hey guys prob a dumb question but i would like to know.... Gravel mode on the 2010 MR... is that made when it rains or what? thats what someone told me when its raining to put the car on gravel mode... snow on snow mode and regular mode on Tarmac...... is GRAVEL for RAIN or DIRT ... let me know.... thanks...

 

Yup... use gravel mode in the rain...

 

Agreed

 

The different names for each mode doesn't literally mean you can only use that mode on that surface. Those modes just allow the front and rear axles to slip more or less relative to each other. I think snow mode is the most restrictive and won't let the two axles spin at much of a different speed. In tarmac mode is allows the two axles to spin at the biggest difference in speeds. You can tell by looking at the S-AWC display on the dash.

 

thanks... so for my next question then .... when i wanna race on the highway .. whats the best mode?!?!?!?!?!?!

 

^ lol probably tarmac with the asc off

 

does anyone know the exact torque difference between these modes? i've always been thinking it was:

tarmac: 30% front / 70% rear
gravel: 50% each
snow: 70% front / 30% rear

i'd like to know for sure though

 

I have been using tarmac mode all the time. Has anyone used the snow mode in the snow and how effective is that?

Thanks

 

I'm still trying to figure out the S-AWC system myself. But from what I can understand... it does not alter the torque split. What it does is change the clamping force between the front and rear axles. (ie... how much faster it'll let one axle turn in comparison to the other).

 

^^^ that's my understanding as well. It's always at 50/50 front rear.

It's not like the DCCD STi has which actually change the torque split.

It's proven to handle better for EVO that's what matters.

 

I couldn't tell a difference, but I was also only driving less than 30 MPH and only drove in snow mode for about 3 days.

 

So there may be different amounts of power going to the front or back wheels... but you aren't directly changing this by switching between the Tarmac/Gravel/Snow modes.

Here is my explanation... so please correct me if I'm wrong...

So going fast thru a corner... and being stable in a straight line (getting traction to put down power) ask for two different things from a car. To get the most power down to the ground... you want all your power going to all four wheels... meaning that they all turn at the same rate. Going thru corners tho... having all four wheels turning at the same rate would be BAD... since each end of the car actually needs to travel a different distance to go around a corner... so you would be bogging the car down by making all wheels turn the same amount.

So to remedy this you have an electronic center diff which alters the settings of how tightly the two ends of the car are linked together. On a dry track for example... you want to have the car as nimble as possible... and to be able to turn really easily. So in this case... the front and rear axle are very weakly clamped together so that the front and rear axles are allowed to turn at different rates. This will help the car turn thru corners... and this is the TARMAC mode.

Now on a very loose or slippery surface... the last thing you want is for the car to be able to move sideways easily. In this case... to make the car more stable you want power going to all wheels equally... which means you want them all turning at the same rate. In this mode the center diff would use a lot of force to clamp the front and rear ends of the car together... in an attempt by the car to turn all four wheels at the same rate. SNOW mode would give the most clamping force... and GRAVEL mode is between snow and Tarmac.

Now in the process of clamping and un-clamping the front and rear axles together... you may have more power sent to the front or rear of the car as the car either tries to make all wheels spin at the same speed or not. But you aren't directly changing the torque split by switching between Tarmac/Gravel/Snow modes.

That's my understanding of how the "Active Center Differential" works... but please correct me if you think I'm wrong.

 

why would you want to do this first of all? try getting the car on the track and using all three setting to see what they do, i never take mine out of tarmac mode.

 

Just to add to my previous post... so the amount of torque sent to each axle is always the same... but because power is a function of rotational speed... since one axle can spin quicker than the other... one axle can receive more power than the other. So for example in Tarmac mode... if the rear axle ends up spinning quicker than the front axle thru a corner... the rear wheels in essence are getting more power than the front. In Snow mode where the front and rear axles are pretty much locked together... they will be rotating at the same speed and thus will be getting the same amount of power.

 

dont know about the winter yet..but at the 1/4 dragstrip...snow mode makes me faster off the line

tarmac gr8 for drifting anywhere or just normal driving anywhere...gravel..havent found a use yet..