C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

L98 TPI to Carb

Old 03-29-2009, 06:37 AM
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snowmanmdp
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Default L98 TPI to Carb

Who has switched over from TPI to a Carb and did it make a difference?
Were you able to pick up RPM's with the switch, I know I will lose mpg's but I put less than 500 miles on my vette last year. I also am not picking up on the fuel injection. Just looking for some input
Old 03-29-2009, 06:53 AM
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rodj
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Originally Posted by snowmanmdp
Who has switched over from TPI to a Carb and did it make a difference?
Difference in what ?
Read
http://forums.corvetteforum.com/sear...rchid=10180086
Old 03-29-2009, 07:19 AM
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Bruce Witherspoon
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Originally Posted by snowmanmdp
Who has switched over from TPI to a Carb and did it make a difference?
Were you able to pick up RPM's with the switch, I know I will lose mpg's but I put less than 500 miles on my vette last year. I also am not picking up on the fuel injection. Just looking for some input
I guess I would question what issues you have with the fuel injection? And what you mean by more r.p.m. There will be issues with hood clearance to the carb given that the car was not designed to have a carb sitting on the top of the engine. Not saying it can be done, just curious why?
Old 03-29-2009, 07:35 AM
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Elephanthead
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Lets face it the C4 is not cutting edge technology, its main appeal is its roadster like ride qualities. I grew up driving carbed cars, and that is what I like, same thing with a manual transmission. If you want to be chauffeured around by a robot, go ahead, but don't cry when the machines take over and you can't do anything for yourself.
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Old 03-29-2009, 08:04 AM
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rodj
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Originally Posted by Elephanthead
Lets face it the C4 is not cutting edge technology,
It was when it first came out 25 years ago , just like the C6 is now.
Still using your 8 track?

Last edited by rodj; 03-29-2009 at 08:06 AM.
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Old 03-29-2009, 08:32 AM
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WW7
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If you carb it, you should get higher rpms just like the 350s of old. The TPI is whats holding the L98 from achieving that (along with a restrictive exhaust). Im not sure what the horsepower increase will be with a carb on the L98, but there is a engine Im thinking about getting called the ZZ4 that is rated at 355hp with a carb,but with the tpi that I have now will only be about 265hp, so you can see there is a great difference in hp between TPI and carb. Higher power can be achievied with TPI but the cost is much greater.I personally won"t go to carb, because thats not how the car was built originally,but if power is what you want, it can be gotten cheaper and easier with a carb..WW

Last edited by WW7; 03-29-2009 at 08:34 AM.
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Old 03-29-2009, 08:51 AM
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MR NICE
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Originally Posted by WW7
If you carb it, you should get higher rpms just like the 350s of old. The TPI is whats holding the L98 from achieving that (along with a restrictive exhaust). Im not sure what the horsepower increase will be with a carb on the L98, but there is a engine Im thinking about getting called the ZZ4 that is rated at 355hp with a carb,but with the tpi that I have now will only be about 265hp, so you can see there is a great difference in hp between TPI and carb. Higher power can be achievied with TPI but the cost is much greater.I personally won"t go to carb, because thats not how the car was built originally,but if power is what you want, it can be gotten cheaper and easier with a carb..WW
Switching to a carb is not cheap,Intake,carb,air cleaner,FPR,Dizzy,TV cable bracket
Old 03-29-2009, 09:04 AM
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Originally Posted by MR NICE
Switching to a carb is not cheap,Intake,carb,air cleaner,FPR,Dizzy,TV cable bracket
Nothing is cheap nowadays but a lot of this can be bought used on ebay an other sites fairly inexpensively. Just go to ebay an do a seach on 350 intakes or carbs and see if you don't come up with hundreds of items...WW

