Orthojoe .2 GT3 Thread
#166
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!!!
edit: NM! it still doesn't work! video isnt sync'd!!!
Last edited by orthojoe; 05-11-2018 at 08:14 PM.
#168
Thank you very much Joe. BTW, do you ever sleep?
__________________
'09 Carrera 2S, '08 Boxster LE (orange), '91 Acura NSX, Tesla Model 3 Performance, Fiesta ST
Jeff Ritter
Mgr. High Performance Division, Essex Parts Services
Essex Designed AP Racing Radi-CAL Competition Brake Kits & 2-piece J Hook Discs
Ferodo Racing Brake Pads
Spiegler Stainless Steel Brake Lines
704-824-6030
jeff.ritter@essexparts.com
'09 Carrera 2S, '08 Boxster LE (orange), '91 Acura NSX, Tesla Model 3 Performance, Fiesta ST
Jeff Ritter
Mgr. High Performance Division, Essex Parts Services
Essex Designed AP Racing Radi-CAL Competition Brake Kits & 2-piece J Hook Discs
Ferodo Racing Brake Pads
Spiegler Stainless Steel Brake Lines
704-824-6030
jeff.ritter@essexparts.com
#169
Originally Posted by JRitt@essex
Thank you very much Joe. BTW, do you ever sleep?
#170
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.
#171
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.
#172
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.
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.
#174
Originally Posted by Nine1won
Nice lap Joe! Was that 1:36?
#175
Hopefully the above makes sense. The thing to always keep in mind is that you only want as much thermal mass as you need. You want the brake system to have enough heat capacity to provide fade-free performance. Anything further is just dead weight to drag around. I typically describe our usual scenario in professional racing. If a pro team wins a race and the brakes fall apart after crossing the finish line, they know that they sized the system perfectly for that race. It accomplished their objective without any unnecessary fat. In NASCAR for example, they have multiple brake setups with different caliper and disc sizes depending on the type of race (super speedway, road course, intermediate). They're always gambling and trying to run the absolute smallest brake package they can get away with, because they don't want any unnecessary unsprung mass to drag around if at all possible. In the aftermarket, we use the same concept, except we obviously recognize that our aftermarket customers don't have Budweiser or Home Depot writing them sponsorship checks for spares. As such, aftermarket systems are a built to be more robust. We want low mass to squeeze out tenths of a second, but we also want the components to last long enough to satisfy the customer. We're always looking to find that balance.
Can you commwnt roughly on what relative service life you expect to see for a stock size pad and AP rotor can the AP BBK for pads and rotors for the same use (based on theory of the material volumes etc.)?
Thanks!
#176
Thanks for the informative post, Jeff. So I assume that since there is less total rotor mass and less total pad mass with your AP BBK vs your AP rotor kit for stock calipers, the rotors and pads will wear faster for the same use and need more frequent replacement?
Can you commwnt roughly on what relative service life you expect to see for a stock size pad and AP rotor can the AP BBK for pads and rotors for the same use (based on theory of the material volumes etc.)?
Thanks!
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
#178
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.
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.
#179
#180