more hp outta 305 tbi?
 

any way to get some more get up and go with a 305 5.0l tbi?

Lots of ways, most cheap and easy.

1. Put about 4 more degrees of base timing in it. The stock timing curve is weak and needs a little help, especially if you are in the good habit of putting 93 octane in the car(honestly, it is like $2 extra a tank, don't be a cheap skate lol )

2. Get yourself an open element air cleaner. Despite popular myth about the temperature of air being oh so important, the truth is that if there isn't enough volume, the temperature won't make a **** bit of difference.

3. Lower temp t-stat and higher pressure rad cap. A little help to the cooling system can help you get a little more timing in the car without detonation and it will also make the cars performance much much more consistent.

4. Look on Thirdgen.org for the Throttle Body "Porting" information. It is a super cheap and easy mod that you can do to pick up some air flow. While you are at it, get an extra gasket for the injector tower and double them up, a little more space between the injector tips and the TB means a touch more airflow.

5. The biggest of the cheap ways to get power is to grab a stock LT1 cam. It will slide right in place of you stock hydraulic roller car, reusing your stock lifters and push rods. Just make sure you put on some fresh valve springs to make sure it stays together. To be extra sure the engine stays happy, a fuel pump with a better than stock capacity and some injectors from an LO5(350 TBI) will ensure that your fueling is all taken care of.

6. GEARS ARE YOUR FRIEND!!!! The stock LO3 was equiped with either a 2.73(auto) or a 3.08(stick) one legger rear. Find yourself a 3.23 or 3.42 posi unit from a Z28/Formula/Trans Am or just buy some gears and a posi and get them put in. More gear is always better, don't be afraid of 3.73's or 4.10's if you don't mind humming a little RPM down the highway. Mileage will not be dramatically effected regardless of what gear you go with and make sure you get the appropriate speedo gears so you have the correct answer when the officer asks if you know how fast you were going :D

7. If you do 1-4 a custom tune from JSPerformance will help a good bit with power and mileage, if you do number 5 I would consider stopping at Josh's for a tune an imperitive.

The other big thing to look at is maintanence items. Make sure you tune up, filters, and fluids are all fresh adn ready to go.

There are a lot of other little things that can be done to the car here and there to pick up the pace. Weight reduction is always a good one and it is free, but that is a completely different discussion.

A lot of people knock TBI, but it really is a cheap and easy fuel system to work with and you can easily make up the little bit of ground in performance between the 305 TBI and the 305 TPI with just a few free/cheap mods.

If you wanna know more just shoot me a PM.

-Tim

my 88 was tbi orginally and i did everything but the cam. i had an edelbrock performer tbi manifold and a ported throttle body, throttle body spacer and an injector spacer.... it was quick :) the 3:73's were very important as well as the shift kit in the trans

i used www.cfm-tech.com to purchase stuff

125 wet shot of nitrous, headers, 3.73's exhaust and 4+ timing with 93 octane and rear suspension mods, and the ultimate TBIwill get you 13.18@104 mph. thats what i got mine to run ( i had all stock from manifold down in the motor). for a while there NJSPEEDER and I were going back and forth with bests.

Wow are you serious?

yep. njspeeder will confirm it. if you need more details just PM or IM me.

joe

Yeah. You were the nitrous guy and I was the all motor guy on the TBI forums. heh

I still say my biggest mistake was putting those heads on. If I had just gone with my gut instinct and done the cam instead of listening to everyone else I think I could have gotten your 150 shot times on motor.

You had those Performer RPM heads on your LOLO3?

- Justin

i always wonder if i put a cam and convertor in i bet i couldve hit mid 12's maybe???

I have a stock LT1 cam that needs a good home...

how reliable do you want it to be?

Bore and stroke could help but then your looking at cooling issues.... (unless my buddys car was a freak accident)

We'll see how fast I can get my lg4 all motor. Stock 116,000 mile bottom end.

416 heads ported and polished, 60101lk Lunati cam, 1.6 rollers, edelbrock rpm manifold, true 3.5 duals.

3.5 inch duals? on a 305? are you spinning it to 18k rpm like an F1 motor or just trying to make horrible noises?

-Tim

Ooopsy meant 2.5's

Just put a single on it, costs less, weighs less, flows more, more ground clearance, and sounds better.

Ummm duals cost nothing on a gbody, plus its already there, ground clearance isnt a problem, and it sounds damn good without the headers...

I thought you were talking about an f-body, my bad.

Hmmm I'm starting to think I shoulda heeded your warning. The car is 1-5/8ths primarys to 3in collectors. 2-1/4 reducers to 2-1/4 true duals with real cats and flowmasters.

I've completely lost my low end punch. I've got nothing below 3500rpms and I'm really pissed. What can I do to help low end exhaust scavenging? Wrap the headers so the heat stays in? Some sort of venturi?

Put more cam and head in it so it uses all the flow available :D

Seriously, you may get more of that low end pop you are looking for by putting stock manifolds back on and making the whole system 2 1/4 off of that collector. It will kill a little bottom end, but should recover a little bit of pop off the line.

-Tim

Crap theres no way those manfiolds are going back on after I just got everything bent and good for the headers. I gotta figure out where to get some sort of collector restrictor.

Figured it out

Whats red and hot and smells like **** all over?

Header covered in oil?

i don't think i should answer that :shifty:

:moon: well if this guy just got done running, he might fit the criteria hahaha

Thank you for playing but the answer is a clogged cat. Man that sucker was hot when I got done flooring it a couple times. When I say that 75% of the body of the cat was glowing red like it had been stuck in a furnace and brought to a solid glow I'm not exaggerating.

Thats what you delete the cat! a der.