Cadillac CTS-V Forum banner

1 - 20 of 41 Posts

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #1 (Edited)
Seriously, 7 attempts on different days in cold weather - I should be roasting them to pieces. 2nd gear, rev to 4k and drop the clutch.

I started data logging for the last two (will post in a minute) and as soon as I get wheelspin the throttle position shuts and timing is pulled to -10 (!), obviously killing the burnout. Traction control is OFF in each burnout (I turn it off on every start up). I do not believe I am letting off the gas, but it looks that way on the data log.

Any thoughts? This is a new phenomenon to me as I have previously (last year) been able to do burnouts without timing getting pulled. I am not seeing any KR on the data logs.

The car pulls hard on the street and will blow off the tires under hard acceleration through the first three gears (cold weather); so I don't suspect a mechanical issue. I also don't suspect a throttle body issue as it ONLY falls on its face when trying to do a burnout; hod-rodding and sliding around corners is no big deal.

ETA:
 

·
Registered
Joined
·
341 Posts
Rev limiter may be set in a way that kills power possibly? Ive felt my car fall flat on its face for a second if i hit the rev limiter between shifts. Ive tried no lift shifting above 6k rpm it can feel like traction control is on.
 

·
Premium Member
Joined
·
798 Posts
I know 2nd gear has plenty of burnout power but have you tried in 1st just to compare? If you're not letting off the throttle, TM is stepping in for some reason. Have you tried it in Competition mode or totally off?
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #4 (Edited)
Rev limiter may be set in a way that kills power possibly? Ive felt my car fall flat on its face for a second if i hit the rev limiter between shifts. Ive tried no lift shifting above 6k rpm it can feel like traction control is on.
I'm not getting above 4500 or 5k before it cuts out. Rev limiter is ~7k and I wind it up to 6500+ all the time and never have an issue.

I know 2nd gear has plenty of burnout power but have you tried in 1st just to compare? If you're not letting off the throttle, TM is stepping in for some reason.
I can just stab the throttle half-way and spin in first; but it's tough to control wheel speed before the car gets fast enough to actually match wheel speed and/or I hit the limiter. I can break them loose around 3500 RPM in second gear so it's just maintaining it...

Here's another attempt:
I drop the clutch around 4500 RPM to really make it work! ...the tires are spinning and then I apply more throttle when I feel it dropping off - but it cuts out anyway. I did NOT take my foot off the pedal, but the TPS signal drops anyway and then whatever TCS issue ends, the throttle comes back up - which is why it has that double-hump pattern. My foot was in it the whole time.
 

·
Premium Member
Joined
·
2,692 Posts
Will it go over 5000 on a rolling burnout? In 1st, 2nd, or 3rd?

My chevelle was doing the same thing last fall, right before I put it away for winter. Tuner said it was dumping so much fuel in at that rpm it couldn't burn it all. Causing it too fall on its face... He "adjusted" it and it still did the same thing. I would assume this isn't your problem, but I'm definitely interested in what the problem really is.
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #6
Will it go over 5000 on a rolling burnout? In 1st, 2nd, or 3rd?

My chevelle was doing the same thing last fall, right before I put it away for winter. Tuner said it was dumping so much fuel in at that rpm it couldn't burn it all. Causing it too fall on its face... He "adjusted" it and it still did the same thing. I would assume this isn't your problem, but I'm definitely interested in what the problem really is.
Per the wideband it definitely gets rich - but that's while the timing is being pulled in large amounts so I don't think it's really flooding there. Certainly a possibility but I've emailed PatG for his thoughts.
 

·
Registered
Joined
·
2,812 Posts
Are you logging all of the spark parameters so you can see where your final timing is coming from? Its getting rich as in going into PE based on the log. And this is all new behavior since when? Particularly your torque mgmt advance might be of interest?

 

·
2X 9 second club
Joined
·
11,148 Posts
sounds like brake tq management
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #9
I could do burn outs just fine last year but I started using PatG. So perhaps he changed something.

I have an email to him and will wait to see what he says, there are a few other things I need adjusted

Sent from my SM-N920V using Tapatalk
 

·
Registered
Joined
·
257 Posts
I could do burn outs just fine last year but I started using PatG. So perhaps he changed something.

