I have a question that goes back to the original start of this thread.

When speaking of AWD Mitsubishis, which are all basically FF cars that have an output shaft to add AWD, are they not inherently more like FF cars with high grip? (Because of their tranverse mounted engines and subsequent transmission placement)

Skylines, Porsches, VT Diablos are RWD cars with longitudinally mounted engines. Particularly with the Skyline which is an FR car with an output shaft going up front. (Or MR, and RR like the last two)

Wouldn't adding a front LSD to any of these cars have different results because of their inherent differences?

 

Short answer.. maybe. Long answer.. not for the Evo. Drivetrain layout wasn't much of a concern for the Evo because of chassis redesign and suspension tuning. If you are talking Eclipse GSX.. then definately. Adding an LSD to an eclipse will drasticly increase grip, but the one's I've seen autocross still react the way a FWD car would at the limit... the limit is just much farther out there.

The evo on the other hand was designed with a rear bias (most rally cars are) just like the RWD cars you listed. Only real difference is weight distribution... but Mitsibishi has done a pretty good job at that too. I mean even with the cars you listed there are still major differences in weight distrubution and engine layout... actually engine layout is different on all three.

It really has more about suspension tuning and chasis design than anything else. The evo is definately no lancer when it comes to either. With just slight suspension tuning the Evo turns into an oversteer nightmare.. but then again you can do the same thing to the Ford Taurus.

 

And that is a point I forgot to make earlier. All of the "what an LSD will do to a car" argument seems to be in a static environment on equally prepared cars. But, suspension tuning can make a drift car out of an EVO. There are a lot of inherent qualities in this vehicle that make an LSD not necessarily a be all and end all solution to improving handling.

As far as the leaving it out because of cost. It may also be a warranty issue too. Combine an open diff with a "weak" factory clutch may mean less drivetrain stress and greater longevity. Just a few hundred dollars per unit may be save thousands on the other end, as well as more satisifed customers. Hell, I wish the car had a locking glovebox, but like the other Lancers and Outlanders, it don't.

 

Locking gloveboxes reduce understeer. Unless its a tumbler lock type.

 

I don't know if they are considering what happens when there is a loss of traction but taken literally that isn't correct.

From: http://www.off-road.com/4x4web/faqs/diffs.html

"The open differential is a system of gears that keeps the same amount of pressure on the faces of the gears that drive each of the axle shafts (to the wheels). When one wheel turns faster than the other, as when turning a corner, the pressure on it is kept up (so more power is applied to the faster turning side)......In poor traction conditions........ When one of the wheels has no traction, it spins. Since the pressure is kept the same on both axle shafts, little or no torque is available on the side that is not spinning."


And since there was mention of the SHO, from:
http://www.shotimes.com/SHO4limited.html

"The MTX-IV differential is an 'open' differential, meaning that it will route all of the drive torque to the wheel with the LEAST traction."

 

I just thought I'd let everyone know, I was reading an old (02/03) issue of Road & Track and they have an article on the CL Type S and another on something else FF. They both mention how the manufacturers both added lsd's in the next model years to combat (drum roll please) torque steer.

 

Is the regular front diff a 1.5 way on the JDM evo's? I mean who power in a turn before the apex ? I'm sure the with the front LSD the evo has more traction and faster laps.

 

a 1.5 diff is a normal LSD in forward motion, open when your coasting or backing up.

From what I have been told by other DSM and WRX owners, adding a front LSD increased the potential for understeer on corner entry, but lets you pull the car out of the corner. That also implies that your on the boost faster (if you have even lifted the throttle in the first place )

 

Allow me to but in,
I have many miles on track in the Evo VIII. My car is set up with max negative camber up front and slight toe out. The rear is at one degree negative and zero toe. The car exhibits mid-corner understeer and massive corner-exit understeer. A lot of this is due to the softness of the car on the stock suspension. My front tires have worn lettering on the sidewalls. Do I think a front LSD would help this car? You bet! I will be roadracing this car next year, and it will have a front LSD.
Cheers,

 

Equal Length Half Shafts - Less torque steer


Josh