Driver theory: Jefferson Expansion Pre-writeup

This will likely be my last event for the year as I have a baby coming so I figured I would tackle a track I haven’t ever driven before. The great Jefferson Expansion. It’s known for being a fast and not drift friendly course.

The map below shows the whole course. The section for drifting is turns 1-11. Though I’ll likely stop drifting around turn 10 to save tires.

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Here’s a quick video of a friend’s first real lap around the course:

The biggies are turns 4 and 5. These are the ones that aren’t too drift friendly. They are very gradual corners with a long stretch between them. David makes it look easy but I figure it’ll be a lot of hand brake action. The wisdom I was given was to stay shallow through those sections as to not over rotate and make stretching the corner impossible.

The other issue is turn 7. Which is a blind, down hill, decreasing radius corner. But really, that’s just a matter of slowing down enough. I’m not foreseeing much of an issue with the corner, but it isn’t too forgiving if you mess it up.

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Snap oversteer on drift transitions

Haven’t written in a while so let’s give this a go with some setup theory. This past weekend I got to drive quite a few cars. But the two that stuck out were an E36 and E30. The E36 was an M3 model with basically no modifications outside of some springs/shocks up front. The E30 had an M3 motor and solid subframe bushings with a J stock style coilover setup. Both had issues with snap oversteer on switch back. Entries weren’t too bad to figure out after a bit (I’m used to massive angle kits).

I’ve been googling around for a while and here’s some general bullet points I’ve come across.

Z-link and Trailing arms change toe massively. Both of these cars had stock (OLD) bushings for their “RTABs”. To quote the great Mike Kojima:

…causes the car to toe out under roll. Lifting the throttle or really heeling the car into a turn will causes instability and snap oversteer.

This leads me to think that both the E30 the M3 were having toe issues due to the really old bushings that deflected on accel/side loading/decel.

The fix here is to swap to better bushings. Spherical preferred but more than likely poly.

Sway bars are exponential in their stiffness. This is really for the M3 and not the E30. Bend a ruler as far as you can. At first, it’s easy but it gets harder the more it bends. That’s basically how sway bars work. With the M3’s stock rear suspension, the sway bar was likely loading the sway bar to toss the weight the other direction when unloaded.

The fix is to stiffen up the suspension in general but mainly the rear.

Suspension settings. The E30 has one way adjustable coilovers with unknown settings. Perhaps stiffening the rear shocks will cause resistance to the snap back and make transitions simpler. E36s and E46s have the toe arms. With some added toe in, the rear won’t be as snappy.

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Wiring gauges and automotive 12v systems

The other day I upgraded my anemic 16″ pusher fan for a smaller fan that pushed out twice as much air. Sadly, it’s amp rating went from 15 ish to 25 amps. I wired in the new fan in place of the old one and started up my car. After a few minutes, the fan just stopped. Eventually, I traced it down to a blown relay. When I pulled the relay, I noticed that the relay holder was melted.

I think the relay holder was a cheap knock off but just in case, I’m going to upgrade all of the wiring from 16 gauge to 14 gauge. It shouldn’t be necessary but I’m riding on the cusp of necessity. I also have both the power for the relay trigger and the power for the fan on the same fuse on my fuse panel. I’m not sure if backfeeding is an issue so I’ll hopefully eliminate that. Backfeeding is simply the power finding the path of least resistance to the ground. Which, in this case, might not be though the fan.

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Image stolen from: http://www.offroaders.com/tech/12-volt-wire-gauge-amps.htm

The ground for the fan is also on some flimsy peace of metal so I’ll sand that down and upgrade it.

If anyone has suggestions, let me know! I figure this is just step 1 basic electrical troubleshooting.

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The 5 different kinds of grassroots drifters

The grassroots drift world is filled with different people with different goals. 99% of us get along very well and the sense of comradery is the reason so many stick with it. Inherently, our goals separate us into “subcultures”. These subcultures tend to be the real distinction that you can plainly see at events.

Pro aspirations – Guys in pro-am generally have their stuff together. Their rigs range from well equipped to shoe string budget. Their cars are sometimes beaten but they are there to tandem and get better at driving. They can be a little bit on the cold side but they hit lots of tracks and are generally a wealth of knowledge.

Fashion drifters – These are the cars that look like pro/pro-am cars but aren’t. Full body wrap and even a cage. But they only visit two tracks and are constantly putting on new wings and wheels. They’ll put their car down for a build for a year or two to build something competitive but end up either with a perpetual build or never attending more than 1 pro-am event.

Hella JDM tyte yo – Their cars are low beyond what is safe and probably rock a stock engine or SR swap. They tend to look like the average hipster; with vapes and tight pants. They’ll show up to a drift event and only do 4 laps at best. They “kill the skid pad all day” and spend the rest of the time chatting with their bros about fitment and cool wings.

Drifting for drifting’s sake – He’s 40 years old and lived in Japan back when drifting was only mountain passes. He comes and drives the whole day. Everyone wants him for his sage advice. Drifting his is release and he only does it for himself. His car’s setup is basic but reliable and without many extras.

The wannabes – They own a drift car but it’s not ready. Ever. If they do come to an event, they’ll spend all day “testing” on the skid pad. On the rare day they sign up for a full event, they will do a total of 3 runs and stop. Or crash.

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Front Caster and Camber

Long time no update right?

Today let’s talk about caster and camber as it pertains to drifting. Originally, I went by this write up by Mike Kojima. But it’s a bit out dated now and either my skills are better and this is for beginners, or the general idea and concept has changed.

I was rolling around with good old Rapper Dan Savage the other weekend and he noted that his “poop coupe” with angle mods had 3.4 degrees of caster. My E30 has 9.6 degrees (not necessarily on purpose). His rationale was that with more steering angle, the extreme caster would cause a lack of contact patch at full lock. This was also mirrored by his low camber (-2.3 degrees)

Stiffer suspensions cause less camber gain with suspension travel but lowered cars without roll center adjustment cause exponential camber gain. So it makes sense to add in some positive camber to gain forward line stability (on a straight away and small turns). The lack of caster will allow for the tires to maintain a greater contact patch near lock and allow for the driver to keep on throttle. Which of course means more smoke and “gangster angle”.

In practice, your ability to modify caster will likey be minimal. When I was younger, I’d just take my camber/caster plates and set them to max pos caster and max neg camber. Ironically, my camber plates are currently set max positive and I’m about to set my caster settings to max negative.

Word of caution: Caster effects for what’s called “self steer” or “wheel return”. The less caster, the less wheel return there will be. Some angle kits have modifications to “trail” which helps this. But regardless, steering might/will require more input with these settings.

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BMW Wheel Search


I’ve screen scraped http://www.bmwstylewheels.com/ and placed the data here. I wanted a way to look at BMW wheels by various criteria and the page didn’t allow me to. For more detailed pictures and info, please click the link on the first column.

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