355gta

Should I stay TPI or go carburated. If I stay TPI I am going to run a edelbrock vortec base and slp runners with port work, ported plenum, 52mm throttle body, etc. If I go carburated I am going to run a super victor and 750 demon. I am not leaving all the details of each combo. I dont want this post to be to long, so I would just like some broad opinions.

Mcdamit

carb, no computers, more horsepower. problem with a carb is its not fuel injection so bogging off idle and fuel consumption

five7kid

iTrader: (14)

One required detail is what you plan on doing with the car. If you trailer it to the drag strip, that's a whole different answer than if you drive it to work every day.

355gta

I agree about the no computer and more horsepower but I like driving my car alot. FI gives great driveability.

355gta

I do drive this to work everyday for now. But I will always drive it to the track and I will do power tour and such, so that is why I am stuck.

five7kid

iTrader: (14)

Maximize power for dollars spent, carb wins hands down.

Maximize driveability and economy over the longhaul, EFI comes out on top. Same can be said if you change altitude, etc.

88 350 tpi formula

iTrader: (9)

carb, I love efi but, carb just leaves you with more money for good things like the extra gas it sucks jk but, really there is by far more intake choices for carbs. plus if you don't get the tune right on your efi it won't run even close to that double pumper or demon

Mcdamit

you know you always could just slap back on the stock tpi and buy your carb stuff and put them on for race days. It takes like a hour to pull the entire manifold if you work fast and maybe about 4 hours to piece it back together, tune it in another hour or so. Then again the Hsr is $500 for the whole system and I believe you can use everything from that tpi even cruise control because you reuse the throttlebody. That works more like a carb in terms of making horsepower.

del91_305

people drive carburated cars for daily drivers all the time, i would go carb.

TBI92Camaro

saw the topic and scrolled right down....go carb, end of story. for driveability, get a Holley vacuum secondary carb, change springs for race days and such

355gta

Thanks for all the replies. You have made my choice a little easier. I do not know why I am so partial to FI. If I go carbed though I will have to buy a new hood to clear the intake because the shortest would run would be an air gap but I will probably run a victor. So there is 400 for the hood, 150 for the intake, 400 for the carb, etc. Price will not be much different. I guess I will have to flip a coin. I appreciate all the help.

Sitting Bull

A QJet will give you a carbed ride that is just as driveable and pleasureable as FI. Don't let anyone sell you on the expense of FI with that line

shaggy56

Someone was just telling me how the drag racers now are using the Demon carbs and telling me how carb technology has come a long way.

Ray87Z

I had a carbed vortec headed 350 that I drove daily and it was IMO a perfect daily driver. It idled and ran like a champ, literally perfect throttle response (better than my TPI cars have had, lol) and it got what I consider decent mileage for a fairly hot 350 (somewhere around 18-19 mpg on my standard daily trip, mostly highway w/ a few stoplights thrown in, etc). However I live in Georgia where the winter is very mild and pretty short, if I lived up north perhaps I would have had more cold start issues, here my electric choke seemed to work perfectly and the car always fired right up even on cold days.

However, I always wondered if it would have been better to go with a vortec stealthram or something if they ever start shipping it out. Since I think it's either available now or will be pretty shortly that may be a option for you, it should be a better setup than the vortec base/long runner TPI setup...

About the only issue I had going from a 305 TPI to a carbed 350 was my intank fuel pump died which I removed to put a standard pickup in the tank and put a mechanical fuel pump back up on the engine at the time, kinda a PITA to drop the tank and junk. Initially I was running a Mallory return-style FPR to allow the TPI pump to stay in the tank, lasted about 2 years I guess. I was never 100% happy with my vacuum controlled TC lockup kit either, it would cycle the TC between locked and unlocked at just the right speed/engine load and was the only major driveability complaint I ever had with the car. Not that you couldn't "drive around" the issue somewhat, but still...

I didn't vote because I'm not sure what I'd do today if I had it to do over now. With the FI route you'd have to get into custom prom stuff which I never got into, which is frankly a little intimidating to me personally and the one big negative that would steer me more torward a carb setup again... Just not sure, I think you can definitely be pretty happy with a carb setup though, I know mine ran and drove great, I could even quickly and easily lean it way down and pass the dyno smog-**** test here, then tune it back to normal in 5 minutes, lol... (only emissions device still on the car is a 3" catco cat).

CamarosRUS

if you are going to build it as cheap as possible and not worry about tuning go carb. you can drive daily with a carb no problem. if you want to take the time to tune everything you can get more power, better overall driveability (cold starts better fuel economy etc) out of EFI but it takes the time to do it right. it sounds like you should go carb but you can always try EFI and sell it if it doesnt work then take all that money and get a very nice carb, manifold, and beer!!!!!


but if you do stay TPI defenitly buy a stealthram and enjoy more power and a wider powerband that doesnt die at 5000rpm because from the TPI mods you suggested you can get a stealthram plenum, intake base, and fuelrails for about the same price

Rockin-Iroc

For a street runner, it's hard to beat the TPI. GM put way too small a cam in the TPI cars. If you put a hotter cam in it, with up to 224 degrees duration at 0.050", the TPI will respond with much stronger performance in the midrange. I have a 221 degree @ 0.050" Isky cam and it BARELY passes emissions every time. But I'm very happy with the power.

