I was just curious as to which one everyone pretty much prefered over the other....or is it like a 50/50. Ones got more HP and TQ at certain RPMs then the others?

 

i would say TPI cuz i really dont like TBI and i don't think i would want to own a crossfire cuz i have heard that it's hard to come by parts for them. My friend had a 82 camaro with crossfire and he had trouble getting parts for it, but it was pretty fast.

 

Odd board for this.

TPI and carb are nice.

Each has their strenghts and weaknesses.

Carb- won't be choked to low rpm breathing like TPI, cheap
TPI- good mpg

that's my input.

 

yeah thats what i heard as well.....that they didnt make a whole lot of the crossfire's for the 3rd gen camaros and firebirds....they pretty much stuck with it for the vette...i believe 84-85. i could be wrong though.

 

yeah sorry bout that mark......posted it before i had a chance to remember i was still in the appearance section...not the tech. Sorrys.

 

no need to apologize to me,

Just lettin ya konw, not a biggie.

 

If I had my choice, I'd go with TPI....definitly more hp.....if reliability is your goal instead of stomping fast. TBI. The TBI LO3 in my opinion is one of the most reliable mounts available, but the TPI's are not far behind.

 

i am inpressed with my TBI and that is why I am staying with it and going with a new vortec and 670 TBI. My bro has TPI and it seems like he has more problems and it cost a lot more.
but he does have a full second on me!! but he has more mods.

 

carbed! computers suck!

 

I'd beg to differ there. TPI is a restriction at higher rpms, where as carbs aren't.

 

TPI is the better setup.

TPI=Incredible Torque, good HP, good MPG, and reliability.

 

Yea I wanted a TPI car so bad, but it looks like im going to have to buy a TBI for now ( going to look at it tomorrow, its a 92 firebird with t tops, GTA's, 5 speed and 305 TBI) very hard to find a 92 trans am with t tops around here 2 hard top 350's but I want t tops, I just have to have them. I love T's and its California here, lots of verts.

 

TPI

-LJ

 

only had three 350 tpi thirdgen's.

 

Ill never run a carb...

ive had TPI and TBI, and ill never buy a car with TBI again...

 

carb all the way

I'd like to get involved with TPI, i know all the principles, but not as well as a carb.



TBI can go to hell as far as i'm concerned!!!!! LOL tbi is good for reliability, but i'm not impressed at all by the perf

 

Mark, I was just basically refering to injected cars alone. TPI is the type injection to have VS TBI or Crossfire. You are ever so correct in what you said though.

 

Oh ok, I still don't see how people can pick TPI, if they really want 1/4 performance, then again, I guess slappin on some boost would be a great help


Still though, if you wanna run a big cam, the TPI is gonna choke it, right?

 

TBI-all the advantages of computerized fuel injection with the simplicity of a carb. carb will never be as efficient because it's still drawing fuel rather than injecting it. somebody had to sick up for it....my stuffs all MPFI and LT1 though..... BUICK BUILT RACE ENGINES RULE Series 1 3800:hail: :hail: :hail: lol

 

Carb is still the best, except for aftermarket FI setups like Holley, Edelbrock, or a cool Hilborn setup. Actually the best is a blower,; either turbo or supercharger.

 

Carb and TPI engines both have their strengths and weeknesses. TPI engines produce a ton of low-end and mid-range torque (great for the street) and with the fuel economy and reliability of EFI. You throw out gas mileage with a carb but its easier to support higher horsepower with one because all you need to do is get a bigger carburetor and an intake. Just do yourself a favor and steer clear of TBI or CFI......

 

It has neither the advantages of a port injection system or the advantages of a carb system. It may be more efficient but if thats your main concern then go buy an old 3 cylinder Geo Metro.

 

Since I've owned all of them, I'll offer my opinion.

