Jeepers and Creepers Bored out 4.0 throttle body...
on a 2.5L engine?
testing in progress...
While the 2.5L are great engines for the trail, their lack of power for street and
highway driving leaves much to be desired. Installing bigger tires makes it even worse.
Installing lower gears seems to be the end-all fix, but with the Dana 30/35 re-gearing
can bring on it's own set of problems, not to mention the cost. Which brings us back to
the age old question: How do I get more power
out of my 4 banger?
I recently had the opportunity to try out a bored out 4.0 throttle body from
JeepersandCreepers.com
The stock 4.0 throttle body is much larger than the 2.5, boring it out takes it a
step further. The throttle body is a simple bolt on installation: Just remove the plastic
air intake, disconnect the three electrical connectors and throttle cable, and unbolt the
throttle body. Slap in the new one, connect everything back up, disconnect the battery
for a minute (to reset the computer), and you're done! I performed this in 10 minutes in
a McDonalds parking lot.
The Results?The best way I can describe it is I feel like I'm riding on 30's
again (I have 33" tires on now). I've noticed an immediate, stronger throttle response
and smoother acceleration with the JeepersandCreepers.com throttle body. It takes much less pressure
on the gas pedal to get the Jeep going, which means I don't have to ride the clutch for
1st gear anymore. The acceleration throughout the low end is stronger, and the engine
just comes alive above 3000rpms. Hills that I was having a hard time climbing before I am
able to power over at 75mph now. Another thing is I now have the power to use 5th gear
again. Sound too good to be true you say? Well, there does seems to be a few drawbacks to
using such a large throttle body on the 2.5L. Although there is a definite increase in
horsepower, I believe the torque may have suffered. On even small hills, the engine speed
can drop very quickly. The trick seems to be keeping the rpms above 3000 to help avoid
this. There is also a chance of the engine running lean. If there is a problem, the check
engine light should come on. I haven't had any lights so far.
Testing in progress... So far I have been more than pleased with the results of
the
JeepersandCreepers.com bored out 4.0 throttle body. However, there's always
the question, is it too much? I plan on hooking up a meter to check the air/fuel
meter and inspecting the plugs for possible lean conditions. I haven't heard any pinging
even under load with 91-octane California gasoline. There may be a chance of problems
with fuels of lesser octane. I also have a large dent in my exhaust pipe, which up to
this point I just left in since I noticed it helped the engine's torque with the stock TB
by creating more back pressure. I will be removing that soon for a more accurate test of
how a "stock" 2.5L responds to the bored out 4.0 throttle body. I will be posting the
results as soon as I find them.
If you have any questions you can always e-mail
me, or check out
JeepersandCreepers.com for info on their throttle bodies.