Hey gang, I was doing some surfing this morning and came across RENNtech, who does aftermarket performance mods for Mercedes and Chrysler. I was wondering if any of you have utilized RENNtech services before or heard about an SRT-6 owner who may have used these services? RENNtech purports to have a Performance Package for the Mercedes SLK32 AMG that includes a larger crankshaft pulley and ECU upgrade worth an additional 45 HP and 60 FP of Torque. The cost is $3,500.00...so you can make your own conclusions regarding the price vs the gains. Since the SRT-6 shares the same engine as the SLK32 AMG I was wondering if anyone has had this particular performance modification done to their SRT-6. It might even be possible that the ECU upgrade might find the 19 HP that the SRT-6 is missing in the first place too...but just guessing here.

 

RennTech, Kleeman and Startech (Brabus) are very expensive, don't know of anyone on the forum that has done the upgrades as yet.

http://www.startech.de/homee.htm

http://www.kleemann.dk/site

 

Hey, I am new to the board...So far I have installed phenolic spacers (keep intake temp. lower than stock), magnecore wires, iridium sparks, and the sl55 amg air splitter kit. I drove the vehicle like new for about a week or so...I figured I would let the ECU figure out the add-ons. I will tell you this thing kicks faster toward redline, idles better, gas mileage a little better, anyways I was doing roll-ons with a friend and we are no longer even!

 

I called and spoke to someone at Renntech two weeks ago about getting their pulley/pcm package.
They do have a package for the SRT-6 and its only $3,000 vs $3,500 for the SLK 32.
I am not sure what the difference is, or if there is a difference, I forgot to ask.
They have you ship your pcm to them next day air, they do the program, then ship it back with the pulleys next day air...so the car is only down for 3 days or so.
I was leaving for vacation...so I opted to wait until I got back before going through with it.
I think I'm going to call them tomorrow and get more details and before shipping off my pcm...
So far I have Magnecor wires and IK16 plugs sitting on my work bench, K&N filters on the way, and Renntech pulleys/pcm coming soon... I can't wait!

 

Have you run the car in the quarter yet?
I'd be real interested in seeing what the difference is before and after the mods.

 

$3k for an ECU upgrade and A pulley, all together for a gain of about 40 hp!?! I think I would have a hard time walking after that. Just because it is a German engine they really like to stick it to people. Thats about as much as I spent on a complete turbo kit for a Mustang. I don't know why I complain though, I'll probably bite the bullet someday. Just think though if some company made reasonably priced performance parts for German cars, I would invest in there stock.

Unless a pulley made an additional 100hp I can't see it being worth $2k. IT DOESN'T EVEN HAVE ANY MOVING PARTS!!!

 

Eracer 76: Sounds great...I agree with feets...some kind of baseline for measuring the performance before and after would be a good idea...be it a Dyno or quarter mile time...although the variables at the track can be problematic when making comparisons. A before and after Dyno on the same machine would really be informative and let you know if you really got your money's worth. I wonder why there is a $500 difference between the prices since it is the same engine...paying for the Mercedes name perhaps. I sent RENNtech an e-mail asking questions about their performance package to include a question regarding the 19 HP difference between the SRT-6 and the SLK32 AMG...
Keep us posted as you move forward...thanks.

 

The best performance upgrade is made by evosport. I have their underdrive pulleys for my mercedes 3.2L V6 and they really work. For the amg model (srt) they make a kit that overdrives the supercharger (more boost) and underdrives the rest (less resistance). The kit is about $1,800 and will put 30 hp more to the wheels. I talked to the guy there and they also offer an ECU reprogram that will add about another 20 hp AFTER the pulley kit.

 

Thanks. Great info and another source to consider.

 

If you are interested in the Evo stuff wait for their new pulley to come out. The current pulley does not have a harmonic balancer.

You can't go wrong with RENNtech or Kleeman.

 

Yeah, I've haven't hear too many good things about Evosport on the couple MB forums I've been reading.
There have been many debates on the crank pulley needing, or not needing the harmonic balancer.
I know for a fact that I've haven't seen one complaint from any Renntech customers though.
I've also read that even though Evosport supposedly makes more "dyno" power...Renntech packages are faster with 1/4 mile times to prove it by many happy customers.

