What happened?
I've only had this car for about 3 or 4 weeks, so I decided to do some testing. I stopped on a desolate road, turned off the ESP, left the tranny in sport mode and nailed it from almost a dead stop. This is the first time I've ever done this in this car. Well, the car started to roll, the turbo's kicked in, the tires let loose, she quickly went to red-line before she started to shift to second gear, so I let off,...and then,...there was no tranny. Like it was in neutral. I thought, Great!, There goes the transmission. I let her roll to a stop, put it in park, turned it off, and then restarted her. Seems to be fine now. What happened? What did I do?
Personally I have found them to be less than reputable,
Performance WITH Compromise!
This is not my first car with them. My SL65 was a real beast thanks to them. My S600 now feels almost like the 65 did when it was stock. Not bad for a large sedan. I have had nothing but positive experiences with RENNtech.
Now let me say that RENNtech did not build my car. Mercedes Benz did.
StephenK, I can accept the way that you feel about RENNtech. Everyone is entitled to their own feelings. And, I'm not here to debate Good RENNtech, Bad RENNtech. I just want to know if this has happened to anyones car before. So do me a favor, unless you have some helpful information with this particular problem, please don't respond. Thank you.
I've only had this car for about 3 or 4 weeks, so I decided to do some testing. I stopped on a desolate road, turned off the ESP, left the tranny in sport mode and nailed it from almost a dead stop. This is the first time I've ever done this in this car. Well, the car started to roll, the turbo's kicked in, the tires let loose, she quickly went to red-line before she started to shift to second gear, so I let off,...and then,...there was no tranny. Like it was in neutral. I thought, Great!, There goes the transmission. I let her roll to a stop, put it in park, turned it off, and then restarted her. Seems to be fine now. What happened? What did I do?
Trending Topics
The Best of Mercedes & AMG
When you find out anything via the dealer or Renntech please post, I would be curious to see what the problem was.
11.9 in the 1/4 mile is very good for a 4500 lb car. Doesn't seem like anything's wrong with your car. Why all the hubhub about RENNtech?
I CANNOT get any specifics at all as to what the dealer should check, the only thing mentioned was "SENSORS", which means nothing to me.
If I travel all the way there and there is a problem with the car, it is a meaningless trip, if they are going to be looking at things, I don't see why they can't tell me what they are and I can get the dealer to check them for me.
They do not like to get specific.
What kind of dyno numbers is your car producing? I'm very curious. I think we have the same engine, Right?
I'm going to bring mine in Monday or Tuesday for a dyno. I'll let you know what kind of numbers I get. My car in stock form is supposed to be 493 at the flywheel. RENNtech says 620 with the ecu/tcu upgrade. That's an increase of 127 flywheel HP. That's a hell of a lot. I seriously doubt it's that much, but we'll find out. OK, now if it's 620 at the flywheel, then it should be around 496 at the wheels with a 20% drivetrain loss. I'll be happy if it's anywhere close to that. I'll post what happens.
If the shift wasn't fast enough and the engine hit the rev limiter (which in itself sounds like a TCU calibration problem), I can see a TCU torque limitation cutting in at the same time. In the S65 it has the ECU reduce boost to stay in the transmission's safe area. The S600 might not have the capability for that so Renntech might just do a brute-force disconnect if things get too torquey.
But it does sound like their issue.
If the shift wasn't fast enough and the engine hit the rev limiter (which in itself sounds like a TCU calibration problem), I can see a TCU torque limitation cutting in at the same time. In the S65 it has the ECU reduce boost to stay in the transmission's safe area. The S600 might not have the capability for that so Renntech might just do a brute-force disconnect if things get too torquey.
But it does sound like their issue.
Thank you. Much appreciated! I'll ask them to take a look.
Dyno run @85 degrees turned out 500.68 RWHP and 582.49 Max Torque. Car was hot when I got it to the dyno. We could have had a better run if the car and air was cooler. But I'm still very happy with the numbers. This would put it at about 625 at the flywheel. RENNtech advertises 620. So the numbers are better than they advertise.



Now that's a helpful comment....



