Red Bird

I am still pretty new to this website, but I wanted to discuss quick and easy horse power additions to the TBI 305. I just got a 92 firebird with the 305 TBI and I was wondering what bolt ons, or other mods, others have done to add easy horsepower to their f-bodies. I have added flowmaster exhaust and k & n airfilter, but want some other advice on stuff to make it faster and or more powerful. I know that TBI does not mean slow forever, and that there are tons of horse power bolt ons to tap into...so what do you have and how did you do it? Lets share our budget friendly mods in order to help everyone make their bird faster and more ready to put some new model luxury sedan in its place shall we meet at a stop light. haha...please add your input to this post! Thanks in advance!

Reputation7

iTrader: (3)

150 shot.

robertfrank

iTrader: (27)

I really hate to throw this out but a search is your best friend. Go to the thread "305 build up suggestion" for alittle more info if you don't mind alittle bickering. Also read the stickies at the top of this forum for even more info.

Welcome to the boards!!!

thomas1976

EBL flash, is in my opinion the best start point.

titchener

Here's what worked for me on my stock '91 L03/305.

If haven't already, get everything on the engine in good shape. Replace the 02 sensor if its still the original one, use an AC one, the Bosch single wire units can be troublesome. Rebuild the TBI, and have the injectors cleaned and tested by witchhunter.com. Check your distributor, cap, rotor, plug wires and plugs and replace if needed.

Check your timing setting, typically from normal wear of the distributor gear they will lose a 2 or 3 degrees over the original factory setting.

Open up your air intake either with an open element or an improved cold air setup.

Put in a 180 degree thermostat.

Make sure your throttle is really opening up all the way, and make sure the trans TV cable is adjusted correctly.

Sounds like you already have the exhaust taken care of, but make sure your cat converter isn't old and clogged.

Do some chip tuning. In my case some extra advance really made the 305 wake up compared to the stock settings. The EBL from dynamicefi.com is a slick way to get this done. If $ is tight Moates.net can set you up with basic chip burning and logging for less dough. Use TunerPro RT for bin editing and logging.

These changes really made my stock L03 run well, better than I thought it would. Someday I'm hopefully yanking it out for a TBI'ed 383, but I'll have to wait until my $ situation is a little fatter.

Paul T.

igotta355z28

iTrader: (1)

id go with more of a 75-100 shot but yeah quick easy hp=N2O

campin1983

iTrader: (4)

In trying to pull power out of your motor, I think its also important to judge where your starting from and where you want to be. I've got a 167,000 mile 305 TBI, and I'd like this car to see 350 hp+ when I'm done with it. Well... that's just not happening. For me the only sensible, long term answer is to swap in a different motor (or maybe a rebuild, convert to TPI and mods). So I'm saving money and just letting the TBI rumble along until that time comes. I know that's not the answer you want, I'm certainly tempted to try to bolt something on for an instant 50 hp gain, but on this old motor, its either gonna not do much, or blow it up.

On the other hand, if your not looking to increase it by that much, and the motor still has plenty of life left, start modding.

DM91RS

What trans and rear gears do you have?

Red Bird

M5 or A4 with I believe 2.73's...how can I find out for sure?

DM91RS

Is the car auto or stick?

Red Bird

ahh ha...auto. i guess its the A4

galvarado

Before I even touched the engine and trans I rebuilt the suspension on my 88 Sport Coupe. Poly bushings, new shocks, new springs and Hotchkiss LCA's. I also switched from an open 10 bolt drum rear to a 9 bolt posi 3.27 with discs and an aluminum drive shaft from a 200 SS Camaro. The car felt quicker after the work was done and that was without even touching the engine or trans. It didn't give me more horsepower but freed up some horsepower that was already there.

Gene

DM91RS

If the car is stock then it "should" have the 2:73 rear. galvarado gave you a great tip and that's to change the rear gears/rear end assy. The car will have better acceleration that you will enjoy. After changing mine I wished I had done it years earlier........

kcb37

This won't help alot, but just changing the fluids can help too.
I know this is a truck, but just changing all the fluids in my 96 Silverado made it run and drive a lot better. I also just changed the oil with Mobil 1's 0W30.
It runs a lot better. Idles smoother, and accelerates better. Feels quicker.
At anyrate synthetic is better for it anyway.

Other then that make sure it is running the best it can. "good tune up"
If you want something to reference my 89 RS Camaro, 305 TBI, 5 speed ran a best of 16.2 last Sat. But I couldn't get into second without slowing down.
I don't know how much diff the auto and manual have in gearing though.

1989rs305!

Did you notice any HP gains or better gas mileage after removing the smog?
I plan to remove it and and put headers on. Will this cause the engine light to come on? Is it worth my time and money? Will 350 headers fit on the 305?