Pneumatic_Tire

Hello again everyone. As you may or may not know, I recently bought my 85 Camaro z28. It's got a 305, computer controlled 4bbl engine. I'd like to do away with the computer carb, but that's where you guys with the Camaro experience come in. I really don't want to go after a TPI 305, or 350, rather I PERSONALLY like the thought of a 300 rwhp and high torque 305. I'm not into the drag racing, so I aint interested in insane horsepower and torque. I just want the most outta my 305. It's got 93k original miles currently on it. I understand it only has 155hp, but the torque seems pretty decent @ 245 @ whatever rpm. I don't see why it wouldn't be acheiveable to get 300 horses or so outta it. Here's my thoughts. My ideas are a Edlebrock RPM performer intake, a Edlebrock performer 600cfm non computer carb, and a good camshaft. I highly doubt those 3 things will get me 300 horses, but it would be a large increase wouldn't it? What if I add a good set of vortec heads? Just let me know the best way to go. I'd even be happy with 250 horses. I'm just craving some more umph, and want to be able to say to people, it's a 305. Thanks!

Sitting Bull

Do a search for 305 buildups and you'll be busy reading for a week.

Pneumatic_Tire

Why didn't I think of that? Thanks!

86305Z28

155HP!?!?!?!?!?

i hope thas a typo......cuz from what i've heard they came wit 175 or a lil more HP

Pneumatic_Tire

nope, not a typo. Either that, or you seen it's rating at the flywheel and not the rear wheels.

splinter_cell

yeah no typo. my 83 z came with 145 hp from the factory

92RS305#2

my 305 TBI only puts out 170HP from the factory, which means like 145 rwhp (my guesstimate )

Pneumatic_Tire

Actually, I'm pretty sure it's 170 rwhp. If gm says it's 170 hp, it's been measured at the drive wheels with all accessories installed and operating.

Sitting Bull

No, it is at the flywheel with exhaust and accessories.

Ray86IROC

Gm rates it's engines at the crank, with accessories currently. Some cars are underrated enough (like the LS1 Fbodies) that it comes pretty close to being the actual rwhp, but that is the exception, not the rule...

Anyway, you can definitely make 250-260hp with a cam, intake, and exhaust swap, and up close to 300hp with a budget head swap (like Vortecs or S/R Torquers). That will be 300hp at the crank btw, to get 300rwhp with the 305 is frankly not too practical without forced induction or a bigger budget...

CHP magazine did a buildup awhile back on a LG4. With a good intake, cam, and full exhaust with headers they made 269hp at the crank. With S/R torquers they made just below 300hp, with Vortecs (milled to avoid compression drop) they made 325hp. That was with the CompCams XE262 cam which might be a bit much for an auto car without a higher stall TC. Anyway, the point is you can easily reach mid 250s hp on the little 305 for not much cash outlay...

Pneumatic_Tire

Thanks Ray, that's all I wanted to hear. I don't want 400hp for my daily driver, rather I opt for 250-300hp range, so going to a 350 doesn't seem necessary.

EDIT: Wait, is S/R tourqers? A cylinder heads brand? So the vortecs were a better choice then of the two?

urbaNHunter44

The intake is a good idea, but leave your original Quadrajet carb on there, it is more than enough for the LG4. Just tune it up a bit with the info on thirdgen.org.

Fix the airflow problem by either getting an open air element or a dual snorkel setup.

Screw the camshaft, finish the rest of the exhaust system and if you have time, port and polish your stock heads.

That should give you an extra 40-50 or so horses and a similar amount of torque for under 700 bucks, plus open the door for more power increasing mods.

And yes I definetly think the 85 LG4 was underrated at 155 stock HP. I have an 85 Z28 with the LG4 as well, and when I first got it was stock, and man it flew. Definetly had more than that, or maybe I just got lucky.

Make sure when you get new parts, they can be used on a 350, because eventually you'll want one in there.

Pneumatic_Tire

"And yes I definetly think the 85 LG4 was underrated at 155 stock HP. I have an 85 Z28 with the LG4 as well, and when I first got it was stock, and man it flew. Definetly had more than that, or maybe I just got lucky"

No, you didn't get lucky. My Camaro is alot faster, and I mean ALOT, than my Caprice 305 TBI, and it's thanks to the gearing. Higher ratio in the Camaro compared to my Caprice.