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Discussion Starter #1
does anyone know if the 3.7 in the commander is the same 3.7 in any other jeep? what im trying to get at is there isnt much out there for engine upgrades for the commander. would parts for a wrangler or cheroke 3.7 fit on the commander?
 

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I'm pretty sure they are different engines. wranglers have 3.8L so its different.
best you can do to 3.7L (i have one as well)
1. Cold air intake.

Programmer chips dont work on 3.7L because the engine is already maxed out with power. as high as it will go.
if you want more power, you have to do either engine upgrade or gear ratio change to a 3.73 like the 4.7Ls. the 3.7L has 3.03 gears.
 

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If you wanna swap the gears for 3.73's you have to do both front and rear axles, right? Are there any even avaliable for the XK front yet???
 

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Well....you are only working with 222 or 223 cubic inches here.
It is close to optimum output for a two valve engine designed more for low rpm torque output.....if I remember correctly, horsepower is at 210.
Not to shabby for its dispacement......I don't know its torque rating but I'll bet it is in the 250 ft lb range.....again, fairly respectable.
More aggressive camshafts could eek out a bit more power but that would occur at a higher RPM.....not very useful in a truck application.
So, what I'm getting at is there isn't a magic bullet that currently exists to make more power and torque without changing the characteristics of the engine.
The lower gears (higher numerically) would provide a bit more 'snap' off the line.
The QT II 3.7's used 3.55's and these could be a direct bolt in with a computer reflash to recognise the gearing.
As far as intake or exaust changes the odds are there would be little change with exception of operation at the last 1000 RPM before redline......there might be a bit of restriction at those high cfm requirements but the butt dyno likely would not be able to feel it.
So, gearing or jack up the radiator cap and slide a V-8 Commander under it are, in my opinion, your only options.

All the 3.7's are the same, whether installed in a Commander or Liberty or Grand Cherokee.
The 3.8, found in the Wrangler, shares nothing with the 3.7.


Rob
 

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Discussion Starter #7
Well....you are only working with 222 or 223 cubic inches here.
It is close to optimum output for a two valve engine designed more for low rpm torque output.....if I remember correctly, horsepower is at 210.
Not to shabby for its dispacement......I don't know its torque rating but I'll bet it is in the 250 ft lb range.....again, fairly respectable.
More aggressive camshafts could eek out a bit more power but that would occur at a higher RPM.....not very useful in a truck application.
So, what I'm getting at is there isn't a magic bullet that currently exists to make more power and torque without changing the characteristics of the engine.
The lower gears (higher numerically) would provide a bit more 'snap' off the line.
The QT II 3.7's used 3.55's and these could be a direct bolt in with a computer reflash to recognise the gearing.
As far as intake or exaust changes the odds are there would be little change with exception of operation at the last 1000 RPM before redline......there might be a bit of restriction at those high cfm requirements but the butt dyno likely would not be able to feel it.
So, gearing or jack up the radiator cap and slide a V-8 Commander under it are, in my opinion, your only options.

All the 3.7's are the same, whether installed in a Commander or Liberty or Grand Cherokee.
The 3.8, found in the Wrangler, shares nothing with the 3.7.


Rob


so anything for the motor that a website says is for libery or cherokee will fit on the commander? i found a site that sold i think refurbished engines and trannys and they have the hemi pieces. how much extra work other than installing tranny and motor would it be to put the hemi in? i noticed that the v-6's have all time 4x4 and the v-8's have the switches to go from 2wd to 4hi and 4lo. anyway of changing that as well?
 

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Unless you have a really big money bucket and a love for this particular Commander a engine switch would be unwise.
You would create a freak that no longer lines up with its vin numbers, and only you could (maybe) correctly service it.
A engine, transmission, transfer case, gearsets, computer(s) related wiring harnesses.....on and on.....

