Gald to hear you did well eith the B.M.I. chassis at the New Zealand Nats.
for mod motors we always run alumium diffs. I really like the RRP diffs but I think they quit making them. next is the Hardcore diffs. the work really well but you might have to grind a little on your diff cases as they are a little thicker on the short end where the diff gear fits and they might rub on the cases here. IRS diffs are ok I have a couple that I will run but I don't like how you bdon't have a recess for the diff nut like the hardcore ones do. Niftech diffs are really nice but a little pricey. I also run lightened steel diffs. these are by far the heavist of all.......... but they are almost buttetproof. even 7x1's on carpet don't even phase them.
gee. I could go on forever on this subject. I have a Fantom and a Turbo Dyno 45. I use both for different reasons TD 45 for load/eff readings. and the fantom for rpm/watts/and sometimes gearing.
seeing that you run mod you might want a TD45. you can program your own amp/torque/rpm settings (or use the default ones). I mostly use the Fantom for stock (that's what we mostly race).with the new windows program it's even better. I have used a axle speed formula to help with gearing on the TD 45 and it works well in most cases.
Fantoms are easy to get as they are still being made. TD 45's are harder to come by (Ebay) or sell forms if your lucky.
the setup I posted works well on med to high grip carpet tracks. if the rear wants to slide out just change back to the "R" block in the rear. my son likes his cars to rotate hard in the corners so I will run a body that will help him with this. (Losi Lexus) Losi Alfa works well with this setup and is a touch loose in the rear. either the 2.0 or the Mazda6 will smooth everything out and make it feel more netural.
we had a off day of racing............not really sure what was goiing on but Mini ended up in the B........he won it.
I'm off to the dungeon....gotts see if I can figure out whats up with Mini's car...(or maybe it's just me)