alright guys, i know i asked about this before but i need some SERIOUS feedback . as much as possible PLEASE.
Alright, I am purchasing a parts camaro this week and it has a 350 TPI in it. The motor is only 5 years old, and its been sitting for 4 years, so its only been driven for a year. Should i replace my carb with the TPI or what? RIght now my current setup would be: Edelbrock Intake Manifold, Holley Street Avenger Carb (not really sure of the cfm, because it was on ther when i purchased the car.. is there anyway of finding out by something on it?), and an edelbrock air filter. Should i put the TPI on it? is it worth the work?? whats it going to do performance wise. also, if it goes to the TPI side, in the future i will be putting a stealth ram on there.

Or should i just get a better carb? please leave as much feedback as possible. I'm pretty new at the TPI thing, and my dad doesnt know much about it either because he never had a TPI car, only Carb.
FEEDBACK PLEASE!!!!

 

A carb will perform better than the tpi, but at the expense of fuel economy and driveability. If you plan to put a stealth ram on it, that will be better than the carb will. The only downfall will be how radical you want the setup to be. If you are going with a huge cam, stick with the carb because you are limited on tuning possibilities with the tpi. As for your avenger carburetor, it is prob. a 670 cfm. Pull the air cleaner off of it and look at the numbers on the front of the air horn. This is the list number and you can track it in a holley catalog.

 

I'd say get the stealth ram over the carb any day. The carb will give you more power depending on certain things (CFM, and that stuff) but the stealth ram will give you better gas mileage along with power. And seeing as all the LT1's, LT4's, and such have a form of TPI's on them, and they get some good power, i'd go with the TPI. Plus they just look cooler

 

Since you dont have any experience with TPI, I would say for you to stick with the carb. TPI (or any EFI) will just frustrate you and cause you grief until you understand how it works and how to make it work.
Good luck.

 

Hi...If you dont want to incur the expense of replacing the carb to TPI or Ram, The carb is the way to go. I changed my Fuel injection 2.8 liter to a 350 5.7 liter motor with a Edelbrock 600 cfm 4 bbl carb. What a little monster i created. Lots of work but Wow!! It paid off.

 

I like FI.

And there is no clear "better than the other." It all depends on the heads, cam, exhaust, etc.

If you're willing to learn to tune and have the ability to do so with datalogging and such then definately go with tpi. A buddy and I just finished a tpi 350 swap into a jeep cherokee and that monster hauls even without another done to the chip (stock 305 bin)

Otherwise go carb.

 

Swapping from carbed to FI is kind of a pain. As a computer engineer I like FI myself, but If I already had a carbed car (and my state had no emission inspection) I would stick to the carburator. The big advantages of fuel injection are that you are more flexible on intake manifold design and fuel is more precisely controlled across the entire throttle range increasing fuel economy and emissions control. If you don't mind having a large hood scoop, you can always buy a big intake manifold and carburator and you will do just as good or better horsepower wise as the FI guys.

 

plus the tpi will be very expensive to mod compared to the carb'd setup. for instance how much is a 52 or 58mm tbody? how about that stealth intake? now compare that to a "tuner carb" for about $500-700 for some of the best and an air gap rpm intake at $250. plus, does the car have a/c? do you want it? what about power steering? with a carb you can easily have neither or both. if you go with the fuel inj. setup, you'll need either custom access. brackets or a/c delete pulley.
and, the carb will easily outperform the tpi in the upper rpm ranges, until you get that stealth ram.
chris

 

Knowing what I know about Kevin here, I'd heed his advice. Look at swapping to TPI only if you are in it for the adacemic excercise. It's a good torque-producing system but it really doesnt perform much beyond 5000 RPM. If you are out to get a rip-snorting performance engine, stick with carb. If you try to sew a silk purse out of that sow's ear, you end up tossing out everything but the fuel rails by the time you are done. You know that already, since you mentioned the stealth ram.

That said, I just switched to electronic fuel injection for my 1984, and I absolutely LOVE it! It's plenty fun to tune with the laptop computer. I bought a TPIS Miniram and it flat-out annihilates the tires when the RPMs get up past 3000 RPM. It's totally fun and I'm now knocking down 18 MPG with my Minirammed 385. However, it came at a price (about $1800) that will never pay for itself over the life of the car. I did it purely because I wanted to learn EFI.

I suggest keeping the TPI stuff, but then save up for the fuel pump and stealth ram, pick up a used aftermarket EFI system (e.g. Accel DFI, Electromotive, FAST, Haltech E6GM, etc.) then make the changeover and skip trying to make the factory TPI work. Remember, you will most probably have to run completely new fuel lines and this isnt as easy as it seems. I had to remove my master cylinder, combo valve, and intermediate steering shaft to do it right. I also had to run new wiring to the fuel pump to correct for an insufficient ground wire. Just things to ponder,,,

 

Dan,

Your engine and attention to detail are splendid, as usual. I'm envious

 

As my Michigan locals have typed...A TPI car with modifications is either a headache or an expensive learning experience that requires a laptop and an aftermarket DFI setup.

I have ditched TPI and had Pro Systems build me a Street/Strip Holley 4150 Carb for my new combination. It will be tuned ON A DYNO WITH A WIDEBAN O2 SENSOR FOR MAXIMUM STREETABILITY AND OPTIMUM STRIP PERFORMANCE.

The LT1 AND LSx crowd definately have a better tuning capabilities with their stock ecu setups and software. Goodluck!

 

Fuel injection is really groovy, especially the kind that uses a mass air flow sensor to match the fuel delivery to the atmospheric conditions.

BUT, if you want to go to a fuel injection setup, you would be wise to simply jump into an aftermarket setup where the engineering has already been done for you.


If I were in your shoes, I think I would start with a 4-barrel intake manifold that has bosses for fuel injection rails. I would begin with a good quality carb FOR NOW, then later add an aftermarket system that utilizes a dry flow, 4 venturi throttle body and port injection.

For a carb, there are really two basic choices. Carter AFB designs and Holley designs. As a practical matter, and taking into consideration the improvements that have been made to the old designs; that means an Edelbrock or a Demon.

By the way, keeping your current carb is a perfectly reasonable option, as is keeping your current intake manifold. I'm just assuming that you MAY want to change things.

The Edelbrock is very tunable, because it uses jets AND metering rods, but that can actually get you into trouble; because it makes the carb TOO tunable.

The Demons are nice too, and tune like the classic Holley carbs. The two disadvantages there are that they aren't quite as tunable as the Edelbrocks, and the less expensive models still require you to remove the fuel bowl.

One last thing...
Go for Annular boosters because they give a better fuel pattern, especially below 2000 rpm. Just remember to go slightly bigger than you normally would, because the boosters take up more room.

Assuming you have a fairly typical mild street engine, a 750 Vacuum secondary carb is a nice size. Some folks think that's too big, but not if you tune the secondaries with the proper spring. Or at least, that's MY opinion, which is perhaps worth exactly what you paid for it.

 

Stock for Stock the LT/LS computers are vastly superior, yes. However, there are plenty of cheap DIY-style prom immitators that alllow you the same tuning ability without have to burn a chip each time. The Prominator comes to mind as a great example. Swap it in place of your stock chip, hook a cable to your laptop and change everything or anything you want to on the fly. It's amazing what technology is capable of these days. Plus it cheaper than the aftermark DFI setups.

 

How fast do you want the car to go? Daily driver or not?