JerseyCLK55

Hi All,

If anyone has experience with modding their W209 CLK55, kindly please read on and offer any advice that you see fit. All suggestions and input is apppreciated.

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I've been modding my cars since 1993 and have suddenly come to a stalemate with my W209 CLK55. I believe that I'm entering uncharted, potentially dangerous territory. I just had my transmission replaced under warranty and I am a bit apprehensive about wringing out my car. However, given that no one is interested in buying the beast, I will no longer be able to get that Z06 that I've been eye-balling. Therefore, I will be keeping this thing forever and ever and ever. That being said, I've started my course for modification redemption. Please let me know what your thoughts are regarding the below mods (i.e., are they necessary?, what order would you do them in?, are there better options or manufacturers?, what are your experiences?, etc.) Thank you ALL in advance for your feedback.

-RennTECH transmission reinforcement kit: $2200 Can't find detailed info. without calling them... What does this entail? Anyone have experience with this?

-Kleemann LSD upgrade: $$??? How much is this? Anyone have experience with this?

-Stainless Steel brake lines and Motul RBF600 fluid. $130+ fluid. Are the ones on TireRack any good?

-Repair all dings and dents (paintless): Anyone know a reasonably-priced paintless dent guy in NY/NJ?

-Custom dual-exit exhaust: $1500. I believe that Mufflex can do this.

-19" lightweight BBS wheels and tires (~1 lb per wheel/tire savings): $5000:
Anyone have another suggestion?

-RennTECH Supercharger kit (500 HP+/500 lb-ft Torque): $16,000 OR
-HPS Supercharger kit (475 HP+): $8500 OR
-Some sort of "chip" or ECU tuning....??? Your thoughts?

-Labor (parts installation, full car inspection for weak points, R&D, etc.): PLEASE, does anyone know of a reliable, honest Mercedes tuner in the area? I can't keep going to the dealer for everything, especially these performance mods. Albeit, I love my dealer- I give mad props to Prestige Mercedes.

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I think that with these mods, I can make this car a serious contender that won't BREAK.

Based on my estimates, with the supercharger, the car should be able to do 0-60 in about 4 seconds and do 1/4 mile in the mid-high 12s at around 120 MPH.

Not planning on doing any suspension or brake mods. I haven't found any upgrades out there for the AMG model. I guess it's pretty good from the factory.

What do you think?

Stiggs

Good luck with your mods. Don't forget to post pictures as you go. I wish I could help but I don't know much about performance mods.

SLK55R

First ... please look up HPS on this forum ... and you will see what a nightmare they seem to be.

There are suspension upgrades (coilovers).
The Renntech Supercharger comes with ECU tuning.
You are missing headers, Xpipe, Exhaust, performance cats in your mods.
On LSD I'd look at Quaife to be honest.
Rims I would also suggest taking a look at Carlsson, Renntech, HRE, and Fikse.

I think your estimates are off btw.
"Based on my estimates, with the supercharger, the car should be able to do 0-60 in about 4 seconds and do 1/4 mile in the mid-high 12s at around 120 MPH."Most likely you will be in the LOW 12s possible breaking into the 11s (with Drag tires) and your MPH is going to be around 115-117.

JerseyCLK55

Hi SLK55R-

Indeed, the HPS nightmares seem to be pretty universal. That being said, $16,000 RennTech still seems to be a bit much to swallow.

Could you please provide some manufacturer suggestions on the exhaust mods you've listed? What power gains can be harnessed through these parts?

If you had a $20-25k budget (including labor), what mods would you do? My main goal is to make noticeable straightline performance gains as well as maintaining driveability.

Do you have any details on the Quaife? I was only able to find info on an E55 application. I had one on my VW and it worked well, but made turning a bit hard.

Thanks for your input.

-Mike

SLK55R

Sorry I don't have input on the quaife. Perhaps some other members can chime in here.

20-25k (including labor)

My opinion on mods :
Supercharger (comes with ECU tune, Injectors etc) Also if you have 100 octane conveniently around you ... I would have your shop get multiple programs from the Supercharger vendor so you can play with 100 octane as well!
Rims ... tough call. You will need to save some money here since you only have a budget of 25k. Tires are going to be around 1k to 1.2k by themselves. You won't want to spend over 1k per Rim and that already eliminates a bunch of great rims. (unless you get 2nd hand) I'm sure if you get the RT supercharger they will give you a volume discount.
OBDII scanner/data logger - this can range from 200 bucks to thousands. I got a scanguageII that seems to fit my needs. I am also able to attach it to my windshield so it can be viewed at all times.
Sprintbooster (amg version) its only a couple hundred bucks and I love it. Even if you think its too sensitive ... its a 10 min removal process.

Thats about it on your current budget. You will have some cash left over but I'd save that for another set of tires! Afterwards if you get more cash you can go headers, xpipe, cats, exhaust. They obviously don't provide nearly the same bang for the buck. But when you get to the point where you are looking for every little HP ... you can go that route.
Personally I haven't dyno'd the exhaust stuff yet. I currently have the shorty Renntech headers but I"m switching out to Supersprint Longtube headers, Supersprint cats, Supersprint Xpipe and retaining the stock exhaust. Hopefully I'll have dynos on that in about 2 weeks.

Btw one other thing is that since your model has been around longer ... there are more parts available that can help you pick up speed. HP isn't everything ... you can start going CF stuff to lose some weight.

JerseyCLK55

Thanks for the detail. What do you think about transmission/differential mods before the HP stuff? I'm just a bit afraid of the durability of the stock driveline... Already had the tranny replaced at 50k miles.

