01 CLK55; first trip to drag strip
#1
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01 CLK55; first trip to drag strip
see the attached time slips. it was pretty busy so i only got 4 runs in. with 3-4 more runs i probably could have gotten a perfect launch and hit 13.6's possibly at 104.
best run of the day was the last one: 13.71 @ 103.76
that last run i launched the car barely over idle with the transmission set to 3 so that it would hold third at the end of the run, i think it was maybe 800 rpms at launch. had the tire pressure lowered to 26.5 in the rear.
first run launched at about 1200 rpms
second run launched at 1500
third run launched at 1800 but spun the tires our of the hole, it was one of my faster runs though.
tire pressure for the first 3 were about 30psi, after the pre-stage burnout probably 31-32.
first 2 runs i tried manually shifting the car, the runs werent that far off from the second 2 where it went auto, but less risk of error that way. the first run i definitely mistimed the shift it and bounced off the limiter for a split second, but it seems to not affect the end result that much.
with lower pressure and probably a 1000rpm launch i think might be best, but need more experimentation to know for sure.
I have the bilstein B8's and H&R sport springs with 18" wheels and stiff sidewall RE-11 tires. so i wouldnt be surprised if that is costing me 1/10th on the launch/60' time by being stiffer than stock and not letting the suspension load best for a drag launch.
maybe the car is not running 100% but thats pretty close to the specs that magazines seem to have tested it at when it was new. but im not sure how they got it to trap at 106mph, maybe if i launched at higher rpms and spin more i can hit 105-106 trap, will try it next time out i guess.
WEIGHT: the car weighed in at 3630lbs with me in it and 6-7 gallons of fuel (i weigh 160lbs). so it seemed like it was heavier than expected. i think the magazines rated the car at 3400lbs, but that must be an empty and dry weight. without me in the car it would still be 3470lbs. spare tire was in the car.
My C43 was 3550, so this car is heavier and i was expecting it to be a bit lighter according to the specs ive found in magazines of both.
best run of the day was the last one: 13.71 @ 103.76
that last run i launched the car barely over idle with the transmission set to 3 so that it would hold third at the end of the run, i think it was maybe 800 rpms at launch. had the tire pressure lowered to 26.5 in the rear.
first run launched at about 1200 rpms
second run launched at 1500
third run launched at 1800 but spun the tires our of the hole, it was one of my faster runs though.
tire pressure for the first 3 were about 30psi, after the pre-stage burnout probably 31-32.
first 2 runs i tried manually shifting the car, the runs werent that far off from the second 2 where it went auto, but less risk of error that way. the first run i definitely mistimed the shift it and bounced off the limiter for a split second, but it seems to not affect the end result that much.
with lower pressure and probably a 1000rpm launch i think might be best, but need more experimentation to know for sure.
I have the bilstein B8's and H&R sport springs with 18" wheels and stiff sidewall RE-11 tires. so i wouldnt be surprised if that is costing me 1/10th on the launch/60' time by being stiffer than stock and not letting the suspension load best for a drag launch.
maybe the car is not running 100% but thats pretty close to the specs that magazines seem to have tested it at when it was new. but im not sure how they got it to trap at 106mph, maybe if i launched at higher rpms and spin more i can hit 105-106 trap, will try it next time out i guess.
WEIGHT: the car weighed in at 3630lbs with me in it and 6-7 gallons of fuel (i weigh 160lbs). so it seemed like it was heavier than expected. i think the magazines rated the car at 3400lbs, but that must be an empty and dry weight. without me in the car it would still be 3470lbs. spare tire was in the car.
My C43 was 3550, so this car is heavier and i was expecting it to be a bit lighter according to the specs ive found in magazines of both.
#3
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if you have a buddy who has been before its good to take them with you to just walk you up near the start and explain the pre-staging lights and how they work, etc.
or just go there one day to observe and get familiar with the track and how things run and observe it all and you will feel much more confident the next time you go back to actually run.
lots of little thngs to consider once you get into it, but for beginners who have never been i think the most important thing is to know that if your car runs under 13.99 they require you to wear a helmet, and then understanding how the prestaging and staging lights work. oh and need to wear long pants, no shorts.
...or just go and i can pretty much guarantee there will be guys or gals there there will be happy to give you a rundown of how it works if you just say its your first time and you want to understand what to do so you dont f*ck up. i think most racers respect that more than someone going up there with no clue what to do :-) but that does often happen, i think the guys running the strip are kind of used to it.
#4
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2002 CLK 55 AMG cabriolet Eurocharged
Agreed,
It does not matter what kind of racing you are doing, It takes confidence and strategy learned for the next run.
I shake in my hard hat each auto cross course they are all different. After the 2nd run I am in the points.
Drag racing strategy is in the launch and you tried a plan for each. This is enterprising for growth in the race.
It is all fun and learn, Thanks for sharing
Gator
It does not matter what kind of racing you are doing, It takes confidence and strategy learned for the next run.
I shake in my hard hat each auto cross course they are all different. After the 2nd run I am in the points.
Drag racing strategy is in the launch and you tried a plan for each. This is enterprising for growth in the race.
