2000 Wrangler Top End Power

Matt0320

New Member
Joined
Jan 21, 2009
Location
Jacksonville
Ok, I have a few questions for those of you that have been in this a whole lot longer than I have.

This is what I got!

2000 Jeep Wrangler 4.0 Manual Transmission
8" Skyjacker Lift Kit
37" IROK Super Swampers
4:88 Gear Ratio

My problem is when driving on the Interstate I have trouble getting over 70MPH in overdrive. I can drive for miles with the pedal to the floor and not break 70MPH and if im going up hill I can forget it. I get about 11 MPG intown or on the highway, it dosnt really seem to matter.

How can I improve my top end power and not negatively affect my MPG's? What are my options? I've considered changing gear ration to 4:56 or trying to find a turbo to install or even go down to a size 36" tire but I don't know the pro's and con's of making these changes.

I DEFINITELY don't want my MPG's to get worse, if anything I would like them to be better. Does anyone else have this problem and if so, what did you do? I've even considered these chips that are all over the internet advertising better MPG's and more power but I'm skeptical.

I'm not looking to put in thousands of dollars in this project so cheaper the better.

Any ideas are appreciated!


Matt
 
Your driving a brick, lifted 8", with big tires. With those tires etc. you probably need to be over 4.88 to run OD or just run 4th. 11mpg.. not sure what your expecting with that setup. Easiest thing would probably be more gear, smaller tires, lower lift, more hp or any combination there of..
 
i dont think there's much you can do unless you regear or go to a smaller tire. anything that ads power is going to use more fuel. you could port match your intake and throttle body and go to the bigger ford injectors that a lot of stroker guys use. that might help a LITTLE bit
 
Thanks guys for the info thus far!

I don't have much experience or have heard much feed back on gears over 4:88. Say I went to a 5:13 gear ratio, I know I would have a lot more pull on the low end but how would it affect my top end? With the combination of going to a 5:13 gear and a 36" tire, then do you think I could tell a difference in my top end power?

Also, Is there a website with more info on what hxcjohnny was talking about....

"you could port match your intake and throttle body and go to the bigger ford injectors that a lot of stroker guys use. that might help a LITTLE bit"

Matt
 
if you switch to 5.13s youll be spinning more rpms. therefore youll be better in the power range of your engine. BUT i have 4.88 and 37" toyos and dont have any power issues on the interstate. of course i only have a 4" lift. If you dont have a good 2.5" exhaust that would be a start. I think you should lose some lift.
 
theres always is a tradeoff. you traded power for lift and big tires. the next tradeoff would be a lot of money to get the power back. you could do a few diffrent things that don't cost a lot of money but none of them are going to make a real seat of the pants differnce. all my trucks use to be lifted with 38's 40's but i'm a little older now and am not willing to accept the tradeoff any more.
 
Gas mileage sounds about right, power may be right also.

A factory 4.0 makes the most torque/HP around 3200/4800 rpms respectively. Next time you're doing 70 look at the rpms. If you're at 3000 or more, don't expect much more power - that's about all you're going to get.

You may have to deal with downshifting, just the way it goes. I don't care what gear you run, you still lose some power to the wheels with bigger tires.
 
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