i8urrice

i'm thinking of switching from TPI to a carburetor......want to know if it's a wise choice b/c apparently..at least from what i've seen lately, that it's easier to make a carbureted car fast than a fuel injected car...need some opinions...thanks

Karps TA

iTrader: (2)

If you're looking purely for horsepower and going fast then make the switch. IT'll be much cheaper and easier to tune and diagnose in most cases.

However if your car is a daily driver I'd stick with the FI. It typically has much better driveability, is more reliable and isn't as fickle when it come to things like changes in the weather. Learn how to burn your own PROM's and your way ahead of the game. TPI is a pretty decent starting point. If you had a TBI I'd tell you to run not walk to switching to a carb. But theres plenty of people on these boards with some very fast TPI's. Another positive is the ability to easily add a supercharger or other poweradder with ease.

johndo1707

yeah, if you want pure hp, then go carb. but if you want better gas mileage and driveabliity, stick with the tpi. i'd go carb if i had a better daily driver....lol

88IROC350TPI

I agree. I think fuel injection is better than carb in all categories except ease of tuning and cost. If you wanna go fast for cheap then go carb but don't chicken out on TPI just because you don't understand it. The only thing I miss about TPI is that the air outside really messes with my car. Somedays the air will be thick and my car will run like a dog, other days it will suck you back into the seat like nothing.

MIG-29

in my humble oppinion...
fuel injection sucks big time.
Fernando.

99Hawk120

In my humble opinion, I don't think carbs are less reliable than FI. Just different. Lots of things can go wrong with a carburetor that only cause driveability problems. With a FI car, quite a few things can go bad and leave you stranded, like a fuel pump relay, or the ECM, or a few other things.

Plus, when you DO get stuck with a FI car, you might as well call the tow truck. I've gotten stranded by my carb ONCE in all the years I've been driving--the choke plate stuck shut on my 2bbl in the Oldsmobile. I removed the choke plate with a screwdriver (I didn't have anything to wire it open with) and drove home.

FI sure does have superior year-round driveability though, and in the case of modern FI, superior mileage. (I'm not generally impressed with TPI mileage, I get better than a LOT of them with my CCC carburetor system.)

Jester

I also have to disagree with the reliability of FI. I have never been stranded by a carb problem. I also daily drove a Holley double pumper for a long time, with great reliability and drivability. I've seen many Q jets and Carters destroy otherwise similar EFI cars in the mileage department. I even changed directly from EFI to a Holley, and lost 1-2 MPG. Personally I blame that on the 30 degrees larger cam I put in at the same time.

I have never seen a dyno test that actually gave any power advantage to EFI, and dozens that gave it to carb. I did see ONE, ONCE with a top of the line all aftermarket DFI setup that came out about equal. Total cost into the carb setup: 6 or 7 hundred. Total cost of the EFI setup: 6 or 7 grand.

Trait: advantage

Power: Carb
Reliability: carb
Cost: carb
Tunability: Carb
Mileage: Draw
Cold weather starts: EFI
Adaptability to forced induction: EFI

Thats about it.

Dragula

DITCH THE TPI!
I haven't regretted my switch from TPI to carb. Car is much faster with much higher trap speeds.
(Now if I can only get more traction..... )
Anyways......carbs are reliable once they are set up right, plus they are easier.
FI=better low torque, drivability and gas mileage
Carb=more power!!!!!!!!!!
Heres my power adder formula

350ci+TPI=225hp
350ci-TPI+33ci+Holley=383ci+450hp+450lb/ft or lots of YEE HAW!

