Ok guys, this has probably already been done but what are the cheapest ways to squeeze more power and economy out of a GM TBI engine? I'm talking TB spacers, intakes, headers, ecu reflashes and whatever else. Lets hear what has worked for you!
I dont think economy AND mo' power should be used in the same sentence when beefing up a TPI .... wait, you said "TBI" ...... nevermind! Mess with the CPU ... chip it, thermostat, etc.
I tried a 180* thermostat and noticed a gain in power but was not pleased with the economy loss, nearly 2 mpg and the power gains weren't worth it. More power can also mean better economy depending on the nature of the mod and i'd like to find one that achieves both
There seem to be differing trains of thought on the L03 heads. Some claim they aren't bad (no worse than the LB9 and L98 heads). Others think they are terrible. Honestly I'd probably try what that other guy tried in the link I provided in your other thread. Vortec heads (305) with the Edelbrock intake and the adapter to run the TBI. You could probably also use a mild cam. I think the big issue with the TBI cars and the speed density system is finding someone who will actually take the time to properly tune it. I know a few years back there was a guy on Impalass.com that did TBI system tuning, but I have no clue nowadays.
The fact that it's only got 305ci's to work with is the biggest downfall, and the tbi didn't help either. Throttle body spacers work good with the tbi. Increases the plenum volume, and helps with atomizing the fuel again after it drips off the throttle blades. A cooler t-stat, a new prom chip (can't "tune" tbi computers), and a small bump in base timing will help a little, un-cork the exhaust a bit and an extra 15-20hp is possible. 3.23 tow pack gears to replace the base 2.73s will make a difference as well. Save up for a 350 Vortec out of a late 90's pick up, and a tb and computer off a 350tbi B-body. Easy swap, and will give you a little more help in the go department. You could do this swap on the cheap for $4-500, but more likely $6-700. You may be able to get a 350 tbi wagon for that kind of money though too. Mike
That was my thought, though finding one in decent shape for under $5000 isn't easy in Michigan. Thinking of saving up my pennies and finding a later B body with an LT1 already in it, but going the Vortec route may be a reality if the 305 pukes sooner rather than later.