Bad Ju Ju,
Rob
 

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i myself wanted a bigger engine. since i have a 3.7L rolling 265/70/17 super swampers. and they are heavy. put in cold air intake. and really..just higher RPM gain. was gonna get new gears, decided, id rather just get a new jeep. so mine is for sale. getting a wrangler 4 door with 35" nitto mud grapplers. :)
 

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i myself wanted a bigger engine. since i have a 3.7L rolling 265/70/17 super swampers. and they are heavy. put in cold air intake. and really..just higher RPM gain. was gonna get new gears, decided, id rather just get a new jeep. so mine is for sale. getting a wrangler 4 door with 35" nitto mud grapplers. :)
Decided not to go with a V8 XK afterall? That's actually my next move too. I got a few more years to go before I can sell my XK, I have my eye set on a Rubicon. :banana_hitit:
 

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so anything for the motor that a website says is for libery or cherokee will fit on the commander? i found a site that sold i think refurbished engines and trannys and they have the hemi pieces. how much extra work other than installing tranny and motor would it be to put the hemi in? i noticed that the v-6's have all time 4x4 and the v-8's have the switches to go from 2wd to 4hi and 4lo. anyway of changing that as well?
I have the V8 and it's always 4 wheel drive(I say 4 wheel drive and not all wheel drive as I believe It's a more robust system than what you would find on than something like an acura RDX). The only option I have is to go from 4 hi to 4 low. Really for off roading I find that the 4 hi is more than sufficient for most situations(even on rocks and such)because of the traction control system. I mainly use the 4 low for hill decent espcially when there are staircase type dropoffs scattered around a steep descent.

I'm never able to go to a 2 wheel drive mode.
 

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Discussion Starter #12
if i put 3.73 gears in my jeep how would that affect my rpms at highway speeds from what they run now. running about 2 grand at 65 mph
 

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if you get your electronics updated so they know it has the new gears. your RPMs will run higher, but it will give you better acceleration and top speed. especially with offroad tires.
 

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Decided not to go with a V8 XK afterall? That's actually my next move too. I got a few more years to go before I can sell my XK, I have my eye set on a Rubicon. :banana_hitit:
yea, haha. i found the perfect 4 door wrangler that is EXACTLY what i want. it only has a 2.5" budget lift on it. so i would get a 4" full lift. and a 2 inch body lift. :)
 

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Discussion Starter #15
is anyone running the super lift 4inch kit with 33's on here and have the v-6 commander? how the does the commander ride with that setup? someone mentioned earlier about getting 3.73 gears. how would i update the electronics so the computer knows the gears have changed? wouldnt be doing any heavy offroading in this rig but maybe some light mud and sand would be about all i do in it. just dont want to have my motor completely bogged down trying to turn the tires.
 

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is anyone running the super lift 4inch kit with 33's on here and have the v-6 commander? how the does the commander ride with that setup? someone mentioned earlier about getting 3.73 gears. how would i update the electronics so the computer knows the gears have changed? wouldnt be doing any heavy offroading in this rig but maybe some light mud and sand would be about all i do in it. just dont want to have my motor completely bogged down trying to turn the tires.
No one has upgraded to 3.73 gears from the 3.07 stock gears yet. I would like to do this as well, but since 3.73 gears were not a factory option with the 3.7L V6 and therefore the Jeep dealers will not be able to update you. That leaves aftermarket programmers, of which there is only one option, Hypertech Speedometer Calibrator. However I haven't heard of anyone using one of these for gear ratio change. To me it's untested. And this link has me questioning if Hypertech's product claims are valid.

http://www.jeepforum.com/forum/f67/crd-regear-3-73-3-21-completed-1127766/
 

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Discussion Starter #17
i cant remember who said it to me, i'll have to sift through the posts ive made to find but someone said pretty much the only thing available for the v-6 is to change the gears to 3.73 for my torque and what not. not a whole lot of motor upgrades out there for the 3.7L. was told it would make my rpm's run a bit higher but give me better acceleration and carry the bigger tires better. still looking for anyone else insight on this set up. 4inch lift with 33" tires. nothin crazy. just enough to go play in the sand with the v-6 is all
 

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It might have been me that said that??? Definately the best thing you could do on a V6 would be 3.73 gears.
 

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Programmer chips dont work on 3.7L because the engine is already maxed out with power. as high as it will go.
Yea and No, I think Robby said it best, basically for off-roading or big wheels, you want low end power and torque. Really the only way to improve on that if the motor is tuned well, is more bore & stroke, i.e. more displacement.

The manufacturer usually builds in a lot of safety into the tuning of the motor, and by compromising that tune by going leaner in WOT and advancing spark more, you can get more power. I would be shocked that the 3.7L in OEM form is pushing the edge of that safety margin that is built in from the manufacturer.

