- The suspension setup on any racecar is critical to getting optimal performance
out of it and nowhere is this more true than in the sport of drifting.
And we're here with Aaron Parker who's relatively famous for debuting on the
Hyperdrive Netflix show in the pink FD RX7 that's behind us, however he's also a Pro 1
Formula D mechanic so he knows his way around drift cars and in particular
suspension setups.
We're here to find out a little bit more about what goes into a competitive drift
suspension setup.
So for a start I mean looking at your car here Aaron, it's pretty clear that you've got a
fairly wide track compared to stock and there's a lot that goes into getting that
wide track and something that's going to work as opposed to just a stanced out look.
So can you talk to us about the suspension setup you've got front and rear in the car?
- Yeah so everything we did here was trying to find a company that could
develop something that would actually work rather than just look good.
So I had to find someone that was local and someone who was willing to put the
R&D behind something that was actually going to work instead of just be there.
I found a company called Part Shop MAX and luckily they were looking to move forward
with the chassis, develop something that was available to the public, so we went
through the process of many many different setups, finally came into this one.
It's I guess custom, all the way from the lower control arm to the upper control arm,
to the actual knuckle itself, we had to make something that was drift specific that
didn't bind up and really just made putting an angle kit on the FD RX7 very simple..
- Alright so when it comes to your requirements as a driver, when you're developing a stock
FD chassis, and you want something that's going to be competitive in drifts, can you talk to us
about the requirements from that suspension system and their priorities perhaps.
- Yeah I guess I could go into this chassis, chassis specifics.
So a lot of people think that the chassis is very twitchy which makes it not so easy
to drive so everything with developing this kit was to try to take that out of it to make it
much more drivable.
'Cause it doesn't matter how fast the car is if you're not comfortable behind the wheel.
So very smooth, very easy and yeah I guess that's like the overall feel of that.
- So the first thing I mentioned was the fact you've got that wider track but I mean this
comes into again, your custom Parts Shop MAX components there and the suspension.
Now this is more than just bolting on a wide wheel with a massive offset,
'cause that affects your scrub radius as well which can be negative.
So can you talk to us about that because I think there's a lot of misconception there
about why we can't just bolt on a wide wheel with a massive offset and what's that going
to do to the way the car drives.
- Yeah so I'm not going to get into Ackermann too much because I think there is a lot of
misconception or misunderstanding about it but technically if you're in drift this way,
we've done everything to prevent the leading wheel from doing this.
Because it creates kind of like a floaty sensation that the drivers don't like,
it's very unpredictable.
So we do scrub on the rear, the trailing wheel and that actually helps stabilise the car
to make it more easy to drive.
- Now I'll just dive into that in a bit of detail.
Ackermann's one of those topics that is incredibly difficult to explain without the
help of some visual props but essentially the Ackermann steering is designed in a road
car generally around the fact that if we're turning a corner at low speed in a carpark,
the two front wheel basically turn through different radius' and the idea with the
Ackermann steering is that it equalises those radius' so the car tracks properly.
That's fine if you're driving around a supermarket carpark but when you're at
speed, the slip angle that the tyres tend to work at, that's not always going to work.
I mean everyone has their preference, again without trying to get too deep,
Ackermann, particularly in a factory application basically no adjustment in there.
So how do you adjust it with the Parts Shop MAX components?
- So we made a series of adjustable washers.
The washers themselves are fixed but they have keyways on them that will move I guess
the ball or pivot point to make it fixed for that washer.
So it's upper and lower and depending on which washer you have, you have more or
less Ackermann.
- So you're talking there about where the tie rod end bolts into the knuckle and those
are essentially for all intents and purposes an eccentric washer so you can move
that pivot point and it's the relationship between the steering knuckle where the
tie rod locates and the bottom ball joint, the angle of that essentially is going
to define the Ackermann?
- Absolutely, absolutely, yeah.
- Alright so in terms of the knuckles themselves as well, again this is an
area where drifting is quite unique, you need a lot of steering lock which
most production cars don't get anywhere close to.
So how do you go about getting that additional steering lock?
- So with this knuckle obviously we went through a lot of different renditions
of prototypes, whatever, we ended with a fully cast knuckle with built in trail
that is a kind of Parts Shop, I guess what we know
The built in trail is all of our knuckles for the most part had the same thing so
it's pretty universal for a Parts Shop car to have the same type of trail built into
each knuckle.
- I guess I should probably also just clarify that term.
Depending where you are in the world, it's different terminology.
The knuckle that we're talking about also referred to as the upright, essentially the
hub where the wheel bearing bolts onto correct?
- Correct, correct yeah.
- Alright so in terms of the other adjustments in the suspension setup, again just focusing
on the front for the moment, you've got a adjustable camber system which is quite
interesting.
And camber's one of those things that we're probably going to be adjusting from time
to time trying to make that nice and easy to do and quick to do.
A lot of people use left and right handed threaded rod ends.
You've got a unique take on that with some shims, tells us about those.
- Yeah so we're using shim stacks on the upper control arms to adjust I guess
camber overall.
