at around 7000+. Changing the gears and converter probably would have helped, but we decided not to pursue it any farther.

03-23-2013, 04:47 PM	#5
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: 2 barrel analysis question I have two experiences with the "big" two barrel. In 2004 we compared Q-Jet vs 2 bbl on our 255-350 that was set up for IHRA pure stock at the time. It was a stick shift, with the mandated stock valve spring pressure and stock duration cam. The 2 bbl slowed it about .55 and it was further under the index, by about .15. We didn't need a rev limiter for either combo, it couldn't spin high enough to hurt itself. Two years later, same car with a modern NHRA stocker engine and an automatic. This time the Q-Jet was further under the index by about .30 or more. As the difference between H/SA and M/SA is .70, this must mean it slowed 1.00 that day, although in my mind it was worse. The 2 bbl was going through the traps at 5700, the 4 bbl at around 7000+. Changing the gears and converter probably would have helped, but we decided not to pursue it any farther. __________________ Tony Curcio 1860 STK