Evaluating Angle Kits

Usual disclaimer. I am not an engineer. Nor do I know everything about angle kits. This is a reflection of my current level of knowledge about angle kits. 

For most chassis, angle kits are narrowed down to either cut knuckles or Wisefab. In those cases, competition drivers will likely choose Wisefab and people with limited budgets will likely go with cut knuckles. In the BMW world (e30/e36/e46) options vary wildly and picking the right option is more than money limited. So if you’re in the position to actually pick your angle options, here are somethings to think about.

  1. Adjustable top hats

Angle kits generally come with longer control arms. The problem with longer control arms is that they give massive amounts of negative camber (-6 or more). General aftermarket camber plates will not give enough adjustment to dial this out. Some kits (wisefab pictured above) come with the option of fixed or adjustable camber plates. The camber plate on the left gives so much adjustment that the shock tower will have to be modified. The camber plates pictured on the right solve the same issue but will not be able to give camber adjustments since it’s just a fixed plate. It’s worth more to get the full adjuster plate. It is also worth noting that FD legal plates must leave the shock center point within the factory bolt holes in the shape of a circle.

2. Ackerman Adjustment

This one isn’t as much of a deal to anyone. Most kits these days 0 out ackerman and give no option to adjust it. If you’re a driver just getting into things, having the ability to try out various settings is a very good thing. For instance, the SLR kit for BMWs has 4 or more adjustment settings to go from 0 to close to stock ackerman.


3. Mechanical Trail (Caster)

There are 2(ish) factors that determine a car’s overall caster. The first is the actual caster in degrees the overall suspension components are angled to (what’s on your alignment sheet) and the second is the trail built into the physical knuckle via the control arm’s attachment point. The simplest way to explain trail is the picture above. It is measured by the distance between the wheel’s axis of rotation (blue) and the wheel’s physical attachment to the rest of the suspension (red). The farther apart, the more trail.

Tilting the suspension (caster) can add/remove this effect to an extent. But that will affect camber curves. The reason for wanting trail is that it helps the car’s self steer (IE wheel return). Shopping cart casters have no caster angle but the front wheels still have good self steer due to the mechanical caster.

Above is the SLR adapter bracket (an old version) that utilizes the factory control arm attachment point at the knuckle to maintain trail.

 This is the wisefab adapter. Notice that the yellow line is the actual control arm attachment point. This setup will rely on more caster angle to make up for the lack of mechanical trail. (Also notice the lack of ackerman adjustment)

4.  Actual Caster Adjustment

Most kits these days provide some form of caster adjustment. Either at the top had or at a lower control arm attachment point. But not every one does. Even then, the lower control arm adjuster is more useful than the top hat. It can also help relocate the wheel in the wheel well after the control arm changes its original location. This is one of the overlook ways to dialing in more self steer or other steering characteristics.

5. Back spacing

Quite a few angle kits offset the angle blocks from the knuckle itself. In my experience, this is to gain more realestate in order to properly locate the joints/nuts. The problem with this is that the point of articulation at the control arm is now farther away from the center of the wheels rotation. I don’t know 100% of the other down sides but at minimum, to maintain scrub radius, the wheel would need to be mounted the same amount inboard. Which, with some coilovers, may not be physically possible.

6. Roll center correction

Most kits offer some kind of roll center correction. The problem is that some offset roll center on the control arm but don’t do the same for the tie rod. At rest, suspension arms should be near parallel to the ground. If both control arm and tie rod aren’t on similar planes, suspension compression will cause uneven changes in geometry over travel. This can cause uneven steering feeling.

** Other considerations

  • Spherical bearings over balljoints
  • Parts availability for sections of the kit in the event of an impact
  • Welding/fabrication necessary to fit the kit on
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FD 2018 Technical Rulebook Overview/changes

For some reason, FD’s yearly technical rulebook isn’t readily publicly available. Regardless, I found a copy and looked through it. As usual, the formatting is so wildly different from last year that you can’t just do a straight text comparison. They do highlight major changes in red so that’s nice. It is annoying that, in this not publicly available document, there are advertisements. There are also some typos or accidental duplications, but overall the document is well put together in comparison to last year’s.

There are several additions that seem to just close loopholes not exploited yet (no pressurized refueling allowed) or closing loopholes someone was maybe exposed for (you can have 2 batteries but they have to be connected and in use).

Notable changes are:

12v must be available for FD cameras/telemetry where the rear view mirror mounts. Seems like FD will soon be taking in car telemetry and record runs through their cameras. Later in the document it specifies provisions about data collection. This could be an interesting game changer in the future but looks like it likely won’t be used this year.

