I have a little 2.5 in my tj and i want to keep it a 4 cylinder so i was thinking about a stroker kit and super charger. Has anyone ever done anything similar?
Has anyone upgraded their 2.5?
- Thread starter JP1
- Start date
@StG58 pointed out at one point there was a turbo kit for around 5k. Unfortunately no one that I know of makes a bolt-on supercharger kit, and even if you managed to put a supercharger on it, you'd have no solution for engine management.
So with one of your only options being a $5000 turbo kit, you have to ask yourself it it's worth it. I wouldn't put 5k cash into a 2.5, because with that money I'd either sell it and get a 4.0, or use the money (plus some) to swap in a V8.
So with one of your only options being a $5000 turbo kit, you have to ask yourself it it's worth it. I wouldn't put 5k cash into a 2.5, because with that money I'd either sell it and get a 4.0, or use the money (plus some) to swap in a V8.
Upgrade to a 4.0l. You'll be happy. I had a 2.5l yj and I was doing the same thing you're doing right now. Save up a little, sell the 2.5 and upgrade. I miss the little yj and it was fun to drive, but not on the highway, not up hills. Plus I don't think you can just slap on a supercharger and call it good without changing some of the internals to handle it. I could be wrong though. I know my buddies hot rod had to get stronger rods etc for his supercharger. Besides it's a jeep, we don't move fast we just get dirty. Lol
The 2.5 is what it is... The issue is engine management. You can hang all sorts of forced air induction & etc on the 2.5 and kinda sorta get more power, but the cost is outrageous. And all the power moves into the higher RPMs. Shortly after that your AX5 transmission detonates. Trade into a 4.0 if you think you need more power.
Yep, and that's the issue. The amount of money you'd have to throw at a 2.5 for engine management, forced induction, etc... You'd be able to swap in a V8 (or sell it for a 4.0) for that cost.
The numbers just don't add up any way you look at it. Not even close...
The numbers just don't add up any way you look at it. Not even close...
I looked into turbo systems, superchargers, bore & stroke kits, tuners & cams etc. when I wanted more from my 2.5L 4 cylinder and found that the cost wasn't worth the extra power or reliability issues that could come from such moving parts on the trail. After lots of research I found there were really only two things I could do:
1: Sell the Jeep and buy a 4.0L model equipped with what I wanted on it.
-or-
2: Install a V8 engine that best corresponds to the communications bus your Jeep uses.
I chose option 2 over option 1 for a few reasons. 1st, I bought my Jeep for $300 running and driving. There's no way I'm gonna' beat that shy of winning the lottery. 2nd, I had already installed several modifications and upgrades that would be time consuming and labor intensive to remove and install on another Jeep and I wanted to avoid that if at all possible. 3rd, I already set the stage for the V8 with heavy duty aftermarket axles. See 2nd reason above. And probably the 3rd and biggest reason for why I choose to install a V8 in my TJ over selling my TJ and buying a 4.0L powered replacement TJ: Easier and cheaper to pass smog.
In California, and federal law which is mostly modeled after California CARB (Clean Air Resources Board) mandates, the older the vehicle, the lower the requirements. Usually, some exceptions to the rule. That said, my Jeep is 21 years old and being it was built in the first week of March 1996, it is old enough that I can buy an entire donor vehicle for the transplant. I did just that, bought a same year model Grand Cherokee V8 4x4 for only $1K. Now I have all the emissions, wiring, computer, engine, transmission and other miscellaneous parts to complete the project. $120 in factory service manual sets for both the early 1997 TJ & the mid 1997 Grand were bought on ebay so I have the factory wiring schematics for BOTH vehicles to work from.
Bottom line estimate:
When I am done with the swap and sell the good running 2.5L engine, 30RH transmission, Grand Cherokee body and interior parts, Extra axles and other hard parts not used off both vehicles, I should come out ahead $$$ money wise. That and I have swapped drivetrains in other Jeeps and cars before. The swap is well documented all over the web making it easy to see and ask questions. Take a look at the swap grid to get a look at what Chrysler products have a compatible communications bus with your year Jeep TJ engine controls. here: HOTWIREAUTO
1: Sell the Jeep and buy a 4.0L model equipped with what I wanted on it.
-or-
2: Install a V8 engine that best corresponds to the communications bus your Jeep uses.
I chose option 2 over option 1 for a few reasons. 1st, I bought my Jeep for $300 running and driving. There's no way I'm gonna' beat that shy of winning the lottery. 2nd, I had already installed several modifications and upgrades that would be time consuming and labor intensive to remove and install on another Jeep and I wanted to avoid that if at all possible. 3rd, I already set the stage for the V8 with heavy duty aftermarket axles. See 2nd reason above. And probably the 3rd and biggest reason for why I choose to install a V8 in my TJ over selling my TJ and buying a 4.0L powered replacement TJ: Easier and cheaper to pass smog.
In California, and federal law which is mostly modeled after California CARB (Clean Air Resources Board) mandates, the older the vehicle, the lower the requirements. Usually, some exceptions to the rule. That said, my Jeep is 21 years old and being it was built in the first week of March 1996, it is old enough that I can buy an entire donor vehicle for the transplant. I did just that, bought a same year model Grand Cherokee V8 4x4 for only $1K. Now I have all the emissions, wiring, computer, engine, transmission and other miscellaneous parts to complete the project. $120 in factory service manual sets for both the early 1997 TJ & the mid 1997 Grand were bought on ebay so I have the factory wiring schematics for BOTH vehicles to work from.
