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i just want to offer everyone here a bit of guidance from my testing, Jeff J, and a few others testing. whether you are on some super awesome JB4 custom map 6 tune or if you have a solid ecu tune from the usuals, this car is severely under fueled. you might get that one hero run that is bonk every now and again in perfect conditions, but if you want consistant fast runs and a fast upper end, either WMI or a HPFP is needed. some of you I even see post CEL about low fuel pressure. I can assure that even on "stage 2" tunes, the fuel pressure under certain conditions can drop dangerously low. even if you only run standard fuels, getting WMI or HPFP to support the power you are making is highly recommended. This car is a solid mid to high 11s all day with just tune and conditions proper. if you want to be sub 11.5 all the time, I highly recommend getting additional fueling support. less chance of bad failure and also you will have a lot more fun in the 60-130 range!
Also the times are easily repeatable over and over.
Originally Posted by Star4life
This car is a solid mid to high 11s all day with just tune and conditions proper. if you want to be sub 11.5 all the time, I highly recommend getting additional fueling support. less chance of bad failure and also you will have a lot more fun in the 60-130 range!
Honored that both of you responded to this. I've read and re-read many many many of both of your posts. I'd be really happy to just have the car perform consistently, period. Not sure the GLC will ever get to 11's considering it's heft (weighed at the track at 4500lbs in full street trim with me in it), however, I'd be really happy if I could just replicate a single pass on either the map 1 or map 2 tune. I'm not even getting greedy yet! LOL. I asked for help at tech support with setting my expectations correctly and was told car is behaving normal. I just can't buy into that. It will not, under any circumstance, replicate a run back to back on any level of tune. If there is something going on with the car I'd like to track it down and fix it - then to be able to replicate performance would make me pretty please. EVEN if that means consistent 12.5's. I tracked the car under very consistent conditions over the course of 3 weeks. All runs were done at approximately the same time of day (all within 30 mins of each other week over week) all done on the same track. Weather conditions were very consistent across all three weekends (within 10*) and all runs were performed on the same lane of the racetrack. In stock form the car behaved the same on all 4 passes. The following 2 weekends on map 1 and then maps 3/4/5 on E30 fuel the weekend after, runs from the driver seat were all over the place. Car never went down the track the same way on all subsequent 8 passes. That's my biggest frustration. Is it fuel? Good question. I'd have hoped tech support could have determined or at least pointed to some type of data that would suggest that. I would happily take LESS outright performance if it meant I knew exactly what to expect when I hit the loud pedal. If you gents with experience with both flash tunes and JB4 piggy back tuning are suggesting you get the same thing every time, I've got something wrong and need to figure out what it is. Hell, I'd happily pay someone to consult on my maps and tuning to help get this sorted. Just don't know where to turn and too frustrated at the moment to look.
Honored that both of you responded to this. I've read and re-read many many many of both of your posts. I'd be really happy to just have the car perform consistently, period. Not sure the GLC will ever get to 11's considering it's heft (weighed at the track at 4500lbs in full street trim with me in it), however, I'd be really happy if I could just replicate a single pass on either the map 1 or map 2 tune. I'm not even getting greedy yet! LOL. I asked for help at tech support with setting my expectations correctly and was told car is behaving normal. I just can't buy into that. It will not, under any circumstance, replicate a run back to back on any level of tune. If there is something going on with the car I'd like to track it down and fix it - then to be able to replicate performance would make me pretty please. EVEN if that means consistent 12.5's. I tracked the car under very consistent conditions over the course of 3 weeks. All runs were done at approximately the same time of day (all within 30 mins of each other week over week) all done on the same track. Weather conditions were very consistent across all three weekends (within 10*) and all runs were performed on the same lane of the racetrack. In stock form the car behaved the same on all 4 passes. The following 2 weekends on map 1 and then maps 3/4/5 on E30 fuel the weekend after, runs from the driver seat were all over the place. Car never went down the track the same way on all subsequent 8 passes. That's my biggest frustration. Is it fuel? Good question. I'd have hoped tech support could have determined or at least pointed to some type of data that would suggest that. I would happily take LESS outright performance if it meant I knew exactly what to expect when I hit the loud pedal. If you gents with experience with both flash tunes and JB4 piggy back tuning are suggesting you get the same thing every time, I've got something wrong and need to figure out what it is. Hell, I'd happily pay someone to consult on my maps and tuning to help get this sorted. Just don't know where to turn and too frustrated at the moment to look.
Which map do you daily? Were the runs on that map inconsistent? I have noticed with the JB4 and when adding E85+green plug the car takes some miles of driving to adjust. I can get consistent runs on just JB4, but i daily the map 6 and so long as fuel and conditions dont change the car feels consistent.
