posted on February 20, 2012 00:00
Basic Drift Chassis Setup Part 3
By Mike Kojima
Alignment is one of the most important things in getting your drift car to handle correctly and a subject that is mangled quite a bit on internet forums. It is important to make your alignment adjustable. In the case of you having a popular car like a Nissan S chassis you can get adjustable front tension rods, rear toe, traction and camber links all off the shelf from companies like SPL Parts and Battle Version. If you have a car with MacPherson struts in the front, you can often get camber plates. Ground Control Suspension has camber plates for many different cars.
|Costa Gialamas uses Smart Strings to set up Matt Powers' S14. Smart Strings are one of the best things to happen since sliced bread. They allow precise alignments to be done in the field quickly.
If you have a car without much aftermarket support, Ingalls Engineering, KMac and SPC all make adjustable alignment parts so you can make non adjustable things adjustable for most cars. As a warning, stay away from camber bolts, they use a small diameter bolt with a cam on it and have a tendency to stretch and slip on cars that are driven hard. One way to make the camber adjustable on MacPherson strut cars cheaply is to drill out one of the spindle bolts slightly. Then you can tilt the spindle inward while tightening up the bolts. Surprisingly this will not slip as long as you tighten the stock bolts fully. This can get you a couple of degrees of adjustment.
Once you make your car adjustable you can try these basic alignment settings. These are settings that are good for drifting and are not necessarily good for everyday street driving. Rapid tire wear on the street may occur. However you will probably get better tire wear when drifting!
|Mike Kojima uses a Smart camber gauge to set the camber on Dai Yoshihara's Falken Tire S13. The smart camber gauge is one of the best ways to set camber in the shop or in the field. It can also be used to set caster.
3-4 degrees negative camber helps put the tread flat on the ground when under side load. Under load, the tire's carcass wants to flex and lift the inside of the tread off the ground. Also as the car rolls, it wants to tip the tire to where the inside of the tread is being lifted off the ground. The car’s suspension geometry tries to make up for some of this but it cannot totally compensate. Running negative camber compensates for this. By keeping the tread on the ground you get better front grip and less understeer. You don’t want your drift car to understeer if you can help it. If your car has multilink front suspension, you can use closer to 3 degrees of negative camber, strut type suspension can use closer to 4 degrees. Don’t run crazy amounts of negative camber, like demon camber hellaflush style, it’s going to hamper your front grip.
|Negative camber on the left and positive camber on the right is illustrated here. Modern tires should never be run with positive camber. For a drift car you want to run 3-5 degrees of negative camber.
|Although it is "cool" to run tons of negative camber, please leave that to the hellaflush show guys. Demon camber hurts performance.
For more on drift chassis setup read “The Ultimate Guide to Suspension and Handling”
Monday, February 20, 2012 3:11 AM
A good write up on understanding the basics of alignments. I noticed you didn't describe or define how to find your scrub radius. The picture can be misleading. It just so happens in the picture the wheel has its centerlne right on the hub face. It's my understanding that solid axle cars have no rear camber recovery in roll. So the desire to have rear camber adjustmnet is just to reduce rear grip(slightly). Mike, If solid axle modifications are too expensive would it be safe to say trying different width tires to find the correct balance of grip?
Monday, February 20, 2012 6:26 AM
Can the pictures be hyperlinked so we can see them larger? It's hard to see the detail on a laptop, even with 20/20 vision!
Very interesting stuff. Glad to see someone who has actually worked on a pro drift car give out some of the secrets. Obviously fine-tuning is an art, but this should help get a lot of people going in the right direction.
Monday, February 20, 2012 8:50 AM
Hi Mike, another nice article you have published.
I have a question about adjusting the length of the traction arm. I understand it is used to adjust the knuckle's caster and by increasing it the toe arm mounting point on the knuckle is lowered, since the knuckle is rotated.
What kind of a toe curve would be good to use? Body roll 0-4 degrees vs toe angle at those values for a street driven car and for a track only car?
Monday, February 20, 2012 12:13 PM
Great article! I was waiting for the alignment section to come out :) I also wanted to ask: say you have an S chassis and you are more into the road racing side of things, but like to do a drift event from time to time, which alignment specs would you change between the two, and which ones would be good for both?
Monday, February 20, 2012 5:56 PM
A bit off topic - but how come toe is measured as a distance (which will vary depending on where it is measured. Some measure it at the tread, others the rim as is being done at the photo). From an engineering point of view, specifying it as an angle leaves no ambiguity - Camber is an angle for example. I appreciate that it is easy to measure it as a distance (no trig involved), but in engineering circles is it still done the same way?
Monday, February 20, 2012 6:08 PM
I gave you a very detailed answer and it disappeared somehow. In short I have never done a super detailed toe plot on an S chassis, just a few checks to make sure pivot relocation didn't do something stupid. Personally I just run close to stock.
