Attachment 1344394
BBi Autosport Porsche 991 GT3 StreetCup Weekend Track Car Build
With NEW Billet Aluminum Control Arms

Greetings Rennlisters,
To end a busy and exciting year, we would like to present this beautiful 991 GT3 project that we are building here at BBi Autosport. To make her spirited driving and track duties, we installed our complete BBi Street Cup Suspension & Exhaust Package for improved chassis response and weight reduction behind the rear axle. Here are some detailed pictures of the build process and upgraded parts that we would like to share below.


(Click on images for higher resolution)


Vehicle Specifications

Engine

• BBi 991 GT3 Street Cup Exhaust Bypass

Suspension

• NEW BBi Porsche 991 GT3 Street Cup Billet Aluminum Monoball Control Arm Package
• BBi Porsche 991 GT3 Street Cup Spring Upgrade Package
• Tarrett Front and Rear Adjustable Sway Bar End Links
• BBi StreetCup Competition Corner Balance & Alignment

To properly install harnesses and increase protection, we installed our BBi 991 GT3 Street Cup Roll Bar. It features a 2 piece design and 4130 chrome moly steel tubing (1.625" x 0.095) for excellent strength to weight ratio. With our sensible design approach, the 2 piece design mounts to frame structure, utilizing factory bolts, to provide strongest mounting points and maximum protection. For superior strength and rigidity, the bar utilizes "X" braces on both front and rear sections and each joint has been meticulously TIG welded by hand. Bolt-in installation is accomplished by using Inner Diameter Tube Clamps that are CNC turned and milled for a precise fit. These unique joints allow us to eliminate the more traditional slip fit tubes with an unsightly through-bolt and nut.











BBi Autosport Porsche 991 GT3 StreetCup II Bolt-In Roll Bar





Features

• 1.625" x 0.095" 4130 chrome moly steel tubing utilized for excellent strength to weight ratio
• TIG welded and utilizes "X" braces on front and rear sections for superior strength and rigidity
• Mounts to frame structure (utilizing factory bolts) to provide strongest mounting points and maximum protection
• Utilizes laser cut mounting plates & inner diameter tube clamps that are CNC turned and milled for a precise fit
• Designed to work with stock seats or any aftermarket seats on the market
• Allows full seat travel to accommodate taller drivers
• Can be used with stock seatbelts or 6 point harnesses for track use
• Designed to work with wrap-around style harnesses while optional eyelet bolt provisions are available for clip-in harnesses
• OEM fit & finish. The main hoop contours entire arch of the roof with an even 3/16 inch gap
• Finished in satin black powder coat. Other colors available Bolt-in installation requires no drilling and minimal carpet trimming
• Made in USA

Beauty Shots of the Welds

 

Very nice

 

Next, we outfitted this car with our complete BBi 991 GT3 Street Cup Suspension Package to improves the handling response by upgrading the factory springs with an improved linear rate springs and replacing the factory arms and links with our billet alumimum monball arms. The upgraded spring kit stabilizes the front end with stiffer linear-rate springs that are matched appropriately for the OE dampers to maintain comfort and the adjustable swaybar endlinks helps eliminate swaybar preload during chassis set-up.



BBi 991 GT3 Street Cup Suspension Package



BBi Billet Rear Control Arms


Adjustable Sway Bar Endlinks


Spring Package Matched Specifically to the OEM Dampers


Installed on OEM Dampers






Detailed shot of Top Mount


Detailed shot of Bottom Mount & Helper Springs


BBi 991 GT3 StreetCup Adjustable Thrust Arms


• Connects the Lower Control Arm to the subframe
• Provides precision caster adjustability
• Spacers included for setting stock or anti-squat and anti-dive configurations
• Eliminates factory rubber bushings for improved suspension feedbacks

BBi 991 GT3 StreetCup Adjustable Thrust Arm Bushings


• Provides two eccentric mounting points
• Used to adjust for increasing or decreasing wheelbase, and adjustable caster.
• A must-have for extended lower control arms (GT3 control arms or eccentric monoballs) to correct for unintended caster change
• Eliminates factory rubber bushings for improved suspension feedback

Rear Suspension



Spring Kit & Rear Billet Aluminum Upper Wishbone & Trailing Arms











Rear Billet Aluminum Trailing Arm & Tarrett Adjustable Sway Bar Endlinks







Rear Lower Control Arm Spherical Bearing Flange


Front Suspension





BBi Adjustable Thrust Arms, Adjustable Thrust Arm Bushings, Front Lower Control Arm Spherical Bearing Flange, Tarrett Adjustable Sway Bar Endlinks





Tarrett Adjustable Sway Bar Endlink



BBi Adjustable Thrust Arm Bushing



Front Lower Control Arm Spherical Bearing Flange



Litronic Sensor & Camber Shims

 

Gorgeous! I definitely want to get a set.

