I hope to reprogram my TCU either via DAS or other to match the SRT and/or AMG shift patterns (I have a PM to kansus to confirm). Our squishy, soft shift, american taste doesn't do well with added power so a tranny recal is always in order when adding this much to the wheels. That said, I do plan on putting some time into seeing if I can find any parts for rebuilding the tranny for further reinforcement.

On another note, I did my homework and found a nifty little device! It is a knock sensor with a datalogging output! This will make tuning so nice. I'll pull my wideband, knock, and an external MAP sensor into my SPD so I have everything I need in one set of logs. Then all I have to do is re-scale the AEM tables to match the SPD logs and there you go!

 

Good luck. I hope it turns out well. I was playing in STAR DAS today and noticed that the SLK32 trans which is probably the same as the SRT said it was programable which non of the other transmissions for the SLK had. I went in and it appears that you can (i am no expert!) set shift points, shift speed, and maybe even line presure. This may not work on the Crossfire unless the crontrol module is the same part number. I am not sure the stock trans will hold up. I am keeping my eye for a trans now but intend to use the stock one until I find the right deal or I blow it up. My stock V8 puts out more than 100 ft lbs of torque than the n/a trans is rated for.

 

this may be a bit overkill or out of reach for the two of you, but has anyone checked into the MB 7G-tronic trans?

 

Haven't looked at it. Until I know that I can overcome the electronic issues I am keeping things cheap and simple. If I knew this would work for sure, I would be putting a AMG 55 supercharged engine in.

I am really excited about this Rotrex and had thought about doing this and posted on this subject a couple of years ago.

 

Don't know if you have seen this but I posted this link two years ago. It is a guy who put a Rotrex on a Mercedes 6 cylinder engine.

M104 Supercharger Project Complete - PeachParts Mercedes ShopForum

Here is the link to the pictures including the Dyno sheet:

Shutterfly | View share

Some important info on the dyno run:

I've added a Water/methanol injection kit and jumped the boost up to 0.7 Bar. The Water injection is a Hugh help and money well spent.

And finally Dyno numbers.... 323.7 rwhp and 273.5 ft/lbs. Figure 20% loss though the 4 speed auto and the power at the crank is 404 hp. This is more power than I set out to get so I'm pleased and I'm done (for now).
Link to Dyno sheet:

The spike at 4400 rpm is just a function of trying to get the automatic tranny in the proper gear (3rd) for the dyno. Everything up to 4400 rpm was at 40-50% throttle. It wasn't until thrid gear that I opened it up. Therefore power numbers under 4400 rpm show up a lot lower than they actually are due to the half throttle. With a stick the slope of the curve of the power curve wouldn't have the stairstep look... you'd just drop it into 3rd and open it up.

Trany is a 4 speed auto... no issues yet with 178,000 miles on the clock and over 400 hp though the shaft... a testiment to a fine orginal design! If it lets go some day I won't hold it at fault.... it's done a lot more than it was orginally asked to do.

 

i've seen this before and unless i'm mistaken this was on the old style 3.2, correct? (not the same as ours)

 

Yes the engine was the 6 cylinder that our engines replaced. Still a good thread to learn from.

 

Well, I found a guy that can bullet proof the NA tranny. He can even convert it to the srt tranny and bullet proof that. However, at 4.8k I would be better off buying a low mileage SRT tranny and tcu. This guy builds it for some serious power and way more then I plan on putting to the ground!

I won't have to go there for a while anyway. First, I have to get it to work. Second, I want to explore the limits of the stock exhaust and headers on boost. Also, the rotrex makes boost in a linear fashion and is therefore more gentle on the gearbox.

 

Well, I got side tracked this weekend with mapping out the SC location and most importantly how to drive the SC. I ended up settling on designing a new dual pulley for the alternator and driving the SC from there.

That said, I've completed the design and associated drawings. I'm going to ship the alternator and stock pulley off for fabrication in the morning. Then when it gets back, Ill have to take the alternator down to a local rebuilder. I want to discuss with them, the options and/or need to strengthen the bushings due to the added side loading that will be involved.

I targeted the alternator as my only other options were the water pump or the crank pulley. I don't know about you, but a 150.00 alternator seems like a much cheaper option with which to experiment with than the other two!

