target audience - only M6 guys with DR's with drag experience

[2MCHPWR]

hi all - i went to a track rental yesterday at atco, NJ.
first time dragging the zl1 (but i have many years drag and RR experience).
But i had weird launch issues that I hope you guys can help with.
2013 M6
3955 lbs (no driver) with pass seat removed and lighter weight wheels/tires.
1/4 tank of gas. Torco additive.
MT ET Street 305/45/18 25 psi and 255/18 goodyear RSA's.
only mod is rotofab CAI.
Probably making about 525 hp at wheels.

all nannies off (hold button 10 secs until both lights illuminated); did this all day except for 2 times to experiment (details below).

pass #1 right off street 11.9, 3500 launch
pass #3 11.6. bam. happy as pig in sh!t. i think rpm was 3500 or so.
Since then i started raising the launch RPM but consistently had major bog.
Yes the track was sticky as Sh!t.
4500 - bog
5000 - bog
5500 - bog
6000 - bog.
all above were 12.0 times.
ok time to regroup.
why is it bogging? it has power to spin the wheels! i am thinking torque management killing power. TM is built into the stock tune/ECU.

so then i try to use ptm 5 launch control. i had doubts and i was correct.
first time with LC - bog
2nd time with LC - bog

ok now what? so i think slip the clutch ...
first time with like 5k rpm launch (no more LC) - smoked the clutch.
2nd time slipping it a little less than previous - smoked the clutch.

now i'm annoyed that i can't reproduce the 11.6 and smoked clutch.
rest.

new idea - lower RPMs again (approx 3500) and NO burnout!
first time - slight spin 1.8 short time and 11.6
2nd time - still no burnout! - slight spin, 1.79 and 11.6
3 and 4th time - no burnout - all 11.6's.

all had slight spin.
so now i'm greedy. let's try a small burnout with that lower 3500 rpm launch.
bog - 1.8 and 11.7.
2nd time with above - same result

so i'm done for day. mostly happy with a slew of 11.6's but still i know or feel the car has more in it if i can get a real launch.
the first launch of the day was 1.748 but couldn't reproduce. 2nd best was 1.788, followed by 1.798 followed by 1.830 ( and ironically my fastest ET was from that slowest 1.830 short time).

Are all nannies really turned off with the 10 second hold?
Is torque mgmt real and does it show itself on the hard launches with sticky tires by making the car bog?
Does no lift shift still work with all nannies off? i asked this because i did no lift shift (or as us old-timers called it "power shifting") all day but did bump against the rev limiter a few times until i learned that the tach is slow on 1st to 2nd shift and 2nd to 3rd shift.

ideas or suggestions welcome but only if you have first hand experience please. I posted similar on FB group and got weird answers from people not in the know ("check your plugs", "use PTM5", etc.).

[acammer]

Subscribed for the discussion and information. My car will turn the street tires loose with too much rpm (4000+rpm) at the drag strip. Problem is that with much less than that it'll bog, it's a fine line for sure, and usually the clutch has to get quite a workout for the best launches.

I've looked at the stock LS3 file in HPT (just pulled it up to review for this) and there is torque management even with the M6 trans. I wouldn't be surprised that the ZL1 also has some built into it.

You've got the right procedure for defeating the traction control - the long press on the TC button until both the TC Off and Stabilitrac Off lights illuminate together.

[acammer]

I was in a thread a few month's back where a ZL1 guy was having some major down on power issues and struggling at the drag strip. Turned out to be a low coolant level in the heat exchanger. The car would pull a bunch of timing on the high Intake Air Temps and run like crap, especially once it got heat soaked even a little bit.

You didn't mention if the MPH dropped off significantly on the bog passes, but I'd assume if it still made a 12.0 the trap speed was pretty consistent. The car definitely will be sensitive to heat soak even with everything up to snuff - was it nice and cool when you got the bogs? You made plenty of passes, so I'm guessing it wasn't getting a good 30-60 minute cool down between runs. Hot lapping is great for getting you technique dialed in, but definitely won't yield "maximum effort" ET and MPH.

You probably know all that - just throwing some stuff out to get the conversation rolling.

