dantheman1998

IN Thoery cant you use a fogger on a TBI engine and not have to worry about the injectors? so you wouldnt have to worry about the 330 HP limit on the TBI?

25THRSS

What is this mysterious 330 hp limit you keep mentioning?

dantheman1998

I dont know...I remember reading it on this site....will the setup work is the question

25THRSS

You could use a carb intake manifold with an adaptor plate and put the carb nitrous plate between the manifold and the adaptor. I'm pretty sure it would work.

dantheman1998

I was thinking about that... I gues that would work but the bit would cover %50 of the plate nitrous sinces it for a 4 barrel. I am not sure if this is a bad thing or not?

25THRSS

i don't completely understand what you meant by the bit. can you explain a little further?

onebadwagon

tbi is stupid.



adam

25THRSS

nice way to show your ignorance :lala:

onebadwagon

im not ignorant, you tool.

TBI is probably the worst FI system for performance, hell, tpi isnt great either in its stock form, but at least the problems with the tpi is the intake.

the problem with TBI is poor fuel delivery, choking the engine for air, etc.

if you think TBI is not a stupid device for performance, then you are a fool.


adam

YenkoZ28

Yes you are correct in stock form a TBI doesn't produce much power why? Small heads, low compression, restrictive throttle body, small cam to name a few. But guess what my 350 LM1 that was stock in my 78 Z28 was low on performance too. Basically for all the same reasons, do I draw the conclusion that carbs suck because of that. No I didn't I raised the compression, threw some performer RPM heads on, installed a comp cams extreme energy cam, RPM intake, demon 650, and a set of headers and wow it produces power now. Apply those same things to a factory TBI motor and you'll have some power. The method of fuel delivery isn't the problem its' the air restrictions that are.

dantheman1998

What i ment is that the 4 barrel NOS would go on the manifold and the adapter on top. The adapter is covering 1/2 of the injecter plate while the other half is over the tbi.. I may be wrong in that the adapter covers all 4 barral holes and doesnt cover the plat at all. I am not sure

onebadwagon

and how do you UN manufacture a built in screw up? the throttle body is a horrible design with the injectors 1/8 of an inch out of the venturi.

its a horrible design, quadrajets are great carbs, you could put one on a built motor and make more than 400rw with it. can you do that with stock TBI???

can you do that with any TBI???


adam

Nick89TA

nope :lala:

YenkoZ28

As for the stock TBI no they won't produce 400 hp. But don't compare a 2bbl to a 4bbl. A rochester 2bbl won't produce 400 hp either. Go here for 4bbl throttle bodies
http://www.holley.com/HiOctn/ProdLin...TB/C950TB.html

dantheman1998

How about using two TBI'S or a 454 TBI or 2 454 TBIs? or one of those 900 cfm tbi'S? has anybody done any of these?

Please dont waste my time bashing the TBI. I dont really care I just want to make what i got work. Go complain to someone who cares

B4Ctom1

I think a setup like turbocity.com has can make it work. you figure two TBI units flowing around 400 to 500 CFM each could be real nice using carb plate adapters and a dual quad manifold.

onebadwagon

or you could put carbs on it and go faster.

neat-o huh?

the only fuel injection i would ever EVER consider, would be a multiport EFI, 1 injector per cylinder or bust.


those systems wont give you the adjustability or precision of a multiport system.

oh, and yeah, its a huge waste of money


adam

25THRSS

and you could ruin all the advantages you have with fuel injection

neat-o huh?

