Re: Is 1000 CFM too big for street/strip car?
[Re: BradH]
#2221559
12/27/16 11:58 AM
12/27/16 11:58 AM
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Joined: Jan 2003
Posts: 11,786 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,786
Portage,michigan
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Saying it's all about the amount of air is over simplifying things. DEPENDING ON THE COMBINATION, a smaller carb can ET & MPH better than a larger carb when it has better shift recovery. That I doubt. I had a 950 on my 318, local friends told me car would ET better with a 750. It didn't. Wouldn't run within a tenth of the 950. Brett and others on here said beforehand what happened is what would be the case. Me being hardheaded, I had to try it.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car Best so far, 10.32 1/4 1.41 best 60 foot 6.56 at 104.17
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Re: Is 1000 CFM too big for street/strip car?
[Re: SILVER67]
#2221570
12/27/16 12:45 PM
12/27/16 12:45 PM
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Joined: Oct 2003
Posts: 11,702 W. Kentucky
justinp61
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I Live Here
Joined: Oct 2003
Posts: 11,702
W. Kentucky
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You are aware that is a 1,000 cfm 4150 "3 circuit" correct?
That will take a little extra tuning... I bolted a BLP 3 circuit 1000 to my pump gas 505.....it was borrowed from a local dyno guy I know. So, I didn't want to monkey with it too much. However, it fouled out my plugs in less than 1/2 of idling and one short drive. I'm sure the 3 circuit can work on the street......but like Greg said.....plan on tuning time and prob a set of plugs Mike My BLP main body came with the third circuit plugged. I can't tell from the photos if the carb the OP is looking at has plugs or bleeds in it. Why would a roundy round carb need the third circuit?
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Re: Is 1000 CFM too big for street/strip car?
[Re: justinp61]
#2221578
12/27/16 01:13 PM
12/27/16 01:13 PM
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Joined: Dec 2014
Posts: 304 Florida
Mark Whitener
enthusiast
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enthusiast
Joined: Dec 2014
Posts: 304
Florida
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You are aware that is a 1,000 cfm 4150 "3 circuit" correct?
That will take a little extra tuning... I bolted a BLP 3 circuit 1000 to my pump gas 505.....it was borrowed from a local dyno guy I know. So, I didn't want to monkey with it too much. However, it fouled out my plugs in less than 1/2 of idling and one short drive. I'm sure the 3 circuit can work on the street......but like Greg said.....plan on tuning time and prob a set of plugs Mike My BLP main body came with the third circuit plugged. I can't tell from the photos if the carb the OP is looking at has plugs or bleeds in it. Why would a roundy round carb need the third circuit? I've yet to see any 4150 that needs the intermediate, short of MAYBE with methanol and probably not then. It is a BLP body and tuned right it will work fine. The Dominator you have will work as well, again with the right tuning. On the street plugging the intermediate on the BLP carb would be smart if it's active, all of the bodies have the bleed there but not all have the intermediate discharge tube or metering block for it. Dominator would be best as a 2 circuit as well. I can give you tips either way, use the sheet at the link below to map the carb metering to give you where you are at, and give me where to suggest changes. http://racingfuelsystems.myfunforum.org/viewtopic.php?f=31&t=28
Mark Whitener [url=www.racingfuelsystems.com[/url]
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Re: Is 1000 CFM too big for street/strip car?
[Re: B3422W5]
#2221610
12/27/16 02:30 PM
12/27/16 02:30 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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Saying it's all about the amount of air is over simplifying things. DEPENDING ON THE COMBINATION, a smaller carb can ET & MPH better than a larger carb when it has better shift recovery. That I doubt. I had a 950 on my 318, local friends told me car would ET better with a 750. It didn't. Wouldn't run within a tenth of the 950. Brett and others on here said beforehand what happened is what would be the case. Me being hardheaded, I had to try it. Doubt all you want, but I'm one of at least three people I know who switched from a Holley 850 w/ 1.56" v x 1.75" t to the Holley HP "950" (b.s. CFM #) w/ 1.38" v x 1.75" t and picked up. I dynoed both carbs and they made virtually the same the same peak HP & torque #s, but on the track the smaller-venturi carb was over a tenth quicker in the 60, and .2 ET & 2 MPH faster in the 1/4. It was all in the smaller carb's ability to recover from the drop in shift RPM faster, plus it was more responsive off the launch. FWIW, w/ the 850 it ran 11.7s at 116 w/ 1.70 60-ft; with the "950" it went 11.5s at 118 with a 1.55 60. Is it combination-dependent? Absolutely. And I'm sure the less RPM drop between the shift RPM and the converter RPM post-shift, the less of an improvement it would be. But it does go to show that just putting on a bigger carb is no guaranty of improved on-track performance. A lot of people on here have trouble accepting that, since the same people keep saying "My car always ran faster with a bigger carb." Yep, "yours" did, others haven't. I know what my own results showed, along w/ some others who had similar improvements, in back-to-back testing. Bigger is no guaranty of better.
Last edited by BradH; 12/27/16 02:47 PM.
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Re: Is 1000 CFM too big for street/strip car?
[Re: markz528]
#2221620
12/27/16 02:44 PM
12/27/16 02:44 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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... a Gary Williams built 4150 1000 cfm carb that he ran once and will no longer use. I can get a good deal on it... My suggestion: Buy it (cheap?), send it to Dom ("Thumperdart") to let him tear it down and see how it's been set up. Then you & he can figure out what changes ought to be made for it to better suit your application. Or not.