FD will be impounding all podium finishers immediately after end of competition and they will be checked for weight and tire size compliance. I suppose this will be quick to perform but why the sudden change? I feel like there’s drama here I don’t know about.

Technical manager is now called competition director. Although I have no idea why this is a change. Kevin got a promotion?

Bumper structures must be magnetic steel. This is one supposedly due to JR’s aluminum crash support system to save weight. I’m not sure why it was outlawed. Maybe just due to cost savings for other drivers.

Wing standoffs no longer allowed at specific tracks. Unless it’s trunk mounted. This appears to keep wings from hitting walls and shattering. Tracks include “but not limited to Long Beach, Orlando, Wall, Las Vegas, and Seattle”

If your vehicle has chassis tearing or subframe stud problems please contact the Formula Drift Technical Department. This isn’t new, I just like how there’s an exception for the E36/E46 chassis.

Brake systems may be biased only front to rear. No brake bias may be used in a side to side configuration. Again this isn’t new but I have heard of drivers biasing side to side in order to not lock up one of the front tires when lightly left foot braking without turning on the brake lights.

Wheel paint/tire stickers. This is likely related to the bullet above. Perhaps this will also help show ebrake drags too. I can see how many people will hate this change but I personally like it.

Wheel tethers are recommended on the front and rear wheel for 2018, but may be required for 2019. I like how they hint that it might become mandatory. I haven’t looked into ways of tethering wheels but if they aren’t too obtrusive, it should be a simple change.

Pro and Pro2 will have different patches for 2018. Because we need to remind Pro2 guys that they aren’t Pro1 drivers?

Tires sponsor section is completely blank. It’s definitely TBD but it’s odd that there isn’t anything listed at all. I don’t recall this in previous years.

Pro2 specifics:

Minimum 2900lbs, mandatory 260mm max width tire, and 18 inch wheels. The 260 width rule is fine. I find it a little odd that they are mandating an 18 inch wheel. This will level the playing field and most drivers would be on an 18 anyway.

Tires must be used unmodified, as supplied by an Official Tire Supplier. Filing, buffing, or any other disguising of tire sidewall is prohibited. This is a Pro2 specific rule. Maybe drivers wind up having to use a tire they don’t like and are sanding off the logos of the manufacturers? That’s a lot of effort to go through to hide what tire you’re running. The unmodifying tire rule (like sticky compounds or bead lockers) is still around for both Pro and Pro2; this is simply on top of it.

Changes that I think are odd, newly specific, or weird:

Air jacks are now explicitly prohibited. I don’t know of anyone currently using them and they would add extra weight. But I can see why this is now explicitly prohibited.

Skid plates are now allowed but can only cover what’s necessary. That’s nice.

In cabin adjustments are not explicitly not allowed. Except brake biasing front to rear but that isn’t allowed between runs or during runs.

Helmet visors must be down during runs. That makes sense but why is it written in the rules all of a sudden?

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Case for the E46 330i/330ci

In an attempt to not make this a blog, I’ll keep this short. I crashed the E30 on a friendly private day, parted the car, kept the LS2, and now I’m in an E46 330. This posting will go over my thought process on choosing this chassis.

E46 Vs other models:
At the time of writing, possible drift chassis are still limited. With my primary concern being financial, anything with an initial cost over $5-7k was immediately removed from thought. 370zs, FRS/BRZs, newer mustangs, etc. Also, running costs were also taken into account. M3s/M5s can be found with dead engines but replacement ‘M’ specific parts can be very expensive. Even S14s/S13s are getting older and receive a heavy “drift tax”. Staying on the financial aspect, any chassis in the 90s and before were removed as parts are getting harder to find and prices for used parts are going up.

With all of those depressing conditions in place, the next logical step is to look into a vehicle’s merit as a possible drifter. You can see the drift car master list I used here. Due to weight, the G35/G37 were removed as possibilities, Mustangs in my price range were removed due to my dislike of solid rear axles, and miatas were removed due to the their short wheel base and my physical inability to fit in them.

With that, the field was narrowed down to RX8s, 350zs, and E46s. The RX8 was ruled out due to the LS swap difficulty and my inability to work on rotary engines. I was heavily debating between the E46 and 350z but ultimately picked the E46 because I could get one in 4 door and parts were far cheaper than the 350z. On top of that, locally, 350z are more common and I wanted to try to be different.

