A crazy idea of a crappy Chrysler vehicle mashup

"As Du Volant" (skuhnphoto)
03/03/2015 at 11:35 • Filed to: ideas

So I've got this crazy idea. An idea of taking a couple of really shitty Chrysler vehicles and putting them together to make a pretty insane project.

Back in 2007 Chrysler introduced the Jeep Compass, to the ire of Jeep enthusiasts and delight of rental car companies everywhere:

Using the same platform and many of the same parts, they also introduced the completely sucky Dodge Caliber, which the rental fleets liked even better:

2007 also saw the Jeep Patriot released on the same platform, but that one isn't relevant to this discussion.

The Caliber had a slightly more interesting variant, the SRT4, with a 285hp turbocharged 2.4l:

...but it was available in FWD only.

An oft-forgotten variant of the Compass is the Compass Rallye. It was a cosmetic upgrade only, but actually looked pretty damn good:

And yes, it was available in AWD with a manual. All the Compass and Patriot models were, as was the nonturbo Caliber.

So here's my idea...

Buy a wrecked Caliber SRT4, which there are plenty of...

Buy a manual transmission AWD Compass, which are starting to get pretty cheap and will get into "fuck it, why not?" territory in a few years...

Preferably a Rallye, but if I can't find one I could always install the Rallye pieces from a wrecked one.

Then swap the Caliber SRT engine into the Compass and make a kickass little rally project. I've already thought the Compass would be a total blast to rally, having driven one with a manual trans in all kinds of conditions. It's very easy to handle and you can slide the ass around without much effort, but still keep it under control without much fuss. The only problem is they're sloooooow. Almost 300hp on tap would help that. Of course all that power would probably destroy the transmission, but with as dime a dozen as these things are becoming I could just keep a couple spares on hand and swap them when they break.

What say you, Oppo?

DISCUSSION (19)

Twingo Tamer - About to descend into project car hell. > As Du Volant
03/03/2015 at 11:37

Edit: didn't read everything before posting.

Milky > As Du Volant
03/03/2015 at 11:40

Sounds like a lot of time and money invested to get a not as nice version of this IMO.

Kinja'd!!!

Snuze: Needs another Swede > As Du Volant
03/03/2015 at 11:41

I love crazy mash-up parts bin specials, so I wholeheartedly approve. And you already covered the one glaring issue I would've point out, and that is the transmission. I know next to nothing about Chrysler products, so do a little digging, see what gearbox it uses, maybe it's pretty stout and just needs a better clutch, or maybe there's a similar but uprated box in a different car. Also, if you are using it just for rally, you'll probably slip tires before you get the trans in a bind, so as long as you're on loose surfaces it may not ever be a problem. Tarmac stages, taking it autocrossing, or general hooning may shorten it's life, though.

I had a very simliar plan for an S-10, Bravada, V6 Camaro, and Pontiac Grand Prix GTP, but lack the time, funding, and work space to fool around with it.

BmanUltima's car still hasn't been fixed yet, he'll get on it tomorrow, honest. > As Du Volant
03/03/2015 at 11:42

Isn't that like quite heavy? I don't think it would make a great platform for a rally vehicle.

As Du Volant > Milky
03/03/2015 at 11:42

It's really not about the money, it's about the craziness of it and doing it because you can.

I don't have anywhere close to the cash and time to do this and probably won't anytime soon. And when I do I'd probably do something different anyway. It was just a thought exercise.

FJ80WaitinForaLSV8 > As Du Volant
03/03/2015 at 11:43

Guessing you're going to have issues fitting the turbo in there with what ever PTO they have to get power to the rear of the car. I'm sure this could be overcome however.

Logansteno: Bought a VW? > As Du Volant
03/03/2015 at 11:44

Better idea: Evo X engine into a Patriot.

They all shared basically the same platform I think.

Or, Patriot body on Evo drivetrain, somehow.

Milky > As Du Volant
03/03/2015 at 11:48

Well if thats the case, a 300hp version of this would be cooler.

