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i tend to find the aggressive boost map to overshoot which could make transitions/exits more “exciting” but unnecessary. Curious what your thoughts are
I’ll be back at the home track Thursday. The Cobb tuner is in the glovebox and I’ll re-flash at lunch with video to compare. Re.:PDK aggressive tune—applying throttle out of turns the trans had these weird lags on shifts which I don’t get from my GT3. After talking to my shop it was suggested that it was caused by the traction control which I will turn off on Thursday and see if that does the trick.
For those that track with PCCBs... I've recall seeing the recommendation to replace the pads at about 50% to greatly reduce the chance of rotor damage and increase rotor life, but I can't find any spec on what the original pad thickness is. I know there was a thread discussing this somewhere but I can't find it!
I'm at about 6mm pad thickness now, wondering if it's time to swap pads?
I’ll be back at the home track Thursday. The Cobb tuner is in the glovebox and I’ll re-flash at lunch with video to compare. Re.:PDK aggressive tune—applying throttle out of turns the trans had these weird lags on shifts which I don’t get from my GT3. After talking to my shop it was suggested that it was caused by the traction control which I will turn off on Thursday and see if that does the trick.
that sounds more dangerous/backwards. I think the stock boost response Profile would be better. Stock the car doesn’t have weird gear shifts so why would turning off traction “help” unless the boost Onset is causing it behave non smoothly and kick it on?
For those that track with PCCBs... I've recall seeing the recommendation to replace the pads at about 50% to greatly reduce the chance of rotor damage and increase rotor life, but I can't find any spec on what the original pad thickness is. I know there was a thread discussing this somewhere but I can't find it!
I'm at about 6mm pad thickness now, wondering if it's time to swap pads?
I hit metal backing plate on the PCCB rotors when they measured 4mm on the top of the outside front pad, because the pads don't wear evenly inside/outside and top/bottom. I usually replaced them at 5mm until I went to Girodiscs. I think they are 12mm when new.
that sounds more dangerous/backwards. I think the stock boost response Profile would be better. Stock the car doesn’t have weird gear shifts so why would turning off traction “help” unless the boost Onset is causing it behave non smoothly and kick it on?
that was the problem and shutting off the PSM worked great with the stock boost response no more weird stutters in shifting adding throttle in corner out. It was a quiet club day so it was open track which got me a lot more laps. After the 1st 1/2 hr I came in and loaded the stage2 aggressive tune. Took a few easy laps and then pushed it a little which made things interesting. I did something I’ve never done which is spin on pavement coming out of a turn 720 to be exact. I end up on the grass, which was nice and brown given the dry summer and with windows down the inside of my car looked like I went through a hay bail. No harm no foul I guess. Took it down a notch but still felt squirrelly on the straight PSM back on and worked up to more aggressive driving and it felt good but after the 2X360s I’m pretty sure I wasn’t driving as hard as I normally would. I reviewed the Lap data and I was about .75 seconds faster with aggressive tune PSM on thanksgiving anything else I’ve tried. 4th day on OEM size cup2s they are getting a bit tired. Next set will be 265/325 which I think new and wider will tick things up a notch. I was hoping to post a video of my spins but I didn’t set Harry’s up correctly and only got data. There will be no repeat.
I hit metal backing plate on the PCCB rotors when they measured 4mm on the top of the outside front pad, because the pads don't wear evenly inside/outside and top/bottom. I usually replaced them at 5mm until I went to Girodiscs. I think they are 12mm when new.
Thanks for the feedback... I re-measured my pads more carefully today, fronts look to be ~8mm inside and out, rears ~9mm. Looks like I'm good for a while!
that was the problem and shutting off the PSM worked great with the stock boost response no more weird stutters in shifting adding throttle in corner out. It was a quiet club day so it was open track which got me a lot more laps. After the 1st 1/2 hr I came in and loaded the stage2 aggressive tune. Took a few easy laps and then pushed it a little which made things interesting. I did something I’ve never done which is spin on pavement coming out of a turn 720 to be exact. I end up on the grass, which was nice and brown given the dry summer and with windows down the inside of my car looked like I went through a hay bail. No harm no foul I guess. Took it down a notch but still felt squirrelly on the straight PSM back on and worked up to more aggressive driving and it felt good but after the 2X360s I’m pretty sure I wasn’t driving as hard as I normally would. I reviewed the Lap data and I was about .75 seconds faster with aggressive tune PSM on thanksgiving anything else I’ve tried. 4th day on OEM size cup2s they are getting a bit tired. Next set will be 265/325 which I think new and wider will tick things up a notch. I was hoping to post a video of my spins but I didn’t set Harry’s up correctly and only got data. There will be no repeat.
