Well, Here it is!! Dyno Numbers! Although I am pleased with the gain, I was not pleased with this testing. My Q-Jet starved the motor of fuel very badly so the data on the lower revs is unusable. Also we battled a bad ignition misfire all afternoon, but it the run here was pretty good although the graph is wavy. I want to try a 1000 CFM Holley on there, but $750 for a carb I won't use often = These pulls were in 2nd Gear FYI. I'll be at home all night, call me at 205-383-6169 if you would like to talk to me about it. Brown=X-Factor Blue=Boat Anchor:laugh:
Heckuva good start. If your combo was ideal for the dual plane intake, usually going to a single plane manifold like this will require rejetting the carb and recurving the distributor. Looks like you're OK in the exhaust department. Tweaking on the dyno helps, tweaking on the track is where it counts... Devon
Man I'd love to see some fat jets and 6000 RPM!!! The X-Factor is one fuel hungry S.O.B. ! Jim had a hard time keeping it fed at over 7 grand. I am pleased to see such a substantial gain on a mild engine though.
24.5 hp gain with no retune is pretty good may have to upload this dyno to the website what's your mods again? just a typical 750 q-jet, mild cam, and headers? n/m i see it
That is the last dyno I am going to do for a while. That session cost me $120. I am planning on going to the track June 8th:TU: Of course I'd be happy to try anyone's ideas if they would be willing to subsidize me:beers2:. I have nearly a grand invested in this project so far!:shock:
Cason, you are an animal! Beat that sucker. It looks like the huge plenum is creating an as expected lug at low rpm. I would suggest cutting back a bit on the primary jetting, and keep feeding the secondaries fatter jets until you see a loss. Then just back the secondaries down to the previous step and call it good! I am VERY happy to see that it gave a significant power increase on a street motor. On a twin turboed motor those gains would be huge. Add a 7000rpm shortblock into the equation and things can get scary in a hurry!
And MPFI with the twins, X-factor, and the forged bottom ends and we should be having some REAL streetable fun that is self tuning! It will be nice to set fuel curves with the laptop....
Lol, I'm going to fatten up those secondaries a TON! When driving on the street it pulls hard at ALL RPMs
Here's a comparison of my combo today, and stock everything! Whoever built my 2 Barrel sure did do a fine job!:laugh:
Duh, I just looked at the A/F charts. Looks like it could use more fuel in the primary, not less like I said before.
Thanks Bill. I think now Cason needs to give it about 6psi on pump gas. He'll be the envy of his friends!
Lol, they already envy my electric exhaust cutouts. :TU: From driving it I feel like it needs more juice in the secondaries. Pulling away from red lights it doesn't feel lean at all, but perhaps I need more aggressive metering rods. I need a A/F meter with a digital reading, that way I can tune without a dyno.
Could I borrow that from you? Update: 850 CFM Holley 4150 carburetor is being delivered tomorrow. I am not willing to change the Q-Jet. I don't think its ever going to provide the WOT power I need.:beers2:
I would lend it to you except shipping seems to really suck across the boarder... Good call on the larger Holley, I bet it will feed the beast!!
Used ALOT of Ultra Black RTV you know the trick with RTV gaskets don't you? finger tighten all of the bolts so it just starts to push out the RTV and then leave it to cure for 4-5 hours. then go back and torque it down.
