At the end of the day, we would be happy if there was an objective test, on a same car, to show how any aftermarket LSD affects its handling and laptimes.

Say Evo 9, tested on same circuit with Torsen, swapped to ATS, swapped to Cusco, swapped to Wavetrac, driven by pro to get realistic laptimes.
Maybe even swap tires, have fresh tires, to keep that consistent, and do the test on cool fall/winter California day to keep atmospheric conditions constant.


We get a lot of voodoo grumble, suggestive sentences about secret sauce, but no results/data to demonstrate.

The closest to some positive encouragement I got was from Andy when he went to ATS, but mind you he was possibly on OEM torsen and perhaps mediocre RS rear, in 700whp car.
Going from well worn, and limited functionality setup- that could benefit from refresh-service, to a high $ Dollar new setup. Of course, results were very positive change.

revisiting this. is the helical kind of like a 1.5-way, having some lock-up in both directions?

i just want to make sure i'm going to be good with a 1-way in the front on track and not a 1.5-way

It entirely depends on driver preference. There is no setup that's right for everyone.

of course. just hoping to gather some data, if anyone felt like a 1-way was too loose/unstable on braking or trailing in on their car. their setup will be different, so setup notes would be nice.

i think the data is really limited here regardless though

Its not really that hard to pull the front diff out in the car. Get a 1.0/1.5 way cusco and try it both ways. I know the 1way was such a dramatic mid corner difference from the Wavetrac that I have no interest in trying 1.5way but mid corner attitude is so good now that I have no interest in trying other things.

appreciate the input. mid corner attitude pre-apex or post? ie on throttle or off? can the car sweep now? lol

Well if we're talking 1 vs 1.5, then definitely its the off throttle attitude. It does sweeper about as good as possible considering front weight, but it'll never be a miata in sweeper. I still focus on diving into entry, settling the car, then throttle from apex to exit. The magic comes in smoothing that settling zone and looking at the data from Nats last year with broken diffs, that's where Marshal is super smooth and fast. He maintains g-force through the corner better than I do where I have a bit of a g-dip in some turns where I came in too hot.

In braking, I'm not concerned about the front diff having the center diff locking at its highest pressure and the high rear preload. But I haven't had to do heavy braking in triple digit speeds.

thanks - this is my mindset too re: the behavior of a 1-way in the front, which is recommended by most diff manufacturers. i'd consider it in a front wheel drive car, but an awd car with center diff, rear 1.5, i just feel like it makes more sense to get a 1-way and maximize that turn-in/alleviate any kind of binding for the front wheels