konrad h1

I wanted to share my experience with certain modifications and other hardware I use both on the street and on the track. I have owned several Porsches, my son and I are HPDE Instructors for several organizations and we target 5-10 HPDE events a year. We are mindful of our track budget and approach modifications from a value to performance impact. We do our own work on our cars as much as possible be cause we love to do this an get to spend quality time together.

THE CAR: 2014 GT3 with 49K miles, G6 Engine (put in at 18K miles), 18 way seats, FAL (full factory options specs at https://vinanalytics.com/car/WP0AC2A94ES183385/) I bought the car with 40K miles earlier this year.

To date I have experimented with the following areas: Exhaust, Brakes, Suspension, Tires, Track focused maintenance.

EXHAUST (Valved muffler delete): The car came to me with the side mufflers removed and the soul valved bypass installed. I did track down the prior owner and picked up the original side mufflers. With the factory center exhaust still in place, this modification gives you a very nice tone that is not too loud at idle or startup but gives a beautiful tone at full throttle. In hindsight I should not have bought the side mufflers as I don't think I will ever use them. I do think the stock exhaust is heavy and slightly restricting. This configuration does meet the noise regs of some picky tracks like AMP. The soul valved side muffler delete retains more than half its value on the used market. When this car is sold I will likely remove this system and sell it for about a grand. New the system is $2K. My incremental cost was $0 in this case. I like this modification but don't "$2K" like it. Good value if you can pick it up between $750 and $1K mostly for the weight and restriction reduction, or if you can justify buying it for $2K with a residual value of $1K. At the limit could this help my lap times: Yes.

EXHAUST (Center muffler delete): I drove the car with the valved side muffler delete for a bit. This configuration is a very nice and most people that have a dual use of the car and don't want to scare the neighbors. I picked up a used Fabspeed center muffler delete for $300 locally. It had been repaired, as a couple of welds had cracked (apparently a common issue). Repair was not bad and not visible when installed. Removing the center muffler I damaged a couple of studs that I had to repair - no big deal. Both mods installed the startup is loud. Cabin noise goes up a little bit but outside the noise increases significantly. I personally like it. Seat of the pants acceleration improvement. Beautiful full throttle tone. Not sure if it will pass AMP noise limits. Will report back on that. Original part was $1800, so residual value less than 25% for this mod. Totally worth it for $300 but not for everyone. At the limit could this help my lap times: Maybe.

BRAKES: When I bought the car, the prior owner had just put in new OEM rotors, pads and sensors He spent about $4K on this with labor. I flushed the lines with castor SRF. I put 4 track events on this setup (AMP, CMP, RA and VIR). Recently I picked up a full set of AP Racing calipers, J hook AP Racing rotors, stainless steel brake lines, and Ferodo DSC3.12 pads for under $5K - I figured low risk test as this setup used can fetch $7-$9K ($13K+ new). I tested them last weekend at CMP with PCA. There were at least 5 other GT cars with this or similar AP setup (did not realize how popular this expensive upgrade was). This change was made at the same time I installed the DSC suspension controller so it will be difficult to separate the improvement. Braking was better, more consistent and any side-to-side wiggle under max breaking after a few laps on the OEM setup was a gone. Consistent braking performance lap after lap for up to 30 minute sessions. Big improvement. It is anticipated that ongoing costs will be lower as well (with ring replacements). I feel lucky I got this at the price so this is a keeper for me. The only question is if I should retain the OEM setup to reinstall upon car sale or sell it now for $2-$3k. Overall a massive improvement but at a high cost. $13K retail with generally a $8K-$9K residual. On the pads, changing them with the AP Racing calipers is much easier (even compared to the stock calipers) so I may swap them to less aggressive (and less dusty, less expensive) pads. At the limit could this help my lap times: Yes.​​​​​​​

SUSPENSION CONTROLLER: The DSC V3 controller and latest software is the most valuable upgrade of the bunch for those of us that drive both on the track and on the street. at $1400 and given the timeline of hardware and software changes it makes sense to buy this new and from the manufacturer. Residuals are currently over $1K even for older models. CMP has a high speed "kink" that tests both the suspension and your guts. With the DXC V3 controller it is nearly a non-event. Brake diving is significantly reduced and so is body roll. Brake-to-turn transitions are much improved and smoother. Incredibly, Street performance and smoothness is ALSO improved. Overall an excellent upgrade, my favorite of the pack. At the limit could this help my lap times: Certainly Yes.

TIRES: I have been using the Nankang CR-S V1. Rated as a 200 wear tire it is great if you get the right tire pressure. Unfortunately they fall off quickly above 31 PSI hot. You have to get the pressure right and be smooth for these tires to perform for the entire 30 minute session. They are very decent in the rain which makes them a great choice for those of us who don't want to change tires with changing weather conditions. I bought the set for under $1500 delivered, but it will be difficult to get this pricing moving forward. I understand the V2 tires are much improved. I use a different set of wheels and tires (and enter nuts) for the street. Great value for dedicated track tires that can work well in the rain. I strongly recommend a different set for the street. At the limit could this help my lap times: Yes.