E46s vs other E46s
Within the E46 model, there are several models – 323/325/328/330/M3. Immediately the M3 is removed from my consideration due to cost. Here is a comparison between the remaining models.

Above is a comparison of power to weight between all E46 models and E36s. Ironically, even the 330 has a worse power to weight than E36 M3s but I hate E36s. The 323/325 have very lower power to weights but the 328 is also a contender. But due to the 323/328’s MS42 DME/M52B2xTU engines, their tunability is limited and the emissions system is much more complicated/fragile than the 325/328, the 328 was also removed from consideration.

Above is the brake rotor diameter x thickness in mm for E46s and E36s. The non M E46s have all the same front knuckle but very different front brake options. The rear of the 323 is particularly small.

The 330 specifically is a special E46 model, the brakes are so large that the factory equipped wheels at any trim level starts at 17 inches to clear the calipers. The rear has larger axles than the 323/325/328 and therefore a larger bearing, different differential, and trailing arm. Spec E46 specifically uses this model for these reasons. The 330 still uses non M parts for the subframe and many other parts so this keeps running costs down.

The case against the E46
The E46 is not without issue. The frame where the rear subframe mounts to (even on M3s) are known to crack. Reinforcements are a must. Differential options are limited. M3s have a very oddly locking LSDs and there is no other LSD option for the E46 from the factory. This also is coupled with more limited ratio selection in comparison to previous generations of 3 series. The rear suspension design is still trailing-arm-like with a very heavy main “arm” positioned in such a way that toe out on deflection is a major issue.

For my personal situation, the 330 sedan fits my needs. I consider this chassis and 350zs to be the next popular drift chassis. Both are capable, cheap enough, and available.

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Yoshi’s Drift Box: Day 11

To follow up on the last posting, I managed to get the output to Dashware to work correctly. Turns out the GPS isn’t a reliable source of timing.

I wound up having a few issues with finding and syncing datalogs to video. The Gopro was numbering runs by the run in its own order while the logger just continuously took several laps until I turned off the unit. This made linking up what went where difficult.

To solve this, the logger now has a “split” button where it closes the current log and starts a new one. This way, you can format the Gopro to start the file naming from 001 and the logger will do the same. Each run, the Gopro will increment and you can hit the “split” button on the Carduino to keep things in line. When splitting, the screen will flash white so it will help sync the seconds in Dashware. On top of this, the logger now always displays the file ID so you could flash gang signs at the camera or write down the file ID somewhere.

With this addition, the Carduino’s gui is in shambles so I’d like to rewrite it somehow. I’d also like to start coding the drift scoring mechanism. Although that requires the secondary arduino to be setup and logging things like angle and steering angle position.

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Review: The Formula Drift app (it’s terrible)

Full disclosure, I’m a web developer who has done some mobile development for work.

I’ll also start this off with the fact that I hate this app. I’m on android but I doubt the iPhone version is any better. First, FD cheaped out on making an app and instead bought a prefab web app with little to no customization. Here is one and another app in the play store that looks the same minus small cosmetic changes like color theme. This by itself doesn’t mean the app is crap, but it does set my expectations low from the start.

To start off, here’s what the main menu looks like (minus the home link). Most of these menu options aren’t very useful unless you’re actually going to an FD event in person.

The below image is the main “Home” page today. I received a push notification from the app for “Trivia Tuesday” so I clicked on it. All I got was the home page. I clicked around and found nothing about trivia.

Update – After 4 hours, the link on the home page for “Trivia Tuesday” showed up. This is what it looks like. It’s just a cheap google form that displays poorly.
Update2 – It shows up fine now. But it’s still a google form.

Moving along. If you click on the “Buy Tickets” menu option, you get forwarded to the ticketmaster mobile web site. Note that there’s two menus on the top of the screen. I don’t get why anyone would use this feature. Why wouldn’t you buy this on a regular computer? Or why not just go to the ticketmaster website on your phone?

When you click “Watch Live” this is the screen you’re greeted with. Again, like the ticket link, this is just a shortcut to the FD live page. Which isn’t setup for mobile viewing. You could theoretically use this page by zooming in and clicking the “full screen” button but I would not expect this on a professional app.

The Schedule link is actually mostly useful. But clicking on anything just takes you to the main FD page anyway. And every one of those pages shoves tickets down your throat.

Although if you click on anything, you’re greeted with this screen.

The “Athletes” link was the one link I was looking forward to. I wanted stats and information about drivers and their careers. Nope. I just get “coming soon”.