BUT, like Robby was saying and might be what you meant redbulljoker, a programmer chip that takes advantage of that, probably won't do anything in the real world for a Jeep Commander, you'd just increase the top rpm power and torque, when what you really need is low end power and torque.

TWIZ86, I'm a newb to Commanders, but pretty knowledgeable in vehicles in general. From what little I've read so far, the Commander, like most cars in the last few years, have become so intrically linked with electronics, that an Engine/Tranny Swap becomes far more difficult than you first imagine. Requiring getting lots of new electronics boxes as well as the rest of the gear, and then getting all the boxes programmed to work properly together.

On top of that, from a few threads I read, Chrysler tries to idiot proof their electronic servicing system and base everything off data bases for what the vehicle came equipped with OEM, so bad dealership techs don't make mistakes and program things and input the wrong options and/or equipment on your vehicle. Thats results in, if you change the OEM configuration of your vehicle and need the dealership to update all the new black boxes to talk to each other for the new configuration, the dealership being unable to do it. There tools will only work with the OEM configuration, according to the VIN# of the vehicle. i.e. if you Jeep came with a 3.7L and you swap in a 4.7L, the dealer tools will require them to input the VIN# and then would only work with 3.7L control boxes, and NOT a 4.7L engine, even though there is a 4.7L in the vehicle now.

You have to get in touch with Chrysler and get them to change the database to reflect what you've changed in the vehicle.

Honestly, unless you've got money spilling out of your ears, I would NOT even attempt an engine/tranny swap unless you can find a junkyard donor car, configured the way you want your vehicle, in good enough shape, where you can work out a deal with the yard owner to swap the parts you need as you need them. Your bound to find unanticipated pieces to the system as you do the swap, and have to go back and get more parts to swap around. As well, what are the chances of finding a vehicle that fits your needs in a local junkyard in your area?
 

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Yea and No, I think Robby said it best, basically for off-roading or big wheels, you want low end power and torque. Really the only way to improve on that if the motor is tuned well, is more bore & stroke, i.e. more displacement.

The manufacturer usually builds in a lot of safety into the tuning of the motor, and by compromising that tune by going leaner in WOT and advancing spark more, you can get more power. I would be shocked that the 3.7L in OEM form is pushing the edge of that safety margin that is built in from the manufacturer.

BUT, like Robby was saying and might be what you meant redbulljoker, a programmer chip that takes advantage of that, probably won't do anything in the real world for a Jeep Commander, you'd just increase the top rpm power and torque, when what you really need is low end power and torque.

TWIZ86, I'm a newb to Commanders, but pretty knowledgeable in vehicles in general. From what little I've read so far, the Commander, like most cars in the last few years, have become so intrically linked with electronics, that an Engine/Tranny Swap becomes far more difficult than you first imagine. Requiring getting lots of new electronics boxes as well as the rest of the gear, and then getting all the boxes programmed to work properly together.

On top of that, from a few threads I read, Chrysler tries to idiot proof their electronic servicing system and base everything off data bases for what the vehicle came equipped with OEM, so bad dealership techs don't make mistakes and program things and input the wrong options and/or equipment on your vehicle. Thats results in, if you change the OEM configuration of your vehicle and need the dealership to update all the new black boxes to talk to each other for the new configuration, the dealership being unable to do it. There tools will only work with the OEM configuration, according to the VIN# of the vehicle. i.e. if you Jeep came with a 3.7L and you swap in a 4.7L, the dealer tools will require them to input the VIN# and then would only work with 3.7L control boxes, and NOT a 4.7L engine, even though there is a 4.7L in the vehicle now.

You have to get in touch with Chrysler and get them to change the database to reflect what you've changed in the vehicle.

Honestly, unless you've got money spilling out of your ears, I would NOT even attempt an engine/tranny swap unless you can find a junkyard donor car, configured the way you want your vehicle, in good enough shape, where you can work out a deal with the yard owner to swap the parts you need as you need them. Your bound to find unanticipated pieces to the system as you do the swap, and have to go back and get more parts to swap around. As well, what are the chances of finding a vehicle that fits your needs in a local junkyard in your area?
Well said!
 
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