Dyno pull - 5th gear?
08-19-2020, 06:45 PM
#3
Junior Member
Thread Starter
Cool, thanks.
Is there a trick to getting it to not "kick down" a gear, other than not hitting WOT too early? OE Tuning said the dyno guy should know, but just in case he's not familiar with the MB 7-spd I thought I'd ask. Is there a certain rpm where you can go WOT and it doesn't kick down?
Is there a trick to getting it to not "kick down" a gear, other than not hitting WOT too early? OE Tuning said the dyno guy should know, but just in case he's not familiar with the MB 7-spd I thought I'd ask. Is there a certain rpm where you can go WOT and it doesn't kick down?
08-21-2020, 12:31 PM
#4
Junior Member
Thread Starter
Is there a trick to getting it to not "kick down" a gear, other than not hitting WOT too early? OE Tuning said the dyno guy should know, but just in case he's not familiar with the MB 7-spd I thought I'd ask. Is there a certain rpm where you can go WOT and it doesn't kick down?
08-28-2020, 08:47 PM
#7
Super Member
I agree with Dyno Mode, after all, it is called dyno mode.
I don't think 4th makes any difference really, but may cost you some ponies since it's geared. The point of 5th is so the trans is just rotating mass and associated losses, not that + gearing losses. 5th would also give you a longer run to collect more data, and longer spool up time on the dyno to give more accurate dyno data. If for example you used 1st gear, it would be over with so fast you'd likely have crap info from both the car and dyno. However, 5th in a Benz, with it's freeway gearing, is pretty high speed so it might be too much. Like my car in 5th would be 175mph, which doesn't sound like a good idea. First off, can the dyno handle that? If so, are your tires rated for that? Say for example you have tires rated to 149, which I think is typical, and one happens to blow at 175 and the sht hits the fan, people getting pelted with rubber and steel belt, someone loses and eye, your cars body around the wheel is trashed etc etc. Who's fault is it? If I insured a dyno shop, which I would not, I'd set a speed limit that's much lower than 175.
If they do allow that kind of speed, then I'd do both 4th & 5th to see the difference. I doubt it's much diff but you may be able to see it.
I don't think 4th makes any difference really, but may cost you some ponies since it's geared. The point of 5th is so the trans is just rotating mass and associated losses, not that + gearing losses. 5th would also give you a longer run to collect more data, and longer spool up time on the dyno to give more accurate dyno data. If for example you used 1st gear, it would be over with so fast you'd likely have crap info from both the car and dyno. However, 5th in a Benz, with it's freeway gearing, is pretty high speed so it might be too much. Like my car in 5th would be 175mph, which doesn't sound like a good idea. First off, can the dyno handle that? If so, are your tires rated for that? Say for example you have tires rated to 149, which I think is typical, and one happens to blow at 175 and the sht hits the fan, people getting pelted with rubber and steel belt, someone loses and eye, your cars body around the wheel is trashed etc etc. Who's fault is it? If I insured a dyno shop, which I would not, I'd set a speed limit that's much lower than 175.
If they do allow that kind of speed, then I'd do both 4th & 5th to see the difference. I doubt it's much diff but you may be able to see it.
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08-31-2020, 09:26 PM
#9
Super Member
Almost forgot, you asked what dyno mode is, which is a function that apparently allows the rear wheels to spin without the traction control or whatever having a fit. I suppose it might, maybe, turn the fan on full blast or some other stuff but I don't really know. I just assumed the basics which is letting you use a dyno without *****ing.
To get there, my short description I saved on my phone is: Ign 1, scroll to mileage. Press Phone, then OK and hold.
That will be different that what you find online but basically key to the first position, or keyless go button once. Be sure the display reads mileage, not mph or something. Then phone (answer) on the steering wheel, then Ok also the wheel. It takes you to a menu that either shows dyno mode or if not you can figure it out from there.
Note, the doors hood and trunk may need to be closed? I forget but this frustrated me and a zillion others when doing an oil change reset. For some reason all that stuff have to be closed...
Other instructions will say to push the Ok and Phone buttons at the same time, but in reality that means 50% of the time people actually hit Ok a picosecond first and it won't work. So hit phone, then casually hit ok and it works every time.
I actually wanted to drive in dyno mode last friday, the morning of the day you posted, in my efforts to troubleshoot an issue. I discovered the headlights won't come on in that mode! Which is a problem at 0500 when it gets light at 0600... So maybe another day, and I'll see about the kickdown thing too
To get there, my short description I saved on my phone is: Ign 1, scroll to mileage. Press Phone, then OK and hold.
That will be different that what you find online but basically key to the first position, or keyless go button once. Be sure the display reads mileage, not mph or something. Then phone (answer) on the steering wheel, then Ok also the wheel. It takes you to a menu that either shows dyno mode or if not you can figure it out from there.
Note, the doors hood and trunk may need to be closed? I forget but this frustrated me and a zillion others when doing an oil change reset. For some reason all that stuff have to be closed...
Other instructions will say to push the Ok and Phone buttons at the same time, but in reality that means 50% of the time people actually hit Ok a picosecond first and it won't work. So hit phone, then casually hit ok and it works every time.
I actually wanted to drive in dyno mode last friday, the morning of the day you posted, in my efforts to troubleshoot an issue. I discovered the headlights won't come on in that mode! Which is a problem at 0500 when it gets light at 0600... So maybe another day, and I'll see about the kickdown thing too
09-02-2020, 01:39 PM
#10
Super Member
in dyno mode, no automatic functions will work...you gotta actually turn the switch to "on". Also, no traction control, no abs, no cruise control and no satellite tracking/navigation