You can also do it on our caster arm but with this car both things are kind
of integrated.
So one thing adjusts and then the next kind of, or one thing affects the other.
So we have two places you can do that with the caster in the back shims or on the upper
control arm with shims as well.
And it just gives you a little bit finer tunement if you have your caster where
you want, one kind of affects a little bit more and so you'll attack that one less
because you want to keep the caster closer so it just gives you an easier way to dial
in everything.
- Now in terms of the caster that you've just mentioned as well, this is a really key aspect
to affect the self centring effect and particularly with drift we know that
after a lot of people, after they've initiated the drift they'll essentially
let go of the steering wheel briefly and allow the car to counter steer by itself
and that's really that caster effect in action.
Can you tell us how much caster you're running on the car?
- So on this car I'm at 4.8 and that's pretty close to OEM but really you just want the
self steer to make the car easier to drive but you don't want too much because
then you're making all these corrections which could lead to understeer or in competitive
drifting you get deducted from making those steering corrections.
So less caster, more caster, you want to find the right balance so that the steering
is slow enough to control it without making those twitchy little mistakes.
- Alright so that's actually really important to fine tune that caster and get it to
a point where it's suiting the driver and the chassis?
- Absolutely yeah.
- Alright let's talk about the rest of your alignment settings there.
So I mean in the early days of drifting, it was all about breaking the tyres loose,
now as we've seen drifting become more competitive, teams are getting a little bit
more dialled into what's required and it's really come down to grip so that you can
go faster and faster.
So can you tell us what you're doing with your camber and how you're adjusting that
to a particular track, camber and toe I want to talk about there.
- In the rear?
- In the rear and the front.
- OK so in the front it's pretty fixed, I've played around with zero toe and I kind of
liked that just as much as maybe a mil or two of toe out.
And really those two things I can feel a very slight difference but it doesn't
affect anything so as long as it stays within those, I'm OK.
- In general the theory there is a touch of toe out at the front's going to promote
better turn in?
- Yeah yeah and then stabilisation at angle while you're in drift 'cause we very rarely
drive straight.
- OK so and then at the rear?
- So the rear is almost a little more important.
You want me to talk about the full setup?
- Yeah let's talk about the full setup for a start.
- OK so I guess with the rear, what you don't want is for the rear to be unpredictable.
So when I set this car up, pretty much I take the coil over off, put the car up on jack
stands and everything and I cycle the suspension, the rear goes up and down
and I have to make sure that the toe doesn't change throughout that
entire range.
- So you're talking about the potential there for bump steer built into the
factory geometry?
- Yes yes and I mean you'd be surprised what you would find in some setups,
especially OEM stuff, you'll get toe out.
People are like oh my toe is this or whatever and I'm like yeah but it's not
moving and the car is always moving, the suspension's always moving so
you really need to take the coil over off and cycle the suspension up and down
without it in, that way you can see what it's doing throughout the entire stroke.
- OK so once you've eliminated or made sure that you haven't got any significant
bump steer in that rear suspension, what sort of typical toe settings are you
actually running at the rear?
- Depending on how fast the competitive cars are, the other cars, you'd do anything
from zero to, man, really about an inch or, what was it, 25 or 30 mm.
- That's a huge amount of toe in, you'd never run anything like that in a grip racing,
circuit racing application.
So how does that amount of toe in help in a drift application?
- So it gives you a whole lot more forward drive and then a lot of people lose,
in their transitions, they hold too much angle for too long, the next car is holding
shallower angle and they use it in a very small window through the transition to
drive the car forward.
So the car will feel terrible in a straight line but when you're drifting it'll give you
that drive in and out so out of the transition into the next one you'll just
get this slinky effect that the other guys can't catch up to.
- So this is where you really need to understand the application and apply
wheel alignment settings that are going to work for your particular application,
again just talking about the fact you'd never run anything like that in a circuit
racing application but of course you're going straight in a circuit racing application,
you're going sideways when you're drifting.
Now in terms of optimising the camber settings, how are you going about doing
that, and I mean I'm guessing tyre temperature, particularly at the rear is
pretty tricky because you're always turning the rear tyres anyway.
- Yeah so pretty much we use camber in the rear to get more traction out of the car.
And now it's become a game more of getting the tyres to last two laps.
So if you're getting uneven wear that means that you're getting hot spotted on the inside
or the outside of the car, you use camber to flatten that out.
So you really want an even wear around the entire tyre to make sure that you're
utilising all that rubber getting to the ground to propel the car forward.
- So rather than relying on conventional tyre temperature pyros, something like that,
due to the usage you can essentially look at the wear and assess you camber
requirements based on the wear?
- Yeah yeah and I mean you can overheat a tyre and it'll last longer or you're not
getting it up to temp quick enough and then you lose off the line or something.
- Look it's been great to get some insight into that suspension setup Aaron and
from what I understand, you're stepping up to Pro 2 for Formula Drift next year so
we wish you all the best with your season next year, thanks for the chat.
- Thanks man, you guys have a good one.
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