I want to try a different pad to the PFC 01 f & 97 r that I've been using. Don't get me wrong, I love these pads but having moved from an ABS car to a non ABS car has led to some flat spotting tyres. I had no such problem in the old car.

So the car is a modified 951 weighing approx 3000lbs with driver. I have Big Reds and floating slotteds up front and stock 951 / solids at rear. I have used Pagid Blacks before on the old car and like them but again, that car had ABS and the bite wasn't quite the same as the PFCs.

Next thing is that I need to get these ASAP as we need to fit them in the next week....in Australia.

So any advice or vendor who can deliver is appreciated.

 

I would say that the flat spotting is not due to the PFC pads. Perhaps you are using too much pedal pressure.

 

Front or rear tires? Might want to add an adjustable brake proportioning valve.

 

I love the Hawk DTC 70s. I've also used the DTC 60's which have less initial bite and might therefore be less susceptible to locking on you.

http://www.tirerack.com/brakes/brake...+Pads&cat=Pads

 

Mostly the fronts.

Quite possibly too much pedal pressure, but it's by driving as close to 10/10ths that can put you in this position. It's not feeling like a panic stop or anything. Just fairly hard braking from a fast lead into a hairpin. Nothing I've had before with the same pads on an ABS car. Trying a pad that builds up a bit less heat than the PFCs might just give me the margin I need before I master the art of Braking.

 

Less heat? I might be inclined to think you are looking for a pad with less torque.

Are you locking one end before the other? If so you might want to tune the proportion or lower the torque of the pad on the locking end.

 

Patrick, I am not going to get into the brake pad Which Is Better discussion, because they're all good (mostly).

However, I wonder if it's a technique thing rather than a pad thing? The first time I drove a race car with no ABS (and no power brake assist, for that matter), a wise friend & teammate suggested that I come on them very hard for a tiny brief instant, to get them to temp, and then immediately come off them like 10% or so, to prevent lockup at the instant it was likely to happen. Then, I could modulate from there.

It worked like a charm.

Just a thought....








Professional Racing and Driving Coach

 

Yes you're probably right. Less torque is a better term.
I seem to be locking the fronts before the rear. One particular corner comes to mind. I actually think the changed proportioning valve I had in the rear is not in this car. Long story short, I had it in the previous car with abs and think it might have been one of the few things that didn't make it's way across to this current car after a crash. However, there is some evidence that I locked the rears on another track although this was pretty early in the piece from shifting cars and I know where I did this was basically poor technique.

It could easily be the case Dave. I find that I'm not doing this particular corner as well as I 'thought' I used to on the previous car with abs...but it's also possibly in combination with the PFCs which have such great bite. I'm also told that carbon metallic pads have a tendency to bite on the 'way out' of the brake application so I sense that this is where I'm being caught out. Probably need just to make the initial application a tad shorter but firmer. It may even be something as simple as carrying more speed into the previous straights and corners and just getting caught out on occasion. All part of the learning curve.

 

Sounds like you added more brake caliper to the front of the car but left the rear stock. Then ran the 01's up front which are a more aggressive pad then the 97's in the rear.
You might try the 01's all around, also change the rear brake pressure valve if you haven't already. Or just go to separate biasing and get it dialed in for your driving , track, etc.

I also agree with what VR said about braking technique. You have to stand the car up and transfer the weight before you can really stand on it and stay in it. But I kinda presume you already know this.

 

Going up to the Big Reds on the front alone is a pretty common upgrade for the 951. Having said that, it's probably not ideal. I will update to a different setup somewhere in the future. I had run the same calipers and pads on the old car with abs without any sign of lockup. They actually give very good retardation and sometimes I feel like I've overslowed for this corner. The other change I've had is going up in spring rate from 630/708 to 800 / 900. I would have thought that this would prevent less rear to front weight shift during braking?

It's a double apex off camber 'thing' that seems to elicit many different lines. You come into it pretty hot off a 'main straight-fast sweeper-short straight' intro, so it's easy to be doing pretty good speed at the 100mark.
I'm sure I need to adjust some things myself, but I just thought I might try a less torque prone pad just as an interim fix. I'm thinking back to the Pagid Blacks as I tried these in the past and they seemed pretty close but just not as grabby. Any other suggestions?

 

I have run both Pagid Black and PFC 97/01 extensively and can tell you that the Blacks have MORE torque, not less, compared to the PFC 97. By way of example, when Patrick Long drove my non-ABS PFC 97 car he suggested more torque and a pad change, perhaps a switch to the Black, as an option. I think you'll be going in the wrong direction if you do this.

As Viking mentioned, your issue may be having the more aggresive 01 in the front versus the 97 in the rear, causing the front lock up. I might suggest 97 all around, as it has the least torque of the whole bunch. If the fronts still lock, you could put 97 in front with 01 in the rear.

PFC gives better feedback than Pagid, especially on release, and are therefore easier to modulate. They are a good pad to learn non-ABS braking if your technique is off. After getting the hang of it, I would then move on to Pagid if you still weren't happy.

 

I've only heard of 01 in rear and 97 in front (or the same all around) in order to balance out the bias. Seems you've got it reversed. Add to that a more aggressive front caliper and I think there's your problem.

 

The weight shift is still there, it is just perceived as less because of the reduction in nose dive. The stiffer spring makes the transfer more abrupt.

 

I agree with VR. If you got used to having ABS, you will need to change your braking technique and adjust to no ABS. I run PF01s front and rear on my 911. Work like a charm. I have driven 944s with these pads installed and they work fine.

If you need some sent to Australia we can handle that at OG Racing since we do international shipments all the time. We have these pads on the shelf and can get them to you no problem. Send us an email at info@ogracing.com to reach the sales staff. You need the PF0594 for the Big Reds and the PF7725 for the rear which we have made for the standard 951, 964, 4 piston caliper without the cutout for the wear sensors.

 

cant believe this hasnt been asked already, but what kind of rake are you running in the car? Definitely helps with initial turn-in, but your rear brakes don't work as well. I know I was locking up less and could go an extra 20'+ into brake zones when I took 1/4" out of the rear ride height.