I have a 1989 Iroc convertible with a 305 engine. It has 30,000 miles on it and is in like new condition. I bought it in October and have just recently had the time to finally drive it a little. Now my last 4 cars have been Corvettes with 350's in them but I would think the 305 should be able to be stronger than it is. It seems a bit sluggish and needs more pep. It is completely stock. What modifications can I make to bring the car to life a little? I'm not talking about major modifications, just a few things that might work a little. I don't need it to be a race car , just a little more than I have now. I figure you guys have done it all and know what works so you can save me some time. Any suggestions would be helpful. I really love the car otherwise.

 

Start with the basics of better airflow on both the intake and exhaust. K&N filter, and Cold Air Induction, Airfoil, Free flowing catalytic converter and exhaust, maybe headers, fresh tune up with better plugs and wires, a chip or eprom programmer, these are some of the basics, of course you can get into aftermarket runners, or opening up the ports by machining behind throttle body and stuff, it all depends on how much time effort and money you want to spend. I just thought I would throw out some of the basic stuff.

 

Oh and by the way nice snag on a low mile 3rd gen. If you start replacing things like exhaust and intake you probably want to hold onto any stock parts so in years to come you can return it to stock for sake of value on a low mile unmolested car.

 

That all sounds good but anything more specific?

 

well. normally, i would say to put a cam in it, and pull the heads off..

reason being that with the miles most of the cars have, they need new valve seals anyway, so you can pull the heads off, do a lil work to them, replace the seals, and put decient springs in there...


but since your 89 has less miles then the 01WS6 in the driveway, i dont know....

do you want to get into the motor, or do you just want mostly bolt ons...

my thoughts would be one of the milder smog legal computer grind cams (from comp or crane) and a diff TPI intake... the stock intake blows donkey *****.

 

Nice catch--a 30,000 mile '89 IROC 'vert!! You won't like reading this, but... LEAVE IT ALONE!! Not trying to be an a$$. Do the routine maintenance, put gas in it, and drive it. If you want vette power, buy another vette.

 

meanwhile i think totally diffrently.

if it was mine, i would molest and mod it the first day i got it.

 

Put some gear in it.

Change the rear end gears.

Nothing will give you some real seat of the pants go like a
bit o' gear.

Your 89 305 iroc likely has 2.73 or 3.08 rear gears

Have new 3.73's installed by a qualified drivetrain mechanic.

it will make your 305 feel and go much more like a 350.

It will make a big difference and not screw up the car.
Any other modifications will work just that much better once you
step up to a performance rear gear ratio.

A good place to start.