Any ideas on getting more torque from 2.5L

[cybersniper]

My YJ runs nice but I would like to have a little more torque ( and if possible HP) to move those big 35".
With the 4.88 I have an acceleration similar to that of a stock car with 30" but I would like to have the OMPPPFF I had when new with the 205x15.

Any ideas?

Ed

[crawlinTJ]

Originally posted by cybersniper
My YJ runs nice but I would like to have a little more torque ( and if possible HP) to move those big 35".
With the 4.88 I have an acceleration similar to that of a stock car with 30" but I would like to have the OMPPPFF I had when new with the 205x15.

Any ideas?

Ed

Shorting of swapping in a bigger motor, there isn't a whole lot you can do. You can do the throttle body, and headers, exhaust, intake, etc, and there will be some gains if you do them all, but that's a lot of money for not alot of gain.

Swap in a D44 in the front, and go to lower gears all around that will help.

In reallity, you bought a jeep, not a race car, live with it.

Oh and btw, your jeep is not a "stock car", it was never a "stock car". :flipoff2:

[281 Quad Cam]

its a 4 cylinder... there is nothing you can do for more torque, after all the mods that this thread will surely mention - you will pay for a v8 swap and end up with 20 extra lbft and hp. :(

4 cylinder can "fake" torque with gears or an inertia ring. these can get a 4 cylinder around on the trail quite well... but 6.32 gears in the axles and an inertia ring isnt going to get you past 50 miles per hour :rolleyes:

consider two options "dealing with it" or "doing something about it" and you know what both options entail. ;)

EDIT:
about fuel economy. the majority of fuel consumption comes from what your moving, and how. moving it requires an amount of fuel (raw energy) be burned... whether you burn it in a v8 or a 4 cylinder. the difference is the v8 has the ability to burn more fuel - for taking offs and passing in short bursts... however while cruising both should consume roughly the same amount of fuel, if a v8 doesnt do even better! (b/c it wont need to rev at 4000 rpm cruising)

[derf]

If you need torque for the trail, you can put in some kind of doubler like a Klune V. It won't help on the street but you'll sure be able to crawl.

With such a small engine, you'll never have a good combination of low end grunt and acceptable highway performance.

When I bought my CJ project, I decided to waste no time and effort on the stock 4 banger. It's getting a V8 from the start.

[nasvik]

Not sure if anyone noticed, but the OP is from Spain. So maybe excusing comments like "it was never a stock car" would be nice. Or at least translate the sarcasm to Spanish. :flipoff2:

Cybersniper - are the laws/regulations in Spain that would prohibit an engine swap? Emissions regulations or anything like that? Small mods you can make for HP (already mentioned) but forget the low end - just isn't going to happen. As has also been mentioned, gearing to help the 4 banger get the most from it's power band is the best option if retaining the engine.

Paul

[crawlinTJ]

Well I could have gone as far to say Jeff Gordon and Earnhardt drive stock cars! :D

[cybersniper]

Originally posted by nasvik
Not sure if anyone noticed, but the OP is from Spain. So maybe excusing comments like "it was never a stock car" would be nice. Or at least translate the sarcasm to Spanish. :flipoff2:

Cybersniper - are the laws/regulations in Spain that would prohibit an engine swap? Emissions regulations or anything like that? Small mods you can make for HP (already mentioned) but forget the low end - just isn't going to happen. As has also been mentioned, gearing to help the 4 banger get the most from it's power band is the best option if retaining the engine.

Paul

YOU GOT THE POINT !!!

Swaping in a V8 (or any other engine) can be a pain in the ass regarding paperwork...if at all possible.
That is why I NEED more power from the 4 banger

eduardo

[ouch]

stroke the crankshaft, use 4.0 pistons & 258 rods

[cybersniper]

Originally posted by ouch
stroke the crankshaft, use 4.0 pistons & 258 rods

Can I make a stroker from a 2,5?

HELP !!!!!
I thought that the 2.5 was just a 4.0 with two less pistons..... BUT the crackshaft is diferent and I thought that the basis for a stoker 4.0 was the long stroke crank!!!