JRoy91RS

Jester is right. Pretty much the only advantadge EFI has over carb is its ability to cold start and idle consistently under a myriad of conditions. This is why most production cars are EFI. Most cars spend their lives at idle or near idle. Think about a typical commute to school or work. Of course, this is assuming that the IAC, TPS, o2 sensor, ESC module, knock sensor, IAT sensor, MAP sensor, and MAF sensor (if you have one) are working properly and don't need to be replaced, and that you have a PROM correctly burned to match your specific engine combination and driving conditions. This why I decided to change over. Many of the EFI systems themselves aren't expensive. I got my TPI system for around 500 bucks. But once I got into tuning, replacing faulty/broken/burnt out sensors, for both TPI AND TBI setups, it would've been much cheaper for me to go carb. I listed 8 sensors that deal directly with fuel injection above. The average cost of each is around 20-30 bucks. All of these sensors WILL go out during the life of your car, due to planned obsolescence. That adds up pretty quickly. With EFI, I got nickle-and-dimed to death, and I sorely regret ever having messed with it. I spent probably $1000 more dollars than I needed to. Fortunately, there is a huge demand for production EFI systems, so I was able to recoup a great deal of the money I had pissed away. What about a carb? You might have to rebuild it once every dozen years or so. You might have to replace a blown powervalve occasionally, or buy new jets, but that's it. The nice thing about carb is that everything that controls the carb is A PART OF THE CARB itself. Just my opinion after having tried TPI, TBI and carb setups. BTW, TBI was much easier to work with than TPI.

James

johnsjj2

Go carb. THe only adverse effect of switching to a carb that I have experienced is gas mileage. Other than that, run what cam you want, run what stall you want, run any heads you want. The only tool you need is a screwdriver. Much cheaper than a $1000 laptop. I love knuckle dragger technology. Its way cheaper, and still gets the job done.

JRoy91RS

Oh yeah, and don't let anyone ever tell you "It's cheaper to stick with what you already have". Yeah, right. I followed that advice and spent way too much on an EFI system that wouldn't run right. The only time that statement is ever true is if you have a carb already, especially if you plan on any serious mods (and who here doesn't?)

Another myth that EFI-er's like to perpetuate is that going carb is taking 'a step backwards' technologically speaking. I'll tell you what's backwards-- a speed density EFI system that doesn't allow you to run a decent cam without being able to sputter and cough at idle, or just look at GM's big joke--crossfire injection. If you really dissect most EFI systems, except perhaps sequential multiport systems like on the LS1, you'll find that they are very innefficient and finnicky. If you compare a carb that is made using today's technology with TBI/TPI, EFI systems that were phased out years ago, you'll find that it is going EFI that is taking a step backwards. Carbs have come a long ways. Although many designs have remained the same, the manufacturing tolerances and quality control procedures have made carbs better than ever, and have made them a more cost-effective solution to a high-performance engine than any other type of induction. Not meaning to start any fights with the EFI guys, but you are on the carb board!! If I were you, I would also ask people who had other types of induction (TBI, TPI, aftermarket systems) why they decided to stick with it, and what types of problems they run into. You'll find that the majority of them will say that their biggest obstacles are that 1)They don't have the time they would like to have to devote to making trial runs, interpreting scan tool/scanning software data, and burning proms, and
2) They don't have the money they would like to in order to buy the latest gizmo(s) that has come out on the market for their EFI system. This is especially true for TPI, whereas with TBI, it involves quite a bit of your own fabrication work.

Whew! Just my opinion, please ask those with EFI theirs, as well, so that you get a balanced opinion!

James

i8urrice

well...i had a carbureted 69 dodge charger for 4 years...again, it left me stranded only once when the transmission blew out......this car...every problem i've had is centered around the fuel injection....ECM, Mass Air...etc. etc.....now....i have a 305....does that have a possibility of being fast w/ a carb...or should i leave it as is w/ the TPI and swap out for a carbureted 350??

88IROC350TPI

Best time with stock 2.77 gears, stock manifolds, and lots of traction: 14.6 @ 92mph

Switched to carb, 3.27 gears, headers: first night out ran 14.4 @ 96mph with an out of the box Holley 750 pouring out black smoke and bogging a little off the line. Now I've done some tuning and have it almost dialed in. I'm hoping I can pull off atleast a 14.2.

