I am new to the 3 gen F-Bodies i just bought a 1985 Z28 with the 305 TBI 155 hp what mods should i do to up the hp? Im planing in the future to put a new engine in it what engine is the best for that year in Hp and easist to install? Be a really big help to post links where to find the mods for the 305. Thank you very much!

 

intake and exhaust are the best area's to start. there is a great article in this message board about how to make your own cold air intake. i did it and it works great.

also, redo the entire exhaust. get rid of the manifolds and put headers on. make it true duals with flow master mufflers.

this can all be done for under $500 and will add anywhere from 40 to 70 hp.

these should be the first upgrades you do as most other upgrades will require them anyway.

as for anything else, just look around this message board. there is already alot of great info here.

 

Most are gonna say just wait till you swap the motor. For now, do upgrades like as mentioned, ones that will be suitable for a bigger cid motor. Exhaust, chassis upgrades, brakes, etc. Then drop that new motor in there No point in modding the 305, if your just gonna pull it anyways.

 

Back to reality. Your not going to get 40 - 70 from a cold air intake and exhaust work. The bottle neck on these motors is the heads and cam. The exhaust work and intake are a good starting point to build on, but only a starting point. Personally I would start at the suspension and steering. Your car is 20 yrs old and probably needs some work there. Doing the suspension and steering will make for a safer platform when you add a different powerplant with more ponies.

 

While you're right that 40-70hp from exhaust and intake is wet-dream world, You're dead wrong about the location of the "bottle neck". On a stock thirdgen, it is undisputably the exhaust. All of it, from the Manifolds to the tail pipe, is junk.

 

Something isn't adding up here. TBI wasn't offered in 1985, TBI HP was 170. Sounds more like you've got the standard LG4 carburated engine.

https://www.thirdgen.org/techbb2/sho...hreadid=261488

 

40-70 HP gain from an intake swap and full exhaust is real world for a decent running LG4. I gained over a full second and 7mph with a dual snorkel, Performer RPM, headers and full 3" exhaust. MANY others have done the same thing...

 

I almost believe it.

I've stripped a lot of LG4 cars, and they run that weird flap thing in the exhaust. I'm sure that restricts like nothing else.

40-70hp and a second sounds a bit much. But whatever. I've never modded an LG4. What do I know.

-- Joe

 

was waiting to see who would catch that

 

yeah, the whole Z28 post with TBI included didnt add up... lol

 

My bad guys juts got the car this morning love it

 

Yes. But the person who originally said that didn't say intake and exhaust. He said:The exhaust certainly does make a HUGE difference, and it's an essential mod, but you won't find 70 hp from exhaust and CAI on a stock LG4.

 

i dont even know if i found 70 hp going from a stock LO3 to an LO5 w/ catback and an open element...