When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My car with 2 race seats, rear wheel drive, loose items removed, still running Tiptronic, 1/2 fuel, otherwise stock exhaust, A/C, radio, etc weighed 3339. It's astonishing that John got rid of nearly 600 pounds. It's going to be a rocket.
When the car was stripped down to the tub, CTS took out everything that was not necessary. You will notice the parking brake was removed which is normally deleted on all Motorsport tubs. Every bracket that is welded to the street car tubs to secure the interior was cut out including the heavy transverse crash brace that runs along the front edge of the rear "seat" are from one side of the car to the other. At each end of this bar is "crumple box" which was also removed. You can see this bar along with the crumple box in the 1st pic below I found online. The crash bar with the boxes was 30+ lbs. None of this is needed with a full weld in cage and this is deleted on all the Porsche Motorsport tubs also. After cutting out the crash bar, a thin piece of sheet metal was welded in place to cap the tunnel. Incidentally, the sheet metal used came from the solid steel roof panel which was replaced with a carbon roof. Talk about recycling! Every pound removed adds up in the end...
My car with 2 race seats, rear wheel drive, loose items removed, still running Tiptronic, 1/2 fuel, otherwise stock exhaust, A/C, radio, etc weighed 3339. It's astonishing that John got rid of nearly 600 pounds. It's going to be a rocket.
Makes sense as there's 150-175 lbs between removing the awd, 1/2 tank of fuel and the other race seat. If I did that to my car it'd weigh somewhere from 3250-3280...
wow and with the 4L stroker and 1000s, what's the power to the wheels? you are hypercar territory...
how does the car take the power?
It's not a stroker 4L. It's an overbore 4L using 106mm pistons (3.6 uses 100mm). Power is selectable in torque values. We have cockpit switchable maps from 300 to 750 ft.lbs of torque. That corresponds to 400whp to 1000whp. Power comes on nice and gradual like a normally aspirated engine so drivability should be excellent. Here is the default 600 ft.lb map at 1.1bar boost and 95 octane fuel.
It's not a stroker 4L. It's an overbore 4L using 106mm pistons (3.6 uses 100mm). Power is selectable in torque values. We have cockpit switchable maps from 300 to 750 ft.lbs of torque. That corresponds to 400whp to 1000whp. Power comes on nice and gradual like a normally aspirated engine so drivability should be excellent. Here is the default 600 ft.lb map at 1.1bar boost and 95 octane fuel.
If you had stroked it, would it have been a 4.2l or larger?
If you had stroked it, would it have been a 4.2l or larger?
The engine is technically a 4.05L with the 76mm crank. With an 81mm crank it would be a 4.3. If I'm not mistaken, you can't reliably turbocharge a stroked Mezger due to the increased rod angle.
Almost a 1/4" is a fair amount of additional stroke; I'm sure someone with good trig skills could figure it out, but yes, can see how that may no work well over the long run. Torque would be impressive though.
Here are a few pics of the wing mount arrangement and the clever brackets which secure the removable decklid. The wing uprights are hard mounted to the chassis on each side with 5 bolts for maximum rigidity (3 vertically into the existing bolt location the now deleted hinge was bolted and 2 horizontally into the sidewall of the tub via installed rivnuts). Since the wing stays with the car, the decklid is made quickly removable by unclipping the two rear safety pins and simply sliding the decklid from its two front captive CNC brackets which are bolted together with the wing uprights. This then allows one full access to the engine compartment. This is how Porsche has done it on all the RSRs and also the 991 and 992Cups.
Very cool on the wing mounting, looks like Jonny made some revisions since the last set I saw. Car looks great, very excited to hear some driving impressions when you get it out to the track!
07-24-2023, 03:47 PM
