I have been wanting to write up some product reviews for a while, but have also been holding off, wanting to let some time pass, and be sure that what I am writing here is a complete picture. With three months' worth of driving under all conditions, I felt that the time had arrived.

I have another thread about the build project of swapping in a M113K Mercedes V8 into my Crossfire. While that car is the subject of my review, the swap project is not the focus of what I want to communicate here. If you are interested in that build, please click HERE and read about it (I tried to make it not boring).

From the day I settled on a Crossfire as being the platform I would use for my next hot rodding project, I was concerned about the electronics and tuning aspect. I have spent a good deal of my career as a professional tuner of other Chrysler products, but the Crossfire is completely Mercedes based in its underpinnings, and I had not tools or experience there. If I was going to use a Mercedes based platform, I was going to be reliant on other people's knowledge and abilities. However, I am ever the critic in this department, as I take tuning perfection quite seriously. Before I turned a single wrench on my project, I wanted to be sure I had the electronics portion figured out. After just a little bit of research, I settled on Josh Chase @sk8erjosh09 and The Mercedes Swap Shop as my choice for tuning and electronics. After talking with Josh via PM, then email, then by phone, we worked out a game plan, and as we did, my confidence grew with him. Josh would handle the tuning and coding of the ECU, and as the US based distributor of Andrew Tieken's TCU, would also handle the transmission tuning. Josh also would make sure the SKREEM was happy, and program some keys for me.

Being new to the Mercedes platform, I was understandably nervous about the whole affair, but Josh approached it with confidence. When the package arrived, it had my (now) reprogrammed ECU, TCU, a couple of keys and the SKREEM module. All good! It was still a few weeks until it was time to try to fire up the new project, but when the day came, turning the key resulted in an instantly running engine, and NO Check Engine Light (CEL)! Now, I need to pause here for a moment, to tell the reader a few things. First off, that this supercharged V8 into a 2004 limited swap started up and ran immediately was monumental. The engine was basically stock, but let's face it, nothing is straightforward about this. I didn't make the transmission side any easier. The transmission wasn't Crossfire. It wasn't MB. No, that would have been too easy. Instead, the transmission was from a 2009 Dodge Charger R/T 5.7L Hemi. And it was built. More clutch discs, Sonnax kit, blue top solenoids, V8 torque converter, Crossfire bellhousing. Even the dipstick tube was different. What a mess for a tuner!

Even though I own a Chrysler Micropod (DRBIII) *and* a Mercedes SDConnect/SDS/DAS C4, I got impatient, and did not reset the TCU for initial startup (mistake). As a result, the initial drive with the car didn't go as planned. Oh, and I overfilled the transmission by almost a quart. Did not drive well, and fluid was dumping on the ground. After posting about my troubles in the build thread, Andrew @CL770 reached out to me to troubleshoot the problems. With his guidance, the car was soon running properly.

So let me explain "properly". This is a pretty powerful engine. In its most sanguine trim, it is 469hp, and tuned up in some models it is north of 500hp. Josh tuned this for as much power as we could get with the stock pulleys, injectors, etc. The engine performance is stunning. And it starts up, every day, in all conditions. We have driven it in stop and go traffic on a 95° day in Florida. We have driven it hundreds of miles on the highway, with the cruise control set. We have driven the tight roads around Tail of the Dragon. It always starts up and runs properly. That may not seem like a big deal. It may seem like, "yes, of course it should". Unfortunately, few hot rod projects go that smoothly. The engine delivers strong, consistent performance. Couldn't be happier! What's more, I have two keys, instead of one, which is a new thing for my ownership of this car. Two keys? What a thought!

The transmission controller unit (TCU) has two modes, similar to stock. Unlike the regular Standard/Wet or Summer/Winter modes we think of in a stock application, we have come to call it Sport/Wimpy modes Think of each as the same as stock, just more! The V8 works very well with W mode, and is good not only for wet stuff, it works really well in stop and go traffic. W mode starts the car in 2nd gear, which results in few, if any gear changes in the heavy traffic. Overall, shifts in W feel only slightly more firm than stock, and has a high degree of comfort - even with the built transmission under the floor. S mode is where this car comes alive! The shifting is on cue, and very precise. Normal driving, you feel the bump as it changes gears, but engagement is not so harsh as to upset the passengers at all. At wide open throttle (WOT), the shifts are quick, and firm is an understatement. Easily breaking the tires loose with a strong 'bark' on the 1-2, 2-3, and often on the 3-4 shift, there is no flare up, slipping, or other nonsense. This same type of programming would be quite at home in any performance oriented Crossfire owner's ride.

After conversing back and forth for a while, Andrew said he was about to introduce his new 4 mode programming for the TCU. A deal was struck, and Andrew shipped me a new TCU with this Mercedes SLR based programming. In this TCU, we no longer have an S and W mode. This is replaced with four modes of operation: Sport, Comfort, Manual and Agility mode. Switching between modes is achieved by cycling the W/S switch back and forth. If you are in Drive, observing the gearshift indicator in the cluster will reveal a C, S, A or a number (indicating manual and selected gear). Turning traction control off will switch this display to show what gear the trans is in at any given time (neat!). So, how does this all work? Starting with Comfort mode, it is roughly analogous to "W" mode, with the car starting in 2nd gear, but the shifts are softer, and more comfortable than before. However, this doesn't mean that there is any hesitation at gear change. All very smooth. Sport mode is very much like "S" mode in the last controller. It was already awesome, but about to get better! M mode is full manual. No quasi- manual like Autostick typically does. No automatic upshifting/downshifting. No, it is full on manual, minus the clutch, of course. It does what you tell it to do. I can imagine this would be REALLY awesome with the addition of @latemodel21 's paddle shift kit! I think this mode will really shine at the next Dragon event The last mode is the one that people in the MB forums make a fuss about for other model cars. Agility, or "A" mode. This is almost F1 shifting technology in your plain old 722.6. Unbelievable! In this car, the shifts are so fast and so smooth that you only know it did it because you are suddenly slammed in the seat harder. I am not joking, it feels like a booster rocket has been lit, each time it upshifts. Downshifting happens *now*. Not a hesitation. No 'thinking about it'. NOW. The entire attitude of the car changes. I am blown away by it, and it puts a huge smile on my face every time I plant my right foot! This will be the next big thing for all of the performance drivers and hot rodders out there.

In short, I cannot recommend these two gentlemen enough. If you are looking for engine tuning, SKREEM issues, keys, etc, contact Josh Chase. For the ultimate in transmission control for this platform, contact Andrew or Josh. Many thanks to both of these guys for continuing to support and develop for our beloved little cars!

 

I need to send as much props back to you Neil! You were understandably hesitant , but very thorough and easy to work with. I’m glad it all worked out so smoothly and I can’t wait to see it when I finally make it to the dragon. I need a ride in this beast!

p.s. when you’re ready we can throw some more power at it

 

Thanks for the in depth write-up, Neil. It sounds like an awesome ride! Someday I hope to have something similar--need to have Josh build it turn-key, though.