CFI - Despite what people may think, and despite what opinions people may spew out despite having actually OWNED one, the CFI set-up was actually QUITE good. For one, it offered excellent performance for the 305. MUCH better than any LG4 did. It also had the exact same computer (original ODB-1) as the TBI cars did. It was a great system, and corvettes came with it for several years. The only reason why people don't like it, is because it came to the 3rd gen during the era when cars were just starting to come with computers. If you'll remember, the first f-body to ever come with a computer was the 1981. (1980 for California). When back-yard mechanics needed to fix these, they didn't understand what MAP sensors were, or knock sensors, and they didn't care. So the rednecks would just rip it all out and stick an every-day carburetor and intake on it. The CFI flowed AWESOME. And there were (and still are) PLENTY of aftermarket parts available. You just have to know where to look. The CFI consisted of TWO Rochester TBI units. Anyone ever heard of the Pontiac Fiero? The 4 cyl engine used these same TBI units, though only one. Holley offered a PERFORMANCE intake for the CFI engine (for the Vette and 3rd gen). You can still buy this from some performance parts places. Holley ALSO offered a replacement TBI unit that increases flow by 30%. However, they only sold the TBI units specifically for the Fiero, but you can buy two of them for your 3rd gen CFI, and it's a direct swap, no modification necessary. I'd take a CFI set-up over a carb or TBI set-up anyday with the Holley package on them.


TBI - TBI is good for reliability, and top-end horsepower. Realistically, it's the same as a carburetor, but you get more reliable computer control. Your options are usually limited however as to the replacement parts for your TBI. There really isn't a good "generic" replacement for the factory TBI units in the 3rd gen. Generic as in like how you would buy an inexpensive Edelbrock 1407 carb to replace a QuadraJET. You get better response, starting, etc from a TBI over a carb.

CARB - Same as TBI, more performance options, allows better top-end than a TPI unit (in stock form). Harder to tune, but allows for more precise tuning to your application.

TPI - honestly, the best set-up a 3rd gen ever got. The most advanced, injects fuel almost directly into the cyls. The most responsive system you can get. throttle changes are instant. You get better low-end torque... etc.

 

I along with several other people have owned CFI equiped cars. First off Corvettes only came with CFI in 82 and 84 , secondly CFI didnt flow AWSOME , the flow actually was the most restictive of anything ever offered with a v8 thirdgen. The 305 cfis outperfomed the lg4's of the same years (82& 83) because they had a higher compression ratio and it got smoked by the l69. And if you knew as much as you say you do then you should know that the manifold is the major restiction of the crossfire system . With some work it can be made to flow like a STOCK tpi manifold , even then its still wet flow , but slap just about anything else in its place and you will make more power , I know I did.

 

My opinions, from what I've read and heard.. Can't beat a carb for power..they're just awesome..but gas mileage is horrible. I got a friend with an 84 T/A, HO 305... He's beat 350's in it, it's blindingly fast..(for a street car owner by an 18 year old that is!), but it guzzles gas beyond belief. Some days, his mileage is around 8 or 10 to the gallon. It's pathetic. TPI...I want a TPI motor myself for the same reasons everyone else has said.. They're ALL over the place and they make great power and torque numbers....just tricky to work on I imagine. TBI....ugh... Simple? Yes. Power? Not a chance. That's one V8 I'd avoid... Crossfire....well....let's just say I read the power numbers on it and laughed out loud.

 

The power numbers on the CFI are bad because

A) it has a low output camshaft
B) the exhaust is / was more restrictive then than the later 3rd gens were.
C) The heads were more restrictive.

I'll be the first to admit that if you took two motors (blocks and heads), and you put TPI on one, and CFI on the other (induction set-ups were STOCK) the TPI will be more powerful. But I guarantee to you that the CFI will put out more power than the TBI or a factory stock (unmodified) Rochester QuadraJET.

Just because someone may want to go with CFI, it doesn't mean that they have to stick with the LU5 engine block and heads. You could take a 350 sbc, stick a nice cam in it, and then stick the CFI on it, and it'll have oodles of power.

Todd

 

Wrong again , I switched from a fairly modded CFI system to a stock 84 l69 carb and computer and went 5 tenths quicker right off the bat and the difference at higher rpms was like going from walking through mud to ice skating. I have help convert a couple of 84 Vettes from CFI , One to TPI and one to carb and the power difference wasnt even funny. CFI has a top end breathing problem and on the same engine will get royally smoked by a tuned carb setup. Get the Xram manifold or something like that then it may be decent but the stock setup from GM stinks.

