My Modding Progress
Kleemann (autorotor twinscrew) supercharger with 60mm pulley
Custom belt wrap to get maximum wrap around SC pulley
Kleemann headers (I really want longtubes but can't find any)
Custom intake
Custom dual 3" exhaust (Kleemann downpipes are only around 2.5" which is another reason I want longtubes with 3" collectors)
Custom 82mm TB setup with ported SC inlet and bigger MAF housing
Torque converter and built trans
PTE cams and E55 heads I had ported for my car
Custom heat exchanger, Johnson CM90 pump, trunk ice resevoir with large lines
SLR injectors
The ported heads, smaller SC pulley, and better belt wrap I did last week and saw some good gains on the dyno after Jerry from Eurocharged flew in and tuned it on 93 octane. My baseline dyno was from late 2010 so not the best baseline but I hadn't changed anything from then until now. I noticed when I took my old steel pulley off there were grroves on the backside of the pulley, it was spinning on the SC shaft. I don't know why they don't have a keyway on these things. The new pulley is aluminum so its much lighter.
On to yesterday when I took the car out to the track for the first time in about 1.5 years to see what it would trap. If I launch the car axles break. So I would literally roll off the line and then punch it a little later so I wouldn't break axles. I was getting a misfire in 3rd gear at ~5000rpm in cylinder 8 and these cars shut down that bank when it detects enough misfire. Still managed to trap 130.7 misfiring up top rolling off the line with a 2.6 60' (On Bias ply tires so it wasn't spinning I was just easing off the line). I didn't use ice or anything becaue I wanted to see how it would do under regular circumstances. After I saw the misfire I added some VP109 to see if it would go away... it didn't. next run i left a little harder, 2.0 60' and ran 11.2 @129.x misfiring up top again. My usual 60' is low 1.5x and once a 1.49 but I didnt want to launch and risk breaking an axle if the car would misfire up top. The rule of thumb is whatever you take off your 60' it almost doubles on the top end. Without using that rule of thumb that would have been a 10.7 pass misifiring if I did my usual launch. Using that rule it would have been 10.2
So I'm guessing it would be somewhere in between. If I can get this misfire figured we will know for sure 
The things I'm thinking it could be is plug gap (0.027), fuel injector, something related to MAF (most likely since sometimes it revs by itself at idle), restricted headers, etc. If anyone has experienced this let me know.
I'm going to try several things. I did compression test before I put the heads on and all cylinders looked great. Within a few % of each other. So it is doubtful it is bottom end, I also looked at everything when I had heads off and it looked fine. I'm thinking it may be a post MAF leak and I need to spray intake and vacuum lines down and see if there is a leak. I'm also going to pull a plug and do compression test just in case. Another thing it could be is MAF voltage since I have an adjustable resistor on it, car idles pretty lean (I have wideband in the car).
My best run to date it 10.57 @ 128.9 on pump 93 octane but I haven't run since late 2010 except for a couple passes yesterday. I have a feeling I can do MUCH better than that soon as misfire is fixed and I launch it. I'm also trying to figure out the axle situation and bought some parts that should be here Thursday
I will buy long tube headers with 3" collectors or have them made. After looking at mine off the car they are very restrictive for my power level. The power steering box and cramped room makes it difficult to make a good set but I've seen it done before but I lost that guys number 
I'm always open to suggestions and input so feel free to chime in. I'm willing to learn more. This will serve as a log for me to look back on as well and should be very helpful in the future
Last edited by blackbenzz; Feb 19, 2012 at 09:46 AM.
What are your longterm fuel trims?
Things that come to mind to check:
1. Data-log boost on each run
2. Data-log AFR on each run
3. Data-log inj pulse width
4. Data-log fuel pressure
5. Data-log timing etc. etc.....
This might tell you something about your tune on the actual runs.
Items to check for mis-fires:
1. Read plugs in that hole. See if getting fire if wet with oil or fuel etc....
2. spark plug wires to that hole....good shape?
3. coil for that hole? working cond?
4. compression for that hole.... p-test and leakdown.
5. fuel inj performance for that hole.... have them flow tested on a bench. could be faulty inj, dirty, plugged, malfunctioning... leaking o-rings on the inj?
6. spark plug condition?.... gap check, fouled plug?, bad plug, loose spark plug screw on top connector?,
If you are running 11.2's..... easing off the line AND on 7 Cyls..... that is one serious BEAST!
Last edited by betrezra; Feb 19, 2012 at 10:21 AM.
What are your longterm fuel trims?
Things that come to mind to check:
1. Data-log boost on each run
2. Data-log AFR on each run
3. Data-log inj pulse width
4. Data-log fuel pressure
5. Data-log timing etc. etc.....
This might tell you something about your tune on the actual runs.
Items to check for mis-fires:
1. Read plugs in that hole. See if getting fire if wet with oil or fuel etc....
2. spark plug wires to that hole....good shape?
3. coil for that hole? working cond?
4. compression for that hole.... p-test and leakdown.
5. fuel inj performance for that hole.... have them flow tested on a bench. could be faulty inj, dirty, plugged, malfunctioning... leaking o-rings on the inj?
6. spark plug condition?.... gap check, fouled plug?, bad plug, loose spark plug screw on top connector?,
If you are running 11.2's..... easing off the line AND on 7 Cyls..... that is one serious BEAST!
I will upload the slip so you believe me about the 11.2 with 2.0 60'. It was def misfiring in 3rd gear because wideband pegged lean and CEL came on with a code for cylinder 8 misfire on each pass.

This was the first start up after we installed our custom ported heads on my car
http://youtu.be/U3WGxrk9ens
Last edited by blackbenzz; Feb 19, 2012 at 11:10 AM.
I would sort that out before any more fun WOT runs..... (i'm a chicken when it comes to hg's, afr, fuel, and boost......)
http://www.youtube.com/watch?v=if-i4...JZGDSFxx9g8XuP
Yea of course I'm going to sort it out.
Last edited by blackbenzz; Feb 19, 2012 at 11:45 PM.
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If MBH doesn't make headers soon I'm dropping my car off next week to get custom headers made. 1 7/8" primaries and 3" collectors 
Cylinder 8

5 and 6
The Best of Mercedes & AMG
Love your car blackbenzz, gives me so much inspiration for mine!
I love the styling of the W208 and although it's stupid I can't seem to stop dumping money into it lol. I can't wait to get this misfire taken care of

None whatsoever
I dunno but it's worth a shot. I would love to switch to a MAP sensor but is that even possible with our ECU's? I probably wont get around to having the new housing made as I'm going overseas for a few days this weekend but hopefully I will get this resolved.
BB has the cajoles to go beyond the off the shelf mods to build what is arguably the fastest clk on the planet........ in a un-obtainium world regarding parts/labor/tuning! Major props and major committment to pull this off.
I would love to see the look on joe-saleen's face when this little black benz shows him MB TAIL LIGHTS HA.
Thanks buddy, you have been very helpful. Thanks for making that SC pulley fr me on such short notice! If anyone needs a custom pulley made contact 2precise!
BB has the cajoles to go beyond the off the shelf mods to build what is arguably the fastest clk on the planet........ in a un-obtainium world regarding parts/labor/tuning! Major props and major committment to pull this off.
I would love to see the look on joe-saleen's face when this little black benz shows him MB TAIL LIGHTS HA.
Last edited by blackbenzz; Feb 23, 2012 at 08:02 AM.











