Just curious as to whether I might be making a big mistake converting to carb over my tuneport setup????

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Bright red 87 GTA with 350 tuneport. Basic mods such as K&N filter, Flowmasters, Wells MAF, TPIS air foil, Accel 8.8mm plug wires with , Accel distributor cap and rotary buttons.Gutted cat. B&M Shift kit, 100HP shot Nitrous, soon to change over to carburator.

 

You are You're already set induction wise. a Vic Jr. and Holley 700DP will support more HP than you will prolly ever need it to, no further mods needed in that department. A TPI...forget it. costs thousands to get it to that level.

 

I guess it's a matter of what you want from the car. If you're looking for pure speed, bang for the buck carb is definetly the way to go. However with fuel injection you get better driveability, and with the proper setup and software you can tune the hell out of your engine.

Again, it pretty much depends on what your after.

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1985 ASCD Ram Air Trans Am
http://www.execpc.com/~karpsta/home.html
to find out more
-=ICON Motorsports=-

 

Can't disagree with anything said above. For dirt cheap HP the "old school" carb is still king.

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94 Firebird Formula M6- No options but Z rated tires. No mods over $10. 13.5@105.
79 Malibu "beater" w/junkyard 400 SBC, tweaked QJet 4bbl, finally a decent set of heads, a few other tricks. A maddening 13.000001 @ 108 on the motor with little traction. No nitrous runs with the new heads yet.
Grandma's old 78 Malibu (33K miles!) soon to have the powertrain from the 79 put in it.

"One of the last remaining QJet tuners on Planet Earth!"

 

Thats what I wanted to hear

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Bright red 87 GTA with 350 tuneport. Basic mods such as K&N filter, Flowmasters, Wells MAF, TPIS air foil, Accel 8.8mm plug wires with , Accel distributor cap and rotary buttons.Gutted cat. B&M Shift kit, 100HP shot Nitrous, soon to change over to carburator.

 

If you're getting rid of the TPI let me know, I might be swapping back to TPI soon (10MPG with a holley 600 and a TH-350/3.42!)

 

You would not get more power just by adding a new intake, carb and distributor only (don't forget the cost of decreasing your fuel pressure). To increase the power over TPI, you'd have to get a new cam and headers as well. You would increase the power of your current setup by spending the money on a cam and headers, so why not just do that? You'd need new parts to make your NOS setup work on a carb as well.

Going to a carb will perhaps increase the ultimate power possible from your engine, but at the expense of driveability, mileage, and emissions legality. You may have to go with AFPR and chip to get even more out of your TPI, but is that such a big deal? Beyond that you're talking Miniram or lower w/short runners which is some real money, but by then you're well past the power/driveability combo you'd have with carb.

I don't see the logic of your plan.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, ported heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

[This message has been edited by five7kid (edited October 09, 2000).]

 

My logic is why spend 700 dollars on a tuneport intake, when you can spend 160.00 on a carb one. The cost of performance is much cheaper. Plus u have to buy a new chip everytime you do anything to a tuneport. I want pure power, and power means carb. A cam for the tuneport is twice as much as one for a carb setup. See where I am coming from?

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Bright red 87 GTA with 350 tuneport. Basic mods such as K&N filter, Flowmasters, Wells MAF, TPIS air foil, Accel 8.8mm plug wires with , Accel distributor cap and rotary buttons.Gutted cat. B&M Shift kit, 100HP shot Nitrous, soon to change over to carburator.

 

I know what you mean, but you'd be wise to keep everything you take off. Or pray the EPA demons don't come knocking on your city gates.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

The TPI gets better gas mileage is really unfounded. It does get mildly better gas mileage but if you use the money saved from TPI to increase free HP WITHOUT increasing air/fuel flow, then you'll match it close enough. Some things that can be cheaply done to get better MPG out of a carb instead of TPI are easy simple things. Headers, underdrive pullies, eletric waterpump, eletric fans, hell, even what you can save on TPI set-ups you could get a set of aluminum cylinder heads and save weight. The simple fact is that a tuned carb and normal driving can push MPG close to TPI. Emmissions are the same way. As you know, Nitrogen and Oxygen make up most of the lower atomosphere. Gaslone, a hydrocarbon, combines with these during combustion to create water and carbon dixode. Only under exterme heat can Nitrogen work into the equation making the bi-product nitrogen oxides. That usually only occurs under a lean condition, no carb should ever run under a lean condtion. Perfect or midly rich. you never want to run lean because of the heat assicoated with it. Now, in rich combustion, gas is left over, hydro carbons. This is where you're most likely to fail emmissions. However, the main fucntion of the cat. converter is to remove hydrocarbons and re-burn them so if you run one with a properly tuned carb emmissions should be no problem. Fuel injection is nicer though. I'm honestly right in the middle. I love both.