Monday, February 20, 2012 6:28 PM
You still have to measure the toe setting to know what it is and if you want to convert it degrees, that's fine. It's probably because it's easier to measure it as a distance.
I am an engineer and I don't think it's ambiguous, nerther do most motorsports engineers I know!
Monday, February 20, 2012 6:29 PM
2 liter, for a simple non pro drift car, the settings that work for grip driving won't do you wrong,
Monday, February 20, 2012 6:55 PM
So is the convention that toe is measured at the tread or the rim? Or do you quote that as well? Measuring it at those two places will clearly result in a different number.
Monday, February 20, 2012 7:14 PM
No it doesn't. You can measure it either way. The disadvantage of the rim is that if the rim is bent the reading will be wrong. You don't actually measure the tread, you scribe a line in the tread and measure from that.
Monday, February 20, 2012 7:27 PM
Tell me where I'm wrong (I'm not trying to be argumentative)
If toe is the measured as the difference between the leading edge and trailing edge of the tire measured to the centerline of the car. Then if the wheel is kept in exactly the same place, but the measurement point is moved towards the center of the wheel (rim edge), then the difference will be less (and thus the quoted toe number will be less) - I don't see how it can't be. On a 17" rim with a 255/40 tire, if the toe measured at the rim is 3mm, it will be ~3.7mm on the surface of the tire - 25% 'more', but the wheel is at the same angle.
Monday, February 20, 2012 7:31 PM
...I mean ~4.4mm - 46% more
Tuesday, February 21, 2012 1:30 AM
It's not worth worrying about the difference. If you are measuring from the tire, you cannot go to the middle of the tire due to the chassis of the car so the points are about the same.
Tuesday, February 21, 2012 3:45 AM
Hi there ! Nice job describing this.
I do have a problem with the rear traction control arm on S chassis though. I noticed that by lenghtening it on a lowered car makes the spindle "rotate" and help reset toe arm pickup point to its original place. Which means you need to lengthen it to get the suspension working correctly : i noticed that the shorter it is, the more the car toes out on droop before toeing in again. The car is supposed to toe in both on compression and droop, and it is achieved by setting the toe pickup point at an exact place. I noticed that after spending a whole day trying not to spin out when braking and cornering hard ( Grip driving... i spun out many times that day ). After playing with a jack lifting and lowering rear LCA to notice the kinematics and some measurements, i noticed i had the traction arms shortened about 1/2" compared to oem . When i added 2" to its current length, the kinematics was much better (nearly no toe out on droop) and it felt much less snappy.
I dont have your experience, so maybe i am doing something wrong or missing something. Can you help ?
The chassis is an S13 with cage, PU bushes everywhere, soft coilover springs, bigger ARBs. Subframe tilted a little bit forward(1/3" plates between the 2 front bushes and chassis). Alignment was fairly neutral with -1° camber front and rear, 7° caster, 1/10 toe in rear, 1/12 toe out front, and done with me in the car on a laser bench by a good mechanic, so was really well done.
Tuesday, February 21, 2012 8:23 AM
You get toe out on droop when you've overlowered it, you can cut off the the toe link mounting on the knuckle or add a second one and lower it so it would be parallel with the lower control arm.
Tuesday, February 21, 2012 9:20 AM
Is the next part of this going to get into theories of rear squat and anti-squat geometry in drift cars? I've heard some competing ideas on this.
Tuesday, February 21, 2012 9:28 AM
Here is an example of not being able to measure the toe at the tire at the tires midpoint due to stuff getting in the way.
Tuesday, February 21, 2012 9:33 AM
Making the toe rod too short will make the suspension trend to toe out on full droop although this usually isn't a problem.
You should be tilting the front of your subframe down not the other way, and you are running way to little front negative camber. Laser tables are usually very inaccurate even when set carefully.
You should inspect your PU bushings as the rear suspension requires 3 degrees of freedom in movement and poly bushings don't do that well. They can take a compression set and develop play which will result in really bad handling. Unless they are carefully engineered like Whiteline bushings with proper cutouts.
Tuesday, February 21, 2012 9:35 AM
What you want is more theoretical and advanced stuff which we will cover later. As far as it applies to drift cars, their is no hard and fast rules. A high powered pro drift car driven by a top pro is set up a lot different than a drift day person or a lower level pro-am person in a lower powered car.
Tuesday, February 21, 2012 9:52 AM
Just for quick reference, would a less powerful car not need be concerned some much with anti-squat whereas a higher powered car might benefit more? Is it a driver preference subject or will one make for a faster drifting car like you would want in FD? I know this does not apply to my beater but I am curious.
