TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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i have an 88 formula thinking of going carburated any thoughts is it actually easier to make power or not? i have heard good and bad.. i was givin a holley 650 double pumper so maybe i might try it any good or any bad things?? just wonder what everone thinks thanks!!!! also i know with running carb i can run an ear rumbling cam i know i need to get a different stall conv.. if i do that but its just a thought!!! thanks for the help
__________________ 88 formula bird with a new 406 vortec heads ported and polished flat top pistons 451/464 280 duration cam edelbrock air gap intake holley street avenger 770 carb mallory 3 port reg.. hooker headers and true duals with an h pipe with flow masters 2 chamber 40 series mufflers sounds excellent!!!!..accel distributor and super coil msd ign. 6al.. steve spohn adj. lca's brackets and adj. panhard bar. rebuilt 700r4 with all the updates and shift kit 2000 stall..aluminum drive shaft.. 10 bolt 3.73 gears posi... new best time is: 12.783@107.37 mph!!!with a 1.847 60' plus a 97 grand prix gtp runs low 14's 2003 chevy silverado SS k&n series 77 cai, corsa exhaust..
I say "don't do it." I know more and more that are converting their carbed cars to TPI. Seems like it is going in the wrong direction to go back to carb. Having lived many years myself in cold climates I would say the main disadvantage in a carb is cold weather warm up and running.
What are your goals? If this car is a daily driven car then I'd suggest staying fuel injected. I swapped to carb because I only bring my car out on weekends and I'm aiming for more of a race car. Keep in mind you'll be spending probably $400-$900 just converting to carb. For me it was:
Edelbrock Performer RPM manifold - $110
HEI distributor - free, rebuilt with msd stuff $90
750 Holley carb - $240
Fuel pressure regulator - $75
Fuel pressure gauge - $25
Misc fuel fittings/hose - $110 (I went crazy, lots of braided hose)
Misc bolts, studs, brackets, gaskets - $120
Set some goals then decide weither you want to mess with anything. My car was the king of stop light to stop light racing but would fall flat on its face at high RPMs with TPI in a 1/4 so I swapped for ease of modifying and tuning not for gas milage and daily driving
Here is a picture of the 80% done swap:
__________________ heavy and stockish!
Last edited by 88IROC350TPI; 02-16-2002 at 05:46 PM.
gas milage is not an issue i built the car to run hard an fast!! and no i dont drive it everyday infact i have had it for 3 years now and only put 10,000 miles on it so its not an issue at all.. i have the intake and the carb already 750 cfm speed demon.. also when i do the swap can i use my blaster 3 coil and my msd 6al with rev limiter still?? thanks for the help also will i ahve any power gains with the swap?? thanks and how much does a complete tpi unit go for wheni put it up for sale its polished with slp runners airfoil and everything that would go witha tpi unit thanks
Originally posted by 2ponchos gas milage is not an issue i built the car to run hard an fast!! and no i dont drive it everyday infact i have had it for 3 years now and only put 10,000 miles on it so its not an issue at all.. i have the intake and the carb already 750 cfm speed demon.. also when i do the swap can i use my blaster 3 coil and my msd 6al with rev limiter still?? thanks for the help also will i ahve any power gains with the swap?? thanks and how much does a complete tpi unit go for wheni put it up for sale its polished with slp runners airfoil and everything that would go witha tpi unit thanks
You'll still be able to use the ignition stuff. I couldnt tell you about any power gains because when I swapped I did a lot more engine work and today will be my first day taking it out. My guess is you'll lose some low-end torque but gain more overall HP. I got somebody buying my TPI for $200 which is bone stock, old, dirty, and doesn't even have a wiring harness. If you wan't to go fast on a budget then carb is the way to go.
88iroc let me know how your maiden voyage went today then!! i was offered 600 for my tpi stuff with both sets of runners and my tpi unit is very clean and its all polished plus with the air foil and computer i think its close to worth that but i also dont wana rip someone off either soo thanks for the help!!!
