The Mustang Forum for Track Enthusiasts

Track Mustangs Online was built specifically for those who track their Mustangs!

What does this picture say??

Grant 302

basic and well known psychic
Messages
7,444
Reaction score
2,209
Location
In the corner with the squelch turned up
I know that was discussed a bit in another thread, but I think that's less of an issue with coilovers in the rear. As transfer approaches 100% where does bending of the axle/tubes show up? Other effects like compression of the outboard tire need to be considered too.
 

Mad Hatter

Gotta go Faster
Messages
3,092
Reaction score
1,537
Location
Santiago, Chile
This was our attempt to keep the rear wheels better planted... Unfortunately the actual bar broke after about 5min on the track so I could not get a good feeling for the changes... Mechanics Idea is to get the bar putting the inside tire down instead of up. I did get the impression that understeer was less then with no bar but that track only has one slow corner.

Yes the car felt really planted in the long curve before the straight. Thanks for the pics!! Next event will be trying out the P2000 320/650-18 tires on 18x11 Apex wheels, Can't wait!!

Most of the changes were things like spherical A arms etc so more or less I just need to get used to it with out wanting to undo it!! Was surprised to see how much better the car felt, was prepared to have a rougher ride but it did not happen.

Definitely need more track time to get used to all the changes and see the improvements so enrolled myself for track classes again.



 

Grant 302

basic and well known psychic
Messages
7,444
Reaction score
2,209
Location
In the corner with the squelch turned up
Neat looking bar, but I see the potential for bind in the ball joint/rod end (?) connection. Did one of those snap or near that connection?

The bar would still unload the inside, and I think with this arrangement would make it a tad stiffer than the same diameter in the OEM location and connection style.
 

Mad Hatter

Gotta go Faster
Messages
3,092
Reaction score
1,537
Location
Santiago, Chile
Yes, looking at the options now, was 15mm.... the bar broke just by the axle near the black support (just above the 90degree elbow).

Its quite similer to the whiteline rear bar but much much thinner.... That one is 27mm
 

Grant 302

basic and well known psychic
Messages
7,444
Reaction score
2,209
Location
In the corner with the squelch turned up
Yes, looking at the options now, was 15mm.... the bar broke just by the axle near the black support (just above the 90degree elbow).
Not surprising. Binding in that area will stop parts from acting axially in torsion and put some of it in bending. That's why the OEM bars aren't restrained much at the ends.
Its quite similer to the whiteline rear bar but much much thinner.... That one is 27mm
Understood. Yes, except that the mounts are more outboard and will make the the bar for a given diameter relatively stiffer.


Be careful if you're using the left rear wheel plane for reference. That wheel will be at a slight amount of positive camber, half a degree, maybe a bit more. Unless the rear axle has been cambered.
I'm seeing more than ~1.43º compared to the rear wheel. I think the net is negative camber and it looks like it compared to the purple lines along the track width. Red is body roll for reference. Green for the rear, blue for the front.
31144273_10215616696512962_5980397932799590400_o-2.jpg
 

twistedneck

TMO Race
Messages
321
Reaction score
34
Location
Dearborn, MI
Awesome thread. A few notes.. nothing new for these experts but maybe these help.

1. Gain more traction out of the corner by using more rear spring and less bar. I.e. stop un weighting the inside rear wheel.
2. It seems all the uber race cars sit lower in back than yours.
3. You are throwing so much rate and damping at it.. im surprised to see that much roll and or pitch. Maybe its a very high seat position? Sitting more forward. Try burying the seat to lowest.
4. Your diff could be biasing the rear wheels while braking. If its the eaton true track like mine.. unlike torsen these do not freewheel the diff on decel.
5. Anti squat in rear means pro squat while braking. i.e. rear contribution to brake dive increases w increasing anti squat in the rear. (Hence desire to align the link level w ground)
6. Springs first for frequency match front to rear and ride height.. then front bar to balance roll couple then final fine tune w rear bar.
7. ..?
 

Norm Peterson

Corner Barstool Sitter
Messages
646
Reaction score
510
Location
a few miles east of Philly
#5 . . . the braking side of anti-squat for acceleration is anti-lift, where the geometric effect is to allow a portion of load transfer to occur without the rear rising. Increasing the anti-squat increases the anti-lift, which decreases the rear rise under braking.

I suppose you could think through this in "pro-squat in decel" terms, but you'd have to be referencing the "squat" as the amount downward from the rise you'd get if the anti-squat was zero (the anti-lift would be zero as well, and the rear of an S197 would shoot even higher upward than it already does). But I think the potential for confusion is a lot higher with this approach.


#6 . . . is more of a street or dual-purpose approach, though I'm sure you can make it work to give a "more rear spring/less rear bar" configuration as long as you choose damped vibration frequencies appropriate to the use. Damping lowers vibration frequencies - and probably makes it less necessary to match them for flat ride purposes because increased damping causes the magnitude of the vibrations to decay more quickly.


Norm
 

TMO Supporting Vendors

Buy TMO Apparel

Buy TMO Apparel
Top