David_D. wrote:I was thinking more in the line of carbs from builders such as Quick Fuel, Pro Systems, APD, Rupert...the list goes on...vs. a pre UltraHP HP carb. Most of these carb customizers put billet base plates/metering blocks on the carbs and "tune" the fuel curve to your engine combination. How much better, if any are they over a Holley HP carb? Again, this is pre UltraHP.
David_D. wrote:Doug, I'm talking drag racing specifically (since that's what I do).
When it comes to custom carb builders, do you have a preference?
andyf wrote:Well what exactly is a tuner going to do that somebody with a screwdriver and a wide band can't do with an UltraHP? The UltraHP allows you to change emulsion jets, idle jets, pvcr jets, main jets, intermediate jets, air bleeds for all three circuits, etc. So if you can tune every single circuit on the carb what else is there to do?
Tuners used to do things like conversions to four corner idles and stuff like that but once again, the newest carbs have that all built in. Holley has been fairly aggressive over the past 10 years about grabbing up ideas from the aftermarket and folding them back into their designs.
Now there are tricks out there that you can't get from Holley, for instance BLP makes some really nice stuff such as the 3 circuit metering block whree the idle tube is separate from the main well. For people who complain about 3 circuit carbs going lean on the top that might be the solution.
Another trick that the average guy might have trouble with would be changing the length of the transition slot.
David_D. wrote:My custom tuned carb is doing what I want it to, and I'm happy with it. As much as I would like to learn about doing the tuning myself, I don't have the opportunity at the track to do this (limited testing, and I'm there to race, not tinker).
The experience with my carb is based on results at the track, not on a dyno. I'm pretty sure that my custom carb wouldn't have produced better numbers on the dyno than when it was untouched, but it's more consistent than before. So for me, it's different than PS/PM because those guys want max power and to run as quick as they can. Bracket racing, I want consistency.
Doug Schriefer wrote:
And yet even you say how when you bolt on your Braswell carburetor it makes more power than the stuff you've tuned... So based on your logic stated here you should be able to make as much (and actually more since you're there tuning on it) HP than your Braswell..