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Over the weekend I attended the last track event of the year for PCA Potomac Region, and for myself. Here's the report from this event with pics and videos.
On the road before dawn to squat a good parking spot in the paddock.
Parked, unloaded and getting the engine warmed up.
I made two changes for this event. Both changes turned out to very positive. The changes were:
1) Added a little bit more rear camber. This allowed for getting to full throttle more rapidly once max steering angle is achieved at apex. It was a noticeable change to improve corner exit grip/launch. I like!
On a side note, someone mentioned that I should be running even more camber for Pirelli DH slicks. But I think this amount of camber is good for this car with the DSC Sport active suspension system because the spring rates are relatively soft(at 670/1000 in-lb) and since this is an active system that allows the chassis to have initial roll to bite, and then stiffen up to the g-force, the initial roll "camber gain" puts the dynamic camber angle pretty much equal to the static camber angle that's ideal for a stiffer passive suspension. Anyway, I am very happy with it.
2) I adjusted the DSC calibration for Braking. In hindsight, I should have done this immediately after installing the PFC Cup Challenge Brake Kit back in July. Because the 380/380mm PFC Cup Challenge Brake Kit is so incredibly effective I find myself over slowing the car and had to adjust my braking to go deeper with less effort, another words "compress the brake zone". Basically this is a 991 Cup car brake kit. The chassis needs more support to take full advantage of these amazing brakes. So added 20% more rear peak rebound damping force from 45 and 50-bar of brake inline pressure, also started 10% higher at 5-bar to bring up the damping curve only during braking events.This was a huge change. I f-ing LOVED it!
My goal this year was to get in to the 1:17's at my home track, Summit Point. Unfortunately I didn't achieve this goal during this last event with over 40 cars in the Instructors run group of varying capabilities(vintage 911, spec Boxsters, various stock and modded street cars, Cup cars, etc.) on a 2.0-mile circuit. I am disappointed at my self for not being able to pull myself together to do a flyer lap after working through traffic. The silver lining is it was fun, I validated the changes to be positive at different sections of the track, and according to the logged data, I coulda done a 1:17.6 lap had I put a good lap together.
Here's my "best" two laps from this event. In the beginning I was "trying" to hang a pair of 997.2 Cup cars. My driving was lack luster in these laps, they were the best timed laps from being in a traffic-free bubble. The car was great. I just didn't pull myself together to put in my best to take advantage of these two clean laps. Shoulda gotten fresher tires for this, LOL. Bad on me for cheaping out running 3 day old rubber but I also wanted to run the same set of tires from the previous event to validate the two changes made without the benefit of fresher tire grip.
So even though I didn't run a 1:17 lap, I have many things to be grateful for this year. Another silver lining, my green group student made huge progress and he's ready for promotion to the next higher group. It was fun to ride with him and experienced the improvement. All in all, it was a good last event. 2020 track season is a wrap! And on that note, it saddens me to say, it is time for me to wrap up this build of the best car I have built in my career thus far. I have done everything I that I wanted to do to this car to make it my own interpretation of a 997 GT3 4.0 "Clubsport". This build has been an amazing journey with no regrets. I have prepared this car for sale.
Stickers off.
Passenger seat back in.
All cleaned up looking like a fresh Cup car...a streetable one.
Fantastic journey, we will miss your posts in this forum. Can't believe you're jumping into a 991, I guess it makes sense from a business development standpoint.
I have to say Tom, the first thing I looked for on the 997 GT2/GT3 Forum was any new posting on your 997 "new to me 07 GT3" build thread. It will take a bit for me not to look for it anymore. Thanks for the wonderful reading.
Thanks for all the information you have provided and all the questions you have answered. This was one of the best threads going. Best of luck with next project, let us know when you start.
After changing the rear brake hoses couple months ago my brakes have been working very well, for a .1 car with 350mm fronts. But of course, I can't just leave things well alone. So, 380mm front brakes is something that's been on my mind because who doesn't want 997GT3 Cup-size front brakes, right?? Plus they look badass filling up the wheels more. Basic function wise, do I need bigger front brakes? No, not really, as the front braking is limited by the tires not by the stock 350mm brakes. Besides the cool looking factor of the 380mm fronts, I have often felt there should be more modulation without losing braking torque on my car. I could easily just use lower torque rating brake pads for better modulation but not doing that. Also, with the 350 front/350 rear, there are times when I trail brake that I felt there's too much front braking bias and came close to spinning the car, such as at Watkins Glen T6. DSC system has been helping to prevent spinning the car by managing weight transfer but I want to improve the braking bias. You are probably thinking why do you want bigger front brakes to reduce front bias? Normally I wouldn't, but the case of OEM 997.2 GT3 calipers for 380mm rotors the piston sizes works out that way. The .1 non-PCCB calipers(for 350mm rotors) have 28-32-38mm pistons. The .1 PCCB and .2 calipers(for 380mm rotors) have 28-30-32mm pistons. While the 380mm rotors is larger diameter, the calipers that fit the larger rotors have smaller pistons to reduce the amount of pressure on the pads. Here's my rationale- larger diameter to increase available braking torque, smaller caliper pistons for better modulation, and looks badass. Trifecta!
