Carb Vs. TPI
05-22-2006, 07:55 PM
#1
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Carb Vs. TPI
I have a 87 vette and I`m thinking of switching to carb for simplicity`s sake. And the fact that’s it`s a LOT cheaper. I`m look`n for any advice from you guys as to do it or not, and why. I know that in the end injection is better but the price tag....is it worth it?
(single father of 2 so not alot of spare cash)
(single father of 2 so not alot of spare cash)
05-22-2006, 08:31 PM
#2
Burning Brakes
i'll be the first to say it
the search button is your friend...
that aside, if you already have a TPI, stay TPI...it's actually easier for you in the end. if you don't plan on modding the car any, it serves it's purpose wonderfully. carbs are not always a simple solution.
the search button is your friend...
that aside, if you already have a TPI, stay TPI...it's actually easier for you in the end. if you don't plan on modding the car any, it serves it's purpose wonderfully. carbs are not always a simple solution.
05-22-2006, 09:26 PM
#3
Le Mans Master
Alot of guys have went from TPI and CFI to carbs for the same reason,simplicity! It's work, and you're taking a step back in time, they're cost involved..but to each his own! Like said..do a search. Good Luck, Oh, and BTW, all the real high HP seakers use carbs.
05-22-2006, 11:13 PM
#6
Melting Slicks
yeah, ask SKI_DWN_It - he went carb for those low 10 sec runs. 
ACTUALLY, you should realistically be able to make more power in an apples-to-apples comparison because carbs are a wet-intake design (and that reduces flow potential). EFI is port-injection so the same volume runner supplies more air (because fuel does not have to come along for the ride). Add in precise fuel metering, more accurate control of part-throttle and idle (and ambient temp) adjustments... and EFI is more efficient, more mild-mannered, and should make more power under a wider variety of conditions than a carb.
However, there are a lot of "old school" guys who are used to slapping a carb on big runners and making good numbers and are literally afraid of EFI so they continue to believe in the old fashioned engine building. Add in the mystique of the muscle car era (all carbs) and it's a popular myth IMHO. However, most EFI vehicles are production - so drivability and economy are larger considerations. Then there's the "power under the curve" discussion of all those big runner/big carb combos - they make huge peak numbers as FUBAR stated - but are they "faster" than a comparable EFI? That would be tough to say because it seems so many are biased towards one or the other.
The hard part is getting a wild EFI combo and tuning it - that's why many people go carb... it's not that you'll make more power, it's just easier to slap on a carb and drive (even if you're leaving HP on the table). Luckily, the next LS7 crate motor is carb'd, so we can start making some REAL power.
In my opinion, of course.
ACTUALLY, you should realistically be able to make more power in an apples-to-apples comparison because carbs are a wet-intake design (and that reduces flow potential). EFI is port-injection so the same volume runner supplies more air (because fuel does not have to come along for the ride). Add in precise fuel metering, more accurate control of part-throttle and idle (and ambient temp) adjustments... and EFI is more efficient, more mild-mannered, and should make more power under a wider variety of conditions than a carb.
However, there are a lot of "old school" guys who are used to slapping a carb on big runners and making good numbers and are literally afraid of EFI so they continue to believe in the old fashioned engine building. Add in the mystique of the muscle car era (all carbs) and it's a popular myth IMHO. However, most EFI vehicles are production - so drivability and economy are larger considerations. Then there's the "power under the curve" discussion of all those big runner/big carb combos - they make huge peak numbers as FUBAR stated - but are they "faster" than a comparable EFI? That would be tough to say because it seems so many are biased towards one or the other.
The hard part is getting a wild EFI combo and tuning it - that's why many people go carb... it's not that you'll make more power, it's just easier to slap on a carb and drive (even if you're leaving HP on the table). Luckily, the next LS7 crate motor is carb'd, so we can start making some REAL power.
In my opinion, of course.
Last edited by Ramanstud; 05-22-2006 at 11:15 PM.
05-23-2006, 11:19 AM
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Originally Posted by Ramanstud
yeah, ask SKI_DWN_It - he went carb for those low 10 sec runs.
ACTUALLY, you should realistically be able to make more power in an apples-to-apples comparison because carbs are a wet-intake design (and that reduces flow potential). EFI is port-injection so the same volume runner supplies more air (because fuel does not have to come along for the ride). Add in precise fuel metering, more accurate control of part-throttle and idle (and ambient temp) adjustments... and EFI is more efficient, more mild-mannered, and should make more power under a wider variety of conditions than a carb.
However, there are a lot of "old school" guys who are used to slapping a carb on big runners and making good numbers and are literally afraid of EFI so they continue to believe in the old fashioned engine building. Add in the mystique of the muscle car era (all carbs) and it's a popular myth IMHO. However, most EFI vehicles are production - so drivability and economy are larger considerations. Then there's the "power under the curve" discussion of all those big runner/big carb combos - they make huge peak numbers as FUBAR stated - but are they "faster" than a comparable EFI? That would be tough to say because it seems so many are biased towards one or the other.
The hard part is getting a wild EFI combo and tuning it - that's why many people go carb... it's not that you'll make more power, it's just easier to slap on a carb and drive (even if you're leaving HP on the table). Luckily, the next LS7 crate motor is carb'd, so we can start making some REAL power.
In my opinion, of course.
ACTUALLY, you should realistically be able to make more power in an apples-to-apples comparison because carbs are a wet-intake design (and that reduces flow potential). EFI is port-injection so the same volume runner supplies more air (because fuel does not have to come along for the ride). Add in precise fuel metering, more accurate control of part-throttle and idle (and ambient temp) adjustments... and EFI is more efficient, more mild-mannered, and should make more power under a wider variety of conditions than a carb.
