graphicideas1

Will just switching to a carb set up help with performance vs. tpi?

contact

carb lets you use any intake manifold
you want.

graphicideas1

but will switching out preform the tpi on a stock motor?

TRSCobra

It might help over 4500 rpm. But driveability and gas mileage will suffer.

Tobias05

what kind of setup you running now?

I'm going to assume, you have a 305/350TPI as of right now and if everything is in proper working order, its probably not the induction system holding it back...

...I'll talk about an LG4, because I'm not too familiar w/ TPI, never owned one. But I know you want to replace the "weak" links before you start making drastic changes. For example, in an LG4, the cam, heads, and exhaust are your first limiting factors for performance, so ripping out all the electronics and going non-cc would just be wasting money. You're getting rid of the parts that are not holding back performance.

If you don't have a full exhaust system, something like 2055's and a 3" mandrel catback, that'd be worth prolly 40 horses in itself. Pulling emissions items aren't going to make a night or day difference either. A computer friendly cam offered by comp cams would wake things up too, assuming you're stock.

Looking back, i would have kept my all my computer controlled equipment, but that's my bust.

That's just looking at the horsepower end. You need traction to cut ET's. I ran a 97mph 1/4 my second time out, and was spinning rubber prolly through the first 400 ft.

It takes a whole, matched "package" to go fast.

84z28350

A properly tuned EFI will definately see gains over even a tuned carb. Though one problem with a TPI setup is that it cannot breathe too well so you wont be making much power up top.


EFI= sit in car and tinker on laptop for hours on end to get the tune right, but you dont have to get your hands dirty.

Carb= pull apart, replace parts, test and repeat cycle endless times till its dialed in

Chickenman35

You can extract the same horsepower, with carb and manifold than with TPI... for about 1\4 to 1\5th the price.

For a max effort FI motor the TPI system is not adequate. You have to go to a Aftermarket System such as an Stealth Ram ( Excellant choice ) or Super Ram. Then add up all the cost of bigger injectors and fuel pumps, Fuel Rails ....possibly the computer ( though if you have a burner you can unlock some fine sub systems in GM's factory computer ). This all adds up to mucho, mucho money in a hurry.

On a stout 350 , a good combo of parts would be a Holley 750HP series DP on a Edelbrock Performer Air Gap and a regulator or mechanical fuel pump. Total cost about $1000 cdn ( or less ) for brand new pieces.

To equal this combo you would have to spend $4,000 to $5,000cdn for a good FI setup. I know. I've just had two competitors try it.

My combo is very similiar to this. My car puts out 350hp and 370ft\lbs of torque....to the rear wheels. Cam is quite mild. Car is perfectly street driveable, will easily pass emissions ( with Cat connected ) and get 22 mpg ( or better ) on the highway. Car will pull from idle to 7,000 rpm...although power drops off around 6,400 ( mild cam ). Mind you my carb also has Annular boosters and a Weber Power Plate....put it's value at about $1,000 new.

If you already have TPI, and just want a mild performance increase....then IMHO, stick with your TPI. Especially on a 305 motor.

Building a 350 and\or want more RPM potential ( 6,000 RPM plus )? Then be prepared to spent a LOT of money on a Fuel injection syytem or switch to a carb. Just my .02c .

Chickenman35

On a stock motor....definately NO!! A built up 350 ( or bigger ), as I mentioned, is a different animal. But with a stock to mild 305 definately stick to the FI setup.

Even on a mild 305 a TPI system can be made to work, very very well. Especially if you learn the inner secrets of Factory GM computers and learn how to burn chips. Chcek out the Chp burning boards. Discover the wonderfull " hidden" fuel curves that GM never activated. Like the Highway cruise curve that can bump fuel economy on the Highway by over 10%. GM put the code in there....but never activated it because it would not pass the 50,000 mile EPA test. Engine runs super lean at cruise ( Karl Hunter gets nearly 35 mpg on the highway on his stock 305 with 3.45 gears ) with no driveabilty issues.

Why didn't GM develop this code more? Because engine was so borderline lean, that spark plugs would not last 50,000 miles during the EPA test, unless GM put in High Dollar Platinum plugs. $2 more per plug ( at GM's cost ) x 8 x a production run of say, one million vehicles = $16 million ....and the bean counters just ain't gonna go for it.

Gas was a lot cheaper in the early 90's as well....so GM saw no point in further developing the code. Financially to them, it didn't add up.

But the code is in there.... ya just gotta get freindly with Laptops and computer burning programs. So TPI wins in the stock or nearly stock engine scenario.

Me I prefer the old school, dirty hands....and I can fix a stuck N&S on my Holley with a big rock.