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Re: Is 1000 CFM too big for street/strip car?
[Re: markz528]
#2221625
12/27/16 02:49 PM
12/27/16 02:49 PM
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Joined: Jan 2003
Posts: 4,332 Morrow, OH
markz528
OP
master
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OP
master
Joined: Jan 2003
Posts: 4,332
Morrow, OH
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Thank you very much for all the replies!
So here is the rest of the story.........
The BLP body was not legal in his class so he had to send the carb back to Gary Williams to get a Holley main body put back on it (cost another $300 and Gary kept the BLP body - he has done those shenanigans to me too).
So below is a picture of how the carb sits today. Looks like its a 2 circuit but I am not familiar with those bleeds - look a lot different than my Dominator ones. What are these bleeds?
Would think it would still be a good carb - agree?
They used to run Dominators but found that the smaller 4150 carbs were more responsive during restarts.
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
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Re: Is 1000 CFM too big for street/strip car?
[Re: BradH]
#2221632
12/27/16 03:00 PM
12/27/16 03:00 PM
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Joined: Jan 2003
Posts: 11,786 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,786
Portage,michigan
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Saying it's all about the amount of air is over simplifying things. DEPENDING ON THE COMBINATION, a smaller carb can ET & MPH better than a larger carb when it has better shift recovery. That I doubt. I had a 950 on my 318, local friends told me car would ET better with a 750. It didn't. Wouldn't run within a tenth of the 950. Brett and others on here said beforehand what happened is what would be the case. Me being hardheaded, I had to try it. Doubt all you want, but I'm one of at least three people I know who switched from a Holley 850 w/ 1.56" v x 1.75" t to the Holley HP "950" (b.s. CFM #) w/ 1.38" v x 1.75" t and picked up. I dynoed both carbs and they made virtually the same the same peak HP & torque #s, but on the track the smaller-venturi carb was over a tenth quicker in the 60, and .2 ET & 2 MPH faster in the 1/4. It was all in the smaller carb's ability to recover from the drop in shift RPM faster, plus it was more responsive off the launch. FWIW, w/ the 850 it ran 11.7s at 116 w/ 1.70 60-ft; with the "950" it went 11.5s at 118 with a 1.55 60. Is it combination-dependent? Absolutely. And I'm sure the less RPM drop between the shift RPM and the converter RPM post-shift, the less of an improvement it would be. But it does go to show that just putting on a bigger carb is no guaranty of improved on-track performance. A lot of people on here have trouble accepting that, since the same people keep saying "My car always ran faster with a bigger carb." Yep, "yours" did, others haven't. I know what my own results showed, along w/ some others who had similar improvements, in back-to-back testing. Bigger is no guaranty of better. Agree. I went from 750 to 950, and back. An 850 would be an entirely different kettle of fish on my car than either a 750 or a 950 would be I think because of Venturi size
Last edited by B3422W5; 12/27/16 03:03 PM.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car Best so far, 10.32 1/4 1.41 best 60 foot 6.56 at 104.17
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Re: Is 1000 CFM too big for street/strip car?
[Re: markz528]
#2221686
12/27/16 04:45 PM
12/27/16 04:45 PM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
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I Live Here
Joined: Jul 2004
Posts: 19,318
State of confusion
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Thank you very much for all the replies!
So here is the rest of the story.........
The BLP body was not legal in his class so he had to send the carb back to Gary Williams to get a Holley main body put back on it (cost another $300 and Gary kept the BLP body - he has done those shenanigans to me too).
So below is a picture of how the carb sits today. Looks like its a 2 circuit but I am not familiar with those bleeds - look a lot different than my Dominator ones. What are these bleeds?
Would think it would still be a good carb - agree?
They used to run Dominators but found that the smaller 4150 carbs were more responsive during restarts. Those are the high(inner)and idle(outer)adjustable bleeds........If you take the carb apart and plot all the holes/locations sizes, then we can help you make it work for ya...........
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: Is 1000 CFM too big for street/strip car?
[Re: markz528]
#2221909
12/27/16 11:29 PM
12/27/16 11:29 PM
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Joined: Dec 2014
Posts: 304 Florida
Mark Whitener
enthusiast
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enthusiast
Joined: Dec 2014
Posts: 304
Florida
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I would make him send that body back...
Mark Whitener [url=www.racingfuelsystems.com[/url]
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Re: Is 1000 CFM too big for street/strip car?
[Re: Mark Whitener]
#2221915
12/27/16 11:35 PM
12/27/16 11:35 PM
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Joined: Jan 2003
Posts: 4,332 Morrow, OH
markz528
OP
master
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OP
master
Joined: Jan 2003
Posts: 4,332
Morrow, OH
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I would make him send that body back... You and me both...........
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
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Re: Is 1000 CFM too big for street/strip car?
[Re: markz528]
#2221938
12/28/16 12:28 AM
12/28/16 12:28 AM
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Joined: Jan 2003
Posts: 4,332 Morrow, OH
markz528
OP
master
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OP
master
Joined: Jan 2003
Posts: 4,332
Morrow, OH
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Well it looks like we will strike a deal on it. He will attempt to recover the BLP main body.
Thanks to everyone who responded!
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
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