I say don't do it also. My friend did on his car and now is majorly regretting it. He said he'd switch back in a heart beat. You can make just as much power with TPI as you can with Carb if you learn how to burn your own chips or have the money and resources to take your car to someone and have them burn you a custom chip. GM eliminated the Carb on the Fbodies in 1987, personally I would rather move forward to newer better technology than to backtrack to the past. Just my .02
__________________ __________________
1991 Firebird - 2nd Owner (The slow pretty car)
Stock engine setup with K&N Air Filter
T/A Hood
Pre-'91 T/A tail lights
'91-'92 Aero Spoiler waiting to be painted
GTA Emblems
Headlight Conversion Kit to non-sealed beam setup
Remote Start/Keyless Entry/Alarm
2 - 12" Rockford Fosgate P1 Subwoofers in a hatch/wheel well box with 300W Rockford Amp pushing the subs and 200W Rockford amp pushing the mids and highs - Kenwood head unit
__________________
1986 Trans AM (The fast ugly car)
355 TPI (Lots of mods and accessories)
4 Wheel Disc Brakes
i think i am going to go carb!! i dont hardly drive the car and wheni do its just to the track or cruising around.. i never drive it when its cold out so i think that is what i am going to do..tpi took me a long way and i like it but its time for a change.. also hwo much can i get for my full tpi unit thats polished mirror finish!!!
I saw a really nice TPI setup on ebay the other day go for nearly $800, though i believe it might have had aftermarket runners on it. I got SLP runners and airfoil on my set up and its ported, so im hoping to get somewheres between 600 @ 800 for mine.
stick with the EFI. doing a carb is the easy way out. I dont give much respect to guys who swap to a carb when they have a very workable system to begin with. Most people swap over cause they dont want to take the time or effort to figure out how a EFI setup works. IF you want to go faster and you think your intake is what is holing you back, then you can swap to a differnt intake but stay EFI. The options are:
1. stock style TPI intake but with big, siamesed, or semi-siamesed runners, aftermarket base w/ or w/out siamesed runners, and a ported plunum
2. Accel Superram w/ or w/out siamesed base
3. SLP Miniram
4. Converted LT1 intake
5. if you want to go with the best setup to make big HP on a EFI setup, run a carb intake converted to run EFI. All you need are bungs for injectors and some other minor mods. You'll also have to get a new TB or a 90* adapter and run a stock or stock style TB.
On top of the choices for the physical intakes, you also have many choices of engine management systems, stock, FAST, etc. If you go with a system like FAST you have complete tunability og the engine, spark curves, fuel control. You can get yourself more HP at the push of a few buttons. If your gona blow, spray, or turbo the car, EFI gives you many more options on tuneability. My buddy has a 66 El Camino that was running a carb setup and dyno around 475rwhp with the carb tuned as well as it could be. He put on an Accel EFI system (looks like a tunel ram with a plenum on top) and and Accel Managment system. Car dynoed at 550 rwhp in OPEN LOOP with the system untuned!!! Hes going to go take it to get tuned and he already put it in closed loop, this thing RIPS!!!!
SO, stay with EFI. You'll reap the benefits down the road and I think you get more respect with an fast EFI car then a fast carb car.
Carb is the best way to go if you want to go fast for cheap. Why waste money on fuel injection when you can spend a fraction of the price and get the same results? It really makes no sense that you would want to spend more money AND have to work harder to get the same results if you wan't a race car. Why aren't all those million-dollar pro-stock and funny cars using fuel injection? They certainly have the money if they wanted to. The hassle of fuel injection outweighs its benefits. I would love to have a bad fuel injected car and one day when I have lots of money (which will probably be never) I'll convert back.
hey there hoss, sorry to tell ya but funny cars do run fuel injection. you cant make that kinda HP with a carb. Ever heard of Enderle?? They run mechanical fuel injection.
You say its more expensive to run EFI??? Sometimes. But how much is it gona cost to set up an EFI car to run on a carb setup, to take the computer out of the system. Remember your fuel costs are gona go up cause u get worse fuel economy so in the long run EFI might be cheaper anyway. Doing a carb converted manifold itsnt expensive. You could do it for around $400.
88blkiroc... Im not doing this for an easy way out, nor do i think that the TPI is "non-workable", i think it is a very good system, thats why its staying on my 87 TA... but as for my GTA, its just something i wanna try out, im not really worried to much about getting respect for what kind of setup im running under the hood of my car, Dats all
hey at the end of the day its your car, everyone is gona do what they want. Personally being a huge 3rd gen lover I just dont like seeing our cars being "de-technologized". I think carbs, bias-ply street tires and leafsprung rear ends all belong together. Maybe im just a carb hater though