TBI isnt as bad as you think. It can be made to perform just like every other form of fuel delivery, it is just sad that it gets such a bad rap because it happened to be put on top of such lame engines.

onebadwagon

it gets a bad rap because it sucks, what successfully fast cars use it?

people have gone fast through draw through carb turbo, blowthrough carb turbo, multiport efi, mechanical fuel injection, diesel, and various other fuel delivery methods, but it just isnt practical to hang big *** injectors in the middle of the venturi, its a DESIGN FLAW!!!

simple fact is that it sucks, and is NO better than a carburetor in any way, and in MORE ways than one, it is far inferior.


adam

25THRSS

Do you have a carb?

onebadwagon

yes, but i also have a fuel injected vehicle, and i happen to have helped build more than a couple fast carb'ed and FI vehicles, and some injection systems are good, (i hate to admit that, due to being a cheap bastard) but the TBI systems are NOT.


adam

25THRSS

I doubt you have ever had a tbi car before and know nothing about them obviously. There are plenty of fast tbi cars. I even believe there is someone on this board running a holley projection tbi with a supercharger making massive amounts of power. There is currently 1 carbed car, 1 tbi car, and 3 mpfi cars in my family right now. TBI kicks the carbs *** in every catigory.

onebadwagon

you are a fool, im sorry to tell you that, TBI is not superior, and i was talking about CHEVY TBI, and how much is that guy making? either way, i stand by my point, TBI having the injectors in the throttle body is a step away from junk

carb, when well tuned, can have equal driveability, fuel mileage, etc.
but when it comes time for repair, there is no wonder what does this code mean, no worries about intake manifolds, no ecm problems, more horsepower, more choices at cheaper prices, easy parts availability, tuneable with a screwdriver, easy to repair on the road when necessary.


im through with this discussion, i say something technical, you say, NUH UH, this guy had some aftermarket tbi, it rocked WHOO WHOO!

what is that? can you not form any basis for your beliefs/ opinions, besides the fact that you own one, and so does your mom, brother, uncle, cousin, neighbor from down the way, dog, cat and mailman?


adam

25THRSS

Aftermarket or not, it's still tbi. All of the carbs you were refering too that were so great were aftermarket as well. Everything you mentioned about being carb's advantage is its downfall. The computer only helps diagnose problems. Instead of guessing, you now have something telling you exactly what the problem is. Instead of guessing on the tune, you now have a computer that will not only correct for the perfect air:fuel ratio, but will tell you exactly what the engine is doing at any given time so you can fine tune it. Face it, carb is outdated, old, a thing of the past. Fuel injection is here to stay.

onebadwagon

yeah, but not TBI, tbi is crap, nobody produces a high performance TBI system from the factory.

oh, so being easy to tune and diagnose is a downfall?

the engine tells you what it needs,so you need a vaccuum gauge and an assortment of jets, as opposed to having a chip burned then reburned then changing maf's and then reburning the chip, and changing sensors, etc.

you are an idiot, FYI!

im through with this, continue this discussion with a tree.

i listed the Quadrajet as the carb i was talking about, widely considered the worst carb in america, compared to your beloved TBI.

adam

25THRSS

ok, then why does the L03, which is tbi, and has the worst flowing set of heads ever put on a sbc produce more horsepower and torque than the LG4, which is carbed? Both 305's, both have almost identical exhaust and intake, both have the peanut cam, oth have the same timing, and the L03 has worse heads, yet the tbi engine produces more hp and torque.

onebadwagon

give me the cam specs, and i will tell you why, plus its common knowledge that the early cars had smaller exhaust than the FI cars.

adam

25THRSS

No, actually the non g92 305's all had the same size exhaust and manifolds. All 2 1/4 inches. The cam specs on the L03 are .350/.384 and the LG4 is the same as well. The highest hp for the carbed LG4 in 1987 which had a roller cam and 9.3 compression ratio produced 170 hp and 250 tq. The L03, which is tbi, had the same exact everything, and produced 170 hp and 255 tq.

onebadwagon

you gotta be kidding me, youre complaining/bitching/moaning over 5lb ft?

get a real comparison, it could have been a more agressive timing curve, the cam could be advanced in the later models etc.