It is all fun and learn, Thanks for sharing
Gator
#6
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Thread Starter
Went back to the strip again. i have the recaro sportster seats in the car now, they cut 40lbs overall weight. the weight is now 3590 (down from 3630 last time). i had almost identical fuel level so that should be accurate (3/8ths tank). also this was with spare tire in.
i also weighed the car with just the front half on the scale... front only was 1980lbs, so the calculation for weight balance turns out to be 55/45, 55% in the front.
i also weighed the car with just the front half on the scale... front only was 1980lbs, so the calculation for weight balance turns out to be 55/45, 55% in the front.
#7
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Thread Starter
also, here is the slip from my fastest run on that 2nd visit to the strip (also fastest overall in the car). i was able to get 7 runs in this time, so in total i have 11 runs at this strip with my car.
I was able to slightly improve the ET and trap speed, but wasn't able to get within a 10th of my best 60' time from last trip, not sure how i cut that 2.08 60' time before
my last and fastest run was after the ambient temp dropped quite a bit about 90 mins after sundown.
the times got slower right after sundown when the temp was still high but humidity jumped a lot, so when it really cooled off the times got faster again.
also, rear tire psi was 30
fastest ET and trap speed seem to come when i launch the car just barely above idle. also, the trick i did this time to get the fastest time was that i let the car do the 1-2 shift automatically then i did the 2-3 shift manually. i could tell that by letting the car shift manually the 2-3 shift was taking too long sometimes, so doing that one manually helped.
i still preferred to let the car do the 1-2 shift auto as the car approaches redline really fast in first and if you dont time it right its really easy to bounce off the limiter losing precious time
next time i go i will try to put more fuel in the tank just to see if more weight in the rear might help off the line traction
I was able to slightly improve the ET and trap speed, but wasn't able to get within a 10th of my best 60' time from last trip, not sure how i cut that 2.08 60' time before
my last and fastest run was after the ambient temp dropped quite a bit about 90 mins after sundown.
the times got slower right after sundown when the temp was still high but humidity jumped a lot, so when it really cooled off the times got faster again.
also, rear tire psi was 30
fastest ET and trap speed seem to come when i launch the car just barely above idle. also, the trick i did this time to get the fastest time was that i let the car do the 1-2 shift automatically then i did the 2-3 shift manually. i could tell that by letting the car shift manually the 2-3 shift was taking too long sometimes, so doing that one manually helped.
i still preferred to let the car do the 1-2 shift auto as the car approaches redline really fast in first and if you dont time it right its really easy to bounce off the limiter losing precious time
next time i go i will try to put more fuel in the tank just to see if more weight in the rear might help off the line traction
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#8
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2002 CLK 55 AMG cabriolet Eurocharged
There is a term called heat soak. The supercharger/turbo guys know all about it.
Once the engine approaches normal operating temp everything is dandy until you push the peak power of this engine. Heat will de-volumetrisize the fuel into wasted droplets instead of high volumetric efficient vapor.
NA engines are not immune, especially when pushing close to 400 +/- HP.
Cheers
Once the engine approaches normal operating temp everything is dandy until you push the peak power of this engine. Heat will de-volumetrisize the fuel into wasted droplets instead of high volumetric efficient vapor.
NA engines are not immune, especially when pushing close to 400 +/- HP.
Cheers
#9
MBWorld Fanatic!
Went back to the strip again. i have the recaro sportster seats in the car now, they cut 40lbs overall weight. the weight is now 3590 (down from 3630 last time). i had almost identical fuel level so that should be accurate (3/8ths tank). also this was with spare tire in.
i also weighed the car with just the front half on the scale... front only was 1980lbs, so the calculation for weight balance turns out to be 55/45, 55% in the front.
i also weighed the car with just the front half on the scale... front only was 1980lbs, so the calculation for weight balance turns out to be 55/45, 55% in the front.
Any pictures of the seats? How did you install them? just standard rails or did you do a custom setup using some of the poser functions from the original seats? Thanks
#10
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i got the brackets from Planted Technology, it seems we can use the brackets made for a prosche 996 wth some modification (which all seat bracket manufacturers have but nobody has one for our cars...) following the advice from another forum member who found this out for us
though there is modification needed, the porsche brackets have flat or parallel to the ground bolt tabs in the rear of the seat, whereas our cars the bolts are at about a 45 degree angle. so we had to bend the rear tabs of the bracket a bit and also file out the bolt holes as when they were bent the holes were about 5-7mm off center from where they needed to be (not wide enough). once that was done then things bolted right in. we used slider bars from recaro.
we did the install in about 6 hours and that included about 1.5 hours of having to make a couple runs to the parts stores and some learning as is always the case when doing something for the first time. if we had to do it again to another car we could have it done in probably 2.5-3 hours tops.
We added in 1/2 inch spacers between the bracket and the sliders since im only 5'9" and i needed the height to get to the correct seating position i was used to.
also the SRS light in the dash is now on because there is no airbag sensor for the passenger seat. we plan on taking it our of the stock seat and putting it under the cushion of the recaro seat at some point in the future so that works properly as well.
all said and done i think its worth it if you will be autocrossing or racing the car as the seats really hold you in place (this is what i wanted it for, and also the weight savings - though i was hoping for more savings), but if just for street use its a big chunk of change for basically a visual improvement. the seats do look badass in the car though for sure and it would be pretty easy to put the stock seats back in, the go in with 4 bolts, 4-5 wiring harnesses, and the seat belt buckle bolts onto them.
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#13
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