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-   -   4.0 throttle body on 2.5 (http://www.wranglerforum.com/f210/4-0-throttle-body-on-2-5-a-15.html)

khenderson 04-06-2005 08:28 PM

4.0 throttle body on 2.5
 
Anyone had any good/bad experiences with doing this little mod? Found a 4.0 TB at a junk yard, so I figured I'd give it a shot...could use a little more umph out of my little 4 banger.

JeepCrawler98 04-06-2005 09:04 PM

I can't speak personally - but I've heard that it makes a decent improvement in responsiveness. Remember that if your cat or muffler aren't up to part - you won't be able to pass through what you take in, resulting in no increase in power. Just remember that you won't get a powerhouse out of the 2.5L - but every little bit can add up to where it cruises nicely. You may want to look into a taurus fan as well - I've ran a couple of junkyards units and they make a nice difference in mileage and holding power on the hill, but get a newer one, or replace the motor on it, since mine all burnt out after a while. Oh and if you clog em with mud and forget to shut em off - you can forget the longetivity, lol :flipoff:

1BLKJP 04-11-2005 03:10 AM

Quote:

Originally Posted by khenderson
Anyone had any good/bad experiences with doing this little mod? Found a 4.0 TB at a junk yard, so I figured I'd give it a shot...could use a little more umph out of my little 4 banger.

It will work out just fine for you as a pretty cheap way to beef it up a little. Only thing I think you are going to have to do is get a new gasket. While your at it might as well pick up a TB spacer as well for it.

dos0711 04-17-2006 10:00 AM

I just did this mod. I'd have to say the old 4 banger is...um...crisper!:D

khenderson 04-17-2006 11:34 AM

it did help. i could make it up hills in 5th when i used to have to shift to 4th. now with the header and exhaust its got a nicer rumble and a little more top end, even though i think i sacrificed a bit of bottom end torque. gonna be doin the air intake to cowl mod next. can't wait!

dos0711 04-18-2006 09:27 AM

Quote:

Originally Posted by khenderson
it did help. i could make it up hills in 5th when i used to have to shift to 4th. now with the header and exhaust its got a nicer rumble and a little more top end, even though i think i sacrificed a bit of bottom end torque. gonna be doin the air intake to cowl mod next. can't wait!

Seems the ricers think your wanting to race though.:rolleyes:

khenderson 04-18-2006 09:39 AM

Quote:

Originally Posted by dos0711
Seems the ricers think your wanting to race though.:rolleyes:

it's not ricey at all though. was really surprised as i thought it was gonna be. but it sounds more like a WRX(deeper with more balls) than a civic(pissed of bumble-bee). i really enjoy it!

dos0711 04-18-2006 10:09 AM

Quote:

Originally Posted by khenderson
it's not ricey at all though. was really surprised as i thought it was gonna be. but it sounds more like a WRX(deeper with more balls) than a civic(pissed of bumble-bee). i really enjoy it!

I'm sorry...I wasn't implying that yours sounded like a ricer. It's just that when THEY here something other than stock, they think it's race time.

mmasuperman12 04-18-2006 10:27 AM

yeah weld a coffee can on yer tailpipe put some ridiculous exterior accesories right off the pep boys shelf and go race...damn kids when will they learn...its all about the muscle

(i only say this being the very proud owner of a 1970 chevy chevelle malibu)

dos0711 04-18-2006 01:30 PM

Quote:

Originally Posted by mmasuperman12
yeah weld a coffee can on yer tailpipe put some ridiculous exterior accesories right off the pep boys shelf and go race...damn kids when will they learn...its all about the muscle

(i only say this being the very proud owner of a 1970 chevy chevelle malibu)

No kiddin. My stepson went for a ride with his friend yesterday...he put his Honda into a telephone poll. Both were alright but what an idiot!

khenderson 04-18-2006 10:51 PM

Quote:

Originally Posted by dos0711
I'm sorry...I wasn't implying that yours sounded like a ricer. It's just that when THEY here something other than stock, they think it's race time.


i think i'll just hang out til they park somewhere and then i'll crawl up on their hood, put it in first, and then let the clutch out a little, then put the clutch in. i'll do this over and over....are you getting the visual??? :D :eek: :D

hehehehe

lcpl Konicki 04-20-2006 02:42 PM

Can you put a big bore 4.0 throttle body on a 2.5l engine and can you also put a throttle body spacer?

lcpl Konicki 04-20-2006 03:01 PM

also how well a throttle body spacer improve the perormance on this setup?

khenderson 04-20-2006 03:22 PM

some claim gains from spacers, but i didn't notice any difference with or without one. and a big bore throttle body for a 4.0 should fit as well since both engines have the same tb mounting pattern. the only thing you have to do is move over your ais housing and motor, map sensor, and tps.