Last edited by WW7; 03-29-2009 at 11:46 AM.
Old 03-29-2009, 09:33 AM
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Bruce Witherspoon
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Originally Posted by WW7
If you carb it, you should get higher rpms just like the 350s of old. The TPI is whats holding the L98 from achieving that (along with a restrictive exhaust). Im not sure what the horsepower increase will be with a carb on the L98, but there is a engine Im thinking about getting called the ZZ4 that is rated at 355hp with a carb,but with the tpi that I have now will only be about 265hp, so you can see there is a great difference in hp between TPI and carb. Higher power can be achievied with TPI but the cost is much greater.I personally won"t go to carb, because thats not how the car was built originally,but if power is what you want, it can be gotten cheaper and easier with a carb..WW
Not sure how you equate a carb with higher engine speed? The L98 was designed to make h.p./torge in an era when fuel and emission were the still the controlling factor in engine development. As some one already eluded, even the LS9 which makes in excess of 600 h.p. does not run at what would be considered high engine speeds.
I agree that a better intake manifold would increase both the engine operating speed as well as some of the usable horsepower, but for the sacrifice of the lower end torque.
Trying a larger throttlebody and a les restrictive manifold might surprise you. There are numerous articles that you can find on the Web that show improvements in h.p. by increaseing the intake flow and decreasing the exhaust back pressure.
Old 03-29-2009, 10:03 AM
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Originally Posted by rodj
Nothing comes up.
Old 03-29-2009, 10:06 AM
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Originally Posted by MR NICE
Switching to a carb is not cheap,Intake,carb,air cleaner,FPR,Dizzy,TV cable bracket

Maybe a dumb question, but why would the distributor need switched out?
Old 03-29-2009, 10:08 AM
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Originally Posted by Bruce Witherspoon
I guess I would question what issues you have with the fuel injection? And what you mean by more r.p.m. There will be issues with hood clearance to the carb given that the car was not designed to have a carb sitting on the top of the engine. Not saying it can be done, just curious why?
I hate fuel injection I grew up with carbs and understand them. It's just that simple for me....I've seen it done so I don't think unless I get crazy with a high rise intake and spacers it should fit under the hood.
Old 03-29-2009, 10:17 AM
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you're starting w/the wrong Vette.......should have bought an older model equipped w/a carb. if that's what you like.....
Old 03-29-2009, 10:29 AM
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Originally Posted by 856SPEED
you're starting w/the wrong Vette.......should have bought an older model equipped w/a carb. if that's what you like.....
This one basically fell in my lap....I took it in as a trade on a snowmobile....But if it was a case of buying what I really wanted, it would have been a split window big block.
Old 03-29-2009, 10:33 AM
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Be very careful with the transmission TV cable. Carb swaps require dedicated, specific brackets, and careful TV linkage tweakings to allow the trans to remain alive. If the tv is wrong, trans will eat itself up quickly.
Old 03-29-2009, 10:40 AM
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Originally Posted by snowmanmdp
This one basically fell in my lap....I took it in as a trade on a snowmobile....But if it was a case of buying what I really wanted, it would have been a split window big block.


I understand; maybe sell it and buy something else?
Old 03-29-2009, 10:40 AM
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Originally Posted by Pete K
Be very careful with the transmission TV cable. Carb swaps require dedicated, specific brackets, and careful TV linkage tweakings to allow the trans to remain alive. If the tv is wrong, trans will eat itself up quickly.
Thanks for the tip....I work in a prototype shop, so I think if I switch over the brackets and cables will be hand made...we did all the prototype cables for the Dodge Challengers.

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Old 03-29-2009, 10:40 AM
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Originally Posted by snowmanmdp
This one basically fell in my lap....I took it in as a trade on a snowmobile....But if it was a case of buying what I really wanted, it would have been a split window big block.

So when are you buying the 63?

Last edited by CorvetteMike2024; 03-29-2009 at 10:44 AM.
Old 03-29-2009, 10:42 AM
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Originally Posted by snowmanmdp
Thanks for the tip....I work in a prototype shop, so I think if I switch over the brackets and cables will be hand made...we did all the prototype cables for the Dodge Challengers.
Happy to help. Most carb swap guys do not realize it is a throttle valve cable, and not a kickdown cable like the old turbo 350's.

Not a big deal to get them set up properly, but overlooked often.
If I can help, let me know.
Old 03-29-2009, 10:50 AM
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Originally Posted by 856SPEED


I understand; maybe sell it and buy something else?
I like the car... I don't see many Gold 85's or any other years for that matter. I already have put on a ported and polished plenium with bigger runners and a set of Hooker ceramic headers and stainless steel magnaflows...not to mention the ZR1 wheels and recovering the seats. I like being able to work on the car myself and I can't work on the fuel injection....My grandfather worked at holley for 40 years and he told me that the reason they came up with EFI is so you can't work on it.
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