I have an email to him and will wait to see what he says, there are a few other things I need adjusted

Sent from my SM-N920V using Tapatalk
when you say traction control is "off" are you holding the button for 5 seconds or double tapping the TC button?
 

·
Registered
Joined
·
3,101 Posts
I know Pat disabled brake tq management and TC in my tune. Could try comparing your old tune to the new one and look at all the spots it would pull timing.
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #12
when you say traction control is "off" are you holding the button for 5 seconds or double tapping the TC button?
Holding for 5-10 seconds until both traction and stability control are off. I honestly never drive without doing this.

Sent from my SM-N920V using Tapatalk
 

·
Registered
Joined
·
257 Posts
Holding for 5-10 seconds until both traction and stability control are off. I honestly never drive without doing this.

Sent from my SM-N920V using Tapatalk
well that rules some things out. It may be due to some torque mgmt you are triggering with the clutch drop or less likely some kind issue at the throttle body.
 

·
Registered
Joined
·
2,044 Posts
If it happened since you got a new tuner its probably that. He maybe forgot to turn of the tq management or something like this.
 

·
Registered
Joined
·
1,135 Posts
Could try comparing your old tune to the new one and look at all the spots it would pull timing.
Ding, Ding, Ding!

Do a comparison log and look at all the differences especially in the TQ Management portions.
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #16
Ding, Ding, Ding!

Do a comparison log and look at all the differences especially in the TQ Management portions.
Yeah, I could do that... but I guess I've been busy and if I solved the problem on my own - what would I bitch about?


Thanks for the reminder though - I have years of old tune and log files; I should have thought of that already!
 

·
Registered
Joined
·
618 Posts
OK, so when you say you can spin the tires but not do a burnout, what do you mean? How are you doing the burnout? Are you dumping the clutch and then putting your left foot on the brake to hold the car with your right foot on the gas? If so, here is the place where that is limited:




Turning off traction control will not disable this. Notice that it maxes out at 253 ft-lbs at 100% throttle. Once it determines that you are pressing the brake and gas at the same time, it will limit your ETC so that your motor only puts out what it thinks is 253 ft-lbs. I bet if you let off the brake it will continue to fry the tires. Also, ignore the description at the bottom of the image that says Trans Input Torque Limit -- my cursor was hovering over Default Trans Limit when I took the screenshot, so the description is not for the Brake Torque Management setting.
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #19
OK, so when you say you can spin the tires but not do a burnout, what do you mean? How are you doing the burnout? Are you dumping the clutch and then putting your left foot on the brake to hold the car with your right foot on the gas? If so, here is the place where that is limited:




Turning off traction control will not disable this. Notice that it maxes out at 253 ft-lbs at 100% throttle. Once it determines that you are pressing the brake and gas at the same time, it will limit your ETC so that your motor only puts out what it thinks is 253 ft-lbs. I bet if you let off the brake it will continue to fry the tires. Also, ignore the description at the bottom of the image that says Trans Input Torque Limit -- my cursor was hovering over Default Trans Limit when I took the screenshot, so the description is not for the Brake Torque Management setting.
Yes tapping the brake to keep the car stationary - thanks for the tip!

Sent from my SM-N920V using Tapatalk
 

·
Premium Member
Joined
·
14,372 Posts
Discussion Starter #20
OK, so when you say you can spin the tires but not do a burnout, what do you mean? How are you doing the burnout? Are you dumping the clutch and then putting your left foot on the brake to hold the car with your right foot on the gas? If so, here is the place where that is limited:




Turning off traction control will not disable this. Notice that it maxes out at 253 ft-lbs at 100% throttle. Once it determines that you are pressing the brake and gas at the same time, it will limit your ETC so that your motor only puts out what it thinks is 253 ft-lbs. I bet if you let off the brake it will continue to fry the tires. Also, ignore the description at the bottom of the image that says Trans Input Torque Limit -- my cursor was hovering over Default Trans Limit when I took the screenshot, so the description is not for the Brake Torque Management setting.
So disabling the TPS option did not work. I'll probably have to turn off spark limiting too but I haven't messed with it in a few days.

Sent from my SM-N920V using Tapatalk
 
1 - 20 of 41 Posts
Top