Best HP/$$$ mods for 1998 2.5L inline-4
 

Hello:

I have a 1998 Jeep TJ SE that I imported to California from Canada.
While in Canada I installed a 2.5" BDS lift and put 33"x9.5" BFG MTs
on the stock wheels and it was great in the snow, but the tires are
pretty useless here.

I've recently started towing my 5x8 motorcycle trailer (for a
roadracing bike) back and forth a lot. With the small 2.5L inline4
motor and big tires, I'm starting to wish I had a little more HP on
tap.

When these tires wear out, I'm going to 31-inchers for the lower
weight and better match to the stock 4.10 gearing, but that's probably
not for another year or two.

Between now and then, what are the best HP/$$ mods I can do on the
Jeep engine? I want something safe, cheap, and simple. I'm not
looking to make my 128000km engine blow prematurely, I don't want to
run higher octane fuels, and I don't want to spend too much time or $$
installing a blower or anything like that.

The engine is completely stock. Stock filter, stock throttle body,
etc. I can't remove the catalytic converter because I'm in California
and need to smog the damn thing.

Got any suggestions? Has anyone done dyno testing to show what mods
made the most amount of improvement? Thanks for all your help.

Re: Best HP/$$$ mods for 1998 2.5L inline-4
 

I put a bunch of engine mods on mine, and got very little increase in
horsepower. It's louder though, and the fuel mileage is definitely better.
That should in principle keep the enviro-Nazi faction in my town happy with
me. ;o)

In your place, I would forget about engine performance mods and regear, so
you can get your performance back to approximately the same level and keep
those 33 inch tires. Get the biggest (highest ratio) gears you can.

Earle

"William Sitch" <will@sitch.org> wrote in message
news:d0cbe14b.0307251432.3c6d742f@posting.google.c om...
> Hello:
>
> I have a 1998 Jeep TJ SE that I imported to California from Canada.
> While in Canada I installed a 2.5" BDS lift and put 33"x9.5" BFG MTs
> on the stock wheels and it was great in the snow, but the tires are
> pretty useless here.
>
> I've recently started towing my 5x8 motorcycle trailer (for a
> roadracing bike) back and forth a lot. With the small 2.5L inline4
> motor and big tires, I'm starting to wish I had a little more HP on
> tap.
>
> When these tires wear out, I'm going to 31-inchers for the lower
> weight and better match to the stock 4.10 gearing, but that's probably
> not for another year or two.
>
> Between now and then, what are the best HP/$$ mods I can do on the
> Jeep engine? I want something safe, cheap, and simple. I'm not
> looking to make my 128000km engine blow prematurely, I don't want to
> run higher octane fuels, and I don't want to spend too much time or $$
> installing a blower or anything like that.
>
> The engine is completely stock. Stock filter, stock throttle body,
> etc. I can't remove the catalytic converter because I'm in California
> and need to smog the damn thing.
>
> Got any suggestions? Has anyone done dyno testing to show what mods
> made the most amount of improvement? Thanks for all your help.

Re: Best HP/$$$ mods for 1998 2.5L inline-4
 

William Sitch wrote:

> Got any suggestions? Has anyone done dyno testing to show what mods
> made the most amount of improvement? Thanks for all your help.

Swap out the stock TB for one from a 4.0 I6. That will free up some
HP. Just keep the original for when you need to pass emissions.

Stay away from air swirrly things, they just suck cash.

A CA legal cat-back system and header would also help.

Then there is porting and polishing, but that's in the $$$$ category.

--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors

Re: Best HP/$$$ mods for 1998 2.5L inline-4
 

I'd think about trading her, there just too many mountains in
Kalifornia, and If you live in Los Angeles or San Diego counties, then
you can't even get away with an exhaust modification. You'll be able to
do ninety five miles an hours again if you go back to the lighter stock
tires, just like your bike has a lighter flywheel in it, to be able to
win a race.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

William Sitch wrote:
>
> Hello:
>
> I have a 1998 Jeep TJ SE that I imported to California from Canada.
> While in Canada I installed a 2.5" BDS lift and put 33"x9.5" BFG MTs
> on the stock wheels and it was great in the snow, but the tires are
> pretty useless here.
>
> I've recently started towing my 5x8 motorcycle trailer (for a
> roadracing bike) back and forth a lot. With the small 2.5L inline4
> motor and big tires, I'm starting to wish I had a little more HP on
> tap.
>
> When these tires wear out, I'm going to 31-inchers for the lower
> weight and better match to the stock 4.10 gearing, but that's probably
> not for another year or two.
>
> Between now and then, what are the best HP/$$ mods I can do on the
> Jeep engine? I want something safe, cheap, and simple. I'm not
> looking to make my 128000km engine blow prematurely, I don't want to
> run higher octane fuels, and I don't want to spend too much time or $$
> installing a blower or anything like that.
>
> The engine is completely stock. Stock filter, stock throttle body,
> etc. I can't remove the catalytic converter because I'm in California
> and need to smog the damn thing.
>
> Got any suggestions? Has anyone done dyno testing to show what mods
> made the most amount of improvement? Thanks for all your help.

Re: Best HP/$$$ mods for 1998 2.5L inline-4
 

The 4.0L TB swap brought some good gains for me. I also have an AirAid
intake (lots of discussion there) and a PowerAid throttle body spacer
(a.k.a. money-sucker).

Eric


"William Sitch" <will@sitch.org> wrote in message
news:d0cbe14b.0307251432.3c6d742f@posting.google.c om...
> Hello:
>
> I have a 1998 Jeep TJ SE that I imported to California from Canada.
> While in Canada I installed a 2.5" BDS lift and put 33"x9.5" BFG MTs
> on the stock wheels and it was great in the snow, but the tires are
> pretty useless here.
>
> I've recently started towing my 5x8 motorcycle trailer (for a
> roadracing bike) back and forth a lot. With the small 2.5L inline4
> motor and big tires, I'm starting to wish I had a little more HP on
> tap.
>
> When these tires wear out, I'm going to 31-inchers for the lower
> weight and better match to the stock 4.10 gearing, but that's probably
> not for another year or two.
>
> Between now and then, what are the best HP/$$ mods I can do on the
> Jeep engine? I want something safe, cheap, and simple. I'm not
> looking to make my 128000km engine blow prematurely, I don't want to
> run higher octane fuels, and I don't want to spend too much time or $$
> installing a blower or anything like that.
>
> The engine is completely stock. Stock filter, stock throttle body,
> etc. I can't remove the catalytic converter because I'm in California
> and need to smog the damn thing.
>
> Got any suggestions? Has anyone done dyno testing to show what mods
> made the most amount of improvement? Thanks for all your help.