This post is getting super picture heavy so I’ll cut out all the “Buying” screens. Much like the other links, this is simply a frame to the FD shop. Complete with the two menus!

“Raceday Info” actually looks like someone put thought into it. I had some hope. I kind of get that the seating chart for Atlanta is “coming soon”. But the “information” section is simply text straight from the website. At least the driving directions link gives me something useful.

Things like this “Contact Us” screen is just taking up space.

I suppose I should give “plus points” for the valid Long Beach parking link. But OSW’s doesn’t work and that’s 3 weeks away. I also now realize that the “Raceday Info” section isn’t in chronological order of tracks. Orlando Speed World and Road Atlanta are swapped.

Here’s a good one. The FD101 link is straight up scanned pages from PASMag. What’s even better is that I can’t read any of the text. If I zoom in, the text is just pixelated. I can read the title and the months.

Here’s something that works. The rewards system! I did put in a few redemption codes and scroll through stuff. So at least that works.

Of course this is the google forms way of redeeming your rewards. I don’t have near enough points but I submitted for a poster (500 points but I only have 100). I will update with what happens.

Conclusion: The reward points seem to be the only properly functioning part of this app. But the only reason it functions is because it’s most likely part of the prefab app from HopScotch. That’s why the redemption is just a google form. Everything else in this app either links to a literal website, is canned text from the website, or a coming soon image. I hope FD didn’t pay much for this app because it looks like something that could have been made in a week of an intern’s time.

I would be embarrassed of such a useless and incomplete app. I think a mobile version of the main FD website would have been a better use of money. If anyone at FD is reading this, I do both web development and apps 😀

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Yoshi’s Drift Box: Day 10

Beta units have been sent out and I finally got a chance to test out my own unit at the track. So far my own personal use has shown quite a few enhancements I would like. But overall the logging features are working as intended.

This first image shows overall vehicle speed from the GPS (in yellow), coolant temp (in orange), and intake air temperatures (in red). What surprised me was that my coolant temps actually lowered while sideways. They went from 201F down to 192F. This gives me a lot more confidence in my cooling system. I was concerned that my intake temperatures were 92F at idle and got up to 104F. Over 40mph things seem to calm down. I might want to make a heat shield for the cone filter to get cooler air.

The GPS plot out is a nice to show how things apply during the run itself. Google maps doesn’t seem to be 100% accurate so seeing how far off you are from a clipping point can’t be done. The picture above plots coolant temps geographically. The pink color (waiting on grid) is the hottest and orange section on the straight away is where the coolant was the coolest.

This last picture is a plot out of rpm (in red), speed (in orange), and throttle (in yellow). It does seem like a jumbled mess but it shows a point (the green pin) on course where I’ve floored the gas pedal after I’ve dropped off for a bit (note the drop in RPM and throttle just before the red line marker). This is a point where I could have been better with my throttle control. If I had kept consistent on the throttle, I wouldn’t have needed to floor the gas pedal to make it into the straight away.

After reviewing the data, I found a few useful car “health” indicators that I can work on and a few driving points where I can improve. I’m still working on how best to change the UI and incorporate what I want but so far I’m pretty happy with what I’ve accomplished for $180.

My next step from here is to fix the export feature to overlay this data on video using DashWare. Right now the time frames don’t match up and the plots run 4x faster than the video. Hopefully it’s an easy fix.

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Drift Nirvana SC 3/26/17 lessons learned

*Disclaimer – This is mainly a brain dump for my own personal archive

Lesson of the day: Originally, my intent (as it has been the last few events) has to become accustomed to LFB and its proper usage. I did get plenty of Left Foot Braking in, but that was more from the Crown Vics we now use to teach newbies the basics. Basically, they get the steering wheel and I run the pedals on the skid pad.

I actually am playing with LFB in this video below

Regardless, the major point of the day were the 225 40psi Achilles ATR tires I was running. I’ve been told these tires have “less side bite” and I always assumed it was one of those subtle nuances that only good drivers could feel. But no. It was very apparent that the car wanted to float out whenever I was off throttle. If I was on throttle, the car gripped up and slid nicely. Unfortunately, by the time I was getting used to their grip level, they were already dead. After my 4th run, they were too loose to be of any use. By my 6th run, they were dead. So sadly, I barely got any seat time and had no time to practice LFB. They do smoke the most out of any tire I’ve ever used.

Next time, I’ll try to run some triangle tires as I hear they last a long time. I also hear they don’t grip too well and that they don’t smoke. At this point, longevity means the most to me.