I can fill my car up, drive 40 minutes away (half highway, half city) to the race track, make 4 passes, drive home and not even have wasted a 1/4 tank of gas. I think I get maybe 1-2mpg less than I did when I had TPI.

I still think, unless you are having serious problems with the TPI, keep it. Yeah maybe it is harder and more expensive but in my opinion I'd love to have a fast FI car than a fast carbed car. Its a 'hi-tech' car so maybe it should stay that way. If you decide to do it then I'd be more than happy to answer your questions about it.

88 350 tpi formula

iTrader: (9)

wow! you really think having a carb. will keep you running? tpi will just up and quit?? think again I know a lot of people with carbs and they will leave you sitting just as much. you have fuel pumps too and yes both types leave you there on the side of the road. your ign. is electric too so that doesnt help much. both run with vacume leaks tpi will run better and not starve you eng. burning valves or pistions unless you have somthing really wrong. like a bad inj. but, jets clog too. almost any sensor can go out on tpi and still get you home.

basically I would say tpi is a better system but, in the real world money matters and carb is the best bang for the buck!

dimented24x7

iTrader: (2)

carbs are definatly better than the tbi injection systems by far from a power stand point. Im not too familiar w/ the batch fire tpi setups but they do get lousy gas mileage. I hear people say that the tbi's flow as good as a carb and i cant agree less... I could swear ive seen soda straws that have larger diameters than those throttle bores.

EFI has come a long way, though. today's sequential injection systems not only give engines good fuel economy and emmisions but also enable small displacement engines to have large HP numbers that beat out our stock and even some mildly modified setups.

As far as tpi, if i had it, i would definatly put some time into it. The speed is in there, you just hafta get it out w/ some tuning and patience.

Jester

anyone who argues that TPI is better because it's better technology is out of thier minds. TPI was developed in the early 80's, and outdated by 90. If were were talking about a more capable EFI, liek say the managment used on LS1's...it might be a different argument at least.

99Hawk120

Let's argue the reliability standpoint here:

I kind of straddle the line because I still have the stock CCC system, which IMO is less reliable than a standard carb for precisely the same reason EFI is--sensors. Of course, my car wil run (if poorly) with the computer completely disconnected. No EFI carb I know will do that.

You've heard the acronym GIGO (garbage in, garbage out), I'm sure. When your sensors are on crack, the ECM might as well be. Older ECMs (like TPI) are limited in their ability to distinguished faulty sensor inputs. Bad sensor input makes the computer adjust things in completely wrong directions. Bad CTS? Guess what, your car is running in warm-up mode all the time. Bad MAF? Talk about the computer being on crack!

And those sensors are EXPENSIVE. Hell, a MAF costs more than rebuilding SEVERAL junkyard Qjets.

As far as fuel pumps, yes, carb cars have them. Most of them use mechanical pumps which are generally FAR more reliable than the electric in-tank pumps. There's no relays, no crazy ECM controls, and no real fuel pressure problems (carbs really only care about volume).

Carbs simply have less parts to fail, they're less expensive when they do fail, and most failures don't strand you on the side of the road. Not bad for knuckle dragger technology.

Now if you'll excuse me, I need to go invent fire. My cave mates are complaining about the cold winters and raw meat.

JRoy91RS

Bwaa Haa! HAA ha!:sillylol:

Oh, man, that made my day!

Big454blockchevy

I also say go with a carburetor.

MouseCamaro305

i have a fairweaher driven camaro with a demon 4-bbl. never ever had any problem with drivability issues whatsoever.

MIG-29

if your carb goes terribly wrong, you'll still get home, (like hell but still) but...
if any of those many stupid, expensive, crappy, ridicule sensors goes wrong...90% that you'll be calling the tow boys.
also in aviation, we mechanics dont like them very much (not to say WE hate them) a whole system goes nuts because a little piece of crap sensor goes wrong, now try to find it...
LONG LIVE THE OLD SCHOOL. :hail:
Fernando