Also what firmware are you running? I noticed the car felt better after moving to the latest V7 stable release.
i just want to offer everyone here a bit of guidance from my testing, Jeff J, and a few others testing. whether you are on some super awesome JB4 custom map 6 tune or if you have a solid ecu tune from the usuals, this car is severely under fueled. you might get that one hero run that is bonk every now and again in perfect conditions, but if you want consistant fast runs and a fast upper end, either WMI or a HPFP is needed. some of you I even see post CEL about low fuel pressure. I can assure that even on "stage 2" tunes, the fuel pressure under certain conditions can drop dangerously low. even if you only run standard fuels, getting WMI or HPFP to support the power you are making is highly recommended. This car is a solid mid to high 11s all day with just tune and conditions proper. if you want to be sub 11.5 all the time, I highly recommend getting additional fueling support. less chance of bad failure and also you will have a lot more fun in the 60-130 range!
I agree that fueling is quite limited esp on Stage 2 in higher revs,
But I do not have WMI or Hpfp and my times are extremely consistent.
I just have a straight thru exhaust ( to AMG PE) and Wagner Cooler with EC tune. I would get WMI and the Spool if I wanted to push the car further though.
ps look at the dates and times too here.
The fastest times at the top are with Decat .
i just want to offer everyone here a bit of guidance from my testing, Jeff J, and a few others testing. whether you are on some super awesome JB4 custom map 6 tune or if you have a solid ecu tune from the usuals, this car is severely under fueled. you might get that one hero run that is bonk every now and again in perfect conditions, but if you want consistant fast runs and a fast upper end, either WMI or a HPFP is needed. some of you I even see post CEL about low fuel pressure. I can assure that even on "stage 2" tunes, the fuel pressure under certain conditions can drop dangerously low. even if you only run standard fuels, getting WMI or HPFP to support the power you are making is highly recommended. This car is a solid mid to high 11s all day with just tune and conditions proper. if you want to be sub 11.5 all the time, I highly recommend getting additional fueling support. less chance of bad failure and also you will have a lot more fun in the 60-130 range!
Thank you for your post. This may be a loaded question, but what are the differences between the WMI and HPFP. WMI stands for water methanol injection, and that's as far as I got....
Thank you for your post. This may be a loaded question, but what are the differences between the WMI and HPFP. WMI stands for water methanol injection, and that's as far as I got....
HPFP = high pressure fuel pump.
C63 has 3 fuel pumps, one low pressure in the tank and two high pressure ones on the back of the motor to supply each bank of 4 cyl with fuel.
Our V6 has a less powerful low pressure pump (from my understanding), and one of the HPFPs to feed all 6 cyl.
So the "fix" when pushing lots of air into the motor is to get a Spool upgraded HPFP. sold here :http://martintuning.com/w205-my2015-present/
Not sure if coding is required or just retuning the car once the HPFP is swapped.
Definitely not a bad JB4. The car just doesn't like the shifts. Took it back to the track again this weekend and bettered my personal best but even on that run the far fell on it's face on the 2/3 shift. It pisses me off so bad. It's enough that it's easily a couple of tenths of ET left on the table. Trying to get feedback or some idea of why it's doing it is running me in circles. Something is going on in the ECU that it's cutting boost and cutting throttle position.
This is ugly:
In the video clip below I had to edit the 12.3 run that this log was from because I screamed some profanity out loud because I knew it was on a rip of a pass and that stumble on the 2/3 shift robbed ET.
I see the actual boost isn't on this one, but I do see from the other logs that your boost is exceeding the target on almost all the points where you're seeing the timing drop and right before a couple of those bigger throttle closures. That's often going to be the car's response to it seeing higher boost than it's calling for. Do you have the csv files for these logs that you wouldn't mind sharing (those give a more granular view of what's going on)?
If I'm remembering right, it was in the 60's that weekend for temps (I'm in SOMD too, lol) so perfect whether and heat shouldn't be the reason for the timing drop.
Last edited by GuardianVA; Apr 24, 2021 at 12:31 AM.
Reason: Spelling
First time using Dragy. 16' C450 Eurochraged Stage 1, K&N drop in filters. 18" AMG wheels stock tires. Full tank 93 Oct (just filled up before the run)
First time using Dragy. 16' C450 Eurochraged Stage 1, K&N drop in filters. 18" AMG wheels stock tires. Full tank 93 Oct (just filled up before the run)
JB4 on Map 3. Not sure how accurate that thing is overall, so I may try Map 0 vs Map 3 just to see the delta. After this run, I adjusted the weight input from 3700 to 3900, so curious what that will do, but haven’t had a chance to get another saved run in yet.
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