Kind of a goofy ? but hear me out.

we(me and GF) have decided to start looking for a new car for her and she wants another 3rd gen firebird (hopefully TA/ GTA) something a little more valuable and in better shape. The 91 needs a good bit of bodywork and some rust repair and I figure its not worth my time and her money.

I think I would really like to find a TPI car preferably with a 350 already. The thing is I know stock tpi is pretty limited in its RPM capability and everyone goes wild changing runners and porting everything. The potential is there but arent these things just a bitch to work on? I pulled a manifold off of one on a vette a few years ago to replace leaking gaskets And it was far from an easy job.

TBI seems quite a bit simpler which sounds good to me but Im worried if it will take me where I want to go.

I want to build a strong running yet streetable 355. It will have alum L98 heads with a bit of port work done by Me. And a suitable cam. (manifold/ FI style up in the air still) It needs to be daily drivable and run 12.5-13.0 prefferably. and get close to 15 or more MPG

I had origanally just planed on going Carb, but I have a scantool and a laptop and the will to learn so I would rather learn newer technology rather than the old school carb, and again want some fuel economy.

So, would TBI Meet my needs easilly or be a stretch? or would TPI really be the best bet?

If I chose TBI Ill run it on a carb intake with an adapter.
What type of TBI Unit will I need for this goal? worked stocker, 454, Holley? What fuel injectors?

Basically, which would make my goals easiest to acheive?

 

actually now adays it doesnt matter my 91 RS has beaten TPI 305s (3 to be exact) and i got a gruge with a TPI 350 car but in my opinion and everyone does disagree a TBI car built right will get out the hole faster than the TPI cars,it really just all depends on what you prefer

 

I would search until you find a 350 TPI. I am swapping to MPFI and their seems to be many more aftermarket parts to choose from. Also with TPI their are quite a few proven mid 12s setups. With TBI I am unaware of anyone breaking into 12s NA, so you would be forging into new territory.

 

My only recommendation is not going with the L98 heads. Go with a good aftermarket head with 2.02/1.60 valves like Trick Flow 23*, Pro Action Iron/Alum Lightings or ultimately AFR's.

I'm sure the goals are possible. It's not going to be easy, but I'm sure it's obtainable.

 

A TBI car will get out of the hole faster than a TPI car? Only because the TPI car is spinning the tires from all that torque.

You really want a car with a TPI engine. The two injector setup with the TBI intake limits you to about 300 HP, not enough to run 12's in a 3500 lbs car.

You can keep the L98 heads, since you already have them its a good deal. Find a used aftermarket TPI intake or siamese port the stock one, add a decent cam, some prom tuning, and 12's are but a good 60' away.

 

Ok, you guys pretty much talked me into TPI. of course if we find a really nice TBI car (especially w/ a 350 rollerblock already, Ive got a non roller one) I probably wont pass it up, I doubt if I would do a change over to TPI but havent read into it much.

That holley stealthram looks sweet too.

Basically if theres no one in the 12s with TBI thats what will keep me away. Sure it would be cool to do stuff that no one else has but then who can I look to for advice?

Im sticking with the L98s unless I can find some badass alum heads for less than $500 that wont need to be re-done. Sure doubt that will happen.

 

oh, and Dennis, not ******* you but, "nowadays it dosnt matter" because you can keep up with other 15sec TPI 305s and 350s Dosnt cut it for me. I want to run 12s, not beat nice running slightly modified plain-jane cars. Your car seems to run good for what you have so if your happy with it Great.
But based on everyone elses replies theres an obvious difference between the 2 systems in POTENTIAL, which is what Im looking for.
Again no offense.

and Kevin91z.
are those alum, or Iron L98s? im Guessing alum since you stuck up for them. And you also TPI right? what intake parts/work do you have? Your times are about where Id like to be and your in cali so if your legal then what youve done should work slightly better for me without the cat and some extra weight.

 

just checked your site that answered my ?s. So hows the gas millage?

 

Ahem! For the record, this IS a TBI board, so if TBI was so much worse then WTF are you doing in here?? I don't mean to be a jerk or be PRO TBI, but I just hate it when people talk about stuff they don't really know what they are saying.