 

Isn't a Crossfire Injection (don't bag on my for this comaprison ) basically a dual TBI?

 

Its two single injector Throttle bodies on a deballed , choked up , wimpified , wanna-be crossram manifold.

 

man...what do I do! My TBI is getting dissed and dissed! I want an LT1 with a six speed now.

 

Hey, it could be worse. At least it's a V8. I've got a V6 and man does that little motor show some real teeth sometimes, but it's got no bite to back it up... At least it sounds threatening with the exhaust now..people used to pay it no attention. Now I'm up to sideways glances!

 

yea, at least it's a v8....then they say, "all you pull is mid 15's???
but it does sound good

 

With the options mentioned, I don't even see why the question was ask. TBI and CFI are so inferior to TPI that they shouldn't be an option.

As far as I'm concerned, the only useful V8 thirdgen induction systems are carb and TPI.

 

tpi is the better choice, crossfire and tbi are old technology and were only around for cost issues. as for the carb vs. tpi. i'd way rather have a tpi. in stock form the electronic quadrajet and stock intake isn't going to make more power than a stock tpi set up. just like a carb and intake change, there are other intake's to be used on the tpi system like mini ram or super ram.

 

I consider upgradeability in which induction systems are worthwhile. Both carb and TPI can support good power with an intake change.

 

The first thing is to each his own I guess. Carb very simple easy to work on and will make power. Downside is economy goes out the window and you may get into legality problems living in smog areas... Tbi well..im not to keen on it for what it was built to do it does a great job..but as far as making some serious power with it..not sure. I owned a 92 rs with the 305 TBI with a 5 speed and it was a total and I mean total dog. Tpi is a nice setup for torque and horsies for the "street" fuel economy is still reasonable and for me a better choice for my Z..92 L98 to be exact...Now this debate will rage on and on and thats cool...does not really matter i guess what you have as long as you enjoy it...

 

Actually, ZIPPY, I want to make a correction to what you said.

TBI is not "old technology". Well, it might have been around for a while, but it isn't OLD as in outdated. Many cars, or.. should I say, TRUCKS.. still come with throttle body injection. A lot of the big GMC and FORD pick-ups come with TBI.

It allows for better flow than a TPI set-up, which is important for huge motors like 5.8 liter Ford pickup engines or 6.2 liters or something.

 

well ic that alot of people have there opinions.....and so illl express mine also. Ive driven a carb'd 3rd gen and didnt car for it to much.....ill stick with the tpi. Never driven a TBI yet though....

 

I thought carbs only sucked(ha ha) because of the puddling of fuel problem? and tbi really sucked because it increased this problem by now spraying the fuel right on top of the butterfly! they would start better and would change to adapt to temp changes but, that was all. a carb tuned right could blow the tbi away and give a tpi a good challange! but like I said the next day or the day after that the fuel inj car would win


TPI for the street/ carb for the track!

 

Yeah, I don't care much for the TPI setup. Sure, it flows good...but it has a few fuel injectors mounted way up in the intake so it introduces the fuel and air really early, and because it's so high up, it delivers imprecise amounts to the cylinders.. I prefer operation over simplicity...my little multiport has 1 injector per cylinder...now that's some precision fuel introduction....

 

I have owned 3 out of 4 induction setups:

92 RS TBI --> Was dead a$$ reliable and was fun to drive <-- only cause I had a T5

89 GTA 350 TPI -->> nuf said.

85 Z28 Carb -->> current car no restrictions unlimited power and potential, and oh ya easy to work on too.

My first would be Carb but only by the cheaper factor, if I could afford FI (TPI or MPFI) I would in an instant

 

I think TBI cars are known as reliable because they have no power. It's hard to break down or break parts when it doesn't move. I love thirdgens, but i love to pick on TBI RS's when i'm in my daily driver (99 grand am V6), and i haven't lost to one yet.

