im wanting good power + good fule mileage i pull a lot and travel a lot, i have my vavles adjusted my timing is bumped i have my pin ground my afc star is stock and my full power screw is +-1 in, im getting the 3200ve spring for christmas, has anyone found the perfect ratio for power and fuel? thanks
cody

 

well you could replace your injectors, seeing as they have a few miles on them, i would suggest 190's for fuel economy. i have some waiting for a good day to install, and after that i can repost to tell you how it works. but you could also use a BHAF. the biggest thing i have done is a valet switch, just to help full fuel from being applied. seeing as i feel like im flooring it while im getting close to half power, made my milage soar. hope this helps

 

Keep your stock injectors, they are better for mileage than any of the bigger ones. Set your smoke screw and star wheel as high as you can without excessive lag. The smoke screw is more important, it will kill your mileage if it's set too low. Feel free to crank the power screw up. Your right foot is the best mileage control - if you aren't using the power you aren't using the fuel. Having the power available doesn't hurt the mileage - using the power hurts the mileage. An intercooled truck with stock injectors and an aggressive fuel pin grind can make 250 HP - which is a lot of fun. And the mileage will not change if you don't change the way you drive.

 

awesome, my pin is very aggresive which is good i guess, my injectors are stock my full fuel in + 2 or 3 from stock afc is really close to the bottom i have an intercooler. so guess im headed towards mileage, thanks dave makes me fell good!

 

How many threads are showing on a stock smoke screw? I got a consistant 18 mpg before I put the 12cmWG on and 16 after. Do you think I should tighen up the starwheel? Driving down the road before there was like 1-2 PSI boost, now I have about 5-6. I am convinced my milage went down with the smaller housing.

 

Added boost should increase mileage, all other things being equal. More boost = more air to cleanly burn the available fuel.

Smoke screw is just a plug filling the hole on top of the AFC cover on mine - turned all the way out flush. Before I did that and turned up the starwheel I had alot of low boost smoke and reduced mileage. I don't think the smoke screw and starwheel are needed at all once you turn in the fuel screw.

 

awesome info thanks

 

I could be wrong, but wouldn't more boost cause the opposite? More volume or air, or freer flowing would be better, but boost (pressure) is also a product of restriction, isn't it? With more boost, I get higher EGT's.

 

KartRacer- You normaly see higher EGT with higher boost because you are using fuel to make the boost, not a different housing.

In theory, more air will mean better economy and lower EGT, BUT, one must also factor in drive pressure. If the drive pressure gets too high, you will offset the benefit of the added boost.

I noticed a reduction in boost, but the same cruise EGT (and about 50deg higher max) when I went from a 12cm housing to a ported 16. This tells me *MY* engine is working less to make the same power. I think the 12 is too restrictive for MPGs in a 1stGen. All of the trucks I have installed a 12 on have dropped 1-3mpg, towing, empty, hwy, city. Put the 16-18 back on, and I gained it back. Boost is no more than resistance to flow. More boost isnt always a good thing. Put another way- the drive pressure increases with the 12, which makes the engine work harder to get the same amount of air to make the same power. It looks cool on the boost gauge to make the needle bounce, but I dont think it's god for economy or high HP usage either towing or playing. I havent taken a hwy trip since installing the 16 to notice any difference. I drive 2mi to work, so I cant really count my city MPG as being better or worse- that depends more on the weather, and whether I remember to plug it in the night before.

Daniel