Basic Drift Chassis Setup Part 2

Basic Drift Chassis Setup Part 2

By Mike Kojima

In part one of our series we spoke about the importance of good suspension which is probably the first major step in setting up a car for drifting.  Although the suspension is really important, perhaps just as important is a good limited slip differential.

To read more on suspension set up and part one, check out this section. “The Ultimate Guide to Suspension and Handling”

One of the most critical parts of a drift car that isn’t really part of the suspension but worth mentioning here is an LSD or limited slip differential.  Without an LSD, it is really hard to get a car to drift.  An LSD diff is one that locks the two drive wheels together under power.  When the wheels start to spin on a car with a regular diff, all of the power is transferred to the wheel with the least grip so only one tire spins, in a turn it would be the inside rear wheel.  No power is transferred to the loaded outside wheel and it does not spin. This makes it hard to get the car to slide by using the engine's power.

Basic Drift Chassis Setup Part 2
The OS Giken LSD is one of the best on the market.  It is highly adjustable for locking and initial breakaway.  It also has a lot of clutch disks for long life.

Spinning both rear tires using the engine's power, most importantly the outside tire is an important tool to reduce rear grip and to get the car to oversteer.  An LSD allows the driver to throttle steer the car using the engine’s power to help steer that car once it is sideways.

Basic Drift Chassis Setup Part 2
The OS Giken uses these springs to adjust the slope of the lock curve.  The stronger the springs, the more gradual the locking and the more initial bite when the throttle is applied.  Cusco diffs have similar adjustments but it works in reverse, the stiffer the spring the faster lock is applied because with a Cusco the springs work on the opposite side of the pressure ring.  For drifting you usually want a fast steep slope to the lock curve.

An LSD locks the wheels together so they both spin, this makes it easier to achieve on throttle oversteer.  For drifting most people prefer using a 2 way LSD.  This locks the wheels on acceleration and deceleration generally making it easier to keep the car in drift even if the throttle is backed off.  A two way diff also allows a drift to be initiated more easily using the shift lock technique where a downshift is done without heel and toe rev matching.

Basic Drift Chassis Setup Part 2
To adjust a diff, it must be taken apart by removing the housing bolts.  Here Billy Johnson disassembles his OS Giken diff.

When shopping for an LSD a few features are important to look for.  You want to get an LSD with the maximum amount of clutch plates, OS Giken, Cusco and Kaaz all have a lot of plates.  More plates equal stronger locking and longer wear. Adjustable breakaway torque is also a useful feature as for drifting you want the diff to be pretty solidly locked up compared to grip driving.  All of these diffs have adjustable breakaway torque.

Basic Drift Chassis Setup Part 2
These cone springs control the initial breakaway torque for the diff by controlling the preload on the clutches.  A stiff spring has greater initial breakaway than a soft one.  Just about all racing LSD's can be adjusted this way.  Generally for drifting you want a high initial breakaway torque.


Page 1 of 6 Next Page
Bookmark and Share
Monday, December 05, 2011 5:52 AM

I have made a calculator calculating weight transfer ratio in excel for choosing springs and anti roll bars:

Monday, December 05, 2011 11:41 AM
Mike, can you do a similar article for grip cars? *pretty please*
Chubby Chaser
Chubby Chaserlink
Monday, December 05, 2011 12:12 PM

Regarding LSD. I have read that some FD drivers are using spool differentials. Would you recommend this? Many drifters start out using a welded diff, which uses the same principal as a spool diff of locking the wheels together and having them spin at the same rate permanently.
Der Bruce
Der Brucelink
Monday, December 05, 2011 1:08 PM
Tony - Go to the tech section and look through The Ultimate Guide to Suspension and Handling. It should cover all your grip needs!

Chubby Chaser - Mike addresses your question in the article under the LSD portion, it's in the article, not attached to the pictures :-)

Mike - Good Stuff for if I ever decide to break the tires loose!!
Monday, December 05, 2011 1:23 PM
Lots of great tips.

The last picture, that is Henry, its a Motosports Dynamics car, Henry's personal car. They were Falken sponsored. RB26 powered, I also see the RB Motoring sticker down on the corner there.
Chubby Chaser
Chubby Chaserlink
Tuesday, December 06, 2011 7:03 AM

I read the article and saw that he mentioned welded diffs. I was inquiring on whether he would recommend a spool or welded diff over an LSD, considering that many pro drivers are switching to a spool in their quick change diffs.

Mike Kojima
Mike Kojimalink
Tuesday, December 06, 2011 12:22 PM
Chubby, I think an LSD has potential traction advantages over a spool and makes chassis tuning easier. A spool makes the car turn in less sharply and push more on corner entrance so you have to tune around a spool which is sort of more difficult.

I generally do this with toe out in the front and a wide front track through the lower arms, not spacers. I also do stuff with the rear track and rear bar to help the car intitate better.

Usually the additional traction an LSD can provide is overshadowed by the advantages of getting the gearing just right and eliminating unneeded shifts.

The only lSD's available for quick changes are the Detroit locker type which suck and make the car hard to control. Ideally I would like an OS Giken diff for a Winters Quick Change.
Chubby Chaser
Chubby Chaserlink
Wednesday, December 07, 2011 7:16 AM
Thanks, Mike! I thought it was weird reading that some FD drivers are running spools. To each their own I guess.
Wednesday, December 14, 2011 1:54 PM
Driving a miata and now have experienced each style of diff setup, the most recent a welded rear in my street car. I never thought it would be much of a change but wow. The welded now has slower under steer type turn in then a sharp snap to loose and drift.. Not very predictable I've noticed. With a clutch kick or another form of entry it changes the feel but depending on your driving style could be fine..

Now I will say my out of the box OS unit is amazing.. It does everything right. Not noticeable ever really just smooth perfect always. Never thought it would be such a dramatic difference even over a few clutch type setups.. Debating to tinker with it or not.

Miata world now needs some good heim'd control arms/knuckles up front. I'll pay.
Post Comment Login or register to post a comment.

MotoIQ Proudly Presents Our Partners:

© 2018 MotoIQ.com