5lb ft is nothing to worry about.


adam

25THRSS

No, I was trying to be fair so I picked out the highest hp carbed LG4 which is comparable to the tbi engine, and the tbi actually had worse flowing heads than the LG4. Both engines were nearly identical in all ways with the tbi car having worse flowing heads and still producing the same hp and more torque. Both had the same exhaust, cam, timing, compression, and the tbi had the worse flowing heads and produced identical hp and more torque. Happy?

onebadwagon

nope, however i would like to find the specs on head flow/ cam timing that you have.

im not going to take your word for it, and didnt i start this out by saying FOR HIGH PERFORMANCE USE?


the factory can still put more ignition timing in it, play with advance mechanisms, all sorts of things, that they didnt bother doing.


adam

25THRSS

Yes your right, but whatever you do to make more hp with the carbed car you can do to the tbi car. You don't have to take my word for it, but everything I posted was the truth. I don't have flow data from the LG4 heads, but they have the same valve sizes and are iron just like the L03 heads, but the L03 heads have the swirl cast into them effectively blocking almost half the flow. I'm pretty sure everyone else will agree with me when I say the tbi heads were the worst heads ever put on a third gen or pretty much any v8 for that matter, lol.

onebadwagon

but its quite possible that at the low lifts that the heads operate at, that swirl increases port efficiency, and that could NO DOUBT create 5lb ft, especially at the rpm's these cars operate at.


what youre not understanding is that, for less money, you can go faster, and if youre not a moron, you can tune it just as well with a carb.

sounds better to me!

this is going around in circles, my point is made.


adam

25THRSS

I didn't start the arguement, you did. You came on here with your response about putting a fogger plate on tbi as being, "tbi is stupid." Real cool there and tech related. If you like carb so much stick with it. If you have tbi stick with it. Pretty much whichever one came on your car you should stick with because it will be cheaper. Also, any time you increase the flow you will pick up torque and hp. The swirl port heads are crap, and so are the LG4 heads, but the tbi heads happen to be even crappier, lol, yet the tbi doesnt lose hp, and actually has more torque. Funny thing how tbi is "stupid" isnt it?

onebadwagon

dude, TBI is crap, it is simple, you are justifying why its not crap on your whole standpoint being that it has 5lb ft over a carb STOCK.

not like you couldnt tune the carb, and get 5 lb ft.

you just dont understand how much cheaper it would be to go fast, keep driveability, even passing emissions is easier with a carb.

dude, forget it, you keep on enjoying that TBI, but dont wonder why you keep seeing carb'd vehicles taillights.


adam

25THRSS

Not like you couldn't tune the tbi either, not to mention do the free untimate tbi mods and pick up free flow that way. If you think hooking a computer up to a car and easily reading what it tells you the motor is doing is hard then damn man, you really should stick with turning a screw and guessing. Also, I don't believe I'll be seeing many carbed cars taillights unless they have over 550 hp.

firedawg225

just to let you guys know. Holley originally designed the TBI unit for GM but then GM ran with the idea and hired another compnay. Thats why the holley and gm tbi parts are interchangable. Just thought i'd throw that in there.

raggedout91RS

Adam, you are a dipsh*t. Everyone knows that TBI is'nt the best form of FI, but there is room for improvement. I have a carbed SB that runs fairly quick and I also have my TBI '91. Yes, the carbed motor is faster but that does'nt mean TBI sucks. Some people just cant simply throw on a carb for performance cuz of things like EPA and such. I myself like carb better cuz to me it seems easier to tune but you cant beat FI for reliability and drivability. Why dont you quit being a moron and stop arguing about it. Is your life that boring?

JoBy

Just a little side note ...

Guess what type of fuel injection Ferarri is using on their F1 racing engines ?

Yup. TBI, Trottle Body Injection.

They don't use GM parts but still ... It can't be all bad ...

25THRSS

I agree tbi isnt bad at all. It's actually quite reliable and is capable of being a descent form of injection for performance, but I highly doubt the F1 teams are using it. With all their technology I would almost say 100% certain that they are using some type of system with atleast 1 injector per cylinder.

JoBy

I have seen pictures of it.