Once I get the pulley, I can then design the Rotrex mounting bracket and the rest of the hardware is cake!

 

Sounds good. I can't wait to see how it works.

 

PLEASE TELL ME SOMETHING!!!!!! lol

 

?...........

 

Still here! I've been pretty busy trying to wrap up my other stuff and then I get 2 more kit orders. I shipped off my alternator and it sat until my guy could get started on the new pulley. In the meantime, I thought about it some more and am changing the setup. I've ordered a replacement upper idler pulley and some upgraded angular contact bearings. I'm going to use these to build a more robust drive pulley for the rotrex using the idler pulley location.. It will also make the install easier and be less of maintenance concern. I should get everything in this week from suppliers, then turn it around to the machinist by next week. I'm hoping to have a pulley to test within about 15 days if everything goes my way.

I'll use that time to get caught up on everything else to the point where I can pay more attention to the xfire. In fact, it will feel like a new car considering I haven't driven it in so long

I do have some goodies in to play with soon. I found and ordered a knock monitor that I can log with the SPD! I can't wait to get it installed and tested.

 

How is it going? Any updates? I got my V8 running and am about 99% done with that and am starting to look at my forced inductions options. I have absolutely no room left for a Rotrax and am not sure if I have room for the factory Kompressor either. I am starting to lean towards a rear mounted turbo managed by the AEM piggy back system.

 

Well, things are coming together albeit slowly. Little by little I am making some progress despite the set backs of getting sick then hurting my back. That said, I look for things to start picking up over the next week or so. For now, I do have a pic to share.





Next up:

• Design and prototype the support bracket for relocating the Coolant Reservoir
• Design and prototype the Rotrex bracket and belt tensioner
• Design and prototype the front mount HE brackets
• Design and prototype the IC water pump mounting bracket
• Design and prototype the IC mounting brackets

• AEM
• Knock Sensor to SPD input
• SPD - window mount with OBD-II cable in dash
• Wire in my Radar Detector

 

I'm happy to see progress Keep the updates coming!

 

I understand how you are mounting and driving the Rotrax and think that is a great first class way to go. I am starting to look at my options for forced induction on my V8 but have pretty much used all the available space to get the motor in there. I think with a rear mounted turbo I can get to 440 - 480HP on 7.5 to 8lbs of boost. What do you think the maximum boost could be with 10:1 on 93 octane?

 

Well, as you know a lot depends on how much the internals and tranny will take. That said, if we take ultimate power production out of the equation (as well as its impact) and the knock characteristics of this motor are similar to others in my experience. I have been able to run 15'ish psi on 10.5:1 with my other Rotrex setups and 13 psi on 11.5:1 on pump gas (IAT's of 17 degrees Fahrenheit above ambient). Of course you reach a point of diminishing returns as boost goes up and spark comes down.

The real fun with any supercharger is finding the sweet spot between Boost, Spark, Fuel, and Parasitic loss.

Going turbo is another matter as they tend to run hotter but net more HP per psi due to no parasitic loss.

However, back to the diminishing returns statement. Max boost can be somewhat of a misnomer in that you can run a whole lot more boost than you would think as long you can pull spark and add fuel. I guess the real answer is that it depends on your particular setup; the characteristics of your power adder, fuel delivery system, and at what point adding boost fails to net a gain at the wheels on the dyno!

 

Wow that is pretty impressive boost levels. I had a turbo car back in '79 but haven't messed with them since then and a lot has changed. I have always liked super chargers as they just make the engine feel mcuh larger but a turbo may be my best and only option. I am liking what i am reading about the rear mount turbo. Having the turbo where the muffler goes results in no extra heat under the hood and a much cooler charge. Many people have found they really don't need an intercooler but with one you can get very close to ambient temps. Seems like the real key to the rear mount is selecting the right turbo and sizing the pipes right. If I can get anywhre near the boost levels you mention, I will have quite a bit of power and torque. I think the 43AMG, 430 and 500 engines are better suited for forced induction because of their 10:1 compression vs. the 10.5 and latter 11:1 compression ratio of the n/a 55 AMG engines.

 

any news? closing in on a month since you reported anything, and the last update was a sketch and a generic mounting bracket or something insignificant. curious....