SLK55R

Well the 5 speed is supposed to be practically bulletproof. What went wrong with your original?

I'd do the performance mods first ... and then if the tranny goes it goes. Most likely you will need to replace the clutchpacks at some later date.

If you want to do substantial mods you just have to realize that the car wasn't built for that lvl of hp. As a result it will shorten the life of other parts. Just the price we pay for modding ...

Stiggs

What year is your W209? Why did the tranny blow?

ProjectC55

Forget the tranny and diff mod! You don't need it. However read about PTE's(W209 CLK55) and Chappy's car(W208 CLK55). You can do similar mods to what SLK55R has or similar to what I have. Read about all four cars.

Read our threads is all you need to do when you click on all the names I've mentioned. You will find all you needto know about suspension,brakelines,cams,exhausts,ECU upgrade, it's all there for you to chk out.This will save you search time and will give you all the info you want.

Not sure why your tranny went,are you shifting it ,beating the hell out of it,was the car bought used and how many miles? I try to make it a habit of chging my tranny fluid every year or 6 months. Knock on wood,no problems whatsover from several track 1/4 mile runs and high speed runs. I leave it in drive and let the throttle and tranny do it's thing.

PS Brembo does the brake mods for your car. GO to tirerack and you'll see.

ProjectC55

Bullet proof only when you chg the tranny filter and tranny oil every 6 months or yr. Good to chg the diff fluid as well.

Stiggs

So you are saying I should be changing my Tranny fluid every 6 months? I've never heard of that. Can anyone else here confirm?

JerseyCLK55

I bought the car with 18k miles on it, and the car was pretty rough. There was always an issue downshifting in "M" mode from 2 to 1- there would be a jarring clicking/grinding noise. Then, at about 45k miles, an intermittent vibration started surfaced when the car was in the 2,500-3,000 RPM range at highway speeds. I checked around on the forum (thanks guys!) and it was suggested that the tranny was bad.

I went to the dealer and they told me that the trans cooler/radiator was leaking and that corroded the gears in the case. I never had the chance to verify that but they installed a new cooler and trans.

The car has been running smoothly, but I did experience the violent gear clicking/grinding once. I've since stopped downshifting 2nd to 1st gear completely AND stopped downshifting from 3rd to 2nd at higher RPMs. I know, it was probably a stupid idea in the first place, right?

JerseyCLK55

Project C55-

I noticed that you're in my neck of the woods- can I check out your ride sometime? Or, could you recommend a good, reliable and honest mechanic or speed shop to take my car to?

I think I need to get my diff fluid changed- it probably has never been done.

Thanks!

JerseyCLK55

BTW, the car is a 2003.

ProjectC55

Not a problem bro!! I thought I pm'd you my info but i'm not sure!

ProjectC55

MB is not gonna tell you this. Do a search "transmissions" and you shall surely see.

Addicted2Speed

Kleemann LSD is aprox. $3,600 installed. As far as the supercharger, I recommend kleemann over renntech. Its cheaper and produces more power.

SLK55R

I'm not gonna get into this ...

All I will say is please make sure you do the proper research and decide what is best for your needs.

JerseyCLK55

Thank you all, for your comments- very much appreciated.

Anyone else have comments on RennTECH vs. Kleemann?

Also, anyone know a good shop in NY/NJ?

I've got a lot of reading to do on the forum...

DBLNICKL

to touch on this, i went thru a trans. blowout may of this year... 2003/71K+...my mechanic said some parts inside of the trans. broke, which cause them to "lurk" inside of the trans. and clog some sort of passage inside...thus causing the car to lose all "drive" capabilities...no switching manually or anything...i had to remove the key to let it reset before the vehicle would move...used trans. from MB $3,500/2 year warranty...too bad they screwed up the order and i'm just now gettin my whip back next week ...smfh...

JerseyCLK55

...big time.

But, $3,500 was less than the $6,000 I was charged for parts/labor.

My warranty covered most of it except for $600 for the trans cooler.

Did yours make the grinding noise?

When mine was close to dying, it wouldn't shift in "M" mode at all. It just tooled around in 2nd gear.

DBLNICKL

oh, i forgot to mention...i'm 21k out of the warranty comfort zone... luckily my mechanic is only chargin me 1k for labor for everything that needs fixing to be fixed...didnt get a grinding noise, when it first started to go out on me...there was a high pitch zip noise coming from underneath after i reached 2k revs...later on that day, it was sputtering the same way as if the traction control was kicking in...then it just quit out after stopping @ a red light...haha...i repeated that reset 3 times to get less than a half mile back to the house, meanwhile the car had reached temps. hot enough to grill a steak on...i hope this is the "one drastic episode" we all experience with our V's @ some point...lol...

IngenereAMG

We currently do a nice ECU tune for the CLK 55/63. Its always a good idea when adding more power to go with a more powerful Brembo brake system as well.

blackbenzz

$25k budget? This is what I would do:

Kleemann supercharger, Kleemann headers, Kleemann ECU tune, Quaife or Kleemann LSD (I have Kleemann and am happy with it but if it goes I will do quaife), and some R compound tires. If you havent reached your budget yet and your only goal is to go fast in a straight line get a bigger heat exchanger and maybe a nice nitrous setup (I'll let you know how mine goes). I pretty much have all those things and more (no nitrous yet) and plan on getting the level ten "bulletproof" transmission (If you're afraid of transmission failure I highly recommend this although it is costly, it will also make your car faster). Right now I'm just deciding whether to do the level ten transmission or the nitrous next

Fantasm

If it were me, I would do tranny first since its a nice big step in both performance and reliability