trakmor

I know there is probably a fair amount of opinion on this subject, but just wanted a rough guide. Any thoughts on a rotor/pad combination for the GT3 that will get me the most "bang for my buck?" I don't mind giving up a second or two in lap time if I can get endurance/longevity out of the rotors and pads. Thanks in advance.

24Chromium

That's easy! Every pad/rotor combo will last longer if you simply go 2 seconds per lap slower.

But who the hell wants to do that?

MaxLTV

There is a separate thread on that - try searching. But in summary, a lot of people are happy with AP racing two-piece rotors and PFC 11 or Ferodo pads. Apex Performance is a vendor on this forum and they can set you up with parts. From the wear I'm seeing on mine so far (with PFC 11 pads), I'm expecting close to 2x of OEM pad life and well over 2x rotor life. Ferodos are supposed to be even better for longevity.

trakmor

Lol! Well said.

Thanks MaxLTV. I have heard good things about the AP rotors (and pads mentioned as well). I'll check the rest of rennlist too.

orthojoe

Lmao!!!!
That strategy will help with tire life too!

Ferodo ds1.11 pads have lasted the longest for me and have been nice to the rotors as well.

I'm going to try out a set of project mu club racer pads next. I really liked these pads on my old brz and learned recently that they make them for the GT3/4. I'm going to try them on the GT4 and see what happens

KA MOTORSPORT

Here is some feedback: https://rennlist.com/forums/991-gt3-...-girodisc.html

https://rennlist.com/forums/gt4/9169...ite-pad-3.html and https://rennlist.com/forums/991-gt3-...rack-pads.html

Brembo Racing enduro discs and RT RE10 endurance pads are more expensive up front, but last the longest and usually cost less longer term. PM us for specific recommendations and prices. (we cater to RL users).

Olsen motorsports in your area has a lot of Porsche setup experience also.

trakmor

Thanks for the input. Finally warming up here, so hope to get some practical use out of the advice/reccs.

mooty

joe was so fast that he's on backing of pads and took an interesting line ;-)

orthojoe

I don't know what you are talking about. LOL



Ferodo DS1.11 pads are definitely good all of the way down to the backing plate. Unfortunately, this means that I toasted one AP rotor so I won't be able to see how long it will truly last. Had 26 hard days on them and they looked like they had plenty more to give.

Man, I had to trail brake a whole bunch of turns and almost went straight off the back straight before I convinced myself something was wrong with the car and not me!

Here is video of Ben chasing you:

orthojoe

If anyone is curious what the difference looks like in a data trace between a Gt3 and GT4 I did an overlay after my first track day in the GT4 at Thunderhill using the cyclone config.

This is a graph comparing my 2:01.2 GT4 lap against a 1:58.5 lap in the GT3. You can see that the peak velocity down the main straight hits 132.7 mph in the GT4 vs 140.1 mph in the GT3. GT3 in red. GT4 in blue. Speed in the first row, throttle position 2nd row, Brake pressure 3rd row, and time differential 4th row.

MaxLTV

Thanks for posting that. From the data, it looks like you were driving better in the GT4 - smoother brake->throttle transitions and more precise/aggressive timing of both brake and throttle. Probably more familiarity with the platform and confidence, or just more used to the speed after driving the GT3. Contrasting to GT4, it's easy to see some over-braking or braking too early and then a little of coasting into turns in GT3. I do that too, so maybe it's the car. Or the speed - it does get scary. Case in point, the lift in T7 is unnecessary in most conditions, but it may seem like you are about to run out of track. T5 is Sonoma is similar.

In general, it looks like GT4 is a great car, regardless of price - practically same traction and braking and close in acceleration compared to GT3.

skremese

Joe - first off, many thanks for this thread. It's been very informative pre and post purchase of my GT3.

I took the car to Thunderhill yesterday, my first track day with the car, probably my sixth time there so still a noob. Car was awesome (had a 996 Turbo previously). Moved up one run group and was still running in the top half at least. I'm sure it's mostly due to the car. That said, I have a few questions based on observations...