I've read an older SCC article that I think you were involved in that mentions a number of older Nissan chassis have a fair bit of anti-squat built in.
Tuesday, February 21, 2012 1:21 PM
Mike, Epstien on NRR did a bumpsteer graph for the S14 rear subframe.
Wednesday, February 22, 2012 1:47 AM
A grippy fast car is harder to drive. Thats the difference between a pro car and a weekend warrior/lower level semi pro car.
A lower level car/driver should not be concerend about trying to mess with anti.
Wednesday, February 22, 2012 8:19 AM
Another great article, Mike! It has made me think a lot about scrub radius vs. inner wheel clearance on a drift car. Angle (especially on entry) is a key judging point, especially at the pro-am level. Is it worth it to sacrifice some steering angle for correct scrub? What wheel offset/width would you recommend? Right now, I'm looking at 17x8.5 +25 or +35, or 17x9 +15
Wednesday, February 22, 2012 11:44 AM
Thanks for your inputs. I dont think the car is overlowered... coilovers are at the highest setting, and there is quite a steep incline to get out of the garage. It is even going to be a bit higher soon as i am switching from 5-4kg/mm to 7-5kg/mm. I am also currently replacing all suspension arms for ball joint arms . Already did the front, but had to stop before doing the rear as i have no heater in my garage and temp is negative.
I was planning to run 1.5° camber front, do you really think it is not enough ? These are not race tyres (maxxis maz1), and i am driving the car from home to track (i should not i know ... but no room, time nor money for a trailer, new driving licence and another car). It is a 150miles trip every time. I would prefer ruining my tyres on track, not on the road leading there so i have to make a compromised setup. For now :D
Wednesday, February 22, 2012 12:32 PM
Crousti, you need at least 3 degrees of negative camber.
Chubby, we run longer lower control arms to get angle and keep scrub reasonable. We also run a much wider front track width which helps the car as well.
Wednesday, February 22, 2012 3:50 PM
Mike - When you gave that detailed answer to Motary, was it from your phone? I was telling Aaron a while back, I can't write much more than a paragraph from my phone without it disappearing. Speaking of Aaron, do we really need more than a couple of dinner trays to set up his FF platform for some drifting and Youtube fame!? ;-)
Wednesday, February 22, 2012 4:07 PM
Thanks, Mike. Say you didn't have longer/adjustable lower control arms and couldn't run a much wider front track?
You said in one of the threads in the forum that you try to stick with a similar width-to-offset ratio as the factory wheels. i.e. If the factory wheel is 6 inches wide with a +40 offset, that is about 25%. That would mean to upgrade and keep a similar ratio, you would go for an 8 inch wheel with a +48 offset?
That wouldn't leave a lot of inner clearance for increased steering angle.
Wednesday, February 22, 2012 6:50 PM
I would give up scrub to get more angle in that case.
Saturday, February 25, 2012 9:27 AM
I noticed you said.to leave the ackerman close to stock or.add some. I'm wondering if you notice the drag from the wheels toe'd out at full lock. I was always under the impression to reduce ackerman to get faster in drift.
Saturday, February 25, 2012 12:46 PM
I actually run a little less that theoretically perfect Ackerman with the intersection point about the rear of the car instead of the rear axle centerline.
In my opionion taking out Ackerman makes the car less stable in drift and screws up self steering forces if taken to the extreme.
Sunday, March 18, 2012 9:29 PM
What suspension parts for the S14, other than coilovers and LSD would you recommend for a daily driven drift car?
Monday, March 19, 2012 7:16 PM
You wrote " 1/8" total toe out in front." What would that equal to in Degrees? When you say total, is that 1/16" out on each wheel? This is my first post after reading all of the "Ultimate Guide To Suspension & Handling". My knowledge of Suspension was basic and rough at best before so I was just winging it with lucky driving. I am highly motivated about learning more, and open to any suggestions on where to do more research on chassis setup for drifting.
Monday, December 31, 2012 7:38 PM
Hey Mike, I'd love to get advice from you on some suspension fabrication I'm working on. It's for 2013 PRO-AM Formula D, as well as time-attack.
Should I move my pick-up for rear control arms on the subframe side, or knuckles? Or a combination of both?
Also when I reduce my anti-squat to close to neutral (somethign else I'd like advice on), since the rear will squat more, since I'm leaving the rear spring rates at 6k, won't the toe curve (traction rod adjustment) at factory curve be a little too much? So shouldn't I reduce the toe curve slightly to accomodate for having a little more squat? I tend to run with the rear damper really high (last season), just because it's what I've felt comfortable with for aggressive transitions.
Track width, is there any negative affect on the handling of the car with having wider track width on the front than the rear? (difference of maybe 30mm wider per side?)
Any and all input is well appreciated! I've been following your posts for a while and have learned a lot from you. Thanks!
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