Actually cusco might be sending some parts my way(if i am lucky).. Maybe i can get an front LSD out of them

 

how much does that cost?

 

Um, well hopefully nothing..

 

Yikes. Do we believe Quaife will be making a diff for us? It can't be *that* different from the DSM front diff. Although, maybe it can...look at the location of the center diff. Anyway, an expensive Quaife for the DSMs was in the $1500 range.

Thomas Dorris

 

The first step to curing understeer in a car like ours (I have a WRX) is to understand the drivetrain. My car has AWD, with the torque-split front-to-rear being 50/50. The rear of the car has a viscous LSD. I'm not sure about the EVO.

Now, assuming no slip angles or suspension weighting, the front inside wheel is going to "smoke" through turns. Meanwhile, going uphill will cause power to shift to the rear, while going downhill will shift power to the front. It also follows that uneven tyre pressures will cause a power (torque) shift.

I don't know how many of you keep up with Initial D, but I actually learned a lot from that "cartoon" (JapAnime). Of the many technical things I heard, and researched on my own....
1) Weighting the suspension smoothly into the turn will DRASTICALLY help cure understeer. This does NOT mean go slow, just smooth. Remember to make every input (brake, throttle, clutch, steering) smooth and deliberate (smooth inputs). Try to visualize where each wheel is and what it is doing ALL THE TIME, and make the transition to the next turn appear effortless. It will eventually translate to higher exit speed, and allow you to drive at 100% grip.

2) Learning every notch in your transmission will give you precious tenths on your competitors, especially when you heel-toe. Sometimes it's better to shift earlier, sometimes not at all. Sometimes, you need to rev-match and double-clutch down the gears at the last minute, inducing lift-off oversteer that translates to a fast exit speed. If nothing else, learn to rev-match EVERY downshift, and keep your motor in its powerband. There's no excuse! You can do it everyday, and doing it properly will reduce wear on your brakes, transmission bearings & synchronizers... and it will eventually give you the confidence (after 1,000's of miles) to wait until the last second to downshift. Learning to rev-match is, admittedly, embarrassing for the first 3,000 to 5,000 miles of normal driving. Now, I don't even think about the revs, and I can launch the car into last-minute sweeping turns with no understeer.

3) Used with number two, above, is a technique termed left-foot braking. Some people call it "power braking".... but this induces the wrong image. Power braking is for going in a straight line... something I wish no one got excited about. Dragging should be left for men in women's clothing. No.... left foot braking is a technique that is used to induce *small* changes in the chassis balance before and during a turn. Used before a turn, and gradually releasing until the apex, would be termed "trail braking". Jabbing the brake quickly before the apex, and powering out of oversteer would be a pirouet (sp?) turn, usually only accomplished with this technique. Where left-foot braking really helps is when you are trying to keep the car in boost, but slow down before the apex. Not for the weak of heart, this technique can get you ½ a second or more at a Solo II event.

That's my $0.02 regarding techniques to get the most out of your AWD drivetrain. Avoid situations like wet roads, gravel, or narrow blind-corner roads when initially practicing these methods. You have to train both your mind and your muscles to repeat these motions correctly, and at the right time. Slipping off the pedals and hitting the clutch (instead of the brake), or rev-matching the wrong gear could have drastic consequences on public roads. I highly recommend that EVERYONE with a car like the EVO or WRX go compete in a local Solo II event. Not only will you make great friends, and receive useful advice from the people you allow to ride with you on your runs.... but you get to push the ever-loving **** out of your car in a close-quarters situation, and get away with it!

And now, a word from our sponsors:

Negative camber is a wonderful thing, especially on the front wheels. I would probably run 1.5 to 1.8 in the front, and as much as possible (up to about 1.5) in the rear for street tyres down to 140 treadwear. For lower treadwears or enthusiastic driving, you should consult a suspension expert, get a tuned set of coilover double-adjustable suspension with adjustable strut towers, have the suspension tuned for your desired height, corner-weighted for absolutely neutral braking balance, and then matched for side-to-side camber (within .2 degrees). Camber plates, strut tower braces, adjustable struts (correctly valved and properly set for environment and tyre), anti-lift kits, adjustable rear anti-sway bar, lighter wheels (2-piece or 3-piece, with corrected offset for increased width), better brake pads, stainless steel braided brake lines, high-temp brake fluid, directional performance tyres, and a custom alignment will all contribute to the ABC's of handling (Acceleration, Braking, Cornering). Remember to have yourself in the car with a full tank of gas when corner-weighting or getting an alignment. This is very important for spirited drivers.

If you master the above techniques, tune out your suspension.... and you STILL have understeer, then you probably have an issue with tyre pressures. Look into a 12-temperature pyrometer, and take some spirited runs around the block.

I really think an front LSD (in an EVO or WRX) is a quick fix for the loose nut behind the wheel.

:-)