Hello everyone. I'm sure you've seen these posts many times by many hopefull souls trying to get that extra 80 hp. I've begun the project of swapping my 4.3 engine to the 5.5 NA. I got the engine and transmission for $219, and will be doing all of the work myself along with some friends. I know many of you will probably wonder why I wouldn't just sell my 430 and buy a 55, and the reasons are as follows:

1- I am a college student running two benzes. They're both V8 S-classes, and I am grateful to have them.
2- I am very emotionally attached, and don't want to get rid of either (attachment issues. I know).
3- I don't have room for a third car.
3- I crave the speed.
4- The 430 is my daily and the 420 is my future project (S600 AMG build).
5- I have a very limited college budget as I am a UT Austin student "HOOK EM". I don't need ABC as it is too expensive even for a DIY mechanic like me, and I don't want coil-overs because I am not a pleb. Airmatic is perfect for me.
6- This whole project is gonna cost me a weekend, and like 500 bucks which includes stuff I was already due for like spark plugs and mounts.
7- I am potentially the slowest in my crew right now and I don't like that.

For those who are interested. My plans for this car is to hopefully do my own custom AMG build with my parts and options of choice. 600 interior, AMG brakes, retro fit all the options i'm missing if possible, and maybe a custom diamond leather stitching like the newer Mercs, etc. I got the car from an insurance auction for very cheap with 72k miles, but It has literally no options except maybe the light beige interior which kinda looks like the designo silver except it uses the cheap leather stuff. It really pisses me off how somebody walked into the Mercedes dealer 16 years ago and literally skipped the entire options list. He didn't even get the wooden steering wheel. What I ended doing so far is installed the AMG cosmetics kit like the wheels and the bumper kit. Parts are whatever hits the junkyard first. I'm still waiting on the AMG exhaust and all that stuff.

Anyways back to the project. I have the ECU figured out. I do have access to star and know how to swap chips so that the EIS would work. Everything else is bolt on and should be straight forward except the TCU. I cant find any information out there about what chip I would need to swap for the EIS to communicate with the TCU. I was thinking about whether it would be okay to just run the 55 tranny on a 430 computer or if the shift points are gonna be wrong and the tranny is gonna run like garbage. If someone out here is knowledgeable and can tell me what chip I need to swap that would be awesome.

Thank you guys for any feedback, and interest in the project. I will be updating this thread and hopefully provide info to the next soul to try and attempt this.

 

Don't worry about the TCU. With the five-speed (722.6) transmissions, that's not a "Theft Relevant Part", so you can swap TCU's at will, as long as it's from the same type of car (S430/S500 to S430/S500, or S55-NA to S55-NA, S600-TT to S600-TT, and so on). Now, with the seven-speed (722.9), you'd have trouble.

I would swap the engine and transmission both. Put the S55's TCU into your S430. Swap the EIS, ECU, and shifter module to your S430. That ought to do it. You'll be using the S55's keys from that point forward.

 

Thank you for the feedback. I forgot to mention that the donor car is a 2001 E55. We have tried the TCU and it didn't work since the car thinks it's an E class when it's actually an S class which has anti theft in the shiftier which the E class doesn't have. Right now were looking into doing some version coding which ill share that info once I figure it all out.

 

So looks like I'm gonna be doing some SCN coding. I would like to know if anyone has knowledge of what the SCN coding is for a S55 AMG NA or if possible a chart somewhere with the list of all of those codes for Mercedes Benz models that they can attach to this thread.

 

Is there a update to this project?

 

IG: Merc_OutW220
I have done this same exact swap. 2001 S430 with 2001 S55 AMG engine swap. ARP Head studs, long tube headers, cat delete, X-pipe, full custom exhaust, custom cold air intake, Race IQ Performance Stage 2 ECU/TCU tune. The TCU tune also has the proper gearing tuned in for the differential in the S430. With a 100 shot of nitrous & progressive nitrous controller. But, I’ve been stuck with a problem for a couple years now!! THE CAR DOES NOT SHIFT PAST 2ND GEAR!! I swapped transmission with another from a S430, nothing. I checked my ECU for damage, that wasn’t it. I have the proper gearing tuned into my TCU. Idk where to turn from here. Thinking of installing a 2001 S55 AMG transmission, and see what happens. ANY SUGGESTIONS!!?? I VERY BADLY WANT TO DRIVE MY CAR!!

 

Check with Peter. He may be able to help.