Hey guys,

I have been struggling with my car for about 2 years now getting it to launch right. I now have every suspension modification and the best possible setup to get traction, and boy does it get traction. Last night I launched the car at 5,500 rpm and just kinda dumped the clutch, the car did the best 60' its ever done at 1.64 but went slower overall. (Video: )

My thinking is that a clutch dump is way to aggressive out of the hole and the engine (460hp/440tq) can't keep up. So do you M6 guys have any tips or tricks to help me drive the car out of the hole?

Thanks,

 

Have you tried more of a quick slip of the clutch rather than a straight drop?

 

Sadly, I only got 3 runs in last night and didnt get a chance to try it. It's a pretty stiff clutch so I think its gonna be hard to drag the clutch, I guess it will just take lots of practice?

 

Subscribed, I'm in the same boat, last time at the track I bogged it dropping the clutch at 3500 and 4500rpms. Next time I will try 5500, then 6000rpms.

 

I have some experience in this! Doesn't launch to bad but seems to bog. So needs some more rpm or more air pressure. I like running 28 inch tires on manual also.

2 step also helps keep you consistent and work out the bugs on suspension and such. I launched at 6k+ and release the clutch quick/dump. Not really slipping but not a side step dump. Best 1.4x 60ft with 427 rwhp cam only deal. Some other tricks and practice is needed.

 

I was thinking about putting a 2-step in for tuning and learning, I figured launching at 5500 near peak torque would be the best place to launch? I ran 10psi in the ET Street R's and they seemed to love it, what psi do you normally run?

 

11.5 psi in Mickey Thomson ET Drags stiff wall. If it hooks good I'd go higher on rpm.

 

Just be advised, its not easy to be consistent with a stick.

 

What clutch and shocks you running?

 

I ran a McLeod RXT and their 30lb CroMo flywheel, Strange single adjustables on slicks at a well treated track.

 

I run a Monster Stage 3, and Viking DA's on all 4 corners.

 

Sounds like you need more gear. I would definitely try leaving higher.

 

Your next mod should be a two step

 

What rearend gear is it? when I was t56 car I'd launch at 6,200rpm. 28x10.5 slick at 13psi. 4.10 gear. 1.42 60fts. car made 620hp. over the course of 2 years I broke 3 main shafts in the trans. 10.21@134 was best i could get. never got it to 1.3x 60ft and get in the 9's.

 

Dang that's a lot of mainshafts broke. I don't have but around 420 flywheel hp and never broke one or twisted splines but I don't make the kind of power you have.

 

Need a two step so you can be wot on the launch. That should help some. I would launch the car at as high of rpm as I could unless it just blows the tires off. The gearing and tire size needs to be where your almost running out of gear at the stripe in 4th. No doubt your car is bogging down to 3500 or worse from the video you've shown. 2.66 first gear makes a car bog hard without alot of power. The best setups have an adjustable clutch or a clutch slipper device like I have.

Having a way to log rpm, tps, mph and other stuff will help you see what the car is actually doing. I use hp tuners to do this but there is other stuff you can do this with. If you don't have a shift light then that would be helpful for et cause stock tach sucks.

 

You guys might want to talk to Matt in the carb section. (AKA Speed Mullet) He has made launching a manual an art form. Great guy. Maybe he can help ya'll.

 

4.11's and its on a 325/50/15 MT ET Street R radial. (Wish I did bias ply's). Damn thats pretty sweet I only make about 460/440 to the wheels right now.

Yea iv'e been debating adding a 2-step. And the gears and tires are pretty close, on some of my best passes in good air the shift light will come on through the beams. I used excel to log all my shock settings, tire pressures, launch rpms to help me figure my shock settings out. The problem is it isnt real time data so I can't see how hard it bogs.

Im going to the track again maybe tuesday and definitely friday. Probably going to try and launch a little higher and maybe drive the car out of the hole

 

With it dead hooking like that on those radials, your slip yoke won't last long. I would actually already bet it's twisted some. You need some bias plys. If you don't plan on making anymore power for a little while, I would run some stiffwall 26" slicks. You need all the help you can get. Your cars down on power a good bit it seems.

 

Get the lingenfelter true two step if you want a secondary rev limiter like I use it for. If not just get the msd. The lingenfelter needs to be wired different from the msd if you plan to wire it on the clutch pedal sensor. The msd has to go below a certain rpm range to reingage so it's fine. The lingenfelter comes on regardless and will take power out of the car in shifts. My car lost et like that when I had it set below my shift points. I used a relay and wired it through the brake switch and clutch pedal sensor.

I'm not sure what the cheapest way to log runs is. I'm kinda curious to what's out there to use.