89305formula

iTrader: (5)

ive been thinking of swaping my tpi out for a carb set up for hopes of more power i already have a nice tpi set up everything is in my sig but my question is will i have more power with a carb and what about driveability cause right now it sucks since i have a decent size cam with out a tune, it doesnt really run smooth till about 3500, i dont care about fuel mileage, i have everything laying around my house and shop to do the swap besides a manifold so what type of manifold you guys think would work well for me with a q-jet carb, i have about 10 of them laying around not sure which one im going to use yet, the car is only really used for the track and and having fun on the streets, thanks

and ill also be swaping to hooker 2210s with true duals when i do the carb swap if that makes any difference

five7kid

iTrader: (14)

That's a pretty big cam for a 305 TPI.

Performer RPM and 650 double pumper carb.

Benefits would be being able to take full advantage of the cam.

89305formula

iTrader: (5)

yea thats what i was thinking with the cam cause its never run as good as i think it should thats why i thought a carb would be better, a guy i know has a edelbrock performer for sale for 50$ so im going to buy that at the end of the week, and is the holley that much better then the q-jet, i have one that i just took off a 78 vette, that was just rebuilt 2 months before i replaced it, would it be better then the 650dp

five7kid

iTrader: (14)

The Performer isn't enough intake for that cam. You really need the RPM version.

With a manual transmission, a double pumper is your best bet.

89305formula

iTrader: (5)

ok thanks alot for your help im going to start looking on ebay for a manifold and carb, is a 650 db a square bore flange or spread bore, this is my first time using a carb so i dont know much about them

darkride86T/A

The majority of Holley's carbs are square bored, with the exception of a couple of models.

Kevin91Z

iTrader: (1)

You're already running 12.92 with a 305 TPI! What more do you want? I think if you get the computer tuned you'll enjoy the car a lot more and will get that silly idea of going backwards with old technology out of your head.

Is this a race car or a street car? Race cars use carbs because they dont care about torque. Street cars keep the TPI because the torque is awesome and comes on where you use it on the street, from idle to 3500 rpms.

Its always been my opinion if you want a carb car then buy an 87 or older one that came with a carb. Dont hack up a TPI car, sell it to someone who appreciates TPI and is willing to work with it.

xpndbl3

iTrader: (5)

tpi is old outdated technology just like carbs Kevin

I don't see a well setup carb setup making any less torque than a tpi setup at all.

Kevin91Z

iTrader: (1)

Not on a thirdgen. TPI is newer and more recent technology than thirdgen carbs are.

Carb manifolds have short runners to keep the fuel from falling out of suspension with the air. The short runners also promote horsepower at the expense of torque. TPI's long runners promote torque from idle to 4000 rpms at the expense of horsepower above 4000 rpms. An engine with a carb manifold will not make the same torque across the power band as a TPI manifold will. The physics are completely different.

Plus I like plugging in my laptop and adjust the fuel and spark tables without having to get out a screwdriver and getting gasoline and dirt all over my hands. But some people like that stuff.

RWB____s

well thinking about this from a different perspective, I like to know what heads your using on this engine? are they factory heads or aftermarket. The reason I ask is the Performer RPM intake port runner size is big! It actually measures bigger in size than a victor jr port. If you use the RPM manifold I'd check the runner size to be sure its not bigger than the head port. If it is, you'll be having major reversion in the manifold and port flow will be compromized for sure. Stock 305 heads port size are extremely small and to open them up to acommadate a RPM or Vic Jr manifold just may kill your torque down low.
I'd say stick with the TPI and work with it like Kevin said. The TPI was designed initially for the 305 rather than a 350.

Street Lethal

iTrader: (16)

The power your making will be much more linear with a carburetor, yes, but it would be the very same difference w/EFI if you swapped to a Holley Stealth Ram, w/new prom burned....

BLACK ICE

Umm wasnt the TPI originaly designed for the corvette with a 350?

