How do I increase gas mileage?

[fixitman]

I want to know if there is anything that I can change or replace on my 1988 Chevrolet 4x4 that will help to improve the gas mileage? It currently gives me about 11 mpg. With gas prices up there it is costing me too much to drive my favorite truck.

[Palf70Step]

Motor, Tranny, gears?? What is yours running?

Also 1/2 or 3/4 ton model?

[66skylarkpost]

air intake , ignition upgrades (coil , module ) , throttle body spacer , exhaust , headers ... cam ,head porting . how far you want to go ? heres a couple pics of my 89 c1500 .its a 5.7 with 700r4 with 3.07 gears ,small cam , holley 670 tbi . i get about 18-20 at around 60-70 mph , it drops to about 16-18 at 75 and up

[CPNEJR]

66skylarkpost- with the throttle body spacer do you need to adjust the tv cable on the 700r4's? Also where did you get the air intake and for how much?

[piecesparts]

The TV cable bracket can be spaced upwards by putting a standard 1/2" nut under the front bracket mounting pad and that is all that I needed with my TBI spacer. As for the tubular intake, they are all over the market. Just pick up a "Truckin" magazine and use any one of the vendors inside, or go onto the LMC Truck, Stylin concepts, or Summit Racing websites. E-Bay is another source. I put in a standard 14" round air cleaner with a 4" K&N filter and put it together for less than most tube intakes cost.

[66skylarkpost]

i ended up cutting the bracket all together on the flat vertical area , adding material to raise it about an inch and a 1/16 . i felt it was nessecary to get the geomtry back to where it was .then prper adjustment is important as for the air intake , i got it off ebay a couple years ag , where i only run it in the warmer months and i put the stocker bad on when it gets cold .it helps on start ups . also when i changed the cam i had the intake and spacer machined out to 2" to flow with the holley tbi !

[piecesparts]

The picture on the bottom of my last addtion to the post shows that the TV cable is basically flat with the TBI's arm, so I found that just spacinig up the bracket at the front gave me the space I needed.

I run this setup all year long and even into the winter. The change over to a set of electric cooling fans and getting rid of the stock clutch fan and shroud made the winter warm ups easy and the truck runs fine in cold air temps. I never really missed the riser tube on the air cleaner. I live in the middle of Kansas and we do see some single digit temps during winter. I work at a power plant and at times I have to start up in the early morning after sitting out in the cold by the plant's cooling lake and nice North wind blowing.

[CPNEJR]

cool thanks for the info. i am thinking of doing some of this stuff this spring or summer.

[BLE 'BURBAN]

Gear vendors overdrive unit will help out as well.
www.gearvendors.com

[get me on the road]

Originally Posted by 66skylarkpost

air intake , ignition upgrades (coil , module ) , throttle body spacer , exhaust , headers ... cam ,head porting . how far you want to go ? heres a couple pics of my 89 c1500 .its a 5.7 with 700r4 with 3.07 gears ,small cam , holley 670 tbi . i get about 18-20 at around 60-70 mph , it drops to about 16-18 at 75 and up

What will adding a throttle body spacer do? I've done a little research on the web, and some people say they dont do anything. I'm going to be rebuilding my TB this summer and was thinking of adding one, but I would like to know what it does first.

[piecesparts]

Originally Posted by get me on the road

What will adding a throttle body spacer do? I've done a little research on the web, and some people say they dont do anything. I'm going to be rebuilding my TB this summer and was thinking of adding one, but I would like to know what it does first.

The Throttle Body spacer has had many different reviews on it, some good--some bad. I would say that it will depend on what design intake you are dealing with. The TPI design intake (where the throttle body is at the front of the intake and the injectors are in the intake base) will have a poorer performance increase result than one where the Throttle Body is mounted on the center of intake with the injectors installed in the throttle body, itself.

For clarification---The TPI design depends on a straight airflow to move to the cylinders effectively and sweep the fuel from the injectors mounted right above the cylinder into the chamber. The TBI has a flaw in this thought path---the injectors spray against the butterflies and creates a poor air/fuel mix and thus poor performance. The TBI spacer has helical grooves cut into it to get the air/fuel mix swirling and will break up the big drops of fuel (that is falling lazily off of the butterflies into the intake and get them mixed better with the air charge. This action will cause the air/fuel mix to traverse to the outer end cylinders and make those cylinders more efficient in performance (vice just the center four cylinders doing all of the work). If you look at your sparkplugs, you will see that religiously the outer end plugs are running leaner than the center mounted cylinder plugs. (a fact of life even on a carbureted motor)

By increasing the efficiency of the outer cylinders and mixing the air/fuel charge to get it broken up and creating a more ignitable charge to the cylinders, you WILL see a change in performance and an increase in torque is noticeable.

When I put on my Airaide TBI spacer, I noted that there was a new squealing sound that was like the sound that I used to hear in the old down draft carbs in the early years. That was the result of the activation of that air charge in my intake to get the fuel mix going. I noted a change in my trucks acceleration and it was a good change.

[get me on the road]

Thank you for the very detailed response pieces. I found a place online called checker auto parts that sells the airaid spacers for $92. I think advance auto is associated with them, so it should be about the same price, and advance is right down the road so no waiting for delivery. I plan to take the intake off when I do the TBI rebuild, just to replace the intake gaskets and to get a look at the inside of the engine. Do you know of anyone who sells a TB rebuild kit with intake gaskets and a TB spacer?

[piecesparts]

Yep, you can purchase the model 200-540 for our TBI trucks through Summit at $83.95.

Here is a website, that you might look at for some info on your TBI rebuild. http://www.tbichips.com/

[get me on the road]

I think you misread what I was asking. I am looking for a kit that has intake gaskets, tb spacer, tb rebuild parts (all in one kit) and if it had injectors that would be great. Also have you ever ordered from here http://www.fuelinjectorsoutlet.com/p...oducts_id=1240 or heard of them?

[piecesparts]

Good Luck