Chevy s10 mod questions
 

I have a 94 s10 with a 4.3l Z TBI, 4x4. I am getting 22.0 mpg after tune up, and I have made a intake that goes on the end of the snorkel and can be a wai or cai, but am not sure which would be better. The problem is, their is a butterfly valve in the air filter housing that opens and shuts depending on how cold the air is. When shut it draws air from the exhaust manifold which is only 1 1/2 inches wide, and then opens up after the engine is warm. If I make my intake cai, it will keep the valve closed longer, especially on cold mornings on my way to work 15 miles away. My question is, if I leave it as a wai, it would stay open more and allow a lot more air in because the regular intake is 4" wide, and without any IAT or MAF on it what affect will that have on the engine and rich/lean mix? Not sure which direction to go with it?

Getting 22mpg with a 4.3l 4x4 s10? Work on aero, the engine's already fine!

get the tonneau cover that starts from the top of the cab and angles down towards the top of the tailgate, i would try the wai, test and try would be best bet there, and throw the spare tire into the bed which would remove the weight of the spare tire mount and less under body drag

I just put a diy half tonneau on this weekend, and I am driving with a vacuum gauge. Problem is with it being an OBDI I have to wait until I fill up get an accurate mpg. With a wai, am I correct in thinking it would tell the comp that there is less oxygen in the air, so it would lean out the mixture? If so, by driving with the vacuum gauge and feathering the throttle, wouldn't I get better MPG?

I do not use a sg or anything else i just watch my rpms never letting it go over 2000 after i get up to speed i hold the rpms steady and not the speed, i still fill up to get my mileage which ive been doing about 6gal. a trip when testing, putting on a wai would lower the power of your motor which in most cases is better for mpgs, if u learn how to correctly use a vacuum gauge for mileage it will help

Thanks, I will try that, and check out some chevy 4.3l forums for any other tweaks that might go with the wai, such as advancing the timing or tbi spacer.

Search me and see my efans. They should help you, i done mine but have no clue what they gave me

I agree engine wise that 22 mpg is almost unheard of.

Look to some aero mods, like a chin spoiler in my signature below.

At 22 MPG there's not much you can do to improve the drivetrain. I would not spend time or money on intakes or electric fans, etc. Aero mods would be the best bang for your buck.....I agree with the front air dam, but a well designed, light weight aero cap will give you the best drag reduction by far. In the most reliable studies there is a minimal gain with a tonneau (half or full), but a significant gain from the areo cap with a 10-12 degree slope (even more so with compound slopes).

Of course a lot of this depends on the type of driving (speed, traffic, etc) you do.

Thanks for the input. I think I will try to block holes in the front and add a garden edge front spoiler and see if I get any gains. Not sure I am up to making a aero cap that looks good yet, I will have to do some research on that.