 

i will run that grand am with my TBI

 

i tell you i'd for sure line a grand am gt up with a stock tbi camaro any day. for a modded tbi camaro a grand am could be just as modded. as for the tbi, it is old technology and not used on the big trucks in quite a long time. chevy used the tbi on a 5.7 and 7.4 in some heavy duty models with an optional mpsfi system since they don't really need the governer as they just don't rev. your highest technology doesn't go on big trucks as gas milage and emissions isn't as big a concern. tbi was eliminated due to poor cold start emissions and lack of higher rpm performance. the more air you get through a tbi, the larger the injectors need to be. the larger the injectors are, the worse part throttle performance gets. anyone who has ran some real performance will tell you that carbs aren't that easy. when the weather changes your rejetting to get it right and a tpi will self adjust for the most part.

 

If what I've heard is correct, and someone please correct me if I'm wrong. The TBI gets a bad rap because it's on the L03 RS 305. It's not so much the TBI's fault that the car runs like a dog. It's the heads on the engine that drag it down so much. In my opinion, the TBI is a pretty good system and with a little work to the engine, you can have a decent running car.

 

Sorry dude, TBI hasn't been used on a GM vehicle since 1995. OBDII pushed them out.

And i'll say this: I like TBI. Simple, cheap, reliable. Exactly what 90% of most car owners want. It may not appeal to the performance crowd but who cares........TBI is good $hit.

 

I used to believe in TBI too because i was a total efi bigot and hated carbs. The whole "oh the TBI came with crappy heads, cam, intake, and exhaust" excuse holds water like a barrel thats been gone through a few times with a 12-guage. It wasn't a situation where you had a good type of induction that was just hobbled from the factory sub-par parts working underneath it, like a peanut-cammed LG4 with a quadrajet carb. TBI's came with crappy heads and cams because TBI is an inherently flawed design, in terms of performance, that would hobble anything higher than than restrictive swirl port heads and so forth in the first place. CFI is in the same boat but to an even worse degree. And we all like to say "back it up with a timeslip". Well i can back that up with a 100 time slips right off the TBI board. Its pretty routine to see $8000+ in modifications done to some TBI car listed in a signature, and the car run's 14.9 at 89 mph because the guy has a worked motor and a drag suspension. Or you have a blown TBI that runs 15's. I mean with a respectable time like say 13.5@102, you'd be a *** on the TBI board. Take the same time over to the TPI or the Carb board, and they'd tell you to take a number. If TBI is what you have to work with and you don't feel like doing a half-assed conversion to a carb, or taking the time to convert to TPI, then you gotta do what you have to do. But don't come on this board and try to sell us the old line "TBI builds tremendous torque and higher rpm airflow", because thats BS and it produces neither. And thats a fact, not an opinion.

 

Thats a total contradiction. Just because they have used TBI on those big displacement truck motors doesn't mean it can actually flow enough for one, because it can't. . The only reason manufacturers could get away with using TBI is because those truck motors weren't moving much air with mild towing cams and small port heads anyway. By 3700 rpms, that 351 is probably experiencing a "shortness of breath", a volumetric deficeincy syndrome of sorts. And thats acceptable for a truck motor thats only supposed to produce off-idle torque, but not for anything remotely associated with performance.

 

G0d, a TBI 305 doesn't sound that much better than my little 3.1! I remember when I was originally looking for a thirdgen, I would've settled for an RS 5.0 at the time..now I know better....
Of course I'd be LUCKY to crack 15's in my sixer...that's a lot of money involved. Nitrous, rebuilt motor, 3.73/4.11 posi rear, tranny rebuild and shift kit...BLAH.. Stock is something above 17. I just want nitrous...I'd estimate low 16's with as big a shot as possible of the juice on the stock engine without blowing it.....and as much as I hate the idea of pushbutton power, it's the only way I'm gonna make this car quick with this particular engine. No worries, I'm gonna find me an IROC when I graduate and take out a student loan.

 

I have a TBI setup. I run mid 12's @ 119 MPH. I dyno around 440 RWHP.

TBI can make good power. you just need the right combo.


I also get 21 MPG.