Drop-a-Daimler

I have been practicing launching my 7G-Tronic and don't think I have it right yet. So far, ESP off and a lot of wheel spin is best for some reason. If ESP is on it will fall on its face hard. If I launch hard with ESP off, powerbrake it up to maybe 3K, it will seriously roast the tires for the first 50' but run a 2.0 to 2.1 60' time. If I launch soft, with just a slight powerbrake, it will spin a bit and hook up quickly and go but only do a 2.2 60'. I am sure the car can do a 1.8 or 1.9 60' and if so, it should knock 1 or 2 tenths off the 1/4 which would put me right where I want to be. Any ideas that work for launching your 7G-Tronic?

schultzie

I've been away from the forums a bit. Did you run your car at the strip? If so, what are the times?

One of these days I'll get my car to the drag strip in Gulfport if they are able to make it through this hurricane season.

I'll be at the 'ring in a week or two, but unfortunately, I'll be lapping it in a rented Opel Astra or Diesel BMW. It'll still be a kick in the pants.

I've tried to get in touch with my old tuner about dynoing my C350, but he's between shops and I'll be out of pocket for the rest of the month.

Good Luck!

Rich

e1000

were you able to roast the tires before you ECU upgrade? I can't do that in my car to save my life

Drop-a-Daimler

You mean Nürburgring?!? How'd you swing that? I ran it twice at MIR and did a 13.6 @ 103.9 with a 2.1 60' time. I have run a 2.0 60' using my G-TECH but I know it has at least a 1.9 in it. SuperSprint is the only place I have seen a stock M272 3.5L dyno sheet. They got 287bhp out of it stock and 298bhp with exhaust. I would love to see what your did.Not really , no. But I never tried too hard. Maybe if I powerbraked it HARD. Don't know. But when I did the ECU I also lightened the car by 100 lbs. which really helped. Now, from a dead stop on straight hot pavement it will spin if I just tromp it. If I powerbrake it lightly it will lay down 100' of parallel black lines. It will even chirp the tires shifting into 2nd at WOT. The G-TECH shows it will run a high 5.4 0-60 but I think it is quicker than that and I don't have a good launch down or roll out setup. What helps is that it will hit 60 in second, before it shifts to 3rd (the G-TECH flashes a red light at 60) and that helps it put up a quick time.

schultzie

I've got some meetings in the Duesseldorf area and the 'ring is just too close not to visit. Of course, I'd try to say that if I were anywhere in the Eastern hemisphere It's been 19 years since I've been to Germany -- the last time I was defending the kind West German citizens against the evil Communist menace


no dyno yet... maybe in October...


I thought we had an open diff. like the table grade Bimmers. If we have Limited Slip Differentials that's a serious bonus!

Rich

Drop-a-Daimler

Now that's a good question. I didn't think we had a LSD and certainly not a locking diff. I thought we had an open type that uses electronic control to mimic a mechanical limited-slip. But with ESP off (it is never fully defeated unless you put it in dyno mode I think) I wonder how that works? But it DOES work.

Also, I just re-read Edmunds head-to-head with the 2008 C350 automatic vs. the 335i 6-speed. Their best times for the 7G-Tronic were had by launching with ESP OFF, some minimal brake-torque (powerbraking) but with no wheel spin. I haven't tried that approach yet. I have been trying no brake torque, a good amount of powerbrake and then lots of it but not just a little. Maybe if it hooks up I can get my 1.9 or 1.8. I am going to try tonight.

e1000

yeah, no ECU and 265's on 19's means that unless it's wet outside, no big black marks for me

Drop-a-Daimler

Ok, I tried a few lighter techniques and think I have something. If I launch with ESP off, a real light powerbrake (almost none, just holding the brake on with a tiny bit of throttle) and then go WOT just off the line as it gets rolling it will do a 2.0 60' and a low 5.4 0-60 pretty consistently. That nets me a little wheel spin, maybe 10', and then a lot of giddy-up. So with some more traction, like at the track, I am hoping to get a 1.8 or a 1.9 (I'm almost at a 1.9 now) and a 0-60 closer to 5.2 or 5.3. If so then it will be at or hopefully under 13.5 in the 1/4 which would be right on!

AsianML

Do you slam the throttle or roll on it? Oh, and vids and pics or ban.

Drop-a-Daimler

I was banging it down earlier and having trouble doing a 2.0 60' consistently. With too much powerbrake it would smoke 'em too much but I thought that was the quick way. But tonight, on my lonely road, I was taking some advise from another thread and trying to roll it on. Best for me was to apply throttle quickly but not go WOT until it finished the initial "squeal" off the line, maybe 10' to 20' out, then got WOT.

And I thought about getting a vid, setting up my little Exilim and running into the car and doing a quick burnout. Problem is I don't want to do these runs in the daylight, it's a lonely road but it is a public road. I sneak out there after the sun goes down and traffic dies down and do 3 runs and then bolt. I am going to need a camera-man-partner-in-crime and do it at dusk or something. But I am going to grab a few pics tomorrow of the tire marks I laid down a few nights ago.