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Problems with Torsen and Advancetrac on track

I mounted up some Michelin slicks yesterday afternoon and noticed inside wheel spin (think open diff) in tight corners. I also noticed the car was applying the brakes on certain corners trying to straighten the car out. I use the 5 sec Advancetrac method when I turn it off. I also didn't notice either of these on the same track, same day on the stock tires. You can actually hear and see the car one wheel peel and hear it on my in car vid.

7:08 in this vid the Torsen breaks the inside loose.

http://www.youtube.com/watch?v=DhY_jZDmPbg
 
The Boss Torsen has a bias ratio of ~2.5:1 (I don't have the exact number here). It's possible that with the slicks and whatever suspension setup you now have that you are nearly lifting the inside tire, and going beyond what the Torsen can transfer.
 

ArizonaBOSS

Because racecar.
Moderator
8,539
2,368
Arizona, USA
Agreed, there is another version of the Torsen (T2R) that should alleviate that issue when using race tires. Not sure if the "base" T2 in our cars can completely cure the issue.

Have not had issues with Advancetrac as you mentioned, using same "5 second" procedure.

I am running NT01s on the track, for reference.
 
I think its a sign that its lifting the inside tire. I don't believe the T2R will help as its a Torsen and they unload when a wheel gets light. Hopefully track key is the fix for the advancetrac. Arizona, It was mostly on fast 100mph+ sweepers when sliding out of the corner, I think all your tracks have been low speed tracks correct?
 
h2r_6.jpg

Hrm. I'm not buying that it is lifting the inside tire on an uphill corner. I know you had slicks, but how much more can those springs compress? After the point this photo was taken everything is working to keep the rear tires on the track - the angle of the track itself and the acceleration transferring the weight back. Yeah, I'm not sold on it.

Now, on that same corner I experienced a) oversteer, which stopped as soon as I began respecting the throttle, and b) the weird power loss that has been reported after a tight turn (has it's own thread somewhere). So, who knows? Maybe just a slick, tricky corner. Maybe voodoo.

Meh, I could be wrong. ;)

Jimmy
 

ArizonaBOSS

Because racecar.
Moderator
8,539
2,368
Arizona, USA
Correct, we don't have anything out here with that kind of sustained speed when turning. Should be able to hit 150mph at Firebird Main out here but that is in a straight line...

Keep us posted with what you find out!
 
itrack said:
I think its a sign that its lifting the inside tire. I don't believe the T2R will help as its a Torsen and they unload when a wheel gets light. Hopefully track key is the fix for the advancetrac. Arizona, It was mostly on fast 100mph+ sweepers when sliding out of the corner, I think all your tracks have been low speed tracks correct?

Ok, so I looked it up. The Boss version has a bias ratio 2.7:1 (as per Ford Racing) the FR500S T2R from Ford racing has a bias ratio of 4.0, which is fairly significant in terms of the weight transfer it allows in cornering.
http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=10196

Does anything in your rear suspension setup limit droop travel compared to stock? Are you running a stiffer rear bar?
 
Car is bone stock other than running an 18x10 square setup with a 3/8 spacer up front. Suspension was at 3/1 in the video and 5/2 later in the day. Both setups did the one wheel peel, though I was 2 seconds faster with the 5/2 setting.
 

MoscowBoss

BOSS 771
17
0
NC USA
Ford recommended settings

For what it is worth and for those that may not have read the Boss Supplement Manual we got with the car, or forgot, these would be good starting points I would think.

Under Track Prep. section......

Damper adjustment recommendations:
• Boss" 302 - Set all four dampers to position (5) for all tracks.
• Boss" 302 Laguna Seca edition - Set front dampers to position (5) and
set the rear dampers to position (3), (4) or (5) depending on how
smooth the track is or how much curbing the driver likes to use.
• On a rough track, set the rear dampers to position (3).
• On a smooth track with aggressive apex curbs, set the rear
dampers to position (4), but only if the driver uses those curbs.
• On a smooth track with mild FIA-type apex curbs, set the rear
dampers to position (5).
• If the turn-in portions of the track are rough, reduce the front damper
setting by one position until the Boss" 302 turns in on those rough
portions.
• If the rear of the car is skipping over bumps during corner exit so that
the driver has to reduce throttle input, reduce the rear damper setting
by one position until the driver can apply appropriate throttle.
 
Re: RE: Problems with Torsen and Advancetrac on track

MoscowBoss said:
Ford recommended settings

For what it is worth and for those that may not have read the Boss Supplement Manual we got with the car, or forgot, these would be good starting points I would think.

Under Track Prep. section......

Damper adjustment recommendations:
• Boss" 302 - Set all four dampers to position (5) for all tracks.
• Boss" 302 Laguna Seca edition - Set front dampers to position (5) and
set the rear dampers to position (3), (4) or (5) depending on how
smooth the track is or how much curbing the driver likes to use.
• On a rough track, set the rear dampers to position (3).
• On a smooth track with aggressive apex curbs, set the rear
dampers to position (4), but only if the driver uses those curbs.
• On a smooth track with mild FIA-type apex curbs, set the rear
dampers to position (5).
• If the turn-in portions of the track are rough, reduce the front damper
setting by one position until the Boss" 302 turns in on those rough
portions.
• If the rear of the car is skipping over bumps during corner exit so that
the driver has to reduce throttle input, reduce the rear damper setting
by one position until the driver can apply appropriate throttle.

Yes but when running a square setup I feel the car is more nuetral 2 clicks down in the rear to enhance rear grip. Have you run on a square setup yet?
 
I've run square on NT01s. Really felt the car was biased too much for oversteer. You could drive it, but really had to manage the rear end wanting to snap around in most corners. I was advised from someone who spoke to the suspension engineer at Ford to run 1-1.5" stagger with the stock suspension. I was running about 2 seconds faster on a staggered setup than square. To run square you'll have to soften the rear bar or go to the smaller 22mm GT bar. I was also told that softening the rear dampers will not correct that oversteer bias. Take it for what it's worth. ArizonaGT can weigh in on this as well. I'm pretty sure he's found similar results, but has made adjustments to his sway bar to compensate.

I can absolutely fly around the track with a very neutral feeling running staggered. I run two sets of track wheels/tires so I manage the fronts wearing out ahead of the rears by swapping to the other set during a track weekend. Then just replace the worn tires for the next trip. At the end of the day you still get the same benefit as rotating front to rear, you just have to invest in a second set.
 

JScheier

Too Hot for the Boss!
Jake,

If AdvanceTrac is completely off, there is no application of brakes. You can do completely ignorant things when it is off... and the brakes are not applied. Are you sure it came up on the dash 'AdvancedTrac Off'?

I ask this because in Turn 12 at MPH, when following Dean (for the first time), I had the exact same thing happen... turns out that AdvancedTrac wasn't off... guess I was in sport mode (two pushes vs. 5 second (or more) hold).

Stock springs and dampers should really allow for a lot of droop and travel, so lifting the wheel, while not impossible, would take a lot of effort.

Sticky tires, off-camber turn and a bumpy (damn that was bumpy) track could all lead to lifting the wheel. The unloaded tire on a bumpy track is going to have a tendency to skip or spin if it can't get grip.
 
bigman18 said:
Today at Daytona while going about 130 mph on the banking I heard a clunk and all the traction lights came on,then the computer said service advance trac.

Ouch, very interested to hear the results when you know please. What were you running, on-off or sport mode?
 

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