Eduardo

[ouch]

the 2.5L has a shorter stroke than the 4.0, if you stroke it to the same as a 258 it will be 271. with lots of bottom end torque

[cybersniper]

Originally posted by ouch
the 2.5L has a shorter stroke than the 4.0, if you stroke it to the same as a 258 it will be 271. with lots of bottom end torque .

THANKS GOD !!!

But how can I get a longer stroke from the 2,5L crank?
I don´t get it
Ed

[ouch]

Rutter Army in Fresno can do it or there's a place in Kansas City.... can get the name on monday

[cybersniper]

Originally posted by ouch
Rutter Army in Fresno can do it or there's a place in Kansas City.... can get the name on monday

In the meantime, I will try to find the rutters in the web.
Thanks for you super advise.
ED

[derf]

I missed the fact that you were from Spain. Beautiful country. I visited for a couple weeks back in 1986. I don't remember much spanish except for "donde esta el bano?" and "quiero dos cervezas mas por favor." :D

To direct the question about more power from the engine you have:

1. Increase the compression ratio. You can do this by either changing the pistons to dome shaped, shaving some material from the head or finding thinner head gaskets. Naturally, you can combine some or all of these methods. With the higher compression ratio and higher octane gasoline, you will get more power.

2. Computer modifications. The fuel injection system can be changed to deliver more fuel. This will reduce the fuel economy and increase the emissions levels but you will see more power.

3. Increase the stroke of the engine. I don't know of any crankshafts that will fit easily. A custom crankshaft may have to be made. That engine was never offered with a different crankshaft. It's been the same 3.88 inch bore and 3.19 inch stroke since 1984.

4. Forced induction. It might be possible to fit either a turbocharger or supercharger to the engine. The extra air will really help the power. There are kits over here in the states but I don't know exactly where to find them.

[JEEP_TJ_FREAK]

Forced induction....


I have a Garret/ AI research T-25 turbo for sale, < 500 miles.

250 USD

[pcelle]

geting more torque out of a 2.5 .........not worth it

you can get more inertia ...building a sepcial flywheel

basics : the heavier the flywheel more inertia you have ..

[Mikel]

I'm from Spain myself (Guipuzcoa). :):)
A supercharger would probably give you the most bang for the buck, but I'm not sure how you could deal with the computer adjusting for the engine not being naturally aspirated any more. The problem is that the ITV guys would spot that very quickly and you would have to have it homologated anyway.
Good luck.

Mikel Ezcurra

[dorfs]

Cheap enough, may help a little.
http://www2.hawaii.edu/~jyokomur/tech/throttlebody01/index.html

[cybersniper]

Thanks to all I have a clearer picture now.
Eduardo

[pcelle]

suerte con tu proyecto viejo

Saludos de Chile

[jeepinislife]

Ok guys: Hold on!!!

This guy is from Spain, gas is really expensive there. You mention engine swaps for V8's and it is likely he cannot afford the gas consumption. I'd recommend a diesel V8 or V6. Both have torque enough. You can go for a Mercedes Benz engine, or a Cummins one. Not sure IVECO has a diesel plant that could be a good candidate.

[TwistedObsession]

Try a Mopar Performance cam.

If "the man" will let you, look at Avenger Superchargers, the 2.5L versions offer 210 HP and 50% moe torque. I don't know at what RPM range these numbers come from thats just what it says in their ad in the back of JP.

[cybersniper]

Originally posted by jeepinislife
Ok guys: Hold on!!!

This guy is from Spain, gas is really expensive there. You mention engine swaps for V8's and it is likely he cannot afford the gas consumption. I'd recommend a diesel V8 or V6. Both have torque enough. You can go for a Mercedes Benz engine, or a Cummins one. Not sure IVECO has a diesel plant that could be a good candidate.

It´s not really the gas expense (though it always matters) BUT the range of the car. With my engine I have a 400km range with the 4.0 less than 350Km and with the V8 less than 250km ... totally unaceptable to make 4x4 excursions !!!

With a TDI engine I would get 1000km range !!!!

Eduardo