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Yoshi’s Drift Box: Day 9

Ok well it’s almost been a month but a ton has been done. I managed to gather 4 beta testers and get a few of the newer arduinos. The screen is a higher resolution (I think 480×320 instead of 320×240) and shows much better in daylight than the old model. I think the aspect ratio of the screens are different so I’ll eventually need to redo the backgrounds. On top of that, there are now 4 plugs on the side (not that exciting), there is a reset button on the top, and the SD slot has been relocated to the top as well.

I had some issues with the touch screen and images showing up backwards but that’s fixed. I also had an issue with the touch screen sensitivity that the maker of this unit helped me fix.

The diagnostics screen now shows the list of logged PIDs dynamically with what’s in the config file within the SD card. Many bits of screen materials needed to be moved around for the new resolution. There is also new test code to properly read out DTCs that I’d like to test soon. I somehow broke the “Live Data” rpm code but I’d like to make that do more than just the time and RPMs.

For now, I’m working on documentation and polishing these units to be sent out for beta testing. I’m interested to see how people use this. If things go well, I hope to have enough feedback to do some firmware upgrades and logger upgrades. Finally, I have a drift event in just over a week so I’d love to finally test my outputs for video overlay.

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Yoshi’s Drift Box: Day 8

A bunch of miscellaneous things have gotten done but nothing super substantial. The logger viewer is basically in limbo for now. I had a bunch of feature requests and things that I thought would be useful. The GUI layout has changed drastically as I feel it’s very important to see everything at once. As a result, the application now opens in full screen mode.

The finished features include the following:

  • Play back functionality now working correctly
  • Integrated google maps into viewer
  • “Pin” location animated during playback
  • Accelerometer bubble
  • Torque log import/export features
  • Custom heat mapping for gps plotting (kml exportable)
  • General bug fixes/Gui updates

The important thing to note is that Torque logs are now accepted and exported. There is some video overlay software called DashWare I’d like to try out. Regardless, every video overlay software I found requires very rigid inputs and it seemed simpler to just export in a simple and known format.

Other than that, the main arduino unit itself now properly logs data fed in by the slave Arduino Uno. I’ve also tested input from a $4.27 GM clutch position switch (ACDelco part# D2203D). Eventually more inputs will be added but this is the simplest start to the process.

The main arduino mega unit now takes in config files for PIDs. I’m doing a limited release for some beta testers and I don’t want anyone to HAVE to compile and upload the arduino code. As a result, doing config files and images through the SD card is essential. Unfortunately, Freematics no longer sells the exact kit I originally ordered 2 years ago. On the bright side, the new unit has additional inputs and much better hardware options (better GPS module). I’m hoping to not have to recode much but some is to be expected.

So the near future to do list includes recoding for the new hardware, expanding configurations, and displaying your full PID list/etc on the diagnostics screen.

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Manual Brakes Postmortem

Warning: This will be heavily biased towards my specific setup. If you have had issues with boosterless brakes, this might work well for you though.

My brakes finally feel ok. I just finished a drift event 2 days ago and forgot that I even had issues with my brakes until half way through the day. They do take more effort than factory but not much. I feel like the firmness of the pedal is what spec E30 guys want in their cars.

The solution to my issue is still not completely clear. There was a spec E30 forum post I read where a driver hooked up pressure sensors to his brakes and depending on different inputs, the rear brakes would either work or not. He tracked it down to the rear proportioning valve. I debating on just deleting it but instead I replaced it with a factory unit for 12x the cost. At the same time, I swapped to a different (but used) factory cylinder, and deleted the ABS unit. The brake fluid from the old setup was pretty dark so I opted to replace the front brake lines as they were the most worn.

With all of those changes, my brakes felt great. In retrospect, I don’t think I know exactly what did it. My last master cylinder could have been internally fried from the heat from the headers. As a precaution, my new(er) master has a heat shield that attaches to the master cylinder mount. It should be attached to the engine but space doesn’t allow for it. Regardless, I could still grab the master after pulling off track from a run.

The other options are either the ABS delete or the rear proportioning valve. I kind of doubt the ABS unit because I couldn’t find it failing for anyone else. The online spec E30 forum post makes me think it was the rear proportioning valve more than anything.

I highly doubt swapping out the lines and bleeding the brakes did anything but you never know. In the end, this manual braking setup with the moved pivot point will work with the factory master. I went down the rabbit hole instead of simply investigating the rest of a system I didn’t know.

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