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| Alcohol help | Login/Join |
| DRR Trophy |
A friend has a 1/8 mile drag car. Nova, 555 inches,.700 roller, 10.5 compression, 4.10 gear, 32 tire, 1.8 straight cut glide, 8" ATI. 1000 gas carb. I talked him into going to alcohol and he purchased a new 950 Holley HP carb and it slowed by .1 any help? No other changes made. It slowed across the board, 60' through MPH. tried on 2 different tracks 3 weeks apart. Last outing removed power valve, dropped jetting 6 down on all 4 corners and slowedf by app. .02 | ||
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| DRR Sportsman |
Fuel starvation. In my estimation that 950 is way to small for that size engine. Did you use the same fuel system set up as the gas car? What size fuel pump? mechanical or electric? Line size from pump to regulator? to many unknowns to answer this question and correctly address the issue. | |||
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| DRR Top Comp |
Move the tank to the front, or don't. | |||
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DRR Pro |
The 950 Holley has a 750 diameter Venturi. Compare the Venturi size. Also, if the regulator is between the pump and carb, that’s another possibility- low fuel volume. Matt Ward | |||
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| DRR Sportsman |
I've run this same carburetor to 4.90s in the 1/8' What kind of fuel pump (electric or belt drive)? What fuel pressure regulator and how many? Are you still using the stock bowls and .150 NS? Do you have jet extensions on the back? | |||
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| DRR Sportsman |
Why did you install smaller jets especially after removing the power valve. It's been said here hundreds of times, but: Did it gain temperature during a run? How much fuel did you use per pass? Is it responsive off idle? Are you milking the oil? What water temp are you staging at? What fuel pump? Electric or belt? Cell location? And on and on and on... Just trying to help  | |||
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DRR Top Comp |
All good questions there. It should pick up on alcohol. My guess is carb is too small. I would try a known good larger carb. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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| DRR Trophy |
Ok, carb is small all will agree but this is a comparison from 1000 cfm gas to 950 carb on methanol. Fuel system is a new Holley compatible pump with a nice Aeromotive regulator, -8 line. This is not what is on mine but I have seen a SBC run 6.20"s with no problem and was quicker than when on gas. | |||
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| DRR Trophy |
Yes tank is in the rear.. | |||
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| DRR Trophy |
Yes, stock bowls and seats and jet extensions on back jets. All previous questions answered in above post. | |||
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| DRR Trophy |
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| DRR Trophy |
I was thinking on the line of converter. Maybe not right with the 32 tire and 4.1 gear. The only reason I did not look at the pump/ furl system was because i know of a SBC running 6.2 with this same set up. I was also wondering if the carb was junk! | |||
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| DRR Trophy |
160 temp but large radiator, A noticeable amount of furl difference compared to mine which runs 5.7-5.8, Yes responsive, no milking of oil, 140 / 150 stage, electric pump rear cell... | |||
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DRR S/Pro |
What is a holley compatiable fuel pump? What is that actually flow rate? To what Matt said, i always like the regulator at the end of the system and let it bleed off pressure. The regulator is a restriction. With that said does it run though clean, or does it pop at all. Bill Simpkins 74 Nova SBC 406 3240 pounds Speierracing heads 60 1.27 (10/16) 1/8 6.03@111 (10/16) Best 9.87@131 on the rev limitor 1 Feb 2013 nova quarterpanelview wheelie FTI Converter www.speierracingheads.com | |||
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| DRR Sportsman |
One of my cars has a 498 with a 850 holley on alky, bg 280 fuel pump (which IMO is undersized, but works). 7 psi of fuel pressure, and everything runs fine. My good car has a 468 with a 950 holley, Magnafuel 500 pump, 7 psi of fuel pressure. 468 has 148 jets, 498 has 155 jets. | |||
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| DRR Trophy |
140 GPA i think, runs clean and smooth, sounds good | |||
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| DRR Top Comp |
When I ran a carb I ran TWO Mallory Comp 250 pumps. Did it need that much? No, but I never starved it for fuel. My other car ran the large Aerospace Components pump. Having the fuel cell up front is always better as gravity and G forces help feed the pump. Not an absolute requirement but having the pump in the rear and a relatively small pump may be part of the problem. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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| DRR Top Comp |
I would add that with the Comp 140 pump it is marginal as is and if you have a deadhead regulator even worse. If your fuel lines are too small could be another problem. I think he needs to look closely over his whole system. Alcohol uses much more fuel and if the fuel system was marginal on gas he is going to have problems on alcohol. If you removed the power valve you should have went up on the jetting. I like to have the power valve in the front and only remove it from the rear because it can uncover on the launch. From my experience if you have enough gear and stall converter you can not get too big a carb with in reason. Certainly think 950 is too small for a 555 even if the pump can feed the fuel. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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DRR S/Pro |
There is removing the power valve, and there is plugging/blocking the power valve. I’ve owned alcohol carbs with both configurations. If just removing, you can go a lot smaller on the jets. Tony Leonard | |||
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DRR Elite |
Wide Band O2 data removes the guess work when results like this show up. Also, methanol fuel needs/like less trimming than gas. 2005 2000lb 4 link dragster home brew 582 BBC Dart 355 1.058 2.98 4.629@149 6.094 7.310@185 | |||
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