this is my 90 firebird, 305 tbi, pretty much stock except for the following mods

- hypertech stage 2 power chip
- cat back exhaust / dynomax stainless muffler
- K&N air filter
- low temp thermostat

basicly all the mods the stage 2 chip reccomends.

- monroe sensatracs all round

I'm about to add headers and a high performance catalytec converter in a few weeks.



now for my dumb questions!

first, I have to replace my harmonic balancer as the rubber is old and falling apart (making a knocking sound at low idle), is the harmonic balancer the same part as the pulley? I mean can I buy an underdrive pulley for it instead of just replacing the harmonic balancer? same piece or no? I know air cooled vw bugs pretty well, but have never learned all the ins and outs of real engines

if so what is a good pulley and good online store to buy from for my 305 tbi?

last, what would you all think is the next logical step in bolt on power?

thanks
Matt

 

No, the balancer is one piece, and the pulley bolts to it. So you'd need both. Doing a pulley swap is the ideal time, that way yo'd only have to futz with it once. You can get the balancer pretty easy from a machine shop; a common replacement brand that's reasonably reliable is Pioneer.

Headers and high-flow cat is THE #1 BEST mod for that car. Get application-specific ones, not universal; use the ones for a 350 TPI, not for a TBI car; they fit the car exactly the same except they'll be larger where it counts. SLP is the best of those but also the most $$$$, Edelbrock is OK too. Definitely get them ceramic coated.

After that, a cam; and a set of heads. TBI comes with heads that have a big restriction in the intake, that's designed to be a "ramp" to make the mixture "swirl"; mostly it's just an obstruction. The heads to look for are the 87-up carb/TPI heads, casting number ends in 081. A good cam for cheap is a used LT1 cam out of a 93-97 Z28 or Trans Am, or 92-96 Vette. You can get those for $50 or less on ebay or in the classifieds on this site.

 

*EDIT* crap RB....

 

thanks for the advice RB. hard putting this all together from just searching the forums...

Steckman, are you in disagreement with RB's opinion? I appreciate anything you folks can tell me, I don't know anyone in real life or otherwise I can talk f-bodys with besides people here.

thanks again
Matt

 

Nope, i am not in argument with RB. I was going to post pretty much everything he posted. I was just going to add a thing about cam selection. Im not the most familiar with hypertech. They may or may not retain the factory fuel curve (which is a problem as soon as you get into larger cams). But you should be ok with the LT-1 cam. Many people with run that in a 305 and have fairly decent results.

 

great, thanks you guys, you've saved me a lot of research and head scratching

 

so after thinking on it I'm to the conclusion that I will just fix the balancer and stop with the mods after headers and a good cat. then in a while I'll just drop a 350 crate motor in it... but I'm wondering if my stock transmission and rear end will handle 300-350 hp?

obvisously it's not legal to remove my emission crap but is it a common thing that people do in states with no testing? the thought of buying something like that gm crate 350HO deluxe with the carb (and taking out the tbi) is very apealing, would the computer and chip then be completely useless?

sorry if this has been asked a million times, I've been searching the forums and reading for hours now trying to school myself... answered a lot of my own questions... all but a few

 

anyone?

 

Well if you get that crate motor yes...your computer and chip would be worthless and do nothing.

I live in a state with no emissions and I have deleted all of my emissions stuff.

 

if you go with a carburated motor then you won't need your computer except for you tranny maybe, however I don't really think that you will. If you do, just remember to take the fuel pump out of the tank, or else it will cut out at 60 or so because it can't pull enough through it. As for the emission stuff, if you don't have inspection, then how would they know if you didn't?