Carb choice for Street-Strip 512

[JackpotJim]

https://www.holley.com/products/fue.../sniper_efi/sniper_stealth_4500/parts/550-842

I know, love the looks of that thing. if I lived in a part of the country where I could drive my car at least 9 months a year I'd be all over a big Sniper set up.

 

[cudatom]

My 512 low deck stroker build is progressing and all I have left to purchase is a carb and headers. The person I worked with that helped me with a cam choice recommended a 1050 cfm carb. The motor is a flat top piston 11.5 to 1 with TF 270's, cam is 260,264 duration, 656, 662 lift. Transmission is a TCI manual shift 727 with brake, 4.10 rear gear. 28 inch rear tire. I have a couple choices on a torque converter. I have a 4500 9.5 inch and a 3500 11 inch, both are street strip style converters and I'm thinking I'll go with the 3500 to catch some of the massive torque this motor should make between 3 and 4000 rpm. The carb choices I'm looking at are a Gen 3 Holley Dominator 80902BK or a QF Brawler 67209 race carb. Both are 1050 cfm, the QF is a 4150 style carb and of course the Holley is a dominator. Since both flow the same amount of air and gas does one style carb fit my build better then the other? I've never owned or used a Dominator and don't know much about them. This motor is going in my 66 B body that weights 3800 lbs and I drive the car a few 1000 miles during the warm summer months in Minnesota. Any input is welcome, my end result is hopefully a low 11, high 10 second street-strip car that doesn't require 10 hours of maintenance every week. Thank you

You should be able to run much better than low 11's to high 10's. My wagon is 4150lbs, 512 with Eddy performer heads 11.5 comp and a much smaller cam(comp cams 244, 252 duration and .554 and .556). I run a 1050 dominator. It is .2 faster in the 1/4 than my 4150. Been 11.06 at 122. That was with a 29 5" tall by 9" slick and 410 gear. I run a PTC convertor, flashes to 4500 but is tight enough that it will move forward at an idle. This is a street strip car.
I will say that when I got the carb(from Biggs) it was no where close. Ran 11.54 but after 2 weeks of test and tune a pv change, multiple jet changes and high speed air bleed adjustments I tuned in .38 in improvements. Throttle response was crisp and never loaded up.

 

[RemCharger]

4150. you said you want to cruise around with it. 4500 for max hp nothing else.

 

[68 HEMI GTS]

I’ve ran several different carbs on my 512 roadrunner. Everything from six packs to dominators. I do have a 4150/1050 annular carb I do really like. Ultimately though I’ve been able to get 2 circuit 1050/4500 to run just as good drivability wise. I’d also say it makes max power.


This 512 pump gas combo is a bit wilder and took some work but, it’s cruising down the road pretty good with a 4500 and is capable of single digit ET’s.

 

[JackpotJim]

You should be able to run much better than low 11's to high 10's. My wagon is 4150lbs, 512 with Eddy performer heads 11.5 comp and a much smaller cam(comp cams 244, 252 duration and .554 and .556). I run a 1050 dominator. It is .2 faster in the 1/4 than my 4150. Been 11.06 at 122. That was with a 29 5" tall by 9" slick and 410 gear. I run a PTC convertor, flashes to 4500 but is tight enough that it will move forward at an idle. This is a street strip car.
I will say that when I got the carb(from Biggs) it was no where close. Ran 11.54 but after 2 weeks of test and tune a pv change, multiple jet changes and high speed air bleed adjustments I tuned in .38 in improvements. Throttle response was crisp and never loaded up.

Thanks for the info. Sounds like we have similar converters. Mine hits hard at 4000 (love the transbrake) but like yours will idle out of the garage. A couple people have told me the same converter will be more like a 4500 stall converter when bolted to a 512 because of the torque produced. I'm not looking to be the fastest B body in Minnesota, just a quick car that's safe to drive around town a few times a week. I have a QF 750 drag race carb that works perfectly on my 10 to 1 383. I'll use that carb to get the 512 running and broke in, then see how it acts on the street. I'll purchase a 1050 Dom for race nights. I can change carbs on my car blindfolded in 10 minutes.

 

[440rb]

Re my post no. 17....I'm sure you'll make similar hp to us with your spec 700, your heads probably flow more than ours@your lift, + you have 1.5pts more CR, we are 3800@the line, we have a reasonably good sorted chassis, mono's/caltracs, 9-ways on rear and 90/10's, 4.10's, 10x29 Hoosiers, we are now down to 1.43 60fts and a best of 10.35@128+....and all with a small 950HP (830-ish cfm DP), I think we are giving up some ET/mph though. I'd go with a 4150, although a well sorted 1050 Dominator can be made to work just as well if not better for street/strip, its not a race only carb as most people still think, talk to Dominic Thumper about your spec, I'm trying to convince my mate to go that route with the Thumper we have.