[2MCHPWR]

thanks for the info.
I didn't data log (forgot cable at home!!) but i did watch the data on HUD via dashlogic.
timing and KR were great, as was boost.
IAT was typically 70 and IAT2 was 124 at end of run.
even did hot laps and that was pretty consistent.
my bogs were always over 120 mph so timing isn't being pulled and i do not question that it was making full power.
i just friggin bogged down on those launches with the higher RPM launches. so frustrating leaving all that time on the table.
I need to research TM more. That's all i can think of at this time.
Maybe next time i data log and log the TM parameter? i don't even know if there is one but like i said, i need to research that.

[2MCHPWR]

even with bogs, it was over 120 mph. see my "slow" time slips

[Can'tHave2MuchHP]

Originally Posted by 2MCHPWR

thanks for the info.
I didn't data log (forgot cable at home!!) but i did watch the data on HUD via dashlogic.
timing and KR were great, as was boost.
IAT was typically 70 and IAT2 was 124 at end of run.
even did hot laps and that was pretty consistent.
my bogs were always over 120 mph so timing isn't being pulled and i do not question that it was making full power.
i just friggin bogged down on those launches with the higher RPM launches. so frustrating leaving all that time on the table.
I need to research TM more. That's all i can think of at this time.
Maybe next time i data log and log the TM parameter? i don't even know if there is one but like i said, i need to research that.

Interesting you should bring this kind of stuff up as 2NASSTY, who is a 10 second M6 ZL1 driver, found that all torque management wasn't disabled until he yanked a fuse, can't remember which, but obviously the one that controlled traction control/torque management etc. and immediately the car snapped the half shaft.

The management seems to be built in to a degree to protect the car. Not sure if you're going to get much better than 11.6 with a CAI/Tires. That's a really good time for your cars state.

[Can'tHave2MuchHP]

By the way, his best pass that I know of was 10.4 and he left on welds at around 5500 RPM I believe, no bog, just hook and book. Of course slipped the clutch a bit.

[acammer]

Yea - definitely not laying over at all on the big end. Nice low IATs - I didn't see an ambient temp anywhere but Atco this time of the year is nice and cool I'm sure. Definitely some great MPH there.

I'd agree, something's got to be pulling it down with those aggressive launches. I would definitely do some data logging on the next trip and see if you can identify a spark/fuel/throttle adjustment that's happening on those higher RPM launches.

[2MCHPWR]

thanks man. searching his posts now. but he has aftermarket clutch. i'm sure that helps too. using searching function now

[Can'tHave2MuchHP]

Originally Posted by 2MCHPWR

thanks man. searching his posts now. but he has aftermarket clutch. i'm sure that helps too. using searching function now

The majority of his passes were on the stock clutch, and the record pass (Linked above) was all on the stock clutch. He's still been getting used to the aftermarket clutch and in fact a while back his runs were a tad slower due to not being used to it. Anyways, yeah, most of his stuff was on stock clutch.

[acammer]

Originally Posted by Can'tHave2MuchHP

By the way, his best pass that I know of was 10.4 and he left on welds at around 5500 RPM I believe, no bog, just hook and book. Of course slipped the clutch a bit.

Gosh that thing rides out - the launch really doesn't have a lot of drama at all, just boogies. Nice shifts too!

[crazydave]

There is something in the stock tune that causes the bogging. I know for a fact that when I got the car tuned it was alot easier to launch without having the bogging issue. Your best launches are going to be around the 3500 range dragging the clutch out to keep the rpm up out of the hole. On my stock weight car with those same tires and just a CAI I could dip deep into the 1.7s, but its hard to get any better that that due to the power level. The best DA we see around here is +500-1000ish so I was not making the power that you were. I upped the power and tuned the car and have been in the 1.5s.

[frankwjr]

look up BFASTNOTLAST on here...he has (IMHO) perfected the use of the e-brake during the launch to pre-load the suspension which in helps soften the hit....he is runnin 10's...all motor....good luck...

found it...http://www.camaro5.com/forums/showpo...5&postcount=56

[frankwjr]

Originally Posted by 2MCHPWR

really dude? ebrake for dragging?

and hello?

I edited it...get a grip...look at the vid...learn....