 

Can you specify the improvements offered by the suspension components?

Please break it down by what added benefit each component provides.

 

Thanks Porscheflat6. Let us know when! =)

BBi Billet Rear Control Arms - Eliminates the rubber bushings for improved response
BBi Adjustable Sway Bar Endlinks - In addition to the benefits above, it allows the car to be properly corner balanced by eliminating the preload
BBi Spring Kit - This kit improves the handling of the vehicle by using stiffer linear rate springs

BBi 991 GT3 StreetCup Exhaust Bypass

The next modification we did was upgrading the exhaust system to enhance the exhaust note and reduce weight behind the rear axle. The primary mufflers are weigh approximately 44 pounds total while our bypass pipes are 4 pounds in comparison. The result is a substantial reduction in weight behind the rear axle which significantly improves handling and less restriction to produce a much more aggressive exhaust note.



Key Features

• Delivers deep aggressive exhaust sound
• Significant weight reduction of 40 pounds
• 304 stainless steel aerospace tubing
• Meticulously TIG welded
• Brushed stainless finish
• Stainless hardware and clamps
• 100% emissions legal
• Will not void warranty
• Factory secondary mufflers and catalytic converters are all retained
• 50 state emission compliant
• Direct bolt on replacement
• Compatible with 991 GT3 and 991 GT3RS models
• Made in USA

BBi 991 GT3 StreetCup Exhaust Bypass Installed








OEM Side Mufflers vs BBi 991 GT3 StreetCup Exhaust bypass


40lb Weight Savings. 44lb vs 4lb


- Jerry@BBiAutosport.com

 

 

How much drone with your exhaust bypass and at what rpms?

 

Good question.Drone is very subjective.Drone is a audible sound frequency that undesired. Unless it is a silent luxury car, all high performance cars have a certain produces an exhaust sound, including stock cars. Whether it is desirable or not will vary from person to person. Here are some reviews of our BBi 991 GT3 exhaust system.

"Just drove the car home from your shop and must say that it exceeds my expectations. The exhaust sounds just right and this basic mod remedied one of the only deficiencies (to me at least) of the 991 GT3- the very muted and muffled exhaust sound. I was concerned that it may be too loud for street driving or that there would be excessive drone, but didn't find that to be the case.Thanks for a job well done!"

Link to Review: https://rennlist.com/forums/991-gt3-...l#post12675198

"I debated a side muffler bypass but hesitated especially that my mechanic told me the car will be too loud and neighbors will hate me. I thought about Cargraphic's option because it maintains the ability to turn sport exhaust on and off but they are overseas and the product was too pricey. Someone raved about their bbi side muffler bypass so I decided to take the plunge and ordered it. Once it was completed, and before the first engine start, my mechanic said "OK, put your ear plugs on". Surprise!! The car was not any louder at idle (I had to put the stock center muffler/resonator back on). As a matter of fact, one can argue it is as loud as or possibly a hair quitter than the SW with side mufflers. For those who don't know, I had my vacuum lines plugged so the PSE was on from idle on with the stock sides. What has changed is two things. One, the tone. The exhaust now sounds more Cup like at idle with a significantly lower/deeper tone, possibly because it uses one channel versus two to feed the resonator. Two, loudness at upper RPMs. Definitely louder and way better. Driving in my neighborhood at low RPM? You can't tell it is louder, seriously. I personally couldn't appreciate any drone. Considering the weight savings, the sound improvement, usability in DD and around cranky neighbors, this simple piece, which is very inexpensive is a fantastic upgrade. I'm definitely going with it in the RS as well.Because the increase in loudness was not obnoxious, and because I want LOUD, I took the car back and had them put the Cargraphic headers back on (with spacers for the O2 centers hoping to abort CEL) and the car now sounds truly epic Wow!! Sound clips later, going to COTA in 10 days"

Link to Review: https://rennlist.com/forums/991-gt3-...l#post12262419

 

Nice work bbi!
Parts look top rate for sure.
I cannot imagine "track day guys" even come close to GT3 potential but moddin" is a disease!

 

I'll come back to you for the suspension goodies as soon as I can take advantage of them.

 

Very nice, all mods I see in my future. Keep up the good work guys.

 

Thank you everyone for the support!

For the last phase of this project, we dialed this car with our competition corner balance and alignment set up.







And last but not least, here are some beauty shots of the BBS FI-R Wheels. Showing off the relief holes machined into the "Y" shaped spokes here, we chose these wheels for minimum mass & maximum stability. They are definitely the one of the most advanced and sexiest wheels on the market.







- Jerry@BBiAutosport.com

 

Why not CR-9 wheels?

 

Beautiful, can you post pics of the car when it is totally finished? Looks like an amazing GT3 Project