Doing the LT1 carb conversion was the best thing I ever did for my car.
11-14-2003, 09:16 PM
#1
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Join Date: Feb 2001
Posts: 28
Doing the LT1 carb conversion was the best thing I ever did for my car.
I k now there was a lot of debate about the carb conversion. But I'm a firm believer in it. I had nothing but problems with the fuel injection and the programing. Having it done by 3 different people always problems. Decided to convert to a carb setup this year. Well just got back from the track and I'm very pleased. My motor is a 350 LT1 JE 10.5 to 1 compression,stock pistons and rods. Comp cam 230 242 544 576 on a 112. Stock heads slightly ported with 1.56 2.00 valves. With a GM Dual Plane intake. 750 Quick Fuel carb. 350 trans, stock rear end with 4.10 gear. Hooker long tubes and 1.6 roller tip rockers. The car went 11.70 at 116mph. Sprayed 75 shot at it and it went 11.08 at 120mph. I don't think I could have come close to those numbers fuel injected. Just something for anyone debating about the switch to think about.
11-14-2003, 09:51 PM
#2
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Join Date: Oct 2003
Location: Windy City
Posts: 735
Nice times man. You have a very intresting point. Tuning is sometimes everything when it comes to F.I. So if you werent getting good tunes, then I could see why your doing better going carb. I personally have no problems with carbs, I just wouldnt run them on my lt1.
Do you have any pics of the car? I wanna see how that looks in that small compartment. Ive always been told you couldnt run the carb setup, because you wouldnt be able to take out the distributor. But once again nice runs
Do you have any pics of the car? I wanna see how that looks in that small compartment. Ive always been told you couldnt run the carb setup, because you wouldnt be able to take out the distributor. But once again nice runs
11-14-2003, 11:04 PM
#3
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Join Date: Dec 1969
Location: Webberville, MI USA
Posts: 148
Anyone can tune a carb, I grew up with them but I leave them where they belong. On the lawnmower and garden tractor. I have owned about 10 carburated cars in my life and dealt with all manner of jets, metering rods, and idle mixture screws in my years as a mechanic. I will never, ever, own a carburated car that I drive on the street. I would rather just go to the gas station and spill the gas on the ground.
By the way, what is your fuel economy? I would bet that it isn't even 20mpg on the highway after this "mod".
By the way, what is your fuel economy? I would bet that it isn't even 20mpg on the highway after this "mod".
11-14-2003, 11:28 PM
#4
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Join Date: Nov 2003
Location: Under The Hood
Posts: 3,875
Performancewise Carbs are the way to go. Seems almost every Prorace car you see has a carb setup. I'm guess the advantage of the Carb is to escape all the Little programming issues with the LT. But aren't they harder to tune precisely?
11-14-2003, 11:42 PM
#6
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Join Date: Mar 2001
Location: Winston Salem, NC
Posts: 956
the reason there are so many race cars with carbs is rules are still penalizing or outlawing Fuel Injection in lots of classes...If the rules weren't there, believe me top fuel would have went F.I. a long time ago
11-15-2003, 01:03 AM
#7
West South Central Moderator / Special Guest
Join Date: Dec 1998
Location: Coppell, TX USA
Posts: 1,650
like he said.. its the rules. other wise everybody would be running fuel injection.
If you are having problems with people tuning the car, why not do it yourself? either LT1edit or get an aftermarket PCM setup.
Course, cant say I wouldn't throw a carb on a max effort NA setup cause its so simple, but on a 116-120mph car.. i wouldn't call that max effort
If you are having problems with people tuning the car, why not do it yourself? either LT1edit or get an aftermarket PCM setup.
Course, cant say I wouldn't throw a carb on a max effort NA setup cause its so simple, but on a 116-120mph car.. i wouldn't call that max effort
11-15-2003, 01:28 AM
#8
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Join Date: Feb 2001
Location: Bay Area, CA, USA
Posts: 1,967
Originally posted by magius231
the reason there are so many race cars with carbs is rules are still penalizing or outlawing Fuel Injection in lots of classes...If the rules weren't there, believe me top fuel would have went F.I. a long time ago
the reason there are so many race cars with carbs is rules are still penalizing or outlawing Fuel Injection in lots of classes...If the rules weren't there, believe me top fuel would have went F.I. a long time ago
11-15-2003, 01:55 AM
#9
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Join Date: Oct 2003
Location: Windy City
Posts: 735
top fuel isnt carbed.... they use somthing that acts like a big throttle body. Its kind of like this.... http://www.ronsfuel.com/page2.html I used to think the same thing till I found out. And I know in the NHRA devision they have federal Mogual dragsters, which are like guys 1 step from going pro. And I have seen Electronic Fuel Injected dragsters, but they arent allowed to run the blower. Kind of wierd.
