droste

whats an easy (and cheap) way to get some extra h.p out of the 305 tbi? its in my 92 firebird if that makes a differance

Convoy25

iTrader: (3)

depends on what your definition of cheap is, but an exhaust, headers/catback will help some.

and although its not horsepower,

weight reduction will help, there are some thread and a technical article.

some gears in the rear, 3.42, 3.73, 3.90 will help

droste

i would like to keep it under 500 i heard you can take the headers and exhaust of off a formula with the 350 and get like 40 h.p thats probably wrong though

///DAN///

iTrader: (1)

a cam is probaly the cheapest but a fair amount of work. with a cam headers/exhaust and new heads on your stock bottom end will give you a considerable amount of h.p. Google it there are a couple build ups done by I believe lunati and a chevy mag that were pretty impressive .

droste

if i put a cam and a differant exhaust on how bad will it hurt mpg? im not that worried about it but would like to know

1ADan

iTrader: (4)

you definitely won't gain much grabbing other factory exhaust parts from these cars. if you dig through the classifieds, you can probably find headers and a y pipe for about $100. catback's definitely a good thing to do too. both are good starting places for future mods.
LT1 cams are pretty cheap (under $50 used) and will give you a little more power without making your computer go nuts.

Doom86

No factory 3rd gens came with headers they had manifolds. You may pic up something going to 350 manifolds but not worth the hassle.

The Y-pipe is a huge restriction on a 305 car. It's 2 1/4 inch at it's widest and smashed much less then that in at least 3 places.

Also budget in a heated O2 sensor when you swap headers on a computer controlled car. Moving the O2 further away from the heads makes it much cooler and since they need to heat to a certain level to keep the computer in control you can see why this is ideal.

Good idea with the cheapo LT1 cam but laying a cam swap on a noob (no offense!) could be ugly. You could do it with enough patients and intuition but IMO it's not a good "first". Bust your knuckles up a bit doing the headers and exhaust before you jump into something like this.

A friendly note if you do end up going with the headers/exhaust replacing the cat when you do the Y-pipe will save you hours or frustration trying to get them apart. The cat is "slip on" to the Y-pipe and it's pushed about 4-5 inches deep lined with carbon. Real fun getting it out.

johnny89345

you are not going to get much from a 305 tbi.when i was like 17 i didnt listen to anyone either and tried buying part to make it fast i bought the edelbrock intake manifold, the holley tbi unit, full exhaust, under drive pulleys, and a hypertech chip. imo all a big waste of money. for that price you can buy a nice setup from like holley. look in to their mini ram with commander 950. buy that and an exhaust and you will be happy.

Convoy25

iTrader: (3)

yeah i'm just suggesting stuff that could benefit him if he does a swap down the road.

you can always port and polish the heads, there is a write up somewhere around here, and thats free if you have the tools.

torque_is_good

step 1- get rid of the snorkel air cleaner

step 2, headers and y pipe

step 3 cat back (if you can afford it do 2 and 3 together)

then see if that's enough

gears make a car pull harder down low which is where you do most of your driving so you'd feel that on the butt dyno

Doom86

No offense but you did it wrong only one of the things you listed was even worth buying. You wasted a lot of money on things that weren't bottle necks. The TBI and intake manifold are the last things that are holding you back and underdrive pulleys are not even on the list IMO. Don't even think about wasting money on any of that until you have swapped the cam and heads.

Just because you can see it and it's shiny doesn't make it faster.

Convoy25

iTrader: (3)

unless he has a cowl hood an open element air cleaner wont do better than a snorkel

sofakingdom

iTrader: (1)

Get a "bore kit" out of a 87-95 truck. Take the injectors, the chip, and the knock sensor that go with the kit.

Cheeeepest horsepucker money can buy.

Lucid

iTrader: (4)

The heads and exhaust manifolds on the TBI are terrible. A cam and heads swap, and exhaust upgrades are a good place to start, along with some custom tuning in the ECM.

KNBlazer

Open her up and allow her to breath.... intake, headers, hi flow CAT, and exhaust... you're looking at about 900 parts alone... headers and exhaust should give you about 10 HP or so, maybe 15.1240834 hp... ..

Air_Adam

Dual snorkel or open air cleaner and headers/exhaust are where you have to start. They are the biggest bottlenecks, so anything else you might do won't gain you much untill you do those first.

Doom86

I think you are kidding, or hope at least

There is a a LOT of proof that adding headers and exhaust is good for at least 40hp on a 305 motor.

TBH though I've never seen a LO3 tested like this but having a LG4 and a LO3 I can tell you they have the same restrictive exhaust. My LG4 picked up a ET calculated 60hp over stock with headers, exhaust, intake (intake probably hurt more then help since it doesn't match the cam).

I don't think the "bore kit" (sofa you make me man) would even do that good for the investment and hassle in and of it's self. Now the full exhaust followed by the bore kit and/or at the same time would be great but all you really get is a low RPM stump puller either way.

robertfrank

iTrader: (27)

Check my cardomain in my sig for the answers you seek, i'm to lazy to type this again. And yes you can make good power with an L03