Now I will tell you why I don't like that statement.
I have a '92 RS 305tbi with about 78k mi on it. Last summer I dropped a valve while running 80mph. Needless to say Bye-Bye mister engine. Smashed head, piston and broke both crank & cam.

I ran a 12.8 @ 121mph at the local dragstrip here last fall.

4bolt 350 from a wrecked 94 ZR2. $500
Had it checked out and bored .030 over $80
10:1 Compression on 93 octane pump gas
Got an LT1 cam out of a wrecked 94 camaro $50
Ported and polished the stock 350 heads
3-angle valve job cut out to 202/150 valves
performer RPM intake with TBI adapter $250
454TBI unit with THE ULTIMATE TBI MODS (Junkyard item $35)
inline AFPR $60
MSD Blaster Coil, Distributor, and Rotor $200
MSD 6AL ignition box. (not sure on price anymore)
Dynomax Headers, Y-pipe, 2/1/2" exhast (cat deleted with 24" steel pipe)$300
Flowmaster 80 series $80
3.23 gears and B&M shift improver kit stage 2
extensive DIY prom tuning and custom-made Ram-Air system (a dual snorkel air cleaner with TPI ram air boxes and PVC piping)
M/T Street Slicks --> no way this thing would hook up without 'em
Strut Tower brace (prevents flexing)
Adjustible LCA's
Aftermarket Torque arm & Aluminum driveshaft


The car dyno's at 385hp
and 394ft/lbs torque
Best time 12.7@121mph (redlighted) using Cam2 gas
13.9@107 street tires (Goodyear Eagle HP's 245/50/16) & 93 pump gas

IF you don't believe me, drop me a line, I'll be at the track every friday in starting in 3 weeks. I'll be glad to prove it.


What I'm really saying is that a properly built car can achieve whatever the drivers determination and piggybank can allow. There is no real big power or driveability difference between TBI TPI its all a matter of preference. I do think that a well detailed TPI unit looks more appealing and powerfull from in under the hood, but its just opinion. TPI will usually cost more money to get parts and upgrades for. I know that someone is going to say I got mine used cheap, but you know what I mean. Also, if you do end up getting a TBI, just write me and I'll be glad to help you do whatever perversion you can dream up with it.

Good luck and happy hunting. GM POWER 4 LIFE


Also, 12's with the gas milelage your looking for in my opinion is only capable in these cars with NOS. I could be wrong but I only get 12 or so miles to the gallon and I'm barely 12's.

P.S. In the summer, this car IS my daily driver.

 

thanks for your reply 92RS.
I knew there had to be some people running some good times with modified 350/383/400s but this may as well be called the LO3 board and open another seprate one tor TBI performance.

Few ?s for ya though.

13.9 on steet tires and 12.7 on et streets. quite a gap, was this identical tune and set up (time dropped based on tires only) or did you gain some more power in between as well?

I dont know what that gas is exactly but does your car require it to run properly or is that just for an agressive track only type of tune?

and what kind of fuel milage do you get?

I think I would like to find a Car with TPI and 350 but my biggest concern should be the condition of the body. I could learn either type of injection.

Oh, and anyone know if I could use a hydraulic flat tappet cam 350 with either of these systems? I know probably not with the stock chip but do I have to have a roller cam?

 

I'm not sure about the flat tappet.

The times that I posted were the 13.9 on Street tires and pump gas 93 octane. with the same set-up as (I can't get the car to hook-up well on street tires. Too much hp not enough traction I usually smoke them off the line)

the 12.7. This was with the ET streets and on Cam2 gas. (basically 105 octane or so.)
This car with 10:1 compression will run well on 93 octane, but the extra octane in Cam2 really brings it to life.


