orthojoe

Finally a working video off the track app. It's nice when it works, but it only worked 2/5 tries that day....

edit: NM! it still doesn't work! video isnt sync'd!!!

orthojoe

Thanks for chiming in, Jeff. You guys really put together a nice system. Congrats!

JRitt@essex

Thank you very much Joe. BTW, do you ever sleep?

orthojoe

Lol, I actually try to get at least 7 hours. Just learned to be really efficient with my time over the years.

orthojoe

The no lift shift feature on the manual is a really nice feature. The speed of shift between pdk and manual is imperceptible to me. The only slight advantage with pdk is when the gearing is not ideal for an upcoming corner and the system can hold gear and shift up and then back down again quickly or mid corner vs having to short shift with a manual.

JRitt@essex

I hear you. Most of my vampiric physician friends have had the pedestrian sleep patterns trained out of them, so I totally get it. That said, I fully expect someone to post a picture of you standing next to your twin brother at some point in the not-so-distant future.

orthojoe

I'm still on totally stock alignment and sway bar settings. The tire wear looks about the same as when I ran -2.7/-2.4 on the .1. Maybe the rear outer edges of the tires look more beat up, but increasing the rear camber on the .1 never really helped much with that. It seems to be a cup2 issue. When I ran with trofeoR, Dunlop, and Re71r on the .1, I had inner wear from -2.4 in the rear.

I'm having problems with keeping on the power at corner exit. A problem since that is the advantage of a 911. The front end wants to lift and the car understeers at exit so I have to lift to keep the car on track. First step is to stiffen the rear bar. I'll try that at Sonoma at the end of the month and see what happens. After that, the tires will be done and I will try adding more camber without having to go caster pucks.

Nine1won

Nice lap Joe! Was that 1:36?

orthojoe

Thanks. Yes, 1:36. I'm hoping that once I fix the understeer issue I can do 1:35s. Hoping to touch a 1:34 before the RS arrives. Not being able to stay on the power is a problem. I might be forced to play with the alignment if sway bar settings don't fix it. I just want to do the minimal amount this time.

Mech33

JRitt@essex

Predicting pad and disc life is incredibly difficult because there are so many factors involved. Even if you hold the majority of variables constant when comparing two setups, it's still tough to attach a specific number to wear rates. Keep in mind that all of the brake components have a good deal of interaction with each other. If the disc runs cool, that bring down the pad temps, which brings down the piston temps, which brings down the fluid temps, which brings down the caliper body temps, which brings down the level of heat radiating to nearby ball joints. The aggregate effect is that you have less heat soak in the brake system.

If you just look at the iron discs in isolation, we're using a larger diameter disc in our BBK vs the AP discs that directly replace the OEM iron (394 vs. 380mm), though the radial depth of the BBK disc is smaller. Thickness is the same on both at 34mm. The number of vanes is also identical at 84 vanes. Both discs weigh within roughly a pound of each other. Without any other factors involved, I'd expect the disc in the BBK to run a bit cooler as the mass is spread out on a larger OD. We've seen this in some of our other brake kits in the past. A good example would be in our earliest Corvette brake systems (which we still offer). We have one kit with 325x32mm discs, and another with a 355x32mm disc. Both have 72 vanes, and both discs weigh roughly the same because the 325mm had really thick walls and a slightly narrower air gap. We have customers that have extensive experience with both systems, and they universally found that the 355mm system ran cooler and their pads and discs lasted a bit longer. In that case however, those discs were attached to two different calipers, so the results are a bit more muddied.

With the brake kit, you have some design features in the caliper that help with the overall evacuation of heat from the system. When compared to the stock caliper, the AP Racing caliper is going to assist with keeping the entire setup running cooler. Just as I described above with the discs, the calipers absorb and shed heat in similar fashion. All of the voids and gaps in the Radi-CAL calipers allow for greater airflow through and around the caliper (see pics below). If you look at an AP Radi-CAL from different angles, you can actually see right through it. Air flows right up against the piston walls, and even in between the pistons on the AP caliper, while the pistons in the OEM caliper don't have the same level of contact with cooling air. Air also flows behind the pad backing plate through the castellated vents in the AP Racing pistons, putting more surface area of the piston in direct contact with cooling air. That means you have cooling air circulating around the outside of the bores, and circulating inside the pistons. That impacts brake fluid temperatures, which impacts caliper body temperatures, which impacts wear rates. All of the concepts of radiation, convection, etc. apply to the calipers, just like they do to the discs.

We don't have the ability to precisely predict pad and disc wear rates on our BBK vs. our AP discs mated to the stock calipers, but I certainly don't expect anybody to be disappointed with the wear rates they'll see out of our complete brake kit. That's typically an area where people are thrilled with the performance of our system. Again to use our Corvette example...we have lots of C7 Z06's running our Radi-CAL system on both ends of the car. The OEM pad for the front of that car is far larger than the one in our brake kit, and has a radial depth even larger than the pad used on the front of the GT3 (65mm). The OEM iron Z06 discs are 370x34mm, and the carbon ceramics on that car are 394x36mm. The fronts in our system are 372x34mm. Our customers are seeing far superior pad and disc wear rates out of our complete brake system than they are on the OEM iron or ceramics. Most of them state that the system is paying for itself in consumable costs alone. Our system has efficiencies in all components that have a multiplicative impact on overall system temps, heat soak, and wear rates. You can see tons of comments sprinkled all over the corvette forum, including some in this wheel fitment thread: https://www.corvetteforum.com/forums...re-thread.html

BTW...I think the record I've seen thus far for wear rates on our OEM replacement discs is an approximated 70+ track days worth of use.
https://www.essexparts.com/news-blog...g-j-hook-discs

orthojoe

Only one way to find out. On the .1 the ds1.11 front pads lasted 6-7 days.

JRitt@essex

I believe I mentioned it in another post, but I'll repeat it here. If we didn't have to deal with packaging issues on the 991 GT3, I would have recommended a smaller front and rear disc mated to our AP Racing calipers. The 394mm disc we're using in our system is larger than is absolutely necessary from a thermal mass perspective. I'm reluctant to call it overkill, but that's what it really is. We went with that diameter because we needed to go bigger than the OEM 380mm diameter to leave room for our caliper adapter brackets. Frankly, I think our 355x32mm, 72 vane discs would get the job done on this chassis, and they only weigh about 17 lbs. assembled (vs. 21.5 lbs. for the 394's). We have loads of 500 WHP Vettes running on our 355mm front systems all day at Road Atlanta and the Glen with great results, and those cars are absolutely brutal on front brakes. The drivetrain layout of the 911 makes it a bit more balanced in terms of front and rear brake use and abuse. Here's another fun fact...the 355's also won the 2012 Daytona Prototype Championship on the front of the Action Express DP Corvettes: https://www.essexparts.com/news-blog...asons-20142016
Most of the pics in that article show the carbon-carbon discs, but prior to that switch they were running the gold ole' 355mm iron rings.

When dealing with brakes, efficiency trumps sheer size.

JRitt@essex

Good point! Even though the cars are a bit different, you'll get a decent approximation of comparative data when running on the same tracks.

Dr.Bill

I would hope he goes faster than that. He did a 1:33.29 in the 991.1 GT3RS and a 1:33.10 in the RS 4.0.
The new car (and tires) should be faster than either of those for sure.