So...needless to say, my pcm is all boxed up and ready to ship out to Renntech first thing tomorrow!

 

Sounds great...keep us posted.

 

I am sure you will be happy with your choice. Keep us posted.

 

Update...Bob Brady at Renntech called me today (Wednesday) around 11 am to let me know they got my PCM, they had already started on it and were also getting the "pulley kit" ready to ship... all before he even got my credit card # over the phone. He said they should be able to ship it today and I should see it Thursday afternoon...Great service so far, I cant wait to get it all installed, I already have the crank pulley off and waiting.

 

I may have missed it, but how much is this costing u?
And for what kind of gains?

 

Hi, It's been a while since I posted on here last, but I just recently purchased an SRT-6 and am considering the Renntech upgrade kit. I have a few questions for anyone who has first-hand experience with the kit.

1) How involved is the PCM and crank pulley swap for an amateur mechanic?

2) Is the supercharger any louder than stock at WOT due to the increased boost?

3) What are the real seat of the pants or track/dyno performance gains? Are the final horsepower/torque numbers equivalent to those that Renntech advertises with this kit on the C32/SLK32?

 

Katie:

Those are all great questions that a lot of us would like to know. Eracer76 will probably be the most qualified to discuss your questions because he just sent his ECU to RENNtech and is waiting to install the ECU upgrade and new crank pulley. The last car I could actually work on, and know what I was doing, was my 1970 TR6...so I really can't answer your questions with any authority...but I am anxiously waiting to see what Eracer76 has to say about the RENNtech performance package.

 

Well...I received the package that next day (Thursday) afternoon and I installed it all that night and took it for a drive.

The Renntech package did come with a bigger crank pulley, smaller water pump pulley, smaller idler pulley w/bolt, detailed instructions w/pictures, one big chrome Renntech emblem, and two smaller Renntech "bubble stickers".

The install was simple for me and my ability (I've done heads and cams in previous cars of mine) but I still think most back yard wrenchers can handle this job with the right tools.
After removing two clips the hold the fan in, you just unplug it and pull it straight up and out of the car, very simple. Then you just need a strong 1/2 drive impact gun and a 27mm socket to spin off the crank bolt, and the crank is keyed to the shaft so its not pressed on, it just slides right off! (after you remove the belt of course).
The water pump pulley comes off by removing 4 10mm bolts using basic hand wrenches and the idler pulley comes off by removing a 15mm bolt.
Then just reverse the process installing the new pulleys, put the same belt back on, reinstall the fan and your good to go.
The PCM is just a matter of unplugging it, sliding it out and back in, no tools needed.

By no means is this an install-how-to, but just to give you an idea of what's involved...overall its pretty easy to do. The whole pulley job only took me about an hour, about the same as it did to install the spark plugs and wires.

Now for the test drive...
Now keep in mind that I also installed the Magnecor wires and Denso plugs while I was waiting for my PCM to come back (I got bored). lol
I also just turned over the 1,000 mile mark on the odo while testing it out, so the car is barely broken in yet. lol
Anyway...lets just say there is quite a difference in power, not so much from 30 - 80 mph, but the stand still take off is much better and it also pulls real hard in the upper rpm now...around 80 mph this thing really gets moving now!
I also noticed that my ESP light flashes alot more then it used to, like shifting from first to second, which it never did before. Even with it turned off, it still flashes all the time now. I need to figure out how to fully disable the ESP. lol
I also noticed its much easier to get this baby sideways with a stab of the gas pedal going around a turn then ever before!

Sorry I have no other baseline to compare to, I didn't have time to go to the drag strip before hand, and it was too hot the last two weeks, because sitting in the black asphalt staging lanes, in a black car on a hot sunny 90* day is no fun, not to mention the car wouldn't run as good either.

So...overall, I'm very happy with the car and my mods so far, and I've only got about 120 miles on since the engine mods, it seems to be getting a little faster the more I beat on it. lol

 

Here are some pics of the pulley kit...
This is what I got in the package...


Renntech on the left, stock on the right...

 

I thought the RENNtech package came with 5 pulley's. Guess you learn something new everyday.

Anyway we can get a measurement of the crank pulley?