Yes, they use one injector per cylinder but it is mounted before the throttle plate ( also one per cylinder ). It is still TBI.

25THRSS

ah ok, now i see. so basically they have 10 single tbi's?

B4Ctom1

does it really matter if the injector is in the way if the total CFM is 800 to 1000 CFM like in the case of the twin 2bbl TBI unit set up? think about what Im asking here...

JoBy

Yes

JoBy

This is pictures of the TBI Ferarri F1 engines.

The lower one is a newer spec than the upper one (the lower one has the high exhaust, it's a 2001 spec engine)

25THRSS

Thats awesome man, thanks for the pics! I've always said all along that the tbi isnt what holds the L03 back, it's the L03 that holds the L03 back, lol.

JoBy

If the fuel comes from a carb, TBI or MPFI does not matter it is the quality and amout of air/fuel mixture entering the cylinder that is important.

Carb and TBI are both a wet flow design so that is not an issue.

Take ANY carb with XX flow-rate.
Take a TBI with the same XX flow-rate and you will be able to match the performance of the carb only with better part throttle performance. You are free to do a lot more with computer control as you can decide how much fuel and timing the engine will have in every operating point.

Tuning an engines timing mecanically with vacuum, weights and springs will NEVER give you the same freedom as computer control.

Same with fuel delivery. With a carb you have a few jets and pumps to work with. With computer control you have hundreds that you can adjust any way you want. You can also do the tuning without buying new jets ans springs to get it right.

It is a bigger step from carb to TBI than from TBI to MPFI.

A carb with more CFM will be support more power than a TBI with less. It works the just the same the other way around too. A TBI with more CFM will support more power than a carb with less.

Twin_Turbo

iTrader: (25)

Do not forget that on the F1 engine the runner is EXTREMELY short. Also notice that the TB bore is higher on the newer spec engine (or the injector down into the bore). There's nu use in having a port injector here, this type of induction with the conical spray pattern gives a more uniform fuel pattern over the runner. It's in fact placing the injector dead smack in the middle of the flow. The airfilter box goes on top of the injector/throttle base you see. Also, the newer spec engines has better streamlined components for more consistent airflow.

onebadwagon

did i not say that it was impossible to go fast with TBI? NO.

i said you couldnt do it easily with GM TBI.

the ferrarri stuff is a whole different game, using ONE PER CYLINDER INJECTORS, or MULITPORT, idiot.

b4ctom, you have finally dignified this thread with intelligence, (yes i know the irony of what i just said)
cfm = cfm, if you could get 1000 cfm through a soda can with a window screen and a water hose of gas, you would still flow 1000 cfm, but the fuel atomization isnt as good as the MPFI setup.

i actually have a sneaky feeling that those throttle bodies are rated before the injector is put into the bores, based on venturi size.

where did i say NO TBI can make power, we are talking GM issue here.


adam

25THRSS

Infact you did say it was impossible to go fast with tbi. And yes I agree that the ferrari stuff is completely different, but they do not use MPFI, they use sequential fuel injection, "idiot." Whats with all the name calling? You mad that your arguement that tbi is so bad has been proven wrong? The GM and holly tbi's are flowed with the injectors in place. It reallty matters little anyways because they are not placed directly into the bore, like you say, but actually ontop. Turbo city, which is the leading company in modifying the stock GM tbi system, claims the stock unaltered GM small bore tbi flows 520 cfm WITH THE INJECTORS IN PLACE. Their modified small bore unit flows 590 cfm. The holley tbi unit, with the big bores flows 670 tbi. Holley also sells a 4 barrel tbi that flows 950 cfm. I am not saying that a direct port system wouldn't be better, I am simply saying that tbi isn't as horrible as people make it out to be. The common misconception is that the tbi is what holds the L03 back, it isn't. I hear all the time people with the L03 engines say "man if I had tpi or a carb I would be so much faster." No, if they had better heads and cam they would be so much faster.