I usually can get about 12mpg on pump gas

 

My stock 350 had hydrolic lifters, so I would think that there is a way to go flat tappet. I think roller cam is the way to go though

 

tbi has come a long way in the last few years. very soon you will be seeing several 13sec 305 tbi cars that are n/a. i am sure 12second 350 cars are not far away.
the big thing to remeber with tbi is that the only aftermarket support you really need is for throttle bodies and injectors. any good carb intake can be used with a $20 adaptor plate. there are plenty of good 454tb's and after market holley products to support serious hp, well over teh 300hp "limit" that so many people have talked about in the past.
tbi also has a lot of computer and chip development going on. faster sampling rates and wide band O2 sensors are easily obtained and all teh software you need to program with is free for downloading.

later
tim

 

I don't want to call you a liar, but these trap speeds and dyno numbers look pretty off.

12.8 @ 121 with that trap speed you should be running 11.8, unless you had like a 3s 60’.
Also you got 385rwhp with ported stock heads and an LT1 cam.
I would be surprised if those heads flowed more than 250cfm @ .500 and with a 201/208 .447/.459 @ .05 cam, I don't see 385rwhp. If that’s true, stock LT1s would put those numbers down.

But I could be wrong.

 

RSCamaroGuy92,

How did you get a 350 out of a wrecked S-10 pickup?

And if you meant Z71, then you're full of crap. Only HD 3/4 tons and 1 tons got 4 bolt blocks.

IMO, ALL your credibility just flew out the window.

 

All we need to see is a timeslip.

 

Yeah I dont know what a zr2 is so I cant ? it but what gets me is you got an engine checked out and bored .030 for $80 (good price but believable) and you didnt spend anything on new pistons,rings, and bearings? Seriously I dont care about the price list anyway but if you make a list it should make sense and be complete.

I punched the numbers on a calculator. That MPH should = 450 or so HP. And 385 HP should = 12.2 or so. Is that MPH a typo, if so It sounds pretty fair to me.

Honestly guys, everybody is too quick to call on someone else. Sure I quess people do Bs alot but I cant understand why someone would do that anyway.

whatever, we'll buy the car when we find what she and I like and Ill make it nice and fast as we can afford the time and $$$.

cant ever get a straight answer, or a qualified opinion.

 

It's because Kevin is right. If you want to build a fast car, you certainly don't look to TBI. TPI is far more efficient; it's a better fuel injectino system. TBI is what I like to think of as "Carb times 1.5".

And I don't know how the hell you trap 121 on slicks, but 107 on street tires. What does your car weigh? There are LS1s with 385 HP to the rear wheels and only trap about 119 or so in the 1/4...and slicks doesn't improve your MPH. I am calling , but who knows.

 

ok, so I didn't mention that I had the .030 pistons, bearings, crank and rings laying around for about 2 years. I don't even remember how much that they cost. That's why I left it out. Also, I had made custom fiberglass fenders, and a fiberglass hood. There are NO rear seats, just a custom-made interior. Seats were takin out and replaced with lighter imitation Sparco's.
Alot of the heavy steel pieces were changed over to aluminum and fiberglass. I am having 2.4-2.8 60's 'cause I can't get good bite. I am currently looking into getting it tubbed but money's tight right now. I know that there has to be a way to adjust the rear so that I can get better bite, but haven't found that set-up just yet. Any one else have any ideas?

Also, according to what you said about ET vs MPH. Bet you weren't counting on my weight, eh? How many people actually set thier car up to work with a power calculator? I mean really! I like to be able to drive my car on the weekends(not always at the track.)

Also, I'm sorry, I didn't mention, the motor in the truck wasn't stock. (Z71)---> this was a type-o!!!!! It was a buddy's of mine that put a 4bolt in after he ran the old motor out of oil. I never said that it was the original motor. I will look for my old time slip, but I'm sure that in three weeks I'll be able to get a better one. The local strip opens. I think that with some extra tuning, I might see 12.6-12.7's(Hopefully)

These TPI guys just find it hard to believe that what they think about OUR TBI's is So they find every type-o and harp on it. BLAH BLAH BLAH. Sorry if I hurt your pride

I just wanted to give the guy an idea of what is truely capable with a TBI opposed to what is mythodically expected.

Also, car weighs about 2873 with my @$$ in it

 

Also, if you don't get traction until the 100 ft marker, it will affect your MPH & ET. I am still not getting real good bite with the ET Streets(Not real slicks) until a little before the 60ft trap.

