88-300/6 efi 4x4
How much difference does a HP chip make?
Would a cam make much difference?
Eliminate emission controls? (no checks here)
Gears (3.55) want to move from 33" to 35" or 36" tire.
super coil?
So far:
I cut the exaust past the o2 sensor and removed the whole system.
I ran a 3" straight pipe into a 2.5" turbo muffler and turned it out just behind the rear tire. I used a copper post dist. cap and rotor. Taylor spiral core wires and autolite plugs. 190 degree thermostat. New injectors. I enlarged the air intake side of the air box. I left the intake in the same location. It is just larger. 2- 1,000 amp batteries for the 185k KC lights.
4" rancho lift kit. plus one extra inch on the front to level it out. 33x12.5 x/t bigfoots.
I was able to get 15 mpg on hwy. before I changed to the 33' tires. I average about 10 now. I only run about 1800 rpm at 60 mph. I was told that the injectors were wore, so I replaced them $400 and no change. I replaced the fuel filter and did a pressure check. The tune up etc. No change. It does sound better though. I blocked the air tube from the exaust to the intake by making a soild plate at the intake manifold. I unhooked the air pump and noticed a sound change and not much performance difference. I hooked it back up. It does miss at idle with it working. I would like to get the performance up along with the mpg if possible. I figure that if I am only going to get 10 mpg I should at least be able to grunt through the mud and sand at a fairly good pace.Thanks for the help

 

Did you also change out the speedometer driven gear on the end of the cable? hat could be part of figuring the gas mileage. Also, you are pushing bigger tires, this also has an effect on mileage. If you want the lowdown on the chips, go over to the computer chips forum and talk to danny ( D for short), and he can tell you anything you want to know. He's also a superchips dealer, so he should know.

A cam will help, with your horspower, just be sure to get one that will be compatible with your Computer system.

If you have mass air, then you should be set on your cam mods and all. If not, the speed density system will throw everything off and make it not run well at all.



1988 F-150, SWB, 5.0 EFI (formerly 4.9 EFI), M5OD 5 speed, 3.08 gears, Summit shorty truck headers, Custom built Flowmaster exhaust system. Force 4 LP6000 lightbar, Federal signal PA-300 100 watt siren, Icom IC-V100 50 watt mobile radio.
=======================================
1965 F-100 (just purchased 1/18/01), SWB, 390, C-6 auto. Dual exhaust, Not much else to do to it.

Can see both below.

[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]

 

Black a camshaft will do good for the inline 6. As the previous post stated just make sure the camshaft you get will work with your engine. For a computer controlled engine with the Speed Air Density system any advertised duration will work, but make sure the "Lobe Seperation Angle" is more or equal to 112 degrees. I got a camshaft from Competition Cams and they told me a 112degree lobe seperation is a necessity when it comes to a cam for Speed Air Density controlled inline 6s. Call them and ask about the 300-6 cam selections or call Clifford Performance.
Since your running bigger tires install a taller gear ratio. Turning 33" tires is harder than you think. If you want return to a stock "like" gearing then install 4.10s, if you want more rear wheel torque, install 4.56s or taller. This will increase your gas mileage by 1-3 miles per gallon. I used the following equation to figure this out:

Current Gear Ratio * (New tire size/old tire size) = Near Gear Ratio.

For example:

3.55 * (33/29) = 4.01

Not to give you a ration of cr@p but you can get a high flow catalytic converter for your truck, which will reduce emissions big time and not reduce horsepower. As responsible drivers we need to clean the exhaust of our vehicles so we can breath clean air. Just imagine all of the crap you inhale everyday because people don't want to install these devices.

 

That's next up for my rig, Paul: A set of Clifford "Street Rod" dual-outlet headers dumping into a dual-inlet/single-outlet hi-flo convertor, tying into the already-there Gibson cat-back.

Tentative date, third Monday in March, which will give me another paycheck and the weekend prior to do the install.

My Stage 8 locking header nuts should be here this week, and I gotta say, that big ol' factory cat has got to go to make room for a new trans crossmember that needs to anchor right where its at.

I think the silver Jet-Hot coated tubing and the aluminum EFI ram piping all in a row ought to look incredible!

Eddie

 

I was under the impression that if a vehicle is tuned up properly, that the cat. was not doing anything. I was told that all the smog stuff is to compensate for the lack of maintanance?
Does anyone have experience with a turbo on a 6? Is this an option as far as leaving the motor stock and just adding a turbo.
What does a turbo do to mileage? I wonder in the cost/hassle scale, how turbo vs cam and head work compare and what the
MPG and power figures would be. I think it is time for more research. thanks

 

I'm kind of new here, but I just wanted to put my 2 cents in(incidently I think this forum is the best thing since sliced bread) paul seems to really know his engine internals, but one thing I disagree on is the 4.56 gears for improved performance. Anything much past a 4.10, especially being it's usually matched with a tall tire, has less teeth on the drive gear, because you can only fit so many teeth on the driven gear. This makes these high ratio gearsets weaker, and prone to blowing teeth off when the drive train get shocked, which is frequent on big tired off roaders.

 

Holy Cow I did say increase mpg with 4.56 gears!!! Whoops! I meant to say, it would decrease gas mileage. Thanks for catching my mistake woodbutcher! YIKES! I gotta start proof reading my posts before I post them. Sorry about that guys!!!

 

Thanks for the help. I am still a little confused with the gearing. I have 3.55 and I am under powered in OD. I turn about 1,800 rpm on the hwy. My MPG went down 2-3 miles with the change from 31' to 33' tires. The goal here is to get it back to about stock gearing. I was hoping that it would bring back my gas mileage. I have the 5 speed, so I have granny and OD. I just got back from 4-wheeling and had one of the best performing rigs out there. I have been advised by several people to " leave it alone" but there is still a clearance problem. Differential drag.
Does 36" buckshots and 4.56 gears come out close to stock? The motor is on hold, I think I will wait for bebuild time and do my modifications to the engine then. It has been too dependable to mess with. Does anyone turbo these motors. I have access to one?

 

>Thanks for the help. I am
>still a little confused with
>the gearing. I have 3.55
>and I am under powered
>in OD. I turn about
>1,800 rpm on the hwy.
>My MPG went down 2-3
>miles with the change from
>31' to 33' tires. The
>goal here is to get
>it back to about stock
>gearing.

I think the problem lies in your tires, if you want to go back to stick gearing then put stock tires back on it.

I was hoping that
>it would bring back my
>gas mileage. I have the
>5 speed, so I have
>granny and OD. I just
>got back from 4-wheeling and
>had one of the best
>performing rigs out there. I
>have been advised by several
>people to " leave it
>alone" but there is still
>a clearance problem. Differential drag.
>
>Does 36" buckshots and 4.56 gears
>come out close to stock?

Now you're talking real gas hog. You really will be turning some serioous rpms, to try to get those tires rolling with those gears. You have to figure out what you really want first. Gas mileage or severe off road.


1988 F-150, SWB, 5.0 EFI (formerly 4.9 EFI), M5OD 5 speed, 3.08 gears, Summit shorty truck headers, Custom built Flowmaster exhaust system. Force 4 LP6000 lightbar, Federal signal PA-300 100 watt siren, Icom IC-V100 50 watt mobile radio.
=======================================
1965 F-100 (just purchased 1/18/01), SWB, 390, C-6 auto. Dual exhaust, Not much else to do to it.

Can see both below.

[link:www.geocities.com/hotrodford_88/|Hotrodford_88's Webpage]