 

[JackpotJim]

Holy Crap! I've been looking at lightweight mechanical flat lifters for Mopars this week. Average price for solid lightweight Mopar lifters are about $450 with Comp Cams selling a set for $1500. What are these things made of? I thought roller lifters were expensive.

 

[68 HEMI GTS]

Thanks for the info. Sounds like we have similar converters. Mine hits hard at 4000 (love the transbrake) but like yours will idle out of the garage. A couple people have told me the same converter will be more like a 4500 stall converter when bolted to a 512 because of the torque produced. I'm not looking to be the fastest B body in Minnesota, just a quick car that's safe to drive around town a few times a week. I have a QF 750 drag race carb that works perfectly on my 10 to 1 383. I'll use that carb to get the 512 running and broke in, then see how it acts on the street. I'll purchase a 1050 Dom for race nights. I can change carbs on my car blindfolded in 10 minutes.

With a properly set up dominator you won’t need to swap carbs. The dominator will work just fine street and strip.

 

[JackpotJim]

Re my post no. 17....I'm sure you'll make similar hp to us with your spec 700, your heads probably flow more than ours@your lift, + you have 1.5pts more CR, we are 3800@the line, we have a reasonably good sorted chassis, mono's/caltracs, 9-ways on rear and 90/10's, 4.10's, 10x29 Hoosiers, we are now down to 1.43 60fts and a best of 10.35@128+....and all with a small 950HP (830-ish cfm DP), I think we are giving up some ET/mph though. I'd go with a 4150, although a well sorted 1050 Dominator can be made to work just as well if not better for street/strip, its not a race only carb as most people still think, talk to Dominic Thumper about your spec.

Thank you, I did reach out to Dom on Facebook. I haven't heard back yet. Sounds like we have similar cars. I have SS springs on mine with 90-10's front and adjustables on the rear. Will see how the car acts with the SS springs next year before pulling them and installing monos and Caltrac's. There's a nice guy here on this forum from St. Paul Minnesota with a beautiful 66 Satellite that's been real helpful on chassis set up. Thanks again for all the help & info.

 

[fullmetaljacket]

Thank you, I did reach out to Dom on Facebook. I haven't heard back yet. Sounds like we have similar cars. I have SS springs on mine with 90-10's front and adjustables on the rear. Will see how the car acts with the SS springs next year before pulling them and installing monos and Caltrac's. There's a nice guy here on this forum from St. Paul Minnesota with a beautiful 66 Satellite that's been real helpful on chassis set up. Thanks again for all the help & info.

JPJ, You'll hit the Jackpot by talking and getting a nicely set up carb from a guy out west by the name of Thumperdart with his Thumper carbs based on both 950's and 1050's. I'm below 500 inches but a lot lot more lighter than most of y'all here, but Thumper's carb, along with a few other remedies that needed to be sorted out got my car clean on the streets and able to crack single digits but evened out just above that in the low 10's. The rule is good atomization. Both Thumper and the Boyz at BEST machine suggested that I go 1050, but I was on the fence and veered to the side of simplicity and most importantly streetability. I'll let Thumper speak his beat, but he'll steer you with an excellent carb. His mid 9 second Dart with his own 1050 roams the streets and lays down the numbers at the track.
I'm sure that there are other great carbs out there.

 

[440rb]

And its that same 1050-ish BLP carb that we are gonna try next year with some minor mods for our spec.

 

[JackpotJim]

JPJ, You'll hit the Jackpot by talking and getting a nicely set up carb from a guy out west by the name of Thumperdart with his Thumper carbs based on both 950's and 1050's. I'm below 500 inches but a lot lot more lighter than most of y'all here, but Thumper's carb, along with a few other remedies that needed to be sorted out got my car clean on the streets and able to crack single digits but evened out just above that in the low 10's. The rule is good atomization. Both Thumper and the Boyz at BEST machine suggested that I go 1050, but I was on the fence and veered to the side of simplicity and most importantly streetability. I'll let Thumper speak his beat, but he'll steer you with an excellent carb. His mid 9 second Dart with his own 1050 roams the streets and lays down the numbers at the track.
I'm sure that there are other great carbs out there.

Thanks for the info. Looking forward to talking to ThumperDart again. I had one carb builder tell me he thought about a 1000 cfm would be right for my set up.

