1987TPI5speed

84 z28

How much money you have dictates all, gaining 100 hp wont be cheap

Camaro29

The next step: Swap 5.7

mmadden55

350 Vortec transplant would be the cheapest way to go really. Save the matching numbers 305 for when and if you sell it.

Jbuchanan

Im gonna use my matching numbers 305 for a boat anchor or may make a mailbox out of it

84 z28

No such thing

mmadden55

You can make a 305 run but anything you do to it you can do to a 350 and get more, and most of the time do it cheaper too.

1987TPI5speed

I was thinking headers, y pipe and 3” exhaust for starters. Maybe change the injectors. Do the grand national injectors work on the TPI setup? I’m thinking they should and the gn injectors are larger from what I remember. Also what can I do about the air intake? My thinking is that air flow in and out is important. The TA air box seems much more restrictive than iroc.

Drew

iTrader: (58)

Contrary to popular belief, it's not as easy as falling off a log to unleash 300hp from a 305. Most of them (305s) made about 150hp stock. You're already at about 210hp having a TPI 305, with a good cam, and good exhaust. So say you bolt on some headers, and put a 1/4" larger exhaust on there... Let's say it takes the banana out of the tail pipe and frees a staggering 15hp! You're down at least a grand, and maybe you're on equal terms with a 87 350. Throw out the silly straw GM installed as an air box, and replace it with the much improved 88-89 ducting, and you might pick up another 5hp.

Larger injectors will do zip unless the engine actually NEEDS more fuel. It doesn't. And you wouldn't use 30 year old obscurium injectors from a Grand National when you can buy scads of modern production options in whatever size you want. Doing it right means you'd also have to tune the computer. If you do it yourself, get ready to spend a lot of time studying and fiddling, as well as buying a few hundred dollars in tools to communicate with the ECM and make changes to the tune. If you hire the job out, be ready for doing the Hokey Pokey with whoever is burning chips, as you send info, get a chip back, don't like it, send it back with more info, wait for another chip with changes, try again...

Really when you get right down to it, you're pretty close to the best the 305 is going to put out, unless you want to go to some type of power adder (forced induction, nitrous, etc). You'll spend a few grand on any of those options, and it helps if you know what you're doing.

By far the easiest way to increase the power is to increase the cubic inches, aka swap in a 350. But before you do that, consider that if you take a 300hp 350 and bolt it in a thirdgen with the stock TPI setup, you'll have 240hp because the TPI is restrictive. So then you can convert the car to a carburetor, or swap to a Holley Stealth Ram, oh poop, now the hood won't close... Pass me the Sawzall.... Ok, now we got a bitchin' prostreet looking hole in the hood. Rad. Oh ****, what was that loud scary noise? What the... The shifter won't go into any gear except reverse. Better drive home in reverse... Spend 6 months looking for a T56 6spd, now the speedometer doesn't work, and the clutch grabs too low, or too high...

Idk, sounds like you have a nice car. It's not a road-rocket, and trying to make it into one is expensive and destructive to the car. So maybe it's better to just adjust the expectations and enjoy the car for what it is, instead of what it could be? Or sell it and buy something that comes closer to the expectation to start with? Or instead of throwing away a 305 and a bunch of practically new parts, maybe it's easier to start with one of the oodles and scadds of beater thirdgens on craigslist with a blown engine, or no engine, and throw away stuff that's truly garbage...

Jp's camaro

Do full exhaust. Headers, better y pipe and 3 inch catback. Port the stock tpi system. That will give a good difference. Then if you really want 300 throw on some aluminum heads and put in a better cam

1987TPI5speed

sofakingdom

iTrader: (1)

I'd start with getting it road-ready FIRST; then AND ONLY THEN, after all the crumble-to-dust stuff has been worked through, worry about "mods". Leave it the hell alone until it's reliable. Leave the exhaust alone for the time being regardless of "power".

Get the best tires you can afford. Not just the cheeeeeeeepest thing that's round black squiggly on the outside and they say "it fits". My personal preference is Michelin although I've also used Pirelli at times with good results. The rest of that, .... just good quality new is fine. There's no "performance" belts and hoses for example. ((SS and the like notwithstanding... although there are some crappy ones... Goodyear, Dayco, Gates are OK) Plugs, stay away from the "gimmick" plugs; just yerbasic OEM type stuff, from any of the OEM mfrs, works fine. AC Delco of course is a safe bet; but Bosch, NGK, Denso, Motorcraft, Champion, etc. all have perfectly acceptable functional equivalents. Electrons don't care what country or even mfr cast the castings; they either jump the gap, or they don't. All the crap you hear about "I put [fill in the blank] in my car and it wouldn't even start" is mostly just a bunch of drivel, kinda like all the crap about oil. Just avoid the "gimmicks". (+4, E3, SplitFire, etc.)

For filters, avoid Fram. Again, OEM stuff - AC, Bosch, etc. is all fine, as well as some of the aftermarket such as Purolator or Wix. For oil, 10W-30 Mobil1 is about as good as you're gonna get.

88IROC-USA

There is a one word answer and it is NITROUS.

That 305 will eat a 100HP shot AS-IS and not bat an eye. I do not condone otherwise screwing up such a nice, low mileage example for little to no return -outside of lowering the value of your ride! You could take the kit back off...

Jbuchanan

I love the "I want more horse power from my 305" threads, everyone I've seen so far are like a train wreck about to happen............just can't stop watching

dmccain

iTrader: (2)

Leave it alone. Buy a hotrod if you wanna go fast..

Drew

iTrader: (58)

Fact. At least some of the token trends of days gone by, have lost popularity. Used to have someone in every one of these threads talking about gutting cats, dumping the AIR pump, bolting in an airfoil, AFPR, Port the plenum, advance the timing, blah blah "my free mods" made my bucket so fast it'll lift the front tires! Spend $500 on super NASCAR Ceramic Phenolic light weight racing carbon fiber plug wires, an Accel this, MSD that, Moroso, Holley, Orville Redelbrocker, and Splitfire header plugs...

Truthfully none of that REALLY makes much difference in the real world. Every "little bit" doesn't "add-up" to a significant change. People think upgrading an exhaust to 3" is going to be the same as a new set of heads or a camshaft. Yeah, it makes a difference on cars that came with an LG4 or TBI with 2.25" exhaust pipes, but on a TPI car with 2.75" exhaust from the factory, it's not going to make a huge difference. When you've got a 150hp 305, bumping it up to 210hp with exhaust, and a cam change, is significant. It's not nearly as easy to add another 60hp onto the 210hp.

There's nothing new under the sun when it comes to thirdgens. There are tried and true methods to go faster, and then there's the crap that makes your custom signature and "mod list" longer while making the car a bigger pile of grabbage.

88IROC-USA

Especially this one.

86LG4Bird

iTrader: (1)

Exactly.
See my sig.
Then when you get tired of messing with nitrous bottles, drop in the Vortec as was already suggested