If you’ve been reading this blog for a while you know that my ultimate goal is to run a high 8-second quarter mile in the CLK. In order to do that without getting kicked out of an NHRA-sanctioned track, I plan on building the car to the rulebook and having it be 100 percent legal.
According to the NHRA Quick Reference guide, one of the things you need when you go 10.99 or quicker is an SFI 18.1 certified harmonic balancer. Not surprisingly, nobody makes one for the M113 found in the W208 CLK55. Luckily, ATI will make custom versions of their Super Damper, which is SFI 18.1 certified. I was told to expect up to a 2-year wait for a custom damper, so even though the car is currently stock, I placed the order for the damper expecting it to be ready in a couple years when the car should be running sub-11 second ETs.
After all the weight reduction, the CLK was riding high and it needed to come back down to earth. The fender gap was 3″ in the rear and 2-1/2″ in the front. I wanted it closer to zero, with the top of the tire about even with the top of the fender, or within a half inch.
There are a couple different approaches to lowering a W208 CLK. You could buy a set of lowering springs, or just cut the appropriate amount off the factory springs. I decided to take the old-school route and cut some coils out of the springs instead of spending money.
When I first bought the CLK back in 2017, I knew the rear end was going to be the weak link. As luck would have it, I found a guy who was selling exactly what I would eventually need in order to make the back half of the car bulletproof.
I had a chance to take the CLK to the Woodburn Dragstrip over the weekend so I could get some full runs on the new PCS transmission controller and see how the weight reduction over the winter has helped.
As part of my weight saving plan I am ditching the stock seats and replacing them with a cheap set of lighter bucket seats. The factory seats weigh in at about 60lb each; the cheap eBay seats are about 30lb, plus a few pounds for the brackets I had to make to mount them.
I got the seats off the Facebook Marketplace for $200 for the pair, and spent about $50 on parts for the brackets.
I made a set of custom brackets so I can easily install and remove the seats using four bolts each in the factory threaded holes. A couple of pieces of 1/2″ square tubing and 1″ flat bar stock is all that was needed.
I have a set of 3.73 gears I want to put in the CLK, but if you change the gear ratio you need to reprogram the Transmission Control Unit (TCU) so it knows how to perform its speed calculations. I could have a tuner modify my stock TCU, but I decided to take this opportunity to replace the factory TCU with a TCM2800 aftermarket controller by Powertrain Control Solutions. I got the controller from Sound German Automotive in Bellevue, Washington. Russell at SGA is a 722.6/NAG1 transmission guru who knows everything you could imagine about these transmissions.
I don’t know whether you would consider this an upgrade or a downgrade, but swapping the CLK55’s front rotating assemblies for a set of CLK320 brakes and wheels will definitely make the car quicker at the dragstrip.
I’ve been running the heavy 18″ Mercedes-Benz E55 wheels on all four corners of the CLK55, which look great, but they aren’t be best for drag racing. Each corner weighs-in at over 50 lb, leaving a lot of room for improvement. The factory CLK320 wheels are the hot ticket for drag radials on the rear, but they also make a good low-budget “front runner”. They only weigh about 13 lb each (because they’re forged), and at 7″ wide you can fit a fairly narrow tire on them. I bought a pair of inexpensive V rated 205-60/16 tires that can be used as daily drivers, while still saving a good amount of weight for the track.
I took the CLK to a bracket race event at the Woodburn Dragstrip on Father’s Day last weekend. The car performed flawlessly in the heat, running some pretty consistent times. Ultimately I won the class by going three rounds with good lights and good dials.