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.

addicted to mpg
 

I have realized I am addicted to trying to increase mpg's on my truck! I made a front air dam with garden edge today. Earlier this week I blocked off my grill except for the radiator (not sure I want to close it off yet), and am checking my tire pressure weekly and running them 3 to 4 psi over the max. I found out today that when I put the obd 1 code reader on while the engine is running it will go into "field diagnostic mode" so I can see how quickly it goes into closed loop and then whether it is running lean or rich by how the lights blink. This helped me see the O2 sensor seems to be working and how and when the rich and lean conditions correspond to the vacuum gauge I have. Sorry about the running on but my wife's eyes glaze over when i talk about this stuff. Lastly, does anyone know if running a vehicle in field diagnostic mode for longer periods can cause any damage?

Congrats, how about some pictures?

Pics of DIY air dam and 1/2 Tonneau
 

Sorry, can't post pics, won't let me, says it is too large.

22 MPG is very good for the 4X4 model.
The WAI normally helps with true TBI, but it will boil down to the type of driving that you do. If you hypermile and do not have to climb a lot of hills (need for power), then the WAI will boost your MPG.

An electric fan will also help, as the factory clutch fan causes a measurable loss in mileage. By the same token an underdive crank pulley will also help, as would converting from power-steering to a manual steering box.

If your engine comes with a factory oil-cooler, and you do not do any towing, then remove it. Hot oil gives better mileage.

Air dam pics
 

Got pics of air dam and 1/2 tonneau, now need to find an e-fan for cheap or free.

for the efan check junkyards or craigslist for car parts

any better pics of how you made the half tonneau

Also find you an airdam thats not got the holes in it, some modles came with a smooth one.

Check the junkyards for the efan. Most s10 owners use the taurus fan, i chose the 05 or so escort fan, google it and see on s10forum

1/2 tonneau
 

This is just a temporary tonneau until I see how much mpg I gain. Then I will build a better one. It was made out of 1/2 inch plywood and 2x4 and 1x2's. the cover is an old cover off of another truck that was a snap on cover. The wood is not treated for weather and the cover is not tight enough. There are also pictures of a WAI I made that I am trying right now. Both items cost me $0.00 to make.

That front air dam/chin spoiler does look angled down quite a bit. I'm not sure that it will not just direct air down (and underneath), rather than around to the sides.

Adding a splitter would resolve this situation in any case.

kach22i,

Not sure I could easily make a splitter. Didn't you make one out of your front air dam? How did that work for you?

I brutalized some vinyl cove base material to form a mini soft splitter. No noticeable difference, mostly looks pretty.

I'm sort of hoping someone comes up with a better way, so I can copy them next time.;)

Just filled up my 4x4, 4.3l s10 and got 25 mpg. It was only 108 miles, but wanted to check it after the new mods. Heading in the right direction, will go longer this time before fill up.

I had an 84 S10 with the 2.0L stick. Only had a heater, no radio, no A/C. That was my first new vehicle. Simply advancing the timing got me 33 mpg. Remember this was back in the 55 mph national speed limit days.

How much did you advance your timimg and how much of an increase did you get from before advancing? Mine is a 4.3l TBI so I may go to 4 degrees and give it a try.