Tire pressure on track

[911teo]

At this particular track we found the ideal hot pressures were 40 front and 38 in the rear.

I am going to do another DE at Rockingham this weekend. I have never been to the track but we'll start with the same pressures and go from there.

 

[911teo]

You can fool with the pressures but in the end you would be much better off with Michelin's Pilot Sport PS2 (front 265-30-19 rear 335-30-20), with the Good Years you spend a lot of time skating around the corners.

I was thinking about having a set of Kodiak wheels made for the track.

I did not know the PS2 were avaliable in those sizes.... Makes the decision easier. Thanks

On the OEM tires... I am not sure i love them...
They are very noisy on the road and give very little notice before letting go on the track.
The flip side is that the thread wear is great and they are SUPER on the track under heavy rain.

 

[911teo]

You can fool with the pressures but in the end you would be much better off with Michelin's Pilot Sport PS2 (front 265-30-19 rear 335-30-20), with the Good Years you spend a lot of time skating around the corners.

What wheels are u using with the PS2? if custom what offset front/rear?

 

[snaproll]

Without lowering the pressure the understeer on a the tight track was too great.

Derry

Yep, I found that she's an "understeerer" on the tight stuff for sure. Stock tires. Whenever you're not WFO, the fronts are overwhelmed. Of course, it's still faster than anything else that shows up to the track :biggrin

.....
On the OEM tires... I am not sure i love them...
They are very noisy on the road and give very little notice before letting go on the track.
The flip side is that the thread wear is great and they are SUPER on the track under heavy rain.

Yes. I got two good sessions in then the rain hit. The goodyears were great in my opinion. I almost forgot what I was doing: Tracking a $175k car in the rain at my first event with it?!!? I've alway subscribe to the adage that "the only thing dumber than racing in the rain is practicing in the rain."

bb

 

[richardhead]

Updat to Previous Alignment Process Post

Jeff

thanks! I am using the OEM Goodyears. What camber do you run up front? and rear?

Everyone...I received and had a machine shop measure the thickness of the alignment shims for the front and rear. All shims measured except one on backorder from Ford (Rear 4.0mm shim). Shims come color coded as follows for both front and rear: Red=6.0mm, Blue=5.0mm and Black=4.00mm. Although I do not have the black rear yet, I am expecting it to be consistent with the three fronts and two backs I do have. So, for the front shims, the Ford Parts Book is inorrect on thickness. I have edited the previous alignment post on this thread to reflect this information.

 

[cobrar1339]

Richard

Do you have the Part #'s for the shims?

Are these also the same shims that are used to adjust the bump steer on the tie rod ends?

Thanks...good work, my dealer could not find them listed any where.

 

[richardhead]

Richard

Do you have the Part #'s for the shims?

Are these also the same shims that are used to adjust the bump steer on the tie rod ends?

Thanks...good work, my dealer could not find them listed any where.

Front and rear alignment shim information:

Type__Color__Act. Sz___(Ford)_______Part Number____List Price__Hole Size

Front__Black__4.0mm__(NOT 2.0mm)__4G7Z-3A182-AA__$9.67 List__Large-L
Front__Blue___5.0mm__(NOT 3.0mm)__4G7Z-3A182-BA__$9.67 List__Large-L
Front__Red___6.0mm__(NOT 4.0mm)__4G7Z-3A182-CA__$9.67 List__Large-L
Rear___Black__4.0mm___-----------__4G7Z-5A802-AA__$9.23 List__Small-U
Rear___Blue___5.0mm___-----------__4G7Z-5A802-BA__$9.23 List__Small-U
Rear___Red___6.0mm___-----------__4G7Z-5A802-CA__$9.23 List__Small-U

Hole Size: L= Lower control arm; U=Upper control arm

Bump steer shims? At this time I do not know. Check Part number for the bump shims against the above. I'll also look into it if you'd like.

 

[kosupply]

Yep, I found that she's an "understeerer" on the tight stuff for sure. Stock tires. Whenever you're not WFO, the fronts are overwhelmed. Of course, it's still faster than anything else that shows up to the track :biggrin



Yes. I got two good sessions in then the rain hit. The goodyears were great in my opinion. I almost forgot what I was doing: Tracking a $175k car in the rain at my first event with it?!!? I've alway subscribe to the adage that "the only thing dumber than racing in the rain is practicing in the rain."

bb

By understeering, you must mean with the 335 Pirellis on the rear. I have HRE's with 275 fronts and 335 rears and it definitely understeers with that setup. The stock setup is definitely an oversteering situation,,,,unless we are driving different cars????? www.kosupply.net go to links

 

[richardhead]

By understeering, you must mean with the 335 Pirellis on the rear. I have HRE's with 275 fronts and 335 rears and it definitely understeers with that setup. The stock setup is definitely an oversteering situation,,,,unless we are driving different cars????? www.kosupply.net go to links

Did you guys check/re-align the cars when you changed tires/wheels? If not, your settings are probably out and it is affecting your handling characteristics. In particular, check your toe-in if your tire rubber contact patch is good with the resultant camber settings you have, whether stock or not...