However, there are a lot of "old school" guys who are used to slapping a carb on big runners and making good numbers and are literally afraid of EFI so they continue to believe in the old fashioned engine building. Add in the mystique of the muscle car era (all carbs) and it's a popular myth IMHO. However, most EFI vehicles are production - so drivability and economy are larger considerations. Then there's the "power under the curve" discussion of all those big runner/big carb combos - they make huge peak numbers as FUBAR stated - but are they "faster" than a comparable EFI? That would be tough to say because it seems so many are biased towards one or the other.
The hard part is getting a wild EFI combo and tuning it - that's why many people go carb... it's not that you'll make more power, it's just easier to slap on a carb and drive (even if you're leaving HP on the table). Luckily, the next LS7 crate motor is carb'd, so we can start making some REAL power.
In my opinion, of course.
05-23-2006, 12:44 PM
#8
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St. Jude Donor '10-'11-'12-'13
Originally Posted by cemittar
Tuning yes thats the problem.I was told to get it tuned with my new intake cam combo will cost a good $$$$$ To burn a new chip new injectors etc etc so now I`m kinda turned off by it. I`m the first to admite I am not to knowlegable about FI. But I am good with a carb. call it fear of the unknow what ever, But my last go-fast car (don`t yell at me It was a Mustange) I had that car runn`n low 11`s in the 1/4 with FI, then I swapped to carb and with no adjustment to the carb(out of box) I lost 0.12 off my best time. Slapped some juice on it from Nos and bam....10`s in the 1/4 for 1/3 the price of the FI.
Understanding the ECM, how it functions using sensor feedback, and how to interpret that feedback can seem quite overwhelming at first. There is a lot of information to sort through, but IMHO it is well worth it. The DIY PROM section of the Third Gen.org forum has a TON of great information: http://www.thirdgen.org/techboard/diy-prom/
DIY tuning does require investing in equipment, and there are a few options out there, depending on what you prefer and your budget. There are also a few supporting tuners on the forum who would likely be able to burn a chip for approx. a few hundred bucks via mail order, but if your combination is, or you are planning it to be, fairly radical, mail order is a bit tougher to nail down.
05-23-2006, 01:36 PM
#9
Le Mans Master
Ramanstud, I guess I'm one of those old fashioned guys...I admit it 
But, I'm certainly not afraid of my EFI, or the TPI. Owning my 87 for 7 years I've learned a hellava lot, I understand just about everything there is on my vette. Since I don't build or race any more (although the temptation is still there
) there's no way I would change either a CFI or TPI back to a carb. That said, I can still understand some guys wanting or wishing for simplicity-elimination of relays, sensors, 50 feet of vac. lines, ECMs-the list really goes on, so, I can understand what they're saying.
As far as HP goes-hell, almost any long block on the market 450HP plus
are carb setups.
On the other hand, guys like Corky, Ski, and of others are taking these TPIs as far as they possibly can-through trial and error. That's great-but in my opinion (you know they all stink ) there are restrictions with them-whereas I've seen guys making a lot more with carbs. Less restrictive.
But, I'm certainly not afraid of my EFI, or the TPI. Owning my 87 for 7 years I've learned a hellava lot, I understand just about everything there is on my vette. Since I don't build or race any more (although the temptation is still there
) there's no way I would change either a CFI or TPI back to a carb. That said, I can still understand some guys wanting or wishing for simplicity-elimination of relays, sensors, 50 feet of vac. lines, ECMs-the list really goes on, so, I can understand what they're saying.As far as HP goes-hell, almost any long block on the market 450HP plus
are carb setups.
On the other hand, guys like Corky, Ski, and of others are taking these TPIs as far as they possibly can-through trial and error. That's great-but in my opinion (you know they all stink
) there are restrictions with them-whereas I've seen guys making a lot more with carbs. Less restrictive.
05-24-2006, 04:35 PM
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I have seen a few FI vette`s with turbo`s and superchargers that are CRAZY on the dyno. But like I said in the first post, I`m by no means rich
So I have to go with a set budget. I have had a lot of good runs on carb`d cars. 
So I have to go with a set budget. I have had a lot of good runs on carb`d cars.
05-24-2006, 05:34 PM
#11
Melting Slicks
Originally Posted by rick lambert
As far as HP goes-hell, almost any long block on the market 450HP plus are carb setups.
That's true. I've noticed that as well... and a few thoughts:
#1 there is a nostalgia about carbs. the "tried and true" effect - just like why so many of us here copy setups with intakes, etc... we don't want to be TOO unique and not know what to expect. Carbs have been around forever and just as noted previously... a few minutes with a screwdriver vs weeks with a computer. Carb wins for ease of use and simplicity of parts.
#2 EFI is used extensively by the major producers - economy, *compactness* (ie no high-risers), and *proprietary code* all add to the perceived restrictions in EFI. Add in a laptop and it is daunting.
#3 because of the "speciality" knowledge that's needed to run EFI - the aftermarket has been focused on Plug and Play replacements (intake swaps, tuner packages, cams that run on OEM chips or plug-in boxes). This means more moderate gains because the TUNING REQUIRED to run more radical setups is much more "iffy." This is starkly contrasted with carbs and points previously made.
So the availability of extreme EFI setups is more limited because of the intricacies of tuning them. My point is that it's not necessarily EASIER to go fast with EFI, but based on the advantages listed above - you should be able to go faster with better street manners (in a perfect world). There are some sweet EFI crate motors out there (LS7 anyone?) but because the tuning, the wiring, and the intakes have to be matched and all add to the total costs... it's harder to market the same way a carb'd crate motor can be - after all, if you have a low hood line you just change the carb (not the intake, the harness, and the ECM that you just dropped $2K on).
Okay, I'm done jibba-jabbering!
