Alignment - ABS puzzle?
#1
Alignment - ABS puzzle?
I went and got the moderate performance alignment I found on the forum here. If you want to know the actual numbers, they are right out of the moderate column of this:
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
#2
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Only thing I can think of is you have a little less tire surface on the ground when you are braking in a straight line due to the increased camber plus you are carrying a little more speed and the system is detecting a slight lockup condition on one wheel that you weren't getting before. Which braking zones are you seeing this happen in?
Bill
Bill
#3
Le Mans Master
Originally Posted by Bill Dearborn
Only thing I can think of is you have a little less tire surface on the ground when you are braking in a straight line due to the increased camber plus you are carrying a little more speed and the system is detecting a slight lockup condition on one wheel that you weren't getting before. Which braking zones are you seeing this happen in?
Bill
Bill
Unless you know for sure your MPH is the same, I would say it is likely more speed and you may not realize you're trying to brake harder... combined with slightly less contact as Bill highlights.
I know my speeds went up considerably when I went from the showroom alignment to -1.5*f (now I run -2.3*f).
I remember this because I was so amazed at the difference. It took some getting used to though. Faster speeds through corners meant faster at the end of straights and braking zones, but I was still used to certain entry speeds, so I was trying to overbrake (vs. trusting the faster corner entry allowed by the alignment).
Also, one thing I noticed is that the car will become a little more darty under hard braking with this agressive alignment. Corner performance is insane, but with the toe out, there are a few uneven braking zones where you have to hang on a bit, especially after initial loading of the front until it compresses. It's just par for the course, no free lunch as it were. Enhancing some performance (corners) will sacrifice other areas, it's all about balance.
That's just my opinion based on your description. All sounds normal. Hard to tell much more.
Last edited by yellow01; 07-04-2006 at 10:50 AM.
#4
Burning Brakes
Originally Posted by NewC6Toy
I went and got the moderate performance alignment I found on the forum here. If you want to know the actual numbers, they are right out of the moderate column of this:
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
#5
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Originally Posted by C6RAPTOR
I need to get my C6 alignment done soon. I have on order Michelin PS2 275/35/18 & 305/30/19 Tires and wider CCW wheels 18" X 9.5" fronts & 19"x11" rear. I just got membership in the Trackmasters to take a HPDE Novice School in September at the Glen. I did one other HPDE with the NCM at Putmum Park Racetrack. I love the track time. How has your tires worn with the moderate performance alignment. My dealer in Rochester said that this alignment would eat tires up. I drive my C6 a lot but want good track performance. I have over 16K on it.
By the way you should see if you can get into the Phoenix CMR Glen Event 2006 on 8/21 and 22. Joe Q runs a pretty good school and it is a good event for a novice to start running the Glen http://www.phoenixcmr.com/august_track_event_frame.htm . If you get signed up by July 7th the cost is $390 Vs $440 after the 7th.
Bill
#6
Originally Posted by Bill Dearborn
You don't need to go as far on the negative camber as some of the people are doing. There is a consensus that toe is more important than camber for tire wear so you can do what I did on my C5Z. I went with max negative camber in the rear (about -.8) and -1.3 in the front with two settings for front toe. One setting has slight toe in to minimize tire wear and help keep the car running straight on uneven road surfaces. The other setting has toe out for the track. I have red and green nail polish marks on the tie rods so I can make the adjustments. The manager at the local Goodyear Store did the setup for me (the regular tech was relegated to a GoFor). The cost was $99 including tax.
By the way you should see if you can get into the Phoenix CMR Glen Event 2006 on 8/21 and 22. Joe Q runs a pretty good school and it is a good event for a novice to start running the Glen http://www.phoenixcmr.com/august_track_event_frame.htm . If you get signed up by July 7th the cost is $390 Vs $440 after the 7th.
Bill
By the way you should see if you can get into the Phoenix CMR Glen Event 2006 on 8/21 and 22. Joe Q runs a pretty good school and it is a good event for a novice to start running the Glen http://www.phoenixcmr.com/august_track_event_frame.htm . If you get signed up by July 7th the cost is $390 Vs $440 after the 7th.
Bill
#7
Le Mans Master
I'm into ABS all the time in my C5 Z and I've never felt any pulsing. In other cars I've had, I felt it, but not in this one, I can hear the tires or I see it flash on the DIC.
#8
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I use the ABS when autocrossing but very rarely at the track. Everytime I use it during an autocross I can feel it shuddering the car and pulsing the pedal (the pedal actually sinks a little).
Bill
Bill
#9
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Originally Posted by NewC6Toy
I went and got the moderate performance alignment I found on the forum here. If you want to know the actual numbers, they are right out of the moderate column of this:
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
.
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
.
ABS is your freind for on track braking.
#10
Drifting
My guess is that even though you're seeing only three seconds overall that you may be much faster in other spots than before and in competitive mode (street tires?) you're starting to hit the sweet spot of the braking zone (the 90 / the downhill into the boot and the heel of the boot) with ABS.
#11
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St. Jude Donor '07
Originally Posted by NewC6Toy
I went and got the moderate performance alignment I found on the forum here. If you want to know the actual numbers, they are right out of the moderate column of this:
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
http://www.corvetteforum.net/c5/toom...6alignment.htm
The good news is that right out of the box I am three seconds faster. The bad news is that I can't brake as hard as I used to. When I brake hard and there is any unevenness in the track, "ABS Active" shows up in the DIC. The weird thing is I don't feel any pulsing in the brake pedal when the "ABS Active" shows up. I've always felt pulsing in the pedal when the ABS has engaged on the street.
This is on my home track (Watkins Glen) with the same wheel, tire and brake setup I used a month ago. The only thing different in the alignment. What is going on here? Is the DIC not telling the truth? Did the alignment really screw something up? Of course at three seconds a llap faster, I shouldn't mess with anything, but I would like to know what is happening....
My C6 is definitely in the ABS more than I feel it should be (God forbid I forget to turn the nannies off-the car becomes undriveable with them on). It's an odd behavior, it only happens in the longer braking zones. Short, intense applications don't seem to invoke it. We took a little rake out of the car and backed off a tad on the neg camber in the rear which helped-but she'll still get your attention braking for turn 1 at Summit!