Been thinking about this one and wanted to see if I've got it right. Never really thought about it before....

To get the car to rotate more easily the common answer is a stiffer rear sway. Front grips, rear slides, presto. But in thinking about it once the rear gets loose how does the role of the stock center diff kick in? Wouldn't the higher traction bias to the front pull you out (ie behave more like a FWD car) so that, in effect the car still drives like a FWD?

When using a upgraded center diff the traction bias is in the rear and while it would require a bit more weight shift and throttle input, once you got the rear sliding it would be more controllable since the bias is to the rear and you can use the throttle to steer?

I guess what I am getting at, is that a sway bar seems like a quick fix or patch on the handling question where as the better solution would be using a 4:1 center diff and then upping the rear spring rates to get the desired rotation... Is this right?

Just asking as I am pondering the next suspension upgrade. The tracksports work pretty good but there is still too much body roll for my taste and at 600/700 I might have to get these things revalved if I want higher rates. And that being the case the sways are the much cheaper option versa new center diff and revalving the shocks....

Thoughts?


Rob

 

I prefer throttle-controllable oversteer with diff over off-throttle oversteer due to swaybar. My H&R mush-spring'd car is quite neutral off-throttle, I just want to be able to ACCELLERATE and keep turning.

 

do you have touring or sport valving? sport is quite different than touring.

afaik, stasis tracksports were designed to work without a rear sway. ideally springs alone should dial out sway. sway bars are a means to tweak how much sway a driver would like once the spring rate is dialed in.

stasis' high bias torsen enables 80% power front or rear instead of 66%. thus your car would be more RWD when necessary or more FWD. more torque will be available where it's needed.

 

...The higher bias center Torsen will distribute torque under accleration at a higher percentage than stock.

The easy example of this is front wheel spin on a hard luanch, or inside front wheel spin hard on throttle coming out of a turn. Both of these are examples of the front getting to much torque because the 2:1 OEM center can't send more to the rear.

So you go 4:1 or 5:1, now you are sending more torque to the rear in these two examples. But really, what you have changed is the amount of torque front or rear under accleration that can be distributed.

So now we get to the understeer issue. Given the amount of front torque with the 2:1 center, the car will understeer under acceleration coming out of a turn.

Sending less torque to the front and more to the rear will help this condition quite a bit. So yes, the 4:1 or 5:1 center Torsen will help with understeer coming out of a turn.

But bear this in mind. If you jump on the throttle hard, and the rear starts to spin up, the torque will go to the front.

There is a KEY to this, the Torsen does not understand wheel spin. It is looking for front or rear "resistance".

So now you slap on the 1.5" solid NASCAR bar in the back, taking care of that understeer issue, but the inside rear wheel is 6" off the ground, you jump on the throttle and that inside rear wheel is gonna get lit up.

Then EDL kicks in, and starts braking the car. AT this point, you WISH you had a FWD car cause that's the only thing that'll keep you moving forward, except...

Rear LSD (limited slip differential). This guy will take care of the wheel spin issue with lots of rear roll resistance. Now the Torsen NOT being able to pick up wheel spin doesn't matter as the rear LSD is keeping both rear wheels going at the same rate.

That fact keeps EDL from kicking in, and the brakes from being applied.

Forward motion is not only back again, it is in full affect as you are sending torque fore and aft based on traction, and not spinning wheels. No spinning wheels and no EDL braking means no wasted torque. No wasted torque means maximum forward motion.

The sway bar and spring rates will solve your roll resistance and understeer issues, but the differentials will solve your ability to use your torque issues.

 

---> unless you're an expert. It's an unstable condition, and probably not recommended in traffic. On the track, it's the way to get slow lap times. So, I wouldn't worry about any torque balance.

Understeer is front sliding in a turn, and it's stable. To curb understeer, requires reducing or eliminating front sliding. This can be done by forcing the rear end to assume more of the car's roll resistance (stiffer rear bar/springs), thereby adding grip to the front. Front grip can be further enhanced by reducing the front roll resistance (weaker front bar/springs).

IMHO.

 

isn't it 83% torque vs. 80%? thanks!

 

85% vs. 80% I beleive...

 

is it a matter of more available torque being better re: 5:1 vs 4:1 or more being, uh, more. ;-) i'm curious as to what the practical difference is between the two.

is the 5:1 more expensive? one day the stasis website (now newly redesigned i've noticed) will have prices for everything. =) when did you leave stasis, btw? i step away for a few months and... sheesh. :-P

 

...the extreme example would be shifting 100% of the torque fore or aft, but that would be a difficult car to drive as it would change behavior all the time.

It's whatever they are making, I'm not sure if they are 4:1 or 5:1, whatever they are making/selling.

I think pricing will probably not be online since distributors are doing the selling?

I think the Torsen is $500 with a core charge of a 1k on the unit.

 

Does the Torsen transfer torque by the same principle as a Quaife differential?