defpony

im in Australia, got an 85 iroc. Ive got a quote on custom built extractors, larger throttle body, larger port injectors, removal of the air pump and a couple of other small things.

What sort of gains am i looking at?

And can you recommend any other small things to do to the engine? Just looking to do small stuff and build it up.

its a 5.0L 305, everything is stock except for a worked exhaust.

thx for any info.

mako350Z28

Hate to sound stupid but what are extractors? Headers?

defpony

yup extractors are headers.

klumb15

you probably won't see too too big of a difference, but i'm sure you'll definately feel a little more in the seat of your pants...the big thing is your stock TPI intake...it doesn't do any good to just throw a big TB on front of a stock TPI, because your only gonna flow as good as your weakest point, and that would be your intake...the headers should help out quite a bit tho. i would maybe look into porting your intake out maybe, there is some nice pieces of info on thirdgen.org's site for this kind of stuff...but with bigger injectors, bigger TB, full exhaust and smog delete and everything your going to need a custom chip burnt for sure. just something to think about. But go to thirdgen.org board and you can find a lot of free mods that will help to free up a little bit of HP, but a little bit adds up...

defpony

yeah the chev expert in my local area said that he can put the car on the dyno and reprogram the chip after i have done everything.

Will removing the cat gain some hp? Because its not legal to have a cat over here.

f-bodybuilder

Unless you're planning on doing some MAJOR modding to that little 305, getting a bigger throttle body is completely pointless. Do a search on thirdgen.org, there are at least a hundred threads documenting this. If anything, get an adjustable fuel pressure regulator. If i remember correctly, the stock pressure for 85's was very, very low. An adjustable regulator can also make your stock injectors keep up with what you're planning on doing and then some.

85_305

^There isn't a fuel-pressure regulator for carbs right? I dont think so... not positive though.

f-bodybuilder

Maybe the best question to ask right now is...... What type of intake do you actually have?

85_305

I have a carb, lol.

Rice Killer87

The original poster has TPI,85_305 has a carb.

You only need a regulator on a carb if your fuel pump is pushing out too much PSI and you needs to bring it down some...or in my case,about 30 PSI

klumb15

no....we need to know what intake the author of the thread has....i'm guessin he has a TPI, because bigger throttle body isn't what you hear very often on a top mounted TB motor...

f-bodybuilder

After hearing him describing headers as extractors, i'm not entirely positive he's not calling his carb a throttle body.

85_305