 

I just don't think that any 350 no matter the induction will make 385rwhp with an LT1 cam be it TBI, TPI, mini ram, stealth ram, LT1, or carb. To get a 350 to put that kind of power out NA it would have to spin to around 6000rpm, well past the power band of the LT1 cam.

 

The LT1 will make power if set up right up to 6400RPM. I have it set up to shift at 6100RPM's where'd you get your info?? Don't knock it 'til you rock it bro.

 

I'd still like to see a complete list of your set up (apologies if you already posted).

And if you're only spinning to the 100ft mark, big deal. My friend sometimes spins all the way to the 330' mark in his '01 Lightning, and he traps 112 MPH consistently. I don't see how you have a 107 trap consistently on street tires and then a magical 121 on slicks.

 

Either he's not mentioning the 150 shot of nitrous to get 121 MPH, or there was a bad timer that day at the track and it only happened once.

I get 15-17 MPG in the city and 22-25 MPG on the highway. Way better than your 12 MPG.

And yes, I have done lots of research with TBI, both on my dad's 92 RS that came with a 305 TBI, his old 81 El Camino that he converted to TBI, and a friend's 87 El Camino that was converted to a 383 TBI. After playing around with these TBI cars, there's an obvious reason why he converted the 92 to TPI, the friend's 87 383 El Camino is now a single plane MPFI, and his current 87 El Camino project is getting a TPI engine.
I do know what I'm talking about when I say they're not easy to get 12 second ET's out of. Yes there are a handful of fast ones out there, but they're the exception, not the rule. I post here to educate the new people.

Dan is asking for the easiest and most cost effective setup to get 12 second ET's. A TPI or LT1 engine would be the best choice.

 

I ran mid 13 with a cross fire, 5 years ago. In street trim, ie BFG cheapie radials, big sway bars, stiff shocks, full quiet mufflers, etc..

The street never offers the traction that the strip does. So using what you have better then the next guy goes along way in the fun department.

Sure wish I had a buck for ever 12 sec machine I dusted with a 13 sec car.

There's lots of stuff for getting a TPI to go faster with less work, but be sure to have your checking account well supplied.

 

You could always do what I did...sell the TBI car for a LS1.

 

tbi on a 350 can get into the 12's. there is plenty of fuel available to supply the 325-350hp needed to accomplish such a goal and setting up teh rest of the car woudl be as easy as any other 12 second street car. looking at each example as being optimized so that you only need the minimum of 103-104mph to scrape into teh 12's i see it something liek this:

a stock LT1 motor with all the wiring and stuff is normally a 2000-2500 operation for a 275/285 rated motor. figure once you do the littel bit of work need to get the rest of the power you need to attain 12 you are looking at prolly a 3200-3500 investment at minimum.

TPi would be a very similar situation. a stock tpi L98 is most commonly seen running low 14's on street tires( .4 to .2 most of the time here near sea level). while the engine and wiring itself will cost less, the 245hp rating is a bit further from the power you need so you will be spending a bit more on parts. overall i woudl say the TPI woudl prolly cost a few hundred bucks more in teh end than the LT1 motor.

then we come to TBI. if you want the nice easy proven formula there is always teh vortec crate motor. rated at 330hp you are already very close to the power needed for a 12second pass(prevost went 102mph on a failing fuel pump and i seem to remeber a stock LO5 timing table). the crate motor goes for about 2200. add to this a performer rpm or torker intake and an adaptor plate and you are looking at another 350-400bucks. add a holley tb and everything you need to burn your own chips and you are looking at a very similar total to teh other two options discussed here.

seems to me every platform is a reasonable option. i woudl chose the tbi to go after 12's in this case just because it is the form of injection already in teh car and woudl require the least amount of work to complete the swap since it sips having to change over wiring harnesses.

later
tim

 

the hole is getting pretty deep man. please stop digging.

 

Well, so far my motor has spun up to 6000 rpm after my swap. It seems to spin up to that mark easy and seems to have more, but I'm not sure on the 100,000 mile strength of the 305 not until a rebuild anyway, so I'll probably keep it below 6k for now.