I have the Dunlops (stock) on the car. They felt like they got greasy about 2/3rd through each session and start to let go. I was running about 32 in front and 38 in rear. Too high?

I'm hoping to do 2 days at Sonoma beginning of May, will need to replace them after that point. Recommend the Michelins? Similar pressures?

Car geometry is as it came from factory. When I get the tires mounted it may be a good time for adjustment. Any suggestions for me maybe 2k miles total on track, between TH and Sears). Something I can tell the mechanic to do (unless these are adjustments I can do without a rig/alignment.

Finally, do you run with ESC & TC enable? As I'm getting used to driving the car I left it on and could feel it intervening at times, certainly in turns 3, 4, 10 & 11 when I get on the gas too much. Way different than the turbo which was awd and just pulled / under steered through them.

Thanks again for all the info!

Ducati1199

Skremese, I'll let Joe give you the "official" word but I'm in a similar position to you with # of track days and OEM Dunlops. However, I try and run 30/32 hot - 38 is pushing it a bit and might be why you're getting "greasy" feeling at back end of session. I am still on standard factory settings as well and trying to resist the urge to "fiddle".
And "yes" I leave all the nannies on and believe most of us do. At C group level I believe they help way more than they hinder and you'd be a brave person to turn them off at Sonoma!! Hope to see you around - think I'm going to head to Sonoma on May 16th.

orthojoe

I haven't found a single tire that would give me ultimate grip throughout an entire session. Your best shot at a fast lap time is during laps 2-4. That being said, I think 38 rear is too high. I'd bring it back down to 32F/34R and see how that feels.

I was originally told that dunlops needed higher pressures than michelins, but now I'm getting conflicting information. I'd try doing the same 32F/34R with the cup2, which is what I like on the cup2

You are smart to leave alignment alone for now until you see an issue with tire wear

I drive with everything on. If the car is intervening, it is because you are over driving the car and/or not driving smoothly. Unless you are running lap times faster than 1:57 over the top at thunderhill, I can guarantee you that ESC and TC are NOT slowing you down. It's saving you. 3 is off camber and you need to find the right line to stabilize the car. 4 should be a smooth exit. You are probably going in way too hot for 11. It's the slowest turn on the course, but too many try to go fast in and end up slow out. If you do it right you are flat at the apex of 11 and never lift again until 14. If you lift through the esses, you are doing it wrong. ESC/TC has not been an issue for those of us running 1:57-58 at thill over the top. A pro driver took my car out at laguna with ESC/TC on and mentioned that it was only minimal intervention even to him.


Matt is giving you good advice.
IMO, ESC/TC is only going to slow down a real pro, but even then it is only going to slow them down much less than a second. If you want to say that it's 'all you' driving, then I guess you can turn it off, but I'm not interested in wearing that type of badge if it means that something unforeseen happens and I end up balling up the car.

Manifold

A couple things to add:

- Not all 'pros' are equal

- Unless a pro knows this particular car fairly well, even they might not be able to distinguish between ESC/TC intervention versus effects of the RWS, torque vectoring, and e-diff, if their goal is lap time rather than drifting or general hooliganism

I've run my GT3 at length on a wet skidpad with ESC/TC both on and off, and was unable to discern any intervention of the ESC/TC until the car was at rather high yaw angles/rates. The same doesn't necessarily apply on a dry track at higher speeds, but the skidpad does provide some indication that the ESC/TC have been calibrated to provide a safety net without interfering during normal track driving.

Based on everything I've heard and read, I've chosen to leave ESC/TC on, and I haven't discerned it kicking in on track except when I was about to lose it (deliberately overdriving in safe locations to explore the car's limits, expecting ESC/TC to kick in). At some point, I may try a few laps running with it off, but I don't see the point of routinely running without a safety net if it's not normally interfering.

By contrast, in the Cayman R and 997 S, I did run with PSM off because the cars felt 'freer' when I did that. So IMO this decision really depends on the car, in addition to the car control ability of the driver.