TRACK FOCUS MAINTENANCE: When I bought the car I put new plugs and did some fluid changes. Of course oil and filter (Liquid Moly 5w40 in a green container). I did a "drain and refill" on the pentosin clutch fluid (3 quarts) and I plan to do this on every oil change at between 2K and 2.5K miles of combined road/track. The wet clutch fluid change I believe is a nice preventive fluid change that is simple (no PIWIS needed) and will keep all additives relatively fresh on a PDK that gets used to its potential. I also changed the final drive (transmission) fluid (3 quarts). I will do this fluid change annually. Coolant was changed before I bought the car so I will review this annually. I will likely replace plugs annually as well. I did disassemble, clean and relive of all the spindles and wheel lock mechanisms (including the center lock nut). I highly recommend this especially on cars driven in the rain. Of course Castrol SRF flush initially and 4 corner bleed before every track event. At the limit could this help my lap times: Maybe, but it will allow me to have more track time :-)

Next areas to explore: Seats, roll bar and restraints. Certainly looking at this before I consider full slicks. Hope this helps and let me know if you guys have any questions.

K

In street config

Installing AP system

At the Track with my son

74goldtarga

I would consider staying with the Ferodo DS 3.12 pad - it is a great track pad that works perfectly fine on the street even when cold. I would like to have the AP racing brake setup but am satisfied with the stock calipers with the girodisc studs and girodisc brake discs which is a less-expensive "intermediate upgrade".

ParadiseGT3

Great writeup. Similarly positive running CR-S.

Seats & harnesses will really improve the experience.

Have fun with your son.

Skid

Great post, thanks. Am in a similar place (higher miles ‘15 with a G6), ~10 track days/yr, fast end of advanced groups. I have been running AR-1’s on one set of rims and Cup2’s on the other for getting to/from distant tracks and for wet tracks. After 2 sets of AR-1’s am finding they are pretty greasy and gone after just 15-17 sessions (20-25 mins ea.) and am thinking to try CR-S next hoping the increase in longevity outweighs the drop in grip.

Run Ferodo 3.12’s and they are great on both track and street. This after running Endless Blues (which got too soft on the track) as well as PAgid yellows (which squealed a lot on the street). Running Giro rotors now, OEM drilled rotors just crack quickly and broadly. Stock calipers seem ok so far.

I need to stay with the stock exhaust as even then I am triggering db limits at one local track. At that track I may have to use baling wire on the the vaccum cans on the side mufflers to prevent the valves from opening all the way. Short-shifting or lifting is so hard for me to do! I love how hard the G6 pulls. But it also seems to have more top end db than the various other GTx cars at the track (this coming from the guy running the db measuring gear).

I’m most interested in your experience with the DSC. I was thinking to go to stiffer front springs + a DSC. How did you settle on a program for it?

I hope you keep us posted on future seat, harness and roll bar considerations. That’s on my list as well.
Thanks again.

konrad h1

Skid a couple of comments on your post:
1. On the noise level: My son removed all mufflers and was triggering noise limits at a couple of tracks. We tried several (interference) solutions but they all came with performance tradeoffs. This last time on track I had a local muffler shop create a set of "turn down" tips for his car. They reduced his noise by 5dB which is a lot (considerably less than half the noise). The only drawback? I think they look silly and you have to be careful unloading from the trailer.

I believe there are several outfits that make turn down tips for our cars specifically for this reason. I may pick one of these up or fabricate an uglier version for my GT3 just in case.




On the DSC Controller, I spoke with Tom Chan @ DSC and described exactly what I had on the car and how I intended to use it. Let me tell you what Tom did for me and part of the reason why I think they are awesome: Currently DSC is waiting for part to manufacture their boxes. I explained the situation and my timing as I wanted to have the DSC for this track event. Without me asking Tom offered to send a (non-new) unit to me temporarily until they could swap it for a new unit when parts came in. Exceptional customer service, solving real customer issues. Tom is VERY familiar with our generation of cars and the tune was a massive improvement. I like to tweak things sometimes but on this one I am leaving it as received. Get in touch with them, you will not be disappointed. @Tom@TPC Racing is his handle and is generally accessible even in this forum. Disclaimer: I have no financial relationship nor benefit from any of these comments. Just a guy sharing experiences with fellow enthusiasts.

MikeKuhnRacing

Those Soul turn down tips are good for about 3-4db decrease measured at 50 ft. We use them when we blow the 100db sound limit at events.

turtl631

Great thread. I have a 2015 with original engine still, 39k miles, LWB/ PCCB. It came with a Sharkwerks rear muffler delete, otherwise stock. Planning to track it a few times this fall as is and then likely switch to aftermarket steel brake kit and 19-in wheels for track next year (have 19" Apex wheels and Nankang CR-S but they're sitting since I got a good deal on a PCCB car). I am definitely a tinkerer and plan to do quite a few mods over time. Want the car reliable, engaging and fast. I would love to keep the noise reasonable and dump the big heavy hot side mufflers. Will have to look into options there.

I did a CMS roll bar with TPC seat recline brackets, CMS sub belt mounts, and Sabelt GT3 specific 6 pt harnesses in both sides. I am quite happy with how this all worked out. Driver/ machine interface feels perfect.

If anyone is thinking about selling an AP or PFC brake kit, I am interested!

JRitt@essex

It's awesome that you get to enjoy this wonderful hobby with your son. I'm sure neither one of you will ever forget the time you share at the track! I'm glad you were able to score a deal on our AP by Essex brake system and that you're enjoying their performance and convenience so much. They will save you a bundle on spares for as long as you own the car, and you'll be able to make nice money on them when you sell the car. You'll also save a boatload of time by not having to fiddler around with pad changes, disc swaps, and fluid bleeding. They are so popular because once people try them, they're a must-have on all their track cars. Have fun with your son and stay safe out there!

konrad h1

I was surprised how many folks at the PCA track event with amazing cars (GT3, GT3RS, GT4 GT4RS, Clubsports and all sorts of 911s and caymans) were sporting AP racing calipers and/or J hook rotors! Seriously over a dozen cars that I saw with this and they were all fast in their own groups. No question this is a mod favored by the learned....