I haven't made it to the track yet and I'm still working on tuning this thing but I ran side by side last week with my buddies 14 sec flat 95 GT. And I'm positive that with a set of 3.73 gears and no misses in the rpm band it'll be an easy 13 sec ride.

It's all about patients, that is something I've learned with tbi. It's not just going to adapt to whatever you do to it, but with proper tuning it can run like any other system out there. All my buddies are trying to tell me to switch to a carb so I can have out of the box power, but I want to stick with tbi to see what I can do with it.

Oh and NJ, I'm planning on heading to KCIR and the dyno the last weekend of march, so we can get some power numbers on the swap.

 

Well, I should have said making peak power at 6000rpm. In a 305 you should be making max hp around 5000-5300rpm. Porbably shifting at 5500. My ZZ4 camed 305 peaked around 5800rpm.

 

I'm not sure, but when you find that you're at your limit, add a second TBI on a dual carb intake. That's the essence of what the Holley DFI is all about, isn't it?

As for the LT1 cam and it's characteristics, the cam is only part of the equation. "Back in the day", as you guys say so often, there weren't a lot of cam choices to be had, since the aftermarket didn't really start to flourish until the early '70s. Flow was altered with port work and valve SIZE, not lift. We used to fit up a lot of stock Pontiac and Ford and BBC valves to help out the late-'60s SBC heads. And aftermarket heads didn't even exist (you guys have it so frickin' easy these days), so welding and grinding was about the only way to make decent heads from good factory cores. Because of the variables, a blanket statement that an "LT1 cam profile can't make power at 6,400 RPM" is as full of holes as Iraq is going to be in a few weeks. Then again, just because an engine has an LT1 cam doesn't make it an LT1, either.

Another thing to remember - there are a lot of 12-second cars that can't push it beyond 130 MPH, and a lot of 160MPH cars that can't break 14 seconds. "Performance" is all in how you measure it. If you only drive 1300' to the corner, that's great. If you want to cover 200 miles before the next guy, you're going to be hurting in that 12-second car.

 

He's not talking peak power here, that's obvious come on. That's probably peak hp ~5700 rpm, only a few hundred higher than a bone stock LT1.

 

Oh sure... Lets see. Go to http://www.f-body.org/timeslips/ and tell me how many TBI cars do you see in the 12's. Now tell me how many TPI and LT1 cars you see. Let me give you a hint, it'll take more than one hand. The numbers speak for themselves. I dont know anyone who has made the switch away from TBI and wish they hadnt.

One more thing, that 330 HP crate engine you speak of is more like 275-285 HP in the real world. Crate engines are still rated as gross horsepower, meaning the power while sitting on an engine dyno, not the net horsepower as it would be sitting in a car. (and I dont mean rear wheel horsepower either)

 

RSCamaroGuy92 is full of more **** than a broken toilet at a highway service station

 

you can locate one timeslips page from a site that has a long history of having a much greater than 50% use by 4th gen cars and you want to say that tbi can't go 12's? sounds liek you are missing the boat there buddy. when cars start in teh low 14's (L98)to mid 13's(LT1) to low 13's(LS1) you are obviously gonna see more into teh 12's.

jsut because a million people havent' done soemthig does not make it imporssible or impractical. as anyone who has studied racing to any degree knows, it usually jsut makes it overlooked.

as far as crate motors beign rated at gross power, thanks for stating the obvious. then again you may have noticed that jprevost went 102 mph with the 330hp crate already, that was with a weak chip and dying fuel pump. looks liek that motor that is rated at gross power is being turned into a rear wheel power number with the use of a well developed tbi.

i hope that everyone is paying attention this summer as new and better times start rolling in. we have learned a lot in teh last few years, now that more people are applying that knowledge you are gonna be seeing a lot of et's drop and trap speeds sky rocket.

liek i said before, any of the platforms mentioned are perfectly legit routes into teh 12's for about teh same amount of money. since tbi si the existing platform, it makes for the least amount of work/downtime to get the job done.

later
tim

 

what about you tim. IIRC you had cam/heads/intake/TBI 305. did you ever see 12s? and IIRC you had major weight loss and some pretty nice heads.

sure i think TBI can hit 12s NA. but did you "i love TBI and thats all i will ever use" people ever stop and think, why are so many people going to a carb, or a different form of fuel injection? and why is it when i go to my local track i dont see any 12 sec TBIs but i see many 12 (11, 10, etc...) sec carbed cars?

once again i am not PRO TBI or ANTI-TBI. but i have switched to carb and couldnt be happier (yeah thats right even with my not so great MPG JPrevost, lol )

 

I think we're overlooking the main issue in this thread.