the stock tunes are great for street driving and drag racing but not really targeted towards track use. Torque ramps up too fast and then falls off and HP does similar curve. What you really want is a much more linear curve similar to a natural aspirated car. See one example below as you can see torque ramps up slower and it doesn’t taper off until 4K RPM and it’s peak is actually 6.8k RPM. The goal was too keep the torque around 600 but let the HP continue to rise all of the way to 7k on a very linear manner. If you look at the stock Cobb it’s actually the opposite. By 2.9k RPM the torque is almost at 90% of its peak. Peaking at 3.4 and then diving down. The opposite that you want on track. HP too, climbs really fast then slows down after 3.4k rpm
Sam at By Design or Mike at TPC can help you give you a tune that will have a better map for your track needs.
i don’t know if you got this to work but I made airbag simulator plugs and such in the past. I can give you the usual formula and you can likely make up an airbag substitute
Please PM me the details! I've not got them to work yet. The car is at the dealer right now to have the heat shield installed and my friend who is the tech will be doing some minor maintenance items while he's got the car. I was unable to code the seats in with my PIWIS II but he's going to try with the III to see if he can do anything. I'm told that 997 buckets in a 991 simply won't work so please share how you did it!
Originally Posted by Pdtp#16
the stock tunes are great for street driving and drag racing but not really targeted towards track use. Torque ramps up too fast and then falls off and HP does similar curve. What you really want is a much more linear curve similar to a natural aspirated car. See one example below as you can see torque ramps up slower and it doesn’t taper off until 4K RPM and it’s peak is actually 6.8k RPM. The goal was too keep the torque around 600 but let the HP continue to rise all of the way to 7k on a very linear manner. If you look at the stock Cobb it’s actually the opposite. By 2.9k RPM the torque is almost at 90% of its peak. Peaking at 3.4 and then diving down. The opposite that you want on track. HP too, climbs really fast then slows down after 3.4k rpm
Sam at By Design or Mike at TPC can help you give you a tune that will have a better map for your track needs.
On the PDK you might want to run the PDK relearn.
Great advice here - I had Mike @TPC provide a custom tune for me which scaled back the peak HP but moved the peak torque higher up. The power was more tractable which really helped me get on the throttle earlier without unsettling the car.
the stock tunes are great for street driving and drag racing but not really targeted towards track use. Torque ramps up too fast and then falls off and HP does similar curve. What you really want is a much more linear curve similar to a natural aspirated car. See one example below as you can see torque ramps up slower and it doesn’t taper off until 4K RPM and it’s peak is actually 6.8k RPM. The goal was too keep the torque around 600 but let the HP continue to rise all of the way to 7k on a very linear manner. If you look at the stock Cobb it’s actually the opposite. By 2.9k RPM the torque is almost at 90% of its peak. Peaking at 3.4 and then diving down. The opposite that you want on track. HP too, climbs really fast then slows down after 3.4k rpm
Sam at By Design or Mike at TPC can help you give you a tune that will have a better map for your track needs.
On the PDK you might want to run the PDK relearn.
thanks that is really helpful. There is always next week at least for another month +
Guys, a little off topic, I drive a 991.1 Turbo S and track this car regularly.
Recently I have noticed a clicking sound which comes only during turning the car. maximum noise on full lock. the sound starts at half lock onwards.
has anyone had a similar problem ?
would be really great if anyone can help, I am not able to understand where to start looking for this problem.
Guys, a little off topic, I drive a 991.1 Turbo S and track this car regularly.
Recently I have noticed a clicking sound which comes only during turning the car. maximum noise on full lock. the sound starts at half lock onwards.
has anyone had a similar problem ?
would be really great if anyone can help, I am not able to understand where to start looking for this problem.
Welcome. I changed the whole 2 axles/driveshafts 991.349.038.03 You should look into what caused it, probably axle spacers will avoid this in the future. I had my track width maximized with the Cup control arms, and run slicks, so the axles separated from the mount which caused them to fail. Spacers can be found at Tarrett or other vendors. The whole thing is not cheap!
Random question fellas,
My car's getting the heat shield retrofit done right now and I also had the P-tech do the plugs and coils at the same time while he had the car apart. Out of curiosity, I am having them do a quick compression test while the plugs were out but I can't for the life of me find what the correct specs are? Google is finding compression ratio's instead of cylinder compression. What are the ranges?
Random question fellas,
My car's getting the heat shield retrofit done right now and I also had the P-tech do the plugs and coils at the same time while he had the car apart. Out of curiosity, I am having them do a quick compression test while the plugs were out but I can't for the life of me find what the correct specs are? Google is finding compression ratio's instead of cylinder compression. What are the ranges?
I think it should be around 145 psi, or another way to look at it is any cylinder being off from the others, would mean potential problem. A leak down test imo is more important than a compression test
09-15-2020, 07:29 AM
