TBI

[formulaMARK]

I have a 91 GTA 305 TBI. What are some ways i can get more power out of my 305?

[Squirrel]

search on thirdgen.org for free/cheap mods, theres a bunch of them...or just hand on here, theres some tbi guys that know their ****

[formulaMARK]

thanks. Yea thirdgen isnt wokring today for some reason

[j0n]

if you have a 5-speed get 4.10s...if auto get 3.73s...free flowing exhuast...open element air cleaner...and pm fasterthanyou (jon prevost) and ask him to tune it for u...at that point it should hang with and probably beat most stock l98 cars

[90FormulaWS6]

you can talk to tim or jon or me(im gettin a whole lot of education from them) but im online more 8)

[Fasterthanyou]

First headers and exhaust, then go for an open element for like $15. Then make the fuel pressure regulator adjustable and crank up the fuel pressure BEFORE you get a custom chip done by yours truely.
That's what can be done with TBI to make it scoot, other things to do to the car to make it faster; 3.73 rear gears and a torsen posi. Then LCA relocation brackets (which are cheap) and might look into replacing some of the stuff that wears out like the trans/torque arm/LCA/panhard/front LCA bushings, shocks and struts.
One step further on the TBI topic is to install this Lt1 cam I got sitting here for you. Do the above and you've got yourself a low 14/high 13 second car in the 1/4.
Really though, not trying to push a custom tune on you but the stock calibration code is really pathetically mild. There are a lot of "patchs" I do to change some things. For example, the first couple times you go WOT or into "Power enrichment mode" the ecm advances the timing until it detects knock and then pulls 10-20 degrees of timing out. It doesn't help they used ULTRA mild spark tables and tons of fuel to drown out the power, again, easily fixed with tuning. That's where you do it and if you want to DIY I can show you. It only costs $120 for all the hardware needed to burn your own chips!

[90FormulaWS6]

Originally Posted by j0n

if you have a 5-speed get 4.10s...if auto get 3.73s...free flowing exhuast...open element air cleaner...and pm fasterthanyou (jon prevost) and ask him to tune it for u...at that point it should hang with and probably beat most stock l98 cars

you wont need to tune your car after a free flowing exhaust and OE... once you change heads or cam/ intake something that requires something a little bit more radical than the computer is set for then contact jon

a good start with TBI is base timing, open element and free flowing exhaust along with some of the other "free mods"... gears are always a possibility but i would tackle other things first like a posi to get the power to the ground

Derek

[NJSPEEDER]

Originally Posted by 90FormulaWS6

you wont need to tune your car after a free flowing exhaust and OE... once you change heads or cam/ intake something that requires something a little bit more radical than the computer is set for then contact jon

a good start with TBI is base timing, open element and free flowing exhaust along with some of the other "free mods"... gears are always a possibility but i would tackle other things first like a posi to get the power to the ground

Derek

you can make big gains doing custom tning on a stock car actually. the stock programming is extremely weak. just from timing adjustments alone you can make a very noticable gain.
give that thing some gear, 4.10's would make it feel like a new car.
the free mods on thirdgen.org are a good place to start. if you have any q's hit me up on AIM.
i have enough spare parts here that i can prolly put together a "ported" TB and an adjustable fuel pressure regulator for ya.

later
tim

[Batman]

Some quick cheap mods to bump power are removing the air silencer in your air cleaner (it is a metal ting that runs right around the TBI inside the air cleaner), it is tack welded on and comes right off. The air cleaner is very restrictive,you can replace it with a truck air cleaner and put in Â*a 3 inch K&N. Or the way I went was to buy a dual snorkel HO 305 air cleaner (I just happen to have another, check the classifides). A few Minor mods and it goes right on. K&N filter is always a good idea and maybe even a K&N extreme flow lid. The lid doesn't quite cover the whole air cleaner so i added a little foam weatherstripping around the edges to seal it up nicely. A Throttle body spacer is relatively cheap (about $50)and makes some improvement but make sure you don't go more then .5" thick or you will run into throttle linkage problems. A good hi flow cat and car back Â*works wonders also and you can gain some more ponies with a PCM chip. While you are working on it give it a good tune up with some nicer ignition parts from places like MSD, Moroso or Accel. all in all you can probably make between 30-45 more HP with those mods.