i was just wondering, why anyone should go from a TPI to Carburator? what are the benefits?

in other words im a total idiot with cars, so could somebody explain that to me.

thank you..

Avdo

 

Well..lets see what I can come up with off the top of my head..

1. TPI has a very limited airflow potential, even with all aftermarket parts, due to it's absurdly long and reletivly narrow runners.
2. TPI is ridicuously expensive to buy aftermarket parts for.
3. TPI doesn't respond well to engine modifications. Reletivly minor changes require new programming and/or injectors, also expensive and very tedious to get right.
4. The stock ECM (especially MAF cars) has rather short limits oo how far out of stock parameters it can be programmed. Makes getting anything more than a mild motor to run right more or less impossible no matter how long you tune it.
5. Even if you can live with/get past all the above, there still isn't any advantage in the end. Maybe a slight edge in reliability and mileage edge...but both of those are still quite debatable and dependant on the person doing both setups.

I can think of a few more piddly plusses/minuses...but thats the big brick wall stuff.

 

Besides the Luddite thrill of fighting the needless complexity of ECM and TPI, there's the satisfaction of having a car you can work on and understand.

AND, if you ever breakdown in Armpit, Arkansas, and Bubba's Garage is the only game in town, he's more likely to fix your carburated Camaro that that thar Fool In-jected Far-Burd!

 

I converted to carb as a temporary way of being able to easily build up my motor. With tuned port it took forever to get stuff done. Now I can have everything off the top end of my car in a half hour taking my time. Once I meet my goals and have a solid running car I'm going to go back to fuel injection using a Miniram or something similar.

 

I am going with Jester. It is so much cheaper, and much easier to work on for me. Anyone want a TPI?

 

I'm with 88IROC on this one. I converted for easier tuning and of course more power. But I must say driveability, gas mileage, cold starts are definetly worse then TPI. So as soon as I can, I will put a miniram on it

p.s. Learnign how to tune and work on carburetors is definetly an invaluable lesson though.

 

the most common reason to switch is you dont have to change the the prom whenyou upgrade,you just have to tune up the jets usually.Also,you dont have to worry about that closed loop/open loop crap when you change the thermostat,or want to change anything for that fact..Carbs are all mechanical and you dont have to worry about a computer to mess up,i think carbs are great for almost any application,and they are a lot cheaper to replace and have a lot more available parts for them too- my 2 cents anyways.

 

I couldn't get my car to run for crap with the tpi unit on and I expect to have it running decent the first time I fire it up with the carb setup. I have a nightmare computer problem along with other problems that make putting the tpi unit back on it pretty impossiable without putting in a new wiring harness in and tralilering the car to ed wright for the first fireup with tpi. I might have to change the jets and make some adjustments to the carb to get it running right but what is that compared to having the nightmare of running tpi.

Plus I haven't ever messed with a carbed car too much so I expect it to be a learning prosess that I am looking forward to.

 

A TPI gives a big increase in midrange torque,, a bell shape torque curve, due to the long runners. In stock form it does run out of air pretty fast,, especially on 350s. However, the TPI and the increase in midrange power is what allowed the long block of 350 TPI to be able to dip in the 13 second zone with some relatively minor mods. Once you start modifying the engine,, especially when you add better flowing heads,, the benefit of the TPI starts becoming a henderence unless you spend more than a few bucks on air flow upgrades. Just about any decent heads will need either a ported stock base or an aftermarket base with a decent set of runners. If you can't do your own porting on the base,, then you're looking at $375 bucks for the intake,, and at least $200 on a set of SLP runners if you're lucky enough to find them on sale. Then,, you either have to plan the system within the stock PROM's parameters (which is greater than most people think),, or be willing to invest the money and time to burn your own chips (which is not that bad). Anyway,, if you're stock or close to stock,,, a carb set up will not come close to the midrange power a good "long runner" fuel injection system will deliver,,, if it's working properly after all these years. I personally like a modified TPI on 350's with moderate power levels (up to 400 "dyno" horses). I've run mid 12's (TH350, 3.23 gears, 2200 stall) with a custom length TPI system with a fairly mild 350. I mention it only because this same engine combination would be slower with a carb (I've built a number of similar combinations). I'd need to add a higher stall converter and more gear to run close to the same times. Now,, it might not sound like it,,, but I do like the carbs,, especially on larger engines (383 - 447) where you start having trouble hooking the power without aide from tuned runner lengths. Plus,, the short runner single plane intake systems needed to feed more air and generate more and higher RPM power,, MPFI vs Carb,, if not for the benefit of electronic timing the EFI has over most carbed sytems (some carb systems utilize computer timing),,, the carb system can generate every bit if not more power than EFI due to the cooling effect the fuel has on the air charge. The advantages for either under WOT are minimal when the same type intake system is used making the carb the hands down winner in performance per dollar on higher level horsepower applications. However,, most of us are not in WOT all the time,, and while there is not that much of a benefit for EFI over a dead on tune on a good annular discharge carb with an electric choke (set right),, it is there,,, just not sure if it's worth the cash though!!

So,, long story short which is best for you depends on your needs, funding, and application.