Kinja'd!!!

BigBlock440 > As Du Volant
03/03/2015 at 11:53

I support this idea. You should do it.

As Du Volant > BmanUltima's car still hasn't been fixed yet, he'll get on it tomorrow, honest.
03/03/2015 at 12:00

Jeep Compass curb weight: 3097 to 3345lbs depending on equipment.

Subaru WRX STI curb weight: 3386 to 3444lbs depending on equipment.

Mitsubishi Lancer Evolution curb weight: 3527 to 3571lbs depending on equipment.

But as I said to someone else, this is more of a thought experiment than anything and will likely never happen.

BmanUltima's car still hasn't been fixed yet, he'll get on it tomorrow, honest. > As Du Volant
03/03/2015 at 12:13

Much lighter than I expected. Another Idea that would be much more difficult would to be to swap the 4WD into the Calibre SRT4.

and 100 more > As Du Volant
03/03/2015 at 12:42

Having looked into the STR4 swap before, I can tell you, there are some issues that could certainly be resolved with the proper application of liberal amounts money. At which point, you'd have something that, in total, cost more to create than the combined cost of the donor vehicles. And then you'd have a very unique piece that would be awesome in its own unicorn status, but it wouldn't be as reliable nor functional as another engineered A/4WD turbo combo from another manufacturer.

I HATE to piss on this idea. It something that I really feel should be done before we all die, if only just to say, for the history books, that its been done.

I can go into details, if you like...

and 100 more > BmanUltima's car still hasn't been fixed yet, he'll get on it tomorrow, honest.
03/03/2015 at 12:44

About 3100 lbs. Then again, the Caliber SRT4 was about the same weight.

As Du Volant > and 100 more
03/03/2015 at 12:46

I said in a couple other responses that this is really just a thought experiment and will likely never happen. Though I am curious what kind of problems one would run into...

and 100 more > As Du Volant
03/03/2015 at 13:55

I'm happy to play along. Rather than thinking of this as a list of reasons NOT TO do this, think of it as the interesting challenges you will encounter.

Okay, here goes:

The broad overview: what you're looking at is an engine swap. JUST the engine from the CSRT4. You'll keep the Compass basically as is, yank the motor, and drop in the CSRT's 2.4L turbo unit. Details follow.

There are two Compass/Patriot AWD systems, FreedomDrive I and FreedomDrive II. The difference is mostly in software, as the components are largely the same. FDII is better for rock crawling, and has a lower gearing, but only available with the CVT. If you want to maintain the 5-speed transmission, you need the FDI setup. Functionally, its got fewer bells-and-whistles, but is otherwise the same - software is really the only difference. Mechanically, the AWD (or 4WD) setup includes a rear drive ass'y, rear axles and hubs, a prop shaft, and a PTU attached to the transmission (if you're not familiar, it's basically a right-angle drive that sends power to the rear). There is no reason you couldn't bolt this drivetrain up to any Caliber or FWD Compass/Patriot...

However, because the prop shaft to the rear drive unit takes up a lot of space in the center tunnel, the AWD variants have an exhaust "maniverter" that eliminates the need for a separate catalytic converter under the car. If you're willing to say "F U" to emissions controls, then you'll ditch the maniverter and just use the CSRT4 turbo manifold. If you want to street this thing, though, you'll need to do some custom work to make room in the tunnel for the cat.

You'll be ditching the CSRT4's exclusive 6-speed Getrag box ()the one and only transmission option for the CSRT4) for the Compass' Magna/New Venture 5-speed, because I don't believe the 6-speed unit has provisions for the PTU to attach (it was never part of the plan, to my knowledge), nor the internal ring gear to drive the PTU. The 5-speed tranny internals seem decent enough, but the input-shaft-mounted slave cylinder is a problem waiting to happen, and will require removal of the transmission to service. Not sure of any other solution here, as internal slave cylinders seem to suck as a whole. Also, FWD-based drive systems, FTL.

