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HLxDrummer
06-05-2015, 06:19 AM
I took my car to the track for the second time ever this weekend and I need some advice for launching.

I had the Chrome launch control set at 4,500 RPM and -5* timing so it would build about 8 psi. On the street, this worked great and would spin the front tires just slightly. At the prepped track, however, it would either bog down to ~3,000-3,500 RPMs or I would slip it more and the clutch would slip through first and into second.

The clutch is an XTD/eBay Stage 3 sprung 6 puck. I feel like this grabs well on the street... not sure why it was slipping so much at the track.

I was getting around 2.1-2.2 60' times which are horendous. Getting the launch nailed down better and putting on a real DP, I feel I could get my 13.4 down to a 12.9 eventually.

So my thought was maybe bump up the launch control so I don't need to slip the clutch as much to avoid bogging? Should I bump up the RPM, change timing, or the vehicle speed setting?

futurevr4man
06-05-2015, 01:11 PM
It is all very setup dependent on what you should set yours at. I, personally, have it at 5500, and -10* of timing I believe. I would rather spin some than bog down... it's harder on the drivetrain to take all the shock from that bog.

I pulled a 1.59 60' as my best launch :D

stealthee
06-05-2015, 05:31 PM
The track was very sticky that night. There really wasn't a whole lot of cars and they kept reprepping the start every time the "unlimited" slick cars were to run. There were a lot of cars that broke that night due to the excessive stickiness, as well as not knowing not to just dump the clutch.

Lou your terrible 60 was due to the bogging. Like Nate said you'd be better off spinning slightly out of the whole to reduce shock to the drivetrain. If you had been able to nail down the launch you probably would have broken into the 12's.

familyMAN
06-05-2015, 08:12 PM
If the track was that sticky, trying to spin sounds like a recipe for wheel hop and broken parts.

Try higher rpm with a quick slip.

Does chrome have fuel cut for 2step? Fuel cut can get a more stable rpm for 2step which will be more predictable. Will build less boost than an ignition cut 2step or severely retarded ignition anti-lag/drag launch, so you may need to bump the launch rpm.

HLxDrummer
06-19-2015, 10:16 PM
I'm not sure what Chrome cuts to be honest, I was curious about that as well.

I practiced some launches this evening with slightly damp roads. 5,000 RPM -5* timing and I think "target AFR" of 10.5. They were decent but barely spinning the wheels even in the damp. And once I had the clutch out it wasn't running right through the rest of first. Felt like it was flooded or something.

If I nailed it in first from a roll I was able to spin the fronts fairly easily... makes me think the launch control settings are off. I also feel like I was able to get a better launch doing it manually. Do I need to adjust the target AFR more? I haven't heard of anyone messing with this before. I feel like I shouldn't have to go a ton higher than 5,000 RPMs...

The car drives so much nicer with the new downpipe on... really hoping for 12s in a couple weeks when I go back out.

Edit: Here are some videos I took if they are any help (thought I was going to get more dramatic launches than I did, haha).:
https://www.youtube.com/watch?v=AR62esJ2ozo