RsCamaroGuy92.

Post a timeslip please.

 

whats wrong with a dual funcition discussion? yeah i would like to see a timeslip also...
cuz right now i dont believe ya

 

when i ran low 14's i had a stock cam and a stock chip in the car. both were huge problems with the combo. after a lot mroe research i realized that the greater restriction is the stock cam, not teh stock heads i replaced.
teh car also weighed in at 3400lbs when i was running in teh 14.4 to 14.2 range. i don't think that is too radicla from a car taht weighed in at 3580 with a full road racing suspension and fully optioned when i started. when i ran 14.20's the car was down to 3300lbs.
teh tech that is available for tbi has come so far since 4 or 5 years ago when i picke dthe parts and started setting up my combo. the work i did really looks siully to me know that i know i could have had better results for half teh money with intake/cam/chip instead of spending all that money on heads.
as far as people moving to other forms of induction, that is good for them. so far i have not seen anyone post a major performance gain from a straigth swap that couldn't be attained with tbi. people say they run 14.9's and 15 flat from swapping on tpi, thats great, i did it with teh ultimate tbi mods, exhaust and posi + gears(blackbird305 did it with intake, ultimate, posi and a little more gear).
carb guys post gains when they swap over. i hope they woudl pick up with an after market intake over teh stock one, especially when a larger cfm carb is added.

later
tim

 

This is the main reason his car runs 12's and has no traction, it only weighs around 2670 lbs!!! I wish my car was that light, ***, its probably like a honda civic with a V8. Im jelous. Having a 1 3/4 ton mostly stock car does nothing help ET and trap speed.

 

I recently read a article in Super Chevy or some where about a 350 TBI Camaro. The guy bought a crate 350 motor from GM and dropped in his car. He also purchased a Holley TBI from Jegs or somewhere that is intended to be used on 88-95 350 chevy trucks. All he said he needed was the ecm out of the 88 chevy truck to make the whole thing work. I am assuming that you can make some power out of if you want. I was considering doing something similar. I want to build out a 355 and order after market TBI and intake. After that I was wanting to put on a Procharger supercharger that they sell for that year truck. Goodluck with the swap

 

Damnit Kevin, why do you always mix up L03 with TBI and vice versa? It isn't THAT hard to remember is it? Oh yeah, and I think you're "research" on TBI must have been an hour looking at some old posts from Pablo when he was dumb along with the rest of us.
The reason TBI isn't seen more often in performance cars is simple....it's out of date. Not so out of date as carbs but it's getting there. The guys that want every bit of power out of their motor usually have every bit of pocket book to do it. No doubt a properly setup port injection system is the way to do it but I don't think TBI should be ruled out as an option. Too many people dismiss it thinking it was the fault for the slow RS camaro's vs the faster z28's with TPI on a 305. Facts stand that TPI 305's and TBI 305's are NOT similar. The list is long and distinguished.
The L03's got weak fuel pumps, crappy swirl port heads, smaller exhaust manifolds, smaller cam (years depending if not equal sized), smaller y-pipe, smaller exhaust in general, crummy single snorkel air cleaner, weak ecm performance tuning (timing mostly), and a bunch of other stuff I can't think of off the top of my head. As for a TPI vehicle being more cost effective at getting into the 12's than a TBI....that's . I'll give you a run down of how to get into the 12's without TPI and it's expensive parts while retaining great gas milage.
Setup the suspension correctly, this doesn't matter what induction you've got, just make sure it'll hook. Next part is difficult to understand but since the original poster said he's good with computers I'll give HIM the solution. It's called running a 4 barrel holley TBI. The newer ones with the better injectors. Get an extra ecm and use it only for the extra injector drivers. That's enough fuel for power up to 6400rpm (ecm tables limiting). I can think of about 450hp engine combinations that would get you past 12's and into 11's but let's just stick with the task at hand. Get yourself a 350 short block, vortec heads worked for larger cam lift and springs, RPM intake, xe274 cam or larger, do some tuning and go have some fun.
My car when I got the 13.8 at 102 was in full street trim. Not like I need to defend myself again but 3600lbs was what it weighed in with 1/4 tank gas and me in it. That day I started with a half tank and was probably very close to that weight when I ran the best. This spring I've got some suprises....a new fuel pump means you'll be seeing less time and more mph in my sig.
I haven't touched the motor itself so it should be interesting. Only difference now is that I've got a borla cat-back compared to the summit in-house muffler .