You also need really good exhaust. GM built the stock exhaust like they hated these cars. You'll pick up big time power with a good exhaust system. And I'm a firm believer that dual exhaust is still the best exhaust. But something like that is totally custom.

The carb will probably allow you to go above 5500 rpm, but not with the stock tiny cam. You'll still need more cam. However, mpg will be a few numbers lower, and you won't have quite the midrange and low end torque that the TPI will give you.

jbenge

iTrader: (2)

I'd go with a carb especially if the car isn't driven much in cold weather. TPI has its limitations....although there have been a few here who ran some awesome times with TPI like Mark Shields.
Its hard to beat a carb...its so much cheaper and easier to tune. If you have the money then go with aftermarket fuel injection and get the best of both worlds...thats what I'd like to do but just can't justify the cost.

R1UK

For the simplicity as a mechanic, i love carbs.
Ok fuel injection is great when its running fine, when its not its usually expensive.
Its been proved on most road going motorcycles that fuel economy actually suffers too, mind you if your running a 5 litre+ car, economy wasnt the first thought was it.

crazy3rdgen

iTrader: (1)

hey ray87, do you clear the stock hood?

Ray87Z

Yeah it fit under the stock Z28 hood (performer RPM intake, holley 750) with a drop base aircleaner setup (something like a 1.5" drop, not sure just a generic drop base), 14x3 inch filter. Looked like the wingnut would rub the underside of the hood just barely judging by a rub mark, but zero problems.

crazy3rdgen

iTrader: (1)

awsome thanks, later

five7kid

iTrader: (14)

For a regularly street driven vehicle, the lowest long-term cost, including operating cost, is most likely going to be running what you've got. Switching from carb to EFI is going to take a long time to break even with improved fuel economy. Switching from EFI to carb for power is going to reduce economy, and if those funds had been spent on improving the EFI for power instead, most likely economy will not be negatively affected.

So, I say, "Run what ya brung."

355gta

Thanks for all the replies.

Rockin-Iroc

Oops, I replied to this topic but hit the post new topic button.
You'll find my response on "I saw a big improvement in mpg".
Sorry for the mistake.

Maybe someone will think I'm dyslexic...

iroczracer07

iTrader: (2)

I thought he was running T.P.I.

I would get the Super Ram kit from Accel if you go fuel injected. I've seen too many people having problems with the Stealth Ram. Not saying it sucks, but the Super Ram will bolt up without any problems and deliver great horsepower and a wider Torque curve. The problem with Carb's is that you can only tune so much and still might not have the fuel adjustments where you want them. This is what F.I. solves. You get more control and better Torque than you're likely to get with a Carb. Torque is what pins you in the seat and makes your eyes light up. Carb's on the other hand, will deliver more Horsepower than F.I. horsepower is what gets those high M.P.H. trap speeds at the strip. Carb's are also cheaper which is quite a feather in their cap. This post so far isn't really saying anything different though. So I'm gonna go out on a limb now and wait to be lynched for saying the following:

If you choose a good cylinder head then the decision of whether or not to go with a F.I., manifold design, and to some degree Camshaft selction, isn't gonna mean ****! While it's true that you should try to match the components as close as possible, it all comes down to one thing. You can have the best Cam, the best Intake, the best Carb or F.I. unit out there, but if the heads don't flow well your car won't make any real power. The heads are the key to power.

That being said, I say go with whatever your wallet tells you after you get a damn good set of heads. After those heads are in your possession, the rest will fall into place rather nicely.

Rockin-Iroc

I've read hot rod articles comparing carbs to EFI on a dyno, and the peak horsepower and torque doesn't change a bit. That's because carbs are built to run efficiently at full power, and that's where they're optimized. That is why hard core drag racers still use carburetors on their race cars. Because for a lot less money, they can run just as hard.

It's part throttle operation where EFI makes so much sense in a street car. The Edelbrock carb is admittedly better at part throttle economy than a Holley, but Holleys have a reputation for making better full throttle power. However, Barry Grant's Demon line of carburetors have so many adjustments that Holleys don't always have, that if you know what you're doing, you can adjust the air bleeds and everything else to make even part throttle operation more efficient. But not everybody has a dyno at their disposal, and that can't compare to the convenience of EFI in that way either.

The tuned port can be made to perform better on a budget. It just requires better heads, better cam and better exhaust, and then some strategic porting within the upper and lower plenum...or the larger runners, upper and lower plenum, and 52mm TB (but that's more expensive). You can push 5500 rpm with the right combination of parts on a tuned port and still be the torque of the town. Oftentimes, that's cheaper than buying a different type of EFI. Still won't make as much peak hp, but it will probably always out-torque everything else.

iroczracer07

iTrader: (2)

Rockin-Iroc makes a few good points, but I have to disagree with a few things. The intake for the T.P.I. cars, even the 350, is designed for the 305. The heads on the L-98 actually aren't that bad. The intake is the biggest killer on the T.P.I. motor. The other thing I want to say is that, not all hardcore drag racers want to use the Carb still. Warren Johnson has been fighting for F.I. in N.H.R.A. competition for a few years now. Not trying to give the **** burners a good name, but they have been making regular trips into the 7's with F.I. for a while now. F.A.S.T. also has a new controller for F.I. models. Granted, it costs a lot, but check out what you get in return.
http://www.fuelairspark.com/Articles...ID=-1363641029
That being said, I still say the heads are the most important part. After you buy them,let the money left over decide which way you intend to go. Just don't fall prey to the "bigger is better" concept.