Increase horsepower to 85/Z28
 

Hey!

I need some help increasing horsepower to my 84 Camaro Z28 3.05 TPI. Right now I'm looking for bolt on parts that will increase the horsepower.
Please help.

Did you already swap TPI into that 84> because that car shouldn''t have a tpi motor if it was stock. only 85+ had tpi. Alot of guys will tell yuo to go buy a 350 and start from there. You could get some decent power out of a 305, but all and all you would probably be better off going with a 350. Either way its gonna be an expensive project. One I couldn't afford at my age, so I just opted to get a newer 4th gen and go from there. My 86 is super clean and a great car, but it would cost soo much to get a good motor and repaint it. Just my .02 cents

WILL

Do you have the TPI stuck on a otherwise stock LG4 motor or what?

If so most likely you'll want to look into a camshaft swap (a 204/214 @.050, .420/.442 cam can be had for $100 from Summit, should work great), adding headers/high flow cat/catback (get all the exhaust at once, for a TPI single cat car, ie it will all be 3" stuff), and then a little bit of work on the TPI itself. Like at least porting the plenum and adding an adjustable fuel pressure regulator (or shimming the stock one).

That's just what I've done to my old 86 IROC's 305 TPI, responded really well. Assuming it is a LG4 you have it will benefit even more with it's worse exhaust setup, same crappy peanut cam, etc.

85 camaro
 

I'm sorry I was in a hurry when I posted that message. The camaro that I was talking about is an 85/Z28/305/TPI. I am looking for bolt on parts to improve horsepower without spending too much money so far.
Thank you for any help. Sorry for the misprint on that.

Well since you have the 85 TPI, you have a decent cam in it. No need to touch that yet. You should also have either 3.23 or 3.42 gears, so you're good there too. As usual, the first thing you should do to any of these cars are headers and a full 3" exhaust system. Homemade cold air, K&Ns, cut MAF screens and a quarter in the fuel pressure regulator are cheap and will make a small difference. But do the exhaust first.

Oh good deal, I had a 85 IROC with the hotter 215hp 305 TPI too. Bigger difference than 25hp would appear over the peanut cammed 305 TPIs...

Main things I would do are as listed above, a set of headers, highflow cat, and a good catback right off the bat. Big improvements in that exhaust. On top of the standard little intake mods go ahead and port your plenum like I mentioned above, cheap (free...) mod that yeilds a noticeable gain... GMHTP mag got around a .15-.2 quarter mile improvement with the porting if I remember correctly on a fairly stock 350 TPI. I've ported all the TPI intakes on the 3 TPI cars I've had, definitely worth the time/effort. While you have the plenum off for porting throw a shim in the FPR, I used a quarter too...

I have a brand new BBk adjustable fuel pressure regulator for sale cheap. They help a lot if you are planning on doing the intake and exhaust, but wont do much for a car with no other mods. I paid $59+shipping, but its yours for $30.

Email me at m0scholl@wmich.edu