TPC Racing

Here at TPC Racing we currently race eight 991 GT3 Cup cars. While they are amazing race cars right from the factory, we haven't forgotten our company's root of converting high performance street cars to race. This thread is a stellar example of a street car-to-race build. The subject is a 991.1 GT3 with 29K miles that has pretty much dedicated its young life to track. Besides having bolt-in safety equipment and brake pads, the car is stock. The intent of this build is to elevate the handling performance and safety level to that of a competition car, yet can be driven to compete in One Lap of America, Ultimate Street Car Challenge, PCA, NASA, and even AER 9-hour races! At the request of the car owner we are keeping the engine completely stock so regardless of what part of the country the car will be at, parts and services will be very accessible. Here are pics from this build. I'll let the pics speak the words.

Day one of the build. We stripped the interior and removed the front and rear glass.


Cage time. We mimic the cage design of a 991.2 Cup.






A trip to our paint shop at back. Painted to the car owner's choice of color.






Next is air jacks for quick wheel/tire changes during AER pit stops.






Our air jack cylinder support bar adds additional rigidity to the front tub of the car.


Front air jack installed.


Here's what the bottom of the front air jack looks like.


One of the rear air jacks. Flush to the floor.


The bottom of the rear jack. It is tight clearance but it clears the black suspension support brace.


Since we have quick tire changes with air jacks, we now need quick fueling.




More pics to come.

Rick GT3

Tom/TPC Racing

WoW, nice to know you're actually on 991 GT3 cars!
Remember when you were building your 997 GT3, at that time I used to own a 997.2 GT3 and all the info that you posted did help many rennlist members.
keep us posted on the project.
Thanks

zmon

this is awesome! excited to see it in AER!

Tom@TPC Racing

Thanks! I still have the 997 GT3 and still loving it. But the 991 GT3 is really something else!! Definitely more pics and stories to come!

Tom@TPC Racing

This build actually took place over the past 3 weeks. We were burning the candles at out ends to complete the build! This car has been running all this week at Sebring. Anyone at Sebring are welcome to the TPC camp to check it out! Back to the build thread...

JaxEddie

Awesome. What do you estimate the new weight of the car will be?

Tom@TPC Racing

Right at 3K lb. Nominal weight for a showroom stock 991 race car. We took out the carpeting, then welded in the cage(which is a lot of 1.75" steel tubing). The car owner wanted to keep the AC and sound system for highway driving. Also kept power windows and full stock exhaust.

TPC Racing

Since this car came from the factory wired for PASM electronic suspension we are taking advantage of this platform but upgrading the controller and dampers to the best available. Out went the OEM PASM in goes the DSC Sport V3 controller and DSC Sport Tractive RT coilovers with 560/896 in-lb springs.

We removed the OEM PASM dampers. The OEM PASM dampers are actually pretty good. They are limited by damping range and spring rate for advanced level track use and for competition.



DSC Sport Tractive RT electronic dampers(coilovers). Featuring 43mm inverted front mono-tube design to resist flex and stiction during extreme lateral loading, patented DDA electronic Spool Valve with reaction time to command 17x faster than OEM, and 100% impervious to piston head pressure to react to command during mid-stroke. Truly an engineering marvel.



We customize the spring rates to optimize each user's driving purpose.









All rubber bushings are replaced with monoballs using factory Porsche Motorsport GT3 Cup parts.









Some of the Cup car arms have wider metal bushing ends that won't fit on GT3 street car. The metal bushing ends aren't designed to be separated so we didn't take them out to machine them down on a lathe. Instead we used our CNC vertical mill to machine off exactly the same amount on each side to ensure symmetry.







DSC Sport V3 suspension controller installed in the OEM controller's location. The DSC Sport V3 controller is direct plug & play. We programmed it with Tractive damper calibration file.



Stay tuned for the brakes. Very exciting news on the brakes!

Jickel180

Looks like a PFC rotor. Are you running cup car hubs and brakes? Being able to fit the cup 18"s will be a huge plus for tire availability. There's a streetable 991 GT3 here in Austin running the cup upgrights,hubs,brakes, wheels as well.

Excited to see this build!

porscheflat6

Wow it looks great!

TPC Racing

TPC Racing has been working directly with PFC design engineers for 2 years to bring to market a bolt-on brake kit for Porsche 991 cars(including GT3/RS, Turbo/Turbo S, Carrera models). We refer this brake kit as our TPC Cup Challenge Kit. Basically the core design and technology from 991 Cup cars that PFC is very well-known for but without the fitment nuisance on a street car. This kit is perfectly balanced to OEM street car master cylinder and its direct bolt-on to OEM street car uprights, and even fits OEM wheels! Available in 405/380mm and 380/380mm(more ideal for car with 18" wheels). We are keeping the OEM GT3 street car uprights for this build to be eligible for showroom stock racing class and PCA prepared-street class. The caveat for using street car uprights is the rears aren't compatible with 18" wheels. Which is fine, because in recent years 19" track tires have become popular. We have tested prototype versions on our shop cars with great success. This here is the first production set of TPC Cup Challenge Kit by PFC, featuring updated titanium pistons developed for next gen race cars!







In addition to the piston update the seals are further improved.














This brake kit is balanced to the OEM brake master cylinder so no need to convert to dual-master cylinder and mess with bias. Fun fact, the "3.5" indication on the brake booster is the power assist ratio. The non-GT cars have a higher number to increase the power brake assist ratio. The downside of higher assist ratio is less modulation and feel.


PFC is doing the hard launch of this new brake kit at the PCA 48-hours @ Sebring event this weekend. Timing is perfect. We have three cars there been running all week flawlessly with this brake kit.

krell

Looks like PFC continues to use that horrible trim ring to secure the hub to the rotor. It's great when everything is new and clean but removing it from an old rotor and installing it on a new one is a PITA.

TPC Racing

The TPC Racing crew has been working around the clock to complete this build for its first outing at Sebring. The final items for this build are race-mandatory safety nets, GT4 Clubsport steering wheel with paddles, quick release steering wheel hub, AIM data dash and camera, floor board, kill switch, rain light, Cup car fender flares, aero, serviced the PDK, engine oil change, and etc.

















We literally completed the build and loaded the car in the trailer at 10:30pm on Saturday and drove from Maryland to Sebring, Florida.

krell

You said the owner intends to drive this on the road, but I don't believe that can legally be done with front cage elements. Isn't there some DOT statement that says such things aren't permissible because they don't want occupants hitting their heads against the steel tubing in an impact? Remember, this is the same DOT that made Porsche put those silly padded inserts in the carbon buckets because they didn't want someone bumping their skull into it.

RossP

That cage is legit. Nice work!