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1984 WS6 Trans Am Hartop
Former L69 Car under restoration
1984 WS6 Trans Am T-top car
4-bolt main 350, headers, Holley 650, T-5 and 3.23's.
Daily driver and restoration

 

In my opinion, a carbed car turning at around 1800 rpm on highway will get at least 5 mpg WORSE mileage than ANY EFI engine at same rpm/conditions. From experience, of course. Whe you get into lower rear-end gears/higher overall rpm's, mileage difference disappears. This comes from the EFI's ability to operate well under a load with the correct spark advance, something most carbs cannot do.

I do love 400hp carbed motors with the resto f other carb lovers, only for HP for me.

 

Thats just wrong. I tested it. I converted my car from EFI to carb, and a Holley at that. At the same time I also put on a much bigger intake, AND put in a cam with 20something more degrees of duration. I lost 2 mpg, thats it.

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"American made baby. 100% American iron. The muscle among the masses. My hero. Yep, you can take your ergonomically designed, space age, computer controlled, 4 door, cup holding map lighted split double wishbone split fold down retractable cargo covered moon roof piece of transportation and keep it. For I have felt the thunder. And I know the difference!"
Jesters's Page of Sick Pleasure
Florida Thirdgenners Message Board
ICON Motorsports

 

Yeah, but 2mpg where? I can see losing 2 mpg in OVERALL driving, yeah, but highway mileage loss of only 2mpg? I would be more??? What RPM are you at on the highway??? If you are at 2500+, you proved my point.

[This message has been edited by FastBroker (edited October 14, 2000).]

 

Nope. That was highway driving, around 1800rpm, just like you said.

 

When I bought my car brand new in 1986, the EPA was 17/25. It's the slow Carbed LG4. The TPI cars got less mpg (can't remember exact numbers), but more power of course. Just curious to why so many state that TPI is better for mpg?

BTW, at over 200K miles, I still get 27 to 28 mpg highway. This isn't comparing apples to apples, but my LT-1 Corvette gets slightly less at 25-26 mpg. It is an auto, along with the 1986Z28. I onced owned a 4th gen LT-1 six speed that got about the same as the 1986.

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1986 Black/Gold LG4 Z28
Original Owner, 200,000+ near trouble free miles.
Mostly Stock.

1995 Dark Red Metallic Corvette Coupe Original Owner

[This message has been edited by Joey1986Z (edited October 15, 2000).]

 

I think the TPI guys are saying that with the less power you are more likely to push the engine more than if you had more power.

That almost dosn't make sense with the vette. Maybe the LT1 just isn't as fuel efficient, hence it only lasted 6 years(i think).

 

TPI gets better mileage and better emissions. That is the biggie. Plus I think it looks cool.

Depends on what you want, CARB's if tuned right should get more than 10MPG, depending on the engine of course. I'd keep the old induction system when you take it off, don't discard it.

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1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
-vinyl security shade, velcro t-top bag
*****Possible summer '01 mods*****
Dual Snorkle, Auburn Posi, Keyless Entry, Wonder Bar from my IROC, 4th gen seats, T/A tail lights

http://www.geocities.com/krt80/

[This message has been edited by Keith5 (edited February 28, 2001).]

 

oops, I forgot this was a really old post.

[This message has been edited by Keith5 (edited February 27, 2001).]

 

Carbs if tuned right should get 10mpg, what
does that mean? Are you talking about an over carbed, flat tappet cammed, no overdrive carbed 350 driving only stop and go traffic? My friend's Comp Carbed LG4 used to get 20mpg overall city, light hwy driving. So I think it's all in the setup. If he would have had more comp 9.5, a mild 204-214 cam, Edelb intake and rejetted carb and headers he would have been running high 14's and been getting nearly identical mileage because of increased efficiency. More HP equals worse mileage with any induction, depending on how it's setup of course. (Over 10mpg now that's different!, )

[This message has been edited by Mike92 (edited February 28, 2001).]

 

Sorry that was a typo, I left out "more than". Must have been something wrong with me last night, made a bunch of typos, replied to a post in the archives. . . . .