Hey guys, I know this probably should be in the carb or FI section, but I thought I would ask some of my fellow Midwesterners what they have done. For now I am going to "freshen up" and tweak my 305 to get better performance. What I am having a hard time deciding on is should I go carb or upgrade the TBI or go to TPI? I am not a carb literate right now, nor do I have any experiance with burning chips. I can learn though. The TBI system looks to be a good system, and tunable, just don't know how much of a hassale it is to get it running right. Any input you can give me is much appreciated.

Dave

 

Carb would be the way to get the most power out of what you've got. But for a 305 I'm not so sure I would do it. You could get rid of your ecm and all emissions equipment or get a computer controlled carb, but I believe you'd have to get a carb ecm, not just the chip.

If I were you I'd do everything listed in The Ultimate TBI tech article, then some headers, a high flow cat, and some fatter pipe's (2.5 should do you fine). Advancing the timing may help some too. With all that you'll probably run 200hp or slightly less. TPI heads and a bigger cam will liven things up a bit, but then you'll have to burn a new chip.

The only advantage I see to TPI is the ability to use a bolt on under hood supercharger, but running that on stock internals wouldn't be such a good idea.
Alex

 

Thank you Alex. I plan on checking the bottom end out to make sure it is ok and replace the bearings and maybe the rings if everything is ok. Then I will do heads/cam/intake/ and whatever I do for fuel. On the exhaust, I am going to go with headers, but don't want ground clearance issues, any advice? Also I do not live in an emmisions area so any other suggestions for exhaust? I know true duals are good, but even IF i get to 350 TQ/HP could I come off the headers to a single say 3 1/2" pipe then split back to duals kind of like the stock setup? Thanks again.

Dave

 

For headers I'd use Hedmen or similar shorty headers, most good shorty headers have prefab y-pipes available. I think if you use shorty headers you don't have to lift your engine or grind anything for fitment. But I need to do some more research. Going that route you shouldn't lose much ground clearance over stock. For a 305 you should be ok with a single 3" pipe. The thing about using dual exhaust is it usually interferes with subframe connectors. Which are always a good idea. Use a highflow a cat rather than gutting yours as it's illegal and there is quite a stiff penalty for it. Lose your AIR system and if you have t-tops you might as well get rid of you AC as well. Getting rid of those two should give 4 or 5hp.

Don't forget other parts of your car either though. The suspension usually needs upgrading. Lower control arm relocating brackets are a good idea to prevent wheel hop. And subframe connectors to prevent chassis flex. Also check the condition of you floor pans. Between the subframes, they pretty much are the frames. I didn't check mine and found plenty of holes, you're in the same climate so the same thing may have happened to your car as well.
Good luck
Alex

 

Alex, not to worry on the rest of the car. I am doing the suspension/chassis first. I agree with make it safe before you make it fast. I will look into the Headman and other shorty headers and the y pipes as well. Can't seem to find anyone so far that can burn chips so I will start checking that out to get familiar with it. Thanks for all the help.

Dave