lcpl Konicki 04-20-2006 04:51 PM

So would it be worth it Horsepower wise to do this mod? Or do you have any other tips to get some extra inexpensive horsepower out of my pea-shooter engine? And what kind of exaust did you throw on?

khenderson 04-20-2006 09:14 PM

i've got a pacesetter header and dynamax cat back with a universale high flow cat. also running a 4.0 TB, new coil, and plug wires. i'd like to mill out the tb, intake, and spacer(since it's there). there's also a company that makes intake manifolds, cams, and maybe a head for the 2.5. and i've heard that having the head worked will give it close to stock 4.0L power.

lcpl Konicki 04-20-2006 11:15 PM

wow thanks- But when you say getting the heads worked are you talking boaring out the engine or like aluminum heads?

khenderson 04-21-2006 06:01 PM

having it ported and polished. getting the intake manifold then matched to the head, and if you mill out the TB, then mill the top of the intake matched to the bottom of the TB. should vastly improve the little 4 banger. granted there's some good money and time invested in all these. whether its worth it is up to you. but check local machine shops to see what they would charge for such work.

dos0711 04-21-2006 06:41 PM

Quote:

Originally Posted by khenderson
some claim gains from spacers, but i didn't notice any difference with or without one. and a big bore throttle body for a 4.0 should fit as well since both engines have the same tb mounting pattern. the only thing you have to do is move over your ais housing and motor, map sensor, and tps.

That's interesting. I didn't change the AIS housing or motor. Just the TPS. Everything is works fine!

khenderson 04-21-2006 10:16 PM

does it idle any higher? the only difference in the two is that the ais housing and motor for the 4.0L TB is a bit bigger since it needs to flow more air to it than the 2.5L does(obviously).

lcpl Konicki 04-21-2006 11:29 PM

I hadn't thought about getting it ported and polished But i am buying a big bore throttle body(62mm) and a 62mm throttle body spacer also looking into a headder and new exaust! I have to pull a trailer from texas to california w/ my 4-wheeler on it so I could use the extra power!

dos0711 04-22-2006 07:45 AM

It still idles the same. Glad I didn't fool with those tamper resistance torx!!

khenderson 04-22-2006 06:42 PM

i feel so hosed, cause that was a pain in my arse to get those things off!!

lcpl Konicki 05-06-2006 05:27 PM

Well I threw on the 62mm throttle body and spacer and milled out the intake mantifold. Now it is acting like it is congested and maybe not getting enough gas! I'm looking into headers and exhaust Even though it is a 4-banger i would like for it to sound like it has some balls. If anyone has any ideas I would appreciate them!

binaryking 01-22-2007 10:43 PM

Quote:

Originally Posted by dos0711 (Post 11428)
I'm sorry...I wasn't implying that yours sounded like a ricer. It's just that when THEY here something other than stock, they think it's race time.

So race them! :) My Jeep has eaten many a Civic with a fart pipe on it. On straight roads that is.

Steve97TJ 01-23-2007 01:13 AM

So you cant just bolt up a 4.0 throttle body, you have to change some thing?

khenderson 01-23-2007 03:29 PM

as it turns out, you can just bolt one right up. i changed out the AIS housing and motor when i did mine, but you don't have to. the 4.0 TB will just bolt straight up.

kg4kpg 01-23-2007 08:16 PM

Quote:

Originally Posted by khenderson (Post 48479)
as it turns out, you can just bolt one right up. i changed out the AIS housing and motor when i did mine, but you don't have to. the 4.0 TB will just bolt straight up.

I concur. I did this on my last TJ and I will do it again if I can ever afford one or find one off a salvage jeep.

compshooter 01-24-2007 08:26 AM

Quote:

Originally Posted by khenderson (Post 48479)
as it turns out, you can just bolt one right up. i changed out the AIS housing and motor when i did mine, but you don't have to. the 4.0 TB will just bolt straight up.

I had a different experience. It will not "bolt straight up". One little dohicky (official term) on the throttle bodies is different. There is a little tab on the dohicky that points downward and prevents putting a 4.0 TB on a 2.5 and vice versa. You must pull this dohicky off the 2.5 TB and put it on the 4.0 TB and then it bolts right up. As someone else said, make sure you get a new gasket before doing the swap though.

I did notice an improvement on the top end also. Good $50 mod.

Triple88a 05-02-2007 10:18 PM

Quote:

Originally Posted by compshooter (Post 48690)
There is a little tab on the dohicky that points downward and prevents putting a 4.0 TB on a 2.5 and vice versa

Are you talking about the AIS motor housing? I did notice that it has a tab on one side and doesnt on the other :)


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