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-   -   2.5L upgrade info? (http://www.wranglerforum.com/f282/2-5l-upgrade-info-71292.html)

Cory97TJ 12-06-2010 03:43 PM

2.5L upgrade info?
 
Looking for info on the 2.5l 1997 Jeep Tj engine

i have a cracked header and it has 141000 miles on it

somekinda performance exhuast is on it


what are the best ways to get performance of my 2.5l to be a little more


i can barely go 65 on highway with 31's

and i wheel with a 2.5l with upgrades that i think could easily go 95 on highway if he wanted it to


seems my 5th gear is worthless


anything that would add 10-30 HP is all im really looking for

jasonwrangler 12-06-2010 03:48 PM

gear down if you have bigger tires.
a good tune up might give you 2-3hp but 20-30hp? you asking forced induction.

Cory97TJ 12-06-2010 03:53 PM

i have 31's and i am in the green with 4/10s till 35 really

how do you make an engine faster.... new air system? new plugs?

jasonwrangler 12-06-2010 04:00 PM

Quote:

Originally Posted by Cory97TJ (Post 910946)
i have 31's and i am in the green with 4/10s till 35 really

how do you make an engine faster.... new air system? new plugs?

like I said unless you get force induction no way you can get more than 10hp increase. you butt dyno wont tell the difference.
some poorly designed air intakes not only sucks hot air reduces power but also passes dirt causing engine failure.

schnutzy 12-06-2010 04:08 PM

short of forced induction, there is nothing that will give you 20-30 more HP on the 2.5
before looking to add more power, make sure it is already running right. a good tune up, etc will do lots for any vehicle that is running rough. if you are having issues making power, there could be other things wrong. a clogged up catalytic converter can cause issues, there are several things you should look at before you think about bolting on a bunch of "go fast" mods. most of which will be useless any ways.

jasonwrangler 12-06-2010 04:26 PM

Quote:

Originally Posted by schnutzy (Post 910965)
short of forced induction, there is nothing that will give you 20-30 more HP on the 2.5
before looking to add more power, make sure it is already running right. a good tune up, etc will do lots for any vehicle that is running rough. if you are having issues making power, there could be other things wrong. a clogged up catalytic converter can cause issues, there are several things you should look at before you think about bolting on a bunch of "go fast" mods. most of which will be useless any ways.

exactly if they could make more HP outta that engine they would. Ive never heard any auto manufactures say their vehicles were too powerful.

schnutzy 12-06-2010 04:35 PM

Quote:

Originally Posted by jasonwrangler (Post 910995)
exactly if they could make more HP outta that engine they would. Ive never heard any auto manufactures say their vehicles were too powerful.

oh, more power can definitely be had out of that engine. but to do so, you would be dumping so much money into it, that it would be more cost effective to either swap in a built v8, or just buy a jeep with the straight 6.

JD Adams 12-06-2010 04:46 PM

I have a buddy with an all-stock 2.5L TJ that will top 100 mph. pretty easily. I don't recommend it, but I've seen him do it.

Ironic, isn't it? Whomever installed headers, trick exhaust, big tires, stickers, tint, fuel magnets, etc. probably insisted that it was an improvement.

2.5's are not asphault-ripping terrors in any form. It probably ran a lot better before the original equipment was removed.

Cory97TJ 12-06-2010 08:18 PM

goign 65 and 100 is a HUGE differance, how do i check for a clogged cat?


do i need a new distribitur cap with a tune up ? wires plugs cap correct?

Cory97TJ 12-06-2010 08:20 PM

and assuming turboing my 2.5 l would be more then a inline 6 would cost swap out

then i gotta replace the tranny and transfercase too....

4Jeepn 12-06-2010 08:22 PM

Simple way to get more power out of it.. sell it and get a 6cly. 505performance has a turbo that will get you @170hp, but it close to 4k cost.

Bobthegod 12-06-2010 08:27 PM

I agree with most everyone here. I have a 2.5 and I'm fine with it.....70 on the freeway is okay with me....I like to take in the scenery. But if you want more ponies jack up the radiator cap and slide a HEMI under there.......or maybe nitrous (can the 2.5 handle nitrous?) Or sell it and get a 6 cyl.

Cory97TJ 12-06-2010 10:42 PM

it take me everything my jeep has to get to 65, if i hit a hill im down to 55 or less, cant sell it and get a inline 6 i'd rather pull it and make it better

im not looking for a 240sx, just my jeep to be able to get the fuck up and move when i need it too

jasonwrangler 12-06-2010 10:54 PM

Quote:

Originally Posted by Cory97TJ (Post 911649)
it take me everything my jeep has to get to 65, if i hit a hill im down to 55 or less, cant sell it and get a inline 6 i'd rather pull it and make it better

im not looking for a 240sx, just my jeep to be able to get the fuck up and move when i need it too

like I said, gear it down if you have big tires or put stock tires back on.:mad:

schnutzy 12-06-2010 10:56 PM

give it a good tune up, wouldnt hurt to run some of that fuel injector cleaner/tank stabilizer stuff through either. see how it runs after that. if its still sluggish, pull the catalytic converter out(there is a way to check and get an idea if its clogged, i just dont remember how) if its clogged up, replace it.
and if your header is cracked, it might be a good idea to either fix or replace it.

as far as a tune up goes, you can buy tune up kits, or buy each part separately. just depends on how you wana do it.
another thing to look at is performance catalytic converters. how ever this is not for a performance gain, in some cases they are just cheaper then a stock replacement.