 

[440rb]

They'll all work ok, .... our puny old 950HP runs fine, But...you'll give some up at the track with a 4150 unless you go to a twin blade 1200 or a large bore BX4 BLP but these are $$$$, just depends on whats important to you, A Dom can give you both s/manners and all out performance plus they look cool.

https://blp.com/cart/index.php?main_page=product_info&cPath=72_406&products_id=1657

 

[383man]

Myself I run the basic Holley 850 on the street with the choke plate removed in my 493. I agree it would be faster with a Dominator but I wanted good drieability at all speeds and not to use to much fuel. I set my 850 up where the primaries are not real fat since I drive 99% on the primaries on the street so I worked the idle and transfer circuits for nice clean cruising that dont foul plugs every month. Then I open the power valve channels in the primary and jet the secondaries at the track for mph. And it works awesome for me on my car. I have also tried a Proform 950 and the Holley HP 950 both 4150 carbs and the car ran about the same on all three carbs. I did pick up 1 mph on the Holley 950 HP but the best et is still with the 850. If it was a race car only I would definetly run a Dominator but I love this 850 and how it works for the street and strip as when I go racing I dont change a thing on my car. I just drive to the track and lower my tires to 16 to 18 psi and remove my little air filter element and go racing and run 10.80's most days and 10.70's on good days. I feel if you know carbs well you can make most any work good on the street and strip but I plan to stay with my 850 since its such a nice working street/strip carb and even though I believe I could be at least a tenth faster with a Dominator it just works to well with the 850 for me to change it. Ron

 

[33 IMP]

@383man is your 950 really a 950, or is it the one that Holley calls a "950" that's really a 750?
Holley markets a carb as a 950 that has the same jetting, venturi size, and throttle bores as their 750. So how is it a "950"?

 

[JackpotJim]

Myself I run the basic Holley 850 on the street with the choke plate removed in my 493. I agree it would be faster with a Dominator but I wanted good drieability at all speeds and not to use to much fuel. I set my 850 up where the primaries are not real fat since I drive 99% on the primaries on the street so I worked the idle and transfer circuits for nice clean cruising that dont foul plugs every month. Then I open the power valve channels in the primary and jet the secondaries at the track for mph. And it works awesome for me on my car. I have also tried a Proform 950 and the Holley HP 950 both 4150 carbs and the car ran about the same on all three carbs. I did pick up 1 mph on the Holley 950 HP but the best et is still with the 850. If it was a race car only I would definetly run a Dominator but I love this 850 and how it works for the street and strip as when I go racing I dont change a thing on my car. I just drive to the track and lower my tires to 16 to 18 psi and remove my little air filter element and go racing and run 10.80's most days and 10.70's on good
days. I feel if you know carbs well you can make most any work good on the street and strip but I plan to stay with my 850 since its such a nice working street/strip carb and even though I believe I could be at least a tenth faster with a Dominator it just works to well with the 850 for me to change it. Ron

Thanks, You track prep is about the same as mine. Make sure hemet is in back seat, stop at ATM, drive 7 miles to the track. I have QF Brawler drag race carb I've been using on the street that works great on both the street and track. Going to try a 1050 Dom on the street with the 512, if the plugs load up every week I'll put a smaller carb on it for street use. Great photos on your website link. Love a early 60's red Mopar. Thanks for the help.

 

[440rb]

Thanks, You track prep is about the same as mine. Make sure hemet is in back seat, stop at ATM, drive 7 miles to the track. I have QF Brawler drag race carb I've been using on the street that works great on both the street and track. Going to try a 1050 Dom on the street with the 512, if the plugs load up every week I'll put a smaller carb on it for street use. Great photos on your website link. Love a early 60's red Mopar. Thanks for the help.

Good on ya for going for it..........our Thumper 1050>1100+? has .082 pri jets with a 6.5pv put in for us and .090 secs no pv...I'm no carb guru but that tells a story.

 

[beanhead]

@383man is your 950 really a 950, or is it the one that Holley calls a "950" that's really a 750?
Holley markets a carb as a 950 that has the same jetting, venturi size, and throttle bores as their 750. So how is it a "950"?

Ahh yes the old Holley method of cfm rating. My 850 Demon mechanical secondary carb is a 1.561 venturi/1.75 throttle plate carb, which if I remember is the same as Holley's 1000HP....hmmm. However, the 383 man's car is such a beast and looks good doing it! He's got his combo nailed I'd say!

 

[cudatom]

Thanks, You track prep is about the same as mine. Make sure hemet is in back seat, stop at ATM, drive 7 miles to the track. I have QF Brawler drag race carb I've been using on the street that works great on both the street and track. Going to try a 1050 Dom on the street with the 512, if the plugs load up every week I'll put a smaller carb on it for street use. Great photos on your website link. Love a early 60's red Mopar. Thanks for the help.

Takes a little work to get the dominator dialed in but is rock solid when completed. I haven't changed plugs in 6yrs.

 

[68 HEMI GTS]

Takes a little work to get the dominator dialed in but is rock solid when completed. I haven't changed plugs in 6yrs.

impossible they say... lol