However, because the turbo and non-turbo 2.4L blocks are damn near the same, the CSRT4 motor should bolt right up to the 5-speed.

All the above outlines why this endeavor is primarily an engine swap. Now we start to hit the differences...

There is plenty of room between the block and the firewall for the turbo setup, as the firewall is common between the two platforms. However, the frame horns that support the front end of the car are different, and seeing as how they are integral to the chassis, you'll be modifying the Compass ones for clearance (or, at the very least, beefing them up to handle the extra horsepower). Also, you'll need the CSRT4 front bumper bar, as it extends forward farther to accommodate a larger radiator and intercooler (unless you go with a custom top-mount setup). This means a custom front end, as the Compass grille and bumper cover will likely not fit without modification.

So, mechanically speaking, you've done it! You've got a SRT4 motor grafted into an otherwise-stock Compass 5-speed shell.

Now is where the nightmare begins.

So, the computers are a mess. All ChryCo products of the era use a CANBUS system that is not friendly to modification (even less so than other CANBUS systems by other manufacturers). You can't simply swap the engine and be done. Nor can you simply swap the ECU, since the engine computer and the transmission computer are an integral unit, called the Powertrain Control Module. This little fucker is locked up tighter than Fort Knox, and without the ChryCo-proprietary computer system with which to speak to the PCM, you're going to spend your time looking at piggybacks, reverse-engineering the stock unit, or coming up with a completely custom computer.

Now, you'll note earlier that I never once referred to a rear differential. No, it's the "Rear Drive Assembly". It's a differential, but it also has an integrated clutch that disconnects the RDA when AWD is not necessary, and over a certain speed. You can lock it electronically into 4WD mode, but as said, it will revert back to part-time use over a certain speed limit (which you're likely to hit if you planning to rally. Regardless its not going to do ANYTHING unless is gets the proper signal from the PCM... So now, you've got a PCM that controls an engine and transmission that were never meant to be paired, along with a computer-controlled 4WD system.

Assuming you get thru all of that, you've now got to find a way to control all the interior elements, or custom wire everything.

All this being said, you'll likely still need to replace the front LCAs after 40k miles, as the ball joints tend toward self-mutilation as relief from work. That 4ok estimate is typical for mall-duty Compasses, so you'll likely want to replace them even sooner. Nobody has tried it yet, but you may be able to swap in the front and rear control arms from the Lancer Evo X, which are these nice cast aluminum units, vs the CSRT4's stamped steel ones.

Again, it CAN BE DONE. But it will require a LOT of custom work, and frankly, the computer is going to fight you at every step.

As Du Volant > and 100 more
03/03/2015 at 14:30

That computer issue sounds like a nightmare. Thanks for your input!

and 100 more > As Du Volant
03/03/2015 at 14:35

Like i said, I've done some research...

However! There is a turbo kit for the 2.0 Lancer that should bolt up to to the FWD Compass/Patriots. The company that sells them has said they see no reason is shouldn't work, using their piggyback ECU, and they'd be happy to have a Patriot/Compass to test on.

As Du Volant > and 100 more
03/03/2015 at 14:39

That could be fun. The early model mini-Jeeps are getting super cheap. In the amount of time it'd take me to prepare for another project they should be attainable with a manual trans and 4wd, and a decent amount of miles, for under 5 grand.

and 100 more > As Du Volant
03/03/2015 at 15:34

I have an 08 Patriot (FWD 5-speed), and I would absolutely love to get this thing out on a dirt course. Problem is, it's my daily driver. But like you said, you could find one (with AWD) for pretty cheap, and even with the stock engine, you could at least have some fun beating it up on a local rallyX course.

And I know people will call it a "car" and tell you how it shouldn't be out there because it wasn't built for that, but the truth is, Jeep actually made sure that the chassis was robust enough to handle some abuse, moreso than a typical on-road crossover. If you took the skidplates from an FDII model (or made your own) and put on some grippy tires, i think you could have a blast running an otherwise stock Compass/Patriot in the dirt. Might not be competitive in any sense, but it could be fun.