different car but I'm using mixed PFC pads on my M3 with no issues. On that car we need a more agressive front pad than rear so I'm running '01's in the front and '06's in the rear. Might go to '97's in the rear next time as even the '06 seems to have a little too much bite in the rear for that car. I used to run Hawk HT-14's in the front with Pagid yellow's in the rear. That car gets really unstable under braking with too much rear pad.

On my 996 I never got to try PFC's but always ran Pagid orange or yellows in the front and black's rear.

Based on my experience I'm not sure I'd feel comfortable with more front pad than rear in the Porsche. Guess I never tried it though.

 

YUP, no going back... I'm going to try that setup you are thinking for this Sunday's Monticello event, i'll let you know how I like it

 

Martin, please post back your thoughts. What did you run (or have been running) for your last events to compare? 06F&R?

 

YUP... And I will definitely post up my impressions, car is in the shop getting the new rears on now! I ran the 06's F/R for the past 2 events, and as I mentioned I love them, much more bite and better braking feel for an enduro comparable compound to the pagids, which stopped well under hard breaking but had lack of feel anywhere else.

 

i've got front 06's coming to me... i was running 01's front and rear but the front pads have worn down so time for new pads, therefore, 06's for the fronts and keeping the 01's in the rear as they have plenty of life.

with 01's on the front and rear, i get A LOT of dancing under hard braking, does not inspire confidence. this is with deman rotors up front and stock rotors in the rear. stock gt3 suspension with lots of camber: -3.2 in the front, -2.4 in the rear, maybe thats why its dancing so much? i'm on nt01 tires 245/315. it's not the lsd because i've got a guards unit in there and its working perfectly.

so i'm hoping the 06's up front will help... i'll be testing it out at a track day on aug 14, and will share my impressions.

 

Looking forward to what you have to say. The unsettled "dancing" under hard braking may be an alignment issue. Your camber setting seems fine (maybe a little too aggressive for the NT01 but still fine). When was the last time you check your front and rear toe? A dancing car under braking usually means LSD or toe issue from what I have experienced. Since the LSD is rock solid, my next guess would be toe settings.

 

good point about the toe settings... hmmm... i ruled out alignment because it was done at the beginning of the season and i noticed the dancing at my first track event. could be they didnt set the toe right from the beginning but they're a very competent shop who works on porsche cup race car teams all the time. i dont doubt their settings but hey, everyone makes mistakes. i also had the aftermarket rear toe links installed at that time.

i should mention: this particular shop really is against flipping the strut tops for camber. they instead add the cup car lower control arm shims to achieve more camber, however, i get rubbing with the 245/40 nt01's up front. they say the shims give a wider track and is overall better than rotating the tops. i dont know if i completely buy it, i've read positive reviews about rotating the tops for camber on rennlist. i mention this because maybe it has something to do with the dancing?

 

Wow, that makes no sense for them to do that. The strut mounts are that way for a reason and to achieve the perfect balance you want to rotate FIRST and then shim to the desired setting. I'd be curious how "off" your caster settings are using shims only, especially to dial in as much as you have.

You don't have to have a race shop do it (but it's nice). A trip to the dealer (or any place with the proper digital alignment rack) could give you your current setup without even making any adjustments. If they are off (which I suspect they are) you can then make some alignment decisions.

 

thanks for the insight dell! i'll try to get this addressed before the aug 14-15 event. and of course share my impressions about the 06/01 front/rear combo...

 

AGREED... Caster/Toe can be affecting that twitchy/dancing feeling.. I hated my car with added toe, now i'm pretty neutral with more caster and it's rock solid feeling and tracks straight, may want to look into that..

 

Too high of tire pressures at the rear get my car shaking its booty under hard braking. One more thing to keep an eye on.

Cheers,

 

spoke to the shop who did my alignment...

"The alignment is the same as quite a few other GT3 track cars in the area. We may have introduced a small amount of rear bump steer with the new toe arms. The thing to do would be to measure the rear bump steer and see if it is excessive or not before proceeding further."

i asked about how the bump steer is measured, response was:

"The best way is to hook it all up on the alignment machine and raise and lower the car 3 – 4” and record the toe migration. This way I can see both sides at the same time to identify a difference between the sides or excessive bump steer. It can be done with a traditional bump steer gauge one side at a time as well."

the tire pressure is a good one... i'm typically at about 39-40 hot in the rear. i get dancing even at 39 hot.

any thoughts about the "bump steer" theory?

 

So they are saying they did bump steer the car? If they did, my next question would be which toe arms did you move to and what is your ride height setting. If you do not have bump steer adjustable toe arms, you can't bump steer a car properly!

 

i have the ERP non-bump steer adjustable toe links. so good point, not sure how they're planning on adj the bump steer with my toe links... I emailed him back to remind him that mine are not adjutable.

every where else the car is fine... the alignment seems spot on. the only thing i dont like is the dancing under hard braking deep in the braking zone. its scary! i thought maybe it was the front brake bias. tire pressures, alignment, all good things to look at! i'll check it out, kinda fun trying to dial in this car just right

 

If your car is lowered, I would highly suggest the adj. toe arms so your car can be bump steered properly. That very well might be the answer to your problems. Sure wish I could sit right seat with you and get a better feel for what you are experiencing.