"Best" carburetor choice(s) on which to focus tuning efforts?
Posted: Wed Jul 11, 2018 2:10 pm
Still working to get my street/strip junk back together, even though the engine was dynoed last fall.
Based on my 452 BB Mopar making about 680 HP and 600 torque, I'm expecting the car to be capable of solid low 10s at close to 130 MPH in street trim, which would be a few tenths quicker and 3-4 MPH faster than before.
I have a selection of 4150 carbs to work with and am curious if any of them stand out to other people as the most likely on which to focus my tuning efforts. Although I'd like to get one carb dialed in well enough to both drive on the street and run the best on the track, I'm not ruling out having one more street-friendly and another to swap at the track.
Here's "the herd", all of which are 4150s using 1.75" throttle bodies, fully tuneable billet metering blocks, etc.:
BG Gold Claw 1.425v downleg
- My only "known quantity" carb as it was on the car before when it was running mid-10s w/ the old engine combination; wasn't present for the dyno session, though
QFT/Proform 1.45v with BLP-modified Holley downleg boosters replacing the original boosters that came with the body
- Untested new build; interested in how it compares to the BG, since it's the closest in venturi size
QFT/Proform 1.50v with Braswell downleg boosters
- Untested in latest config after changing the boosters from the previous BLP-modified Holley downlegs used when dynoed
QFT/Proform 1.58v annular
- "Semi-tested"; hoping the part-throttle tune is refined from when dynoed
Holley Ultra H/XP 1.58v (1.56v "850" venturi blended out) with Braswell downleg boosters
- Untested new build; also, my biggest downleg 4150
I have a Holley Ultra H/XP 1.60v "950" converted to BLP 12-hole x .600" ID annular boosters, but it's been something of a "problem child" testing a couple different configurations and -- to be blunt -- suspect it may need a complete main body swap in the future to be truly usable
Also, I've made a best-effort guess on their baseline tunes, but only the Gold Claw and the QFT/Proform 1.58 Annular have actually been run in their same basic config... and on the dyno the big annular was OK at WOT, but not so good at part-throttle. In many respects, it feels like I'm starting from scratch.
FWIW, member "PRH" (Dwayne Porter, who ported the heads and ran the dyno session) and I believe the two likely to be the best on-track performers are the QFT/Proform 1.50v with Braswell downlegs and the QFT/Proform 1.58v annular, since they both made good power & torque w/o having been really dialed in during the dyno session. However, I'm interested if others think there's a potential dark horse in the mix.
FWIW #2, we're talking about a 3800#s w/ driver, 4500-stall converter, 4.10 gears, DOT radials, full exhaust, drive-to-the-track street car.
Oh, I don't have pics of all the carbs, but did post a few for "eye candy"...
Based on my 452 BB Mopar making about 680 HP and 600 torque, I'm expecting the car to be capable of solid low 10s at close to 130 MPH in street trim, which would be a few tenths quicker and 3-4 MPH faster than before.
I have a selection of 4150 carbs to work with and am curious if any of them stand out to other people as the most likely on which to focus my tuning efforts. Although I'd like to get one carb dialed in well enough to both drive on the street and run the best on the track, I'm not ruling out having one more street-friendly and another to swap at the track.
Here's "the herd", all of which are 4150s using 1.75" throttle bodies, fully tuneable billet metering blocks, etc.:
BG Gold Claw 1.425v downleg
- My only "known quantity" carb as it was on the car before when it was running mid-10s w/ the old engine combination; wasn't present for the dyno session, though
QFT/Proform 1.45v with BLP-modified Holley downleg boosters replacing the original boosters that came with the body
- Untested new build; interested in how it compares to the BG, since it's the closest in venturi size
QFT/Proform 1.50v with Braswell downleg boosters
- Untested in latest config after changing the boosters from the previous BLP-modified Holley downlegs used when dynoed
QFT/Proform 1.58v annular
- "Semi-tested"; hoping the part-throttle tune is refined from when dynoed
Holley Ultra H/XP 1.58v (1.56v "850" venturi blended out) with Braswell downleg boosters
- Untested new build; also, my biggest downleg 4150
I have a Holley Ultra H/XP 1.60v "950" converted to BLP 12-hole x .600" ID annular boosters, but it's been something of a "problem child" testing a couple different configurations and -- to be blunt -- suspect it may need a complete main body swap in the future to be truly usable
Also, I've made a best-effort guess on their baseline tunes, but only the Gold Claw and the QFT/Proform 1.58 Annular have actually been run in their same basic config... and on the dyno the big annular was OK at WOT, but not so good at part-throttle. In many respects, it feels like I'm starting from scratch.
FWIW, member "PRH" (Dwayne Porter, who ported the heads and ran the dyno session) and I believe the two likely to be the best on-track performers are the QFT/Proform 1.50v with Braswell downlegs and the QFT/Proform 1.58v annular, since they both made good power & torque w/o having been really dialed in during the dyno session. However, I'm interested if others think there's a potential dark horse in the mix.
FWIW #2, we're talking about a 3800#s w/ driver, 4500-stall converter, 4.10 gears, DOT radials, full exhaust, drive-to-the-track street car.
Oh, I don't have pics of all the carbs, but did post a few for "eye candy"...