Now the idea is set, what about the parts? There are number of options available for converting 350mm to 380mm front brakes at different price points. OEM and aftermarket, all are good quality. With my budget and preference, I decided on using OEM adapters, OEM .2 calipers, and AP Racing rotors by Essex Parts.
I have done 380mm upgrades on 997 Turbo using the OEM PCCB adapters(part # 997 351 505 02, with has been superseded to parts # 997 351 505 04) This adapter was used for 997 Turbo/Turbo S to radially space out the caliper and to provide mounting for the wide bolt spacing. I think the superseded part # is for 991 Turbo/Turbo S. Not sure what the difference on the adapter but the old part # not available so it doesn't matter. As I said, I have done this conversion on 997 Turbos as a bolt-on so it should be a weekend afternoon project for a GT3.
Here's my pile of parts.
I'm a big fan of the AP Racing J-Hook rotors by Essex. They are two-piece floating design with spring clips to prevent low speed knocking. I have using the same brand rotors in 350mm for a year and a half with excellent durability. Which is more the reason to go with the same brand for 380mm size.
Here's my 350mm AP Racing J-Hooks by Essex with 20 track days on them. Yes 20!
The new 380mm rotors weights 24.6 lbs. Obviously it weight more than the AP/Essex 350mm but the 380's are still lighter than the OEM 997.1 GT3 iron rotor which weight 27.xx lbs.
Here's the OEM adapter with OEM shallow head bolts.
Everything looks good so far. To be continued.
Hi Tom,
This is Henry from Hong Kong. I bought a 997.1 GT3 2 years ago and would like to upgrade the brakes from 350mm to 380mm at front. I have gone through your post of building perfect 997.1 GT3 journey and noticed that you have done the brake upgrade from 350 to 380mm by replacing the caliper to 997.2 GT3 which I am going to follow. One area would like to clarify, I saw the photo you attached with brake caliper, adapter, screws , as well as brake line (99735558292), is this brake line require in this upgrade?
How about the brake power compare between 350 vs 380? BTW, any website recommended to order these parts in lowest price?
This is Henry from Hong Kong. I bought a 997.1 GT3 2 years ago and would like to upgrade the brakes from 350mm to 380mm at front. I have gone through your post of building perfect 997.1 GT3 journey and noticed that you have done the brake upgrade from 350 to 380mm by replacing the caliper to 997.2 GT3 which I am going to follow. One area would like to clarify, I saw the photo you attached with brake caliper, adapter, screws , as well as brake line (99735558292), is this brake line require in this upgrade?
Yes, you need the brake lines because the 380mm front brakes put the calipers more outward from center so a longer brake line is needed to reach. Alternatively you can use one-piece motorsport style stainless steel braided banjo hose kit such as the brake hose kit shown below.
This one-piece hose design replaces the two separate OEM hoses. I have been using the one-piece hose on my car and have been very happy with it.
Originally Posted by Henry Chung
How about the brake power compare between 350 vs 380? BTW, any website recommended to order these parts in lowest price?
At first, I did the 380 front conversion only for the novelty of having 997 Cup car size brakes. After using the 380 front brakes on track I have wrote in this thread that it stopping modulation is improved, that is on track during 130mph+ braking zones. However, I changed to stiffer spring on the DSC Sport Tractive suspension around the same time so thinking about now as a whole picture, the modulation improvement was made possible by having a stiffer suspension to handle the braking load. Had I not changed to stiffer springs at that time the results may not have been the same. Regardless, I wanted 380 front brakes for the novelty and the looks, that was my original motive. The modulation improvement(from using the same set of pads) was a bonus.
As for lowest pricing, I respectfully prefer not to get into this topic, its really a matter of online searching and the right timing. No one wants to overpay for things, but personally, I prefer to buy car parts from businesses that contribute/support to this tight niche community.
Fantastic journey, we will miss your posts in this forum. Can't believe you're jumping into a 991, I guess it makes sense from a business development standpoint.
Originally Posted by idk_alex
Slow Clap Indeed, will miss seeing this thread update!
Originally Posted by GM.RS
End of an era. Slow-clap.
Originally Posted by lax01
Wow - can't believe you are selling - thanks for an entertaining thread since 2014!
Originally Posted by HarmonyJim
I have to say Tom, the first thing I looked for on the 997 GT2/GT3 Forum was any new posting on your 997 "new to me 07 GT3" build thread. It will take a bit for me not to look for it anymore. Thanks for the wonderful reading.
Originally Posted by wail junkie
It has been a great time following this build! Congrats and thanks for documenting it in such detail.
Originally Posted by TheSilverFox
Thanks for all the information you have provided and all the questions you have answered. This was one of the best threads going. Best of luck with next project, let us know when you start.
Thank you, guys! It has been a pleasure to have you guys follow this build thread. I will keep this thread open for tech questions and visit from time to time.
Last edited by Tom@TPC Racing; 10-30-2020 at 12:09 PM.
10-27-2020, 05:58 PM
The 2020 track season... its a wrap
