most any spirited drive thru very tight canyon turns will make running rwd with an open rear differential glaringly obvious due to massive rear wheel spin. rwd & open diff is essentially "one wheel drive"! is it not?!

that's unacceptable lol.

 

Nope, did it for a year before ditching the front diff this winter.
If you run 4wd set-up at the track you'll notice it.
Car is way more stable under heavy braking and LSD allows for much more trail braking for better turn in.

 

I was looking to build my own dogbones. How did you make your own dogbones? Do you have part numbers for the parts used?

 

Sorry, I don't. It was quite a process actually and pretty enjoyable. The biggest challenge was engineering and designing them and sourcing materials.

First I pulled a rear wheel and removed a stock dogbone. Then I measured everything which was metric. For ease of component sourcing I decided to go with inch rather than metric. I got my 5/8" rod ends from ebay for under $100. I used a RH and LH thread on each dogbone for easy adjustment after installed. I sourced the hex aluminum rods that were the correct length and correctly threaded from a racer parts supply house. I also got the jam nuts from them as well. I needed some reducer spacers in 2 different sizes to make the rod end the same width as the OE mounting eyes. I used ALLSTAR P/N 18610 which was 5/8" to 1/2" ID x 1/4" and 5/8" to 1/2" ID x 1/2" of another brand. This gave me the proper width at each mounting point and reduced the 5/8" ID to 1/2" which equates to 13mm. The OE mounting bolts are 12mm and the 13mm ID of the rod ends created excessive slop that I didn't want. I solved this by sourcing some brass 1/2" tubing at a hobby store and cutting sleeves to shim the ID of the rod ends from 13mm to 12mm for a nice slip fit. All in all I used 5 different suppliers to get what I needed. Everything just fit perfect and screwed together very nicely. I assembled them all to the OE length and mounted them up. When I installed my lowered coilovers, I adjusted the dogbones to get a rough driveway alignment approximation. They worked great. My worst fear was bump steer of which I have none. Sorry I can't be of more help as to P/Ns and suppliers, I didn't keep any of this as I didn't want to be liable for passing on recommendations for parts that could prove unsatisfactory. Good luck!

 

PSM on or off?

 

I left PSM on when I would just run for an hour or two and would unplug it for longer track days, my 1st year with ZC turbos/fueling so car required a little mental re-calibration. When I upgraded the stock 330 brakes to GT3/350mm set-up the PSM started jabbing at the rears more/too often, so I'd turn it off.

Now with 380 brakes I unplug it or just wait till a couple hard laps and it will go out/light up. Have only had one day on track with the bigger brakes, RsPros and 2wd so I'm a ways from being used to the set-up. Impossible to get an accurate feel for it on the street without being overboard.