 

Uhm.... What do you mean mixing up the TBI and L03? They're the same thing. An LO3 is a TBI engine, and a TBI engine is an LO3 (or LO5).

My dad and I have quite a few years working with TBI. He was converting carb cars to TBI way before this message board ever existed. He converted his formerly owned 81 El Camino to a 88 350 TBI, and his 77 Chevy Truck to a 93 TBI as well, in the early 90's. Our first thirdgen was his 92 RS, and we played with that for 6 months before I realized TPI was the easiest way to more power. So we bought my car. Some of you from way back might remember we were going to build up a 350 TPI in my car and a 350 TBI in his car with similar parts and see what we could do. He was a big TBI supporter. But after playing with TPI for a year, we both realized that TPI spanks TBI in performance, ease of modification, and aftermarket support. Remember he built a 383 TBI in an 87 El Camino for a customer, and that car was a dog. Even with 90 lbs injectors we still couldnt get it to run anything but lean. So the owner said screw it and dropped a single plane MPFI setup with a 7730 computer on it and has never been happier with his new found power and performance. He even went from 12 MPG in the city to 15 MPG. My dad was going to put TBI on his own 87 El Camino, but decided to put a TPI unit on it instead. His reasons include the ease of modification, way better computer, better gas mileage (he got 2-3 MPG more after switching to TPI), and more torque for the street.

You can go on and on about how great your TBI is, and I agree with you to a point. TBI is great for daily drivers and trucks that need street power. But for racing and high performance, its a very limited setup. Just ask anyone who has switched away from it.

 

You bring up very good points. We've talked about this before but stock vs stock TPI rocks TBI. Not to mention the aftermarket support is all for TPI, TBI is left to pick from the scrap pile of carb manifolds. This is a weakness and a strength.
I think the opposite of you. For me, I'd rather have long runner TPI in a truck and TBI in a car. TPI would give an L03 or an L05 that extra umph but TBI has a lot of room to expand. It's like the every so compatible EFI setup that was overshadowed by the TPI vs Carb debates back in the late 80's early 90's. One can only speculate what kinds of development could have been possible if only GM had went along with Holley to produce the injection instead of Rochester. I remember how your Dad faired well with converting to TPI but that was on a stock motor and dude, it isn't cheap. For $450 not to mention the added work of going into the fuel tank and crap you could have an Lt1 cam in an L03 with a performer intake, free TBI mods, homebuilt (easy) AFPR, and headers. Well that might be stretching it but it's those reasons alone that make TBI still a viable option for most of it's owners.
My TBI isn't yet impressive, don't get me wrong. When I ran those times the car might have been sick but I feel it's performance level is the same as a carb and I'd LOVE to see somebody with the vortec base and long tube (not superram) TPI running faster times. I get great gas milage and it's all because I took some initiative. There were SO many people with information out there and I took advantage of it instead of listening to the majority. So there, I don't think it's a limited setup. The people I've asked that have switched away from it aren't the kind of people that would impress you or I with their automotive knowledge so let's not even go there.
Someday I have to just make a table of carb vs tpi vs tbi. Almost forgot....I'm still running the stock computer and plan on keeping it with the car well into the 12's n/a.