Cory97TJ 12-07-2010 12:27 AM

4.10's are making me accelerate slower?

jasonwrangler 12-07-2010 12:34 AM

Quote:

Originally Posted by Cory97TJ (Post 911756)
4.10's are making me accelerate slower?

isnt 4.10 stock on 2.5's?

Cory97TJ 12-07-2010 12:38 AM

ya 4.10's and 4.11's depending on year of 2.5l

wranglerYJnewb 12-07-2010 12:38 AM

Quote:

Originally Posted by Cory97TJ (Post 910946)
i have 31's and i am in the green with 4/10s till 35 really

how do you make an engine faster.... new air system? new plugs?

u are not green on 4.10's till 35"'s not at all buddy

Cory97TJ 12-07-2010 12:39 AM

guess ill tune it up this weekend

but i feel its the engine just being old and needing a rebuild from the former owner not doing regular maintenance

wranglerYJnewb 12-07-2010 12:42 AM

Do everything.... throttle body, replace your distributor, cap and wires, fuel pup, air filter....etc etc

edman87k5 12-07-2010 02:06 AM

Ok, believ it or not, fix your exhaust leak. I have seen the 2.5 have huge power robbed by seeming minor exhaust leaks. Do some searches and you should see it.
Also, 4.10 is NOT enough gear for a2.5 with 31s. Remember, the 2.5 is no champ on the highway with stock tires that were 4" smaller. 4.10s are manageable, but you should expect a significant performance drop.
The 4cyl is fine in he trails because you use the low range, but on the highway you are underpowered.

shipjim 12-07-2010 02:35 PM

I get between 70-75mph with mine, 31x10.5 mileage really sucks about 15mpg.

Cory97TJ 12-07-2010 02:38 PM

i got 16 mpg in town, 12 mpg hwy


i guess i need to get a header and make sure my cat is good to go before its too cold

Jeeps4sale 12-07-2010 03:39 PM

How about an electric fan kit?

jasonwrangler 12-07-2010 05:03 PM

Quote:

Originally Posted by Jeeps4sale (Post 912469)
How about an electric fan kit?

you know the monument you said that you made the biggest mistake?:eek:
its even worse than saying having air intake can add power.

Cory97TJ 12-08-2010 12:41 AM

electric fans are unreliable by all accounts i have heard

schnutzy 12-08-2010 12:45 AM

Quote:

Originally Posted by Cory97TJ (Post 913303)
electric fans are unreliable by all accounts i have heard

if they were that incredibly unreliable, then the majority of new cars wouldnt come with them from the factory. its just one of those situations where you get what you pay for, if you buy a cheapo knock off fan, then chances are very good that it will perform poorly. lots of people seem to be happy running electric fans. you just dont hear about it like you do the horror stories

Cory97TJ 12-08-2010 12:46 AM

i was wondering really if

Headers were better then a new exhuast manifold

if i should throttle body spacer on it for a few mroe HP if not more response time
if i should put a cold air intake on it just b/c the stock box is crappy ( there is no way i can beleive that a air intake that is open is worse then stock box)

if my engine is slugged up is there any way to help with that

i put ALOT of miles on my jeep

and from my undersstanding my acceleration is slwo b.c of my gears not b/c of the engine

schnutzy 12-08-2010 12:54 AM

as far as headers go, its kind of a waste of money. just find a good replacement.

skip the throttle body spacer, it will do nothing but sit there and remind you that you threw money down the drain.

keep the stock air box. the cold air intakes you are thinking of are not actually cold air intakes. in the ricer world they are called short ram intakes(or something like that, been a while since ive been there) another issue with those intakes is they dont deal with dust as well as the stock on. you run a higher chance of pulling in things you dont want in the engine. just because you have a bigger opening for air to get to the throttle body, does not mean you can use that. all the info i have found points to the jeep stock intake flowing all the air a stock engine needs.

as far as a sluggish engine. TUNE UP! inspect and replace the cat if necessary and check the o2 sensors, etc. make sure its all running right before you go dumping money products that will not give you the results you want.

while 31s are bigger then stock, the 4.10s you have stock are about as good a gear as it gets. 4.56s might be nicer, but is it worth the roughly $1000 to put those gears in?


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