Bottom line estimate:
When I am done with the swap and sell the good running 2.5L engine, 30RH transmission, Grand Cherokee body and interior parts, Extra axles and other hard parts not used off both vehicles, I should come out ahead $$$ money wise. That and I have swapped drivetrains in other Jeeps and cars before. The swap is well documented all over the web making it easy to see and ask questions. Take a look at the swap grid to get a look at what Chrysler products have a compatible communications bus with your year Jeep TJ engine controls. here: HOTWIREAUTO
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Motor mounts come from Advanced Adapters, Exhaust is a mixture of TJ aftermarket Banks Monster I already have on the Jeep and the Grand Cherokee Y pipe, CATS, O2 sensors etc. Blend the wiring of the two Jeeps by adding the Grand Cherokee extra wires for the V8 into the existing TJ Wrangler harness. The factory 2.5 or 4.0 fuel pump will run the Grand Cherokee 5.2 or 5.9L V8 just fine. All MOPAR, ALL COMPATIBLE with each other. Especially since my TJ has an automatic transmission in it, the 46RE transmission will fit and the shifter will control it.The cooling system will use the Jeep radiator since it is in great shape and works better than most aftermarket units with it's large aluminum core tubes. It has cooled much more powerful V8 engines in another Jeep I had.
I am thinking of doing a detailed write up on the swap when I start on it in earnest this spring when the days get a little longer and the rains stop. If I do, I will pay particular attention to the little details everyone else has neglected to show such as the electrical wiring and motor placement options.
I am thinking of doing a detailed write up on the swap when I start on it in earnest this spring when the days get a little longer and the rains stop. If I do, I will pay particular attention to the little details everyone else has neglected to show such as the electrical wiring and motor placement options.
TrailYacht
Member
Don’t bother upgrading the engine. A swap is a good option, on the other hand. Just saying with some minor work the 2.5l Jeep platform is great..
Also, what do you actually do with the Jeep. I’m assuming daily/ weekend warrior? I’ve run these jeeps on 33” and 35” (RAS) as daily’s for years before my current rig. Off-road I’ve also seen them play with the big boys.
I’ve oddly had very good luck with AX 5 transmissions. Good fluids, venting and yearly/ circumstancial fluid swaps.
Lose weight, not you, the Jeep. As much as possible. Maintain it well and it will last forever. It won’t break things as much as higher torque motors either. Personally I would swap the rear axle especially over 35” tires but plenty of 4L jeeps face the same dilemma.
Also, what do you actually do with the Jeep. I’m assuming daily/ weekend warrior? I’ve run these jeeps on 33” and 35” (RAS) as daily’s for years before my current rig. Off-road I’ve also seen them play with the big boys.
I’ve oddly had very good luck with AX 5 transmissions. Good fluids, venting and yearly/ circumstancial fluid swaps.
Lose weight, not you, the Jeep. As much as possible. Maintain it well and it will last forever. It won’t break things as much as higher torque motors either. Personally I would swap the rear axle especially over 35” tires but plenty of 4L jeeps face the same dilemma.
Thanks for the heads-up on the engine. Having done some Internet research today on this topic, I've come to the same conclusion. I'll refurb the 2.5 lump (top end). I've got a sheered off Head bolt near the bulk head which is seeping water to atmosphere.
I was given the Jeep 4 Years ago and it's been under cover for that time. I've retired now and am looking to give it a fully overhaul and upgrades where needed. It's a keeper and I plan to hand it onto my Grandson once he grounded. (we have beaches and boats to tow where we live).
Can I ask you some other TJ Jeep related questions:
1. The diff has some broken teeth on the Crown Wheel. It runs OK but the out of balance noise drives me mad. I have a Diff from a 2.5 Cherokee, of the same age. Do you know how I can find out if it'll fit before I pull the half shafts, Prop and remove the diff cage?
2. I need to change the clutch amongst other major things, how easy is it to take the body off of the chassis?
Many Thanks, Alan
I will tell you that no upgrade to the 2.5L will give the same performance as a displacement upgrade no matter what you do to it. Just sayin' if heavy armor, accessories and big tires are in your future and you don't want to do a swap then sell the 2.5 Jeep and buy a 4.0L Jeep.
TrailYacht
Member
Ya be selective and minimal with weight if you do keep it.
What year are you’re jeeps? Front axle will swap in. Rear is not worth welding all the brackets on.
Taking the body off unless everything was brand new and even then would add a lot more work to a pretty easy job. It’s pretty straight forward to pull it from underneath. Key points would be, watch your skid plate bolts they like to break. 2 bolts at the top are probably ETorx, hard to get at. Shifter comes off differently between the different transmissions, crank position sensor, don’t forget about it, they sometimes suck to mate back together, alignment tool, don’t draw them together with the bolts when you get mad lol
Rant.....all day...
What year are you’re jeeps? Front axle will swap in. Rear is not worth welding all the brackets on.
Taking the body off unless everything was brand new and even then would add a lot more work to a pretty easy job. It’s pretty straight forward to pull it from underneath. Key points would be, watch your skid plate bolts they like to break. 2 bolts at the top are probably ETorx, hard to get at. Shifter comes off differently between the different transmissions, crank position sensor, don’t forget about it, they sometimes suck to mate back together, alignment tool, don’t draw them together with the bolts when you get mad lol
Rant.....all day...
You're 6 years late to the party, so..... pics or it never happened. Are you AI?
AI? No haha I just found this thread figured I’d toss out some info while I learn. It’ll either go or blow.
If you want to start another thread about it, and have some info to share, I'll add it to the collection.