How far has anyone pushed the smaller 200mm TT Auto/N/A diff with the 6 spd trans? Are there guys drag racing with it on slicks?
Al
Didn't see this years back when you posted it, but just in case you were still wondering - the 200mm Auto diff has gone deep 9's @150ish with a 1.3x 60ft on an auto with bias ply slicks. Typical failure is at the pinion due to crush sleeve compression under severe shock loading. If one did a crush sleeve eliminator, I suspect the diff would be good for about the same on a well driven 6-spd, but probably for a few hero pulls not a consistent season-after-season sort of thing. The fastest 'hero run' I know of with a 6-spd and a 200mm was actually in a Grannas swapped MK4 that was high 9's at mid 140's. Never did get a 60ft on that, though.
People have fragged the 220mm 6spd diff at BPU power levels with the right combo of drag radials, aggressive clutch, clutch dump, etc, so you'd just be one botched launch away from disaster.
If you're going to keep aiming for 9's but don't want to swap to an IRS 8.8, I'd consider the PHR 6R80 conversion instead. Autos are just better at going fast and keeping shit alive.
Why does this trans need a breather filter instead of the poppet valve? Won't that eventually spray trans fluid in the engine compartment? More importantly, how have all the people with factory T-56's in their cars - older Camaro's, etc gotten by all these years?
I would love to install one of these kits in my auto car, but it's things like that preventing me from doing it. I would appreciate any feedback from someone that has installed one in an automatic car?
Al
I've seen those Tremecs occasionally come out of the box with a torn shifter seal, at least they sometimes did when I was still in the industry up through 2015 or so. I can't speak on newer Tremecs since I haven't had hands/eyes on an aftermarket Tremec out of the crate since 2016. Patrick94tt is a pretty diligent dude and I doubt he'd throw a breather on a trans to solve a shifter seal leak without inspecting the shifter seal, so that may or may not be the case on some of these instances.
Venting the trans with a breather would solve the problem of pressure pushing on all the seals, but I'd inspect the shifter seals carefully before doing a vent.
Depending on the application, some Tremec T56's and TR6060's have had vents, but they're like a differential vent in that they're always open but designed to not allow splashing oil to slip past. The vent into the engine compartment prevents fluid splash or leakage because it's simply too much hose to travel upward, since it's a gearbox not a pump it doesn't force the fluid that high or meaningfully displace enough fluid to worry about gearbox lubrication.
I've seen the same trick with a long breather hose done on other manual gearboxes for road racing, etc, both transverse and conventional, to prevent oil from being pushed past shaft seals or shifter seals.