6a was dialed in pretty good when I ran it. AFR was in the low 13's, made 650 hp on my 470 back before the intake was ported, BSFC was 0.400, Correction Factor was 1.02 so pretty good air. Dyno shop is close to sea level.

My dyno sheets show that we had 88 and 99 jets in it for those pulls. That was the Mark W tune. Worked great from 3500 to 7000 rpm. If you're testing near sea level then I'd use the original Mark W. tune and let it rip.

#5, 6B will be nearly identical but 5 gets the nod. Scrap the 1.60 you got from Andy for the test. And the Race Q1000 down leg should be a 1.500 venturi, that might be an interesting test against the 1.59 annular.

Makes sense that as MOST dyno's do from 3500-7500 and up it may have been ok but trust me, it killed my oil n plugs below that and could NOT even do a burnout. I'm not bagging on anyone or pointing fingers but on the steet where it matters most, it was a pig and I know it was loaned out as well so who knows there. IIRC, it had .080-.090 but not 100% and not near my book..............I see zero reasons to EVER run a 4150 on any motor making good power and have proved it many times even on small-blocks that have picked up a several mph and .010's so me, I'd ditch/sell em all and put a real carb on that puppy........... And .088-.099 jets........that's insane and even 1250's rarely run that size which should tell ya something...........

I had been thinking along the same carbs to test (the QFT 1.52 downleg & the QFT 1.59 annular) along w/ the baseline BG.

The Holley 1.60 annular conversion is sitting on a stand ready to bolt on (except I did notice the linkage is binding for some reason). No reason not to at least throw it on to see how it does... time permitting.


That's what I expected, too (i.e., 1.50" venturi). However, I measured mine after you installed the BLP boosters and found it measured 1.52", and later on found a QFT spec sheet that listed the RQ-1000 as 1.52", also. It makes sense, considering their venturi increases from "950" to "1000" is .07", and from "1000" to "1050" is another .07".

This is the carburetor equivalent of "Kill 'em all. Let God sort 'em out.", right?

The evaluation won't be strictly on peak HP & torque #s, but also the fuel curve, amount of air being used, differences in where a particular carb might show better than another, etc.

I've seen where two carbs that made virtually the same power on the dyno still ran .2 & 2 MPH differently on the car. Whatever looks like the most worth testing based on the dyno results will still get flogged on the car to prove it.

Yes

Just put the motor in the car and run it...

NOTHING in my life is that simple...

Any chance you have more carbs than you need Brad?

Oh wait, before you answer that would you like to buy a carb Brad? I don't think I need my QF-1050-AN anymore now that I switched to EFI so I'll make you a good deal on it.......

Why the He11 would you think that???


That reminds me... can you provide me w/ your QFT RQ-1050-AN tune so I can duplicate it w/ all the parts I have sitting around to build one myself?

And that is what I was wondering. If the criteria isn't clear going into your test, you may pick the wrong carbs to test. To me, it would seem that the best criteria would be area under the curve, in the RPM range encountered during the run; the right carb for a narrow range is likely different than for a wider range. Not knowing any of those details, my vote would be for 1, 4, and 6B.

The on-track differences like I pointed out were due to shift recovery (how quickly the carb adjusts to change in RPM & load) characteristics, which a basic engine dyno doesn't take into account.

Survey says...
#4
#5
#6a

That's all for now!