I personally love carbed motors, for different reasons. I love when ever you ride in a old muscle car, and you can smell the fuel fumes coming right off that carb, and the whole sound of the car is different.
I personally love carbed motors, for different reasons. I love when ever you ride in a old muscle car, and you can smell the fuel fumes coming right off that carb, and the whole sound of the car is different.
11-15-2003, 07:04 AM
#10
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Join Date: Dec 1999
Location: Petersham, MA
Posts: 1,697
Going carbed defeats the purpose of owning a late model car, IMO. Driveability, reasonable fuel economy, and the ability to adjust for any driving condition without popping the hood and adjusting jets is a home run. Going carbed was definately a step back, IMO.
11-15-2003, 08:17 AM
#11
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Join Date: May 2000
Location: Under my Car as usual :)
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Originally posted by aintno6
top fuel isnt carbed.... they use somthing that acts like a big throttle body. Its kind of like this.... http://www.ronsfuel.com/page2.html I used to think the same thing till I found out. And I know in the NHRA devision they have federal Mogual dragsters, which are like guys 1 step from going pro. And I have seen Electronic Fuel Injected dragsters, but they arent allowed to run the blower. Kind of wierd.
I personally love carbed motors, for different reasons. I love when ever you ride in a old muscle car, and you can smell the fuel fumes coming right off that carb, and the whole sound of the car is different.
top fuel isnt carbed.... they use somthing that acts like a big throttle body. Its kind of like this.... http://www.ronsfuel.com/page2.html I used to think the same thing till I found out. And I know in the NHRA devision they have federal Mogual dragsters, which are like guys 1 step from going pro. And I have seen Electronic Fuel Injected dragsters, but they arent allowed to run the blower. Kind of wierd.
I personally love carbed motors, for different reasons. I love when ever you ride in a old muscle car, and you can smell the fuel fumes coming right off that carb, and the whole sound of the car is different.
-Shannon
11-15-2003, 10:05 AM
#12
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Join Date: Feb 2001
Posts: 28
My fuel economy is really not that bad. Sure not as good as F.I. but I can deal with it. And as for driveability I put more miles on my car this year than the last two years combined because I wasn't messing with programing. I won't name any names but I had 2 guys that a lot of people have tune there computers do mine and they couldn't get it right. In one case I had 2 send it back to him 3 times. I had a blower on the car at the time and I should have gone D.F.I. Maybe I would still have F.I. if I did that but oh well. And as far as putting a carb on a car only going 116 to 120 F.I. wouldn't add any MPH and you have to remember this is a nothing motor. 350 stock compression, stock heads slightly ported, a cam that I used in my blower motor when it was F.I. and dual plane intake. So I think them times a pretty impressive. I plan on putting a single plane on the car this winter then spraying 175 at it. That should put it in the low 10's.
11-15-2003, 10:08 AM
#13
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Join Date: Oct 1998
Location: Southern CA
Posts: 705
Yes, the FI system on our cars is a little finiky. The trick is you have to be patient. I have redone the hole fuel system on my car, with modified stock fuel rails, stainless braided hoses, aftermarket pressure regulator and big fuel pump. I use LT1edit, thank god for this. The only thing I have changed from the stock program is the injector constant and the idle speed, that is it! The car runs great and has a good idle (not as smooth as stock but I will take it).
As far as FI vs carbed, they will yield virtually the same power if both maximized. The FI is more complicated, mainly due to the higher fuel pressure needed to run the injectors. This requires an electric pump and regulator. With a carb, you can get by with just a mechanical pump. Most guys with old cars stay carbed because of the cost of FI. But, FI has superior driveability.
By putting a carb on your late model car, you have regressed, taken a step back.
As far as FI vs carbed, they will yield virtually the same power if both maximized. The FI is more complicated, mainly due to the higher fuel pressure needed to run the injectors. This requires an electric pump and regulator. With a carb, you can get by with just a mechanical pump. Most guys with old cars stay carbed because of the cost of FI. But, FI has superior driveability.
By putting a carb on your late model car, you have regressed, taken a step back.
11-15-2003, 10:18 AM
#15
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Join Date: Dec 2002
Location: Charlotte, NC
Posts: 41
Friend of mine did the samething...execpt he went 11 flat on stock compression. Changed out the intake manifold, bigger carb, nasty cam....he went 9.xx I forget...it was a high nine because he was getting a low ten and finally got the carb setup right. I'd love to do that!!!! Its pimp!
-Eddie
-Eddie