Hi im new to these forums, i just picked up an 89 Camaro RS with a 305 TBI....wondering how hard it would actually be to change to TPI and would it be worth it? the motor runs great as is but i need more power

 

swapping to TPI isnt the best way to get power. the TPI's make great torque,but as far as im concerned they are JUNK for making horsepower b/c they run out of breath at 5000-5500.

then people are gonna tell you to buy the SLP runners and maybe an Edelbrock base...but the runners are like $350 new (i believe) and im not sure about the Edelbrock base,but im sure its not cheap...and even then im sure it doesnt pull as far as you would want it to in the RPM band for pissing away that much money.

if you want to stay fuel injected,i would look at the Holley Stealth Ram (as long as you dont have to pass emissions,they have no EGR system)

but if your just trying to have more power to drive around town with and not trying to make a race car out of it,TPI would do fine for that.

just my 2 cents

 

tpi is perfectly capable of making power, as well as any other form of induction.
the swap itself is fairly easy, but it is a matter of time/cost to performance gain. you can pick up a good tpi set up for 300-350 pretty easily and then install it over a weekend if all goes well. teh problem is that after you have spent all that money and time you are just as far along at gaining power as you would be if you did free/cheapie mods to your tbi.
do yourself a favor and take the 300bucks and get yourself a posi and some gears(4.10's are preferable, 3.73's are still worth nearly half a second in the 1/4 over teh stock 2.73's)
in the mean time go to www.thirdgen.org and check out teh free mods. if you have any q's about them let me know.

later
tim

 

ok thank you i will check that out

 

http://www.goingfaster.com/spo/modthel03.html

lol, 4th thread i've put this website in...... this is dedicated to the L03 TBI motor... enjoy

 

The differences between a TBI motor and a TPI motor go well beyond just the intake system. Your TBI is strangled with a tiny cam, lousy-flowing "swirl port" heads and a way-too-small exhaust system. Like njspdr said, your gains will be minimal just swapping intake systems. Not to mention the TBI computer/wiring harness was never designed to run 8 injectors like the TPI has.

Engine has to work as a SYSTEM. Changing one part by itself rarely produces a big gain in power.

 

if he has an auto then 4.10s would be rediculous if he ever plans on driving down the street at more than 40mph. and i don't agree that 3.73s are best for a TBI 305 or even a TPI 305/350. i don't think are powerbands go high enough to make use of that quick reving that 3.73s give you and since most of our power is low end. an LT1/LS1 would benefit more from 3.73s since they're peak torque is around 3000rpm and they can shift at close to 6500rpm (i don't know the exacts). IMO i would recommend 3.42s if your gonna do gears, also if your looking for a good power gain don't waste the money converting to TPI and just go with something like a stealthram or carb setup.

 

We just talked about this the other day:

http://web.camaross.com/forums/showthread.php?t=333003

 

so a half second or more off your et, no significant change in gas mileage, and cruising at 75mph at around 3k rpm is bad?

my bad, i thought teh idea was to ACCLERATE!!!!! since when was going through gears quickly a bad thing? if you make it through teh gear quicker it obviously means you are accelerating quciker. duh!
the mileage thing is also very much proven. i know many people who have changed gears and saw little to no loss of gas mileage, i even know one person who had a LO3 that their mileage went up when they switched from 2.73's to 3.73's

stealthram is more expensive than teh tpi conversion for the same gain and a carb would cost a few bucks as well and you woudl lose the advantage of the computer.

later
tim

 

only thing i would change in gunny's suggestions other than the low gear selection( good to see ya again gunny) is teh intake. i prefer teh holley street dominator.
it has a bit more volume which gives more mid range and top end power. it is also already bored for the 2inch 454 gm tb or the holley replacement tb. the cost is teh same, i think it is like $2 cheaper in jegs last time i looked.
if at any time you do a throttle body upgrade i woudl suggest doing an injector upgrade while you are at it. if you buy the holley, get teh one that says it is for a 350, the extra injector will make tunign easier and give you room to grow into other mods in teh future.
one big power gain is and will always be proper tuning. DO NOT buy any off the shelf chip. they are junk. get tuning done from having your car data logged. you will gain more power than you ever thought possible from just a few key strokes.

later
tim