Originally posted by jpusb:
Hi Brian, excellent discussion you started. I will leave my input (although it will only guide you to what you have already decided).
I was in my team from 2007 to 2010. Driving AutoX and endurance from 2008 to 2010 (at MIS). We have used a Torsen for ages (since our first car in 2002). In 2008, we finally got to a VERY reliable design, that didn't break and was light. It costed the team a lot of effort and testing to get there. The same design has been used since then.
In 2008, having tested like crazy during 2007, we moved up in the field considerably (from usually 35+ in AutoX, to the top 15). But it was first year doing so and we had many other things still to take care of. Through 2008, 2009, we were in the top 15 in performance, and in 2010 we did a loooot of performance testing: car setup, electronics, bla bla bla. Long story short, I would have liked (as a driver and being in the vehicle dynamics team) an adjustable diff to make the car even better. It takes a bit to get to that point, but not too much, and it's not rocket science either, AND you will eventually get there.
I would say keep the Salisbury, and leave it almost as an open diff. It will give your drivers more time to understand everything else and then you start locking more (if the setup asks for it). Keep in mind that with slick tires, good track temp, and a LSD diff, you will be able to tell who could be a good driver and who won't. Maybe an open diff does not filter this too much, I don't really know, but anyway.
AND what you said about keeping basically the same car (at least all that is not considerably wrong with it) and focus on testing is PRICELESS for a team in the situation you described yours. Incredibly, a LOT of people won't buy this, because their engineer minds won't let them. People seem to forget that testing is also engineering, and they try to win the competition in SolidWorks. This has been a problem in my team for years, every years someone tries to comeup with new things to design instead of new ways to analize data, organize tests, increase testing times, use each test more, etc.
Good luck!
JP