89305formula

iTrader: (5)

there pro comp 180cc heads ported to a 1205 felpro, and the car is a street strip car but its going more towards a race car but it will always be street legal, i dont really care about driveability or mpg if it will make it faster on the track ill deal with it on the street i want to go mid to low 12s on the motor this year and hopefully low 11s on the juice

89305formula

iTrader: (5)

and another reason i want to go to carb is because i have a miss that i have never been able to find and i lose injector pulse at random times and i cant figure it out for the life of me so i think a carb will just be easier cause im 99% sure its not a ignition problem, and ill probably be using a wieand stealth manifold and a 650db, does anyone know if this will fit under a stock hood

Abubaca

iTrader: (3)

I used to feel that there was no need to go backwards in technology, but honestly, I think you could argue the "no need to backwards" argument with anyone not running an LSx engine. We've come so far in the past ten years, that unless you're cutting edge, you're really just old technology anyway.

So do whatcha want. Carbs are cool too!

Kevin91Z

iTrader: (1)

LS1's are for 4th gens and we are dealing with thirdgens here. My biggest beef is the conversion of a perfectly good TPI car over to a carb. There are lots of people on this board who would kill for a good running TPI setup like you have.

But if its a drag only car, do what you want.

327_TPI_77_Maro

iTrader: (8)

Just get a Stealth ram like I did. I would never ever go from EFI back to carb. You will lose a ton of driveability and tuneability. Don't do it, for the love of God. If you plan your EFI out well, it won't lose you any power over carb. A stock TPI of course gives up power to an old fashioned Holley setup, so ditch the stock TPI intake and get something modern and short-runner.

89305formula

iTrader: (5)

i was thinking about that but i already bought a manifold, carb , and a regulator so im going with a carb, im probably going to keep the tpi stuff for a little while so if its not what im looking for ill go back to efi, plus the track opens in a few weeks so i need to get this thing together

5.7TPI

-Good overall choice going with the carb - TPI (being nice for the street ) will not give you hp numbers like a good carb set up will (due to flow restrictions) - do you see many strip cars with TPI ?
not unless you have 10000 bucks in it right- although I am a fan of the tpi - when I did my swap I was more then impressed also when sensors brake now it dont cost me 100$ here and there - Ohh wait no more sensors = no more problems

Ps- Doesn't everyone H8t thoes stupid fuc*ing torks blots!

82TA_JAIME

iTrader: (1)

on an opposite note, would a tpi set fit in a carbed 400 block? i've been throwing around the idea of doing a tpi swap but thought it might be too much of a pain to wire everything up. i dont drag race too much and wouldnt mind more torque.

92z28camarokid

iTrader: (4)

The main reason behind swampin in a carb for my tpi setup is because I am DONE with all this Computer BS! It is much easier and cheaper to tune a carburator, all you there is to adjust is a screw and your good to go, you dont have to have a tuner or computer with you to adjust it. You can only add so much to a tpi setup until you start wastin your money. The TPI setup is limited, yes you can change it to a stealth ram setup but your gunna spend more money then on a carburated setup.

Just think you can spend the same amount of money on parts to upgrade your engine but when it comes to switching the intake to utilize it all you are saving a bunch of money but going carburated

Street Lethal

iTrader: (16)

Yes, but the stock runners would choke the engine up high, so be sure to siamese them....

Grumbles

If you're till looking to carb that car, I have a holley 650 DP spread bore. It's in pieces and needs a rebuild (obviously), but I have everything for it. 50 bucks and shipping and it's yours.

jcon104

you may want to be careful what heads you are using also tpi heads will not work with a carb due to there being holes where the injectors where suppose to be

89305formula

iTrader: (5)

The holes for the injectors are in the intake manifold, not in the heads.

87WS6

iTrader: (1)

You also lose streetability with a carb. The other problem is that technically, according to Federal Law, you shouldn't be removing the EFI equipment from the car. Your state may not do emissions testing, but that doesn't make the swap legal.

cricket5150

I've got a 91' RS.I tore the old,wore out,170hp 305 last year.I bought an Edelbrock 383 custom built engine which is rated at 450hp.The problem that I am having now is fabricating the electric fuel pump,turning it into a pickup and sending unit.Having to run all new fuel lines and finding the right throttle bracket that works.If I had known what I was getting into,I believe I would have stayed with the 305 and built a computerized high performance power plant...My biggest worry is doing the modification of the wiring harness,considering half of the wires I'm not going to be using.If this car wasn't spotless and in awesome condition inside and out,this car would be sitting in a junkyard rotting away...