- Hey team, Andre from High Performance Academy here, welcome along to another one
of our webinars.
Today we're going to be diving into a more advanced way of adding switches and driver
controls to the steering wheel.
Now we are in our SR86 and I'll just get the steering wheel here into view and we've got a
bit going on here.
Obviously going to dive in a lot deeper as we go through today's lesson but basically a bunch
of switches to control things.
On the back of that steering wheel as well we also happen to have our paddles for our
paddle shift.
And traditionally one of the problems with doing this is it requires a lot of wiring to get
between the steering wheel and the chassis and yes there are ways of doing this with a
passthrough connector, basically an autosport connector build into the detachable hub.
Those are expensive and require quite a lot of tricky wiring to get those working.
The more usual technique is a curly cord and once you start getting up in the conductor count
in a curly cord, these become somewhat problematic in their own sense so we're going
to talk about CAN switchpads, what they are and how they work.
We'll have a look at how we've interfaced the Ecumaster CAN switchpad in our SR86,
some of the functionality that we are using within that.
Before we dive into today's lesson though, just to catch up on a few things that have been going on
over the last couple of weeks.
And these pre shows have of late become a bit of a rundown on our racing endeavours with
the SR86.
We're kind of in our off season at the moment, we've got a few months to go before we get into
the meat of our racing which is our endurance series and for those who are long time followers,
you'll know that we continue to have our challenges thrown up by this car, we started
really strong with an outright win in our first round and then basically self destructed into
a range of problems from suspension failures to cracked main caps in our SR20 block.
We are hoping that we are getting closer to being on top of that.
But one of the things we have been playing around with is some of the aero development
and again for those who have been following, we have put a Top Stage composites rear wing,
rear diffuser and front splitter on the car.
And those in their own right really transform the car.
For those who maybe are sort of wondering, well what does this bolt on aero componentry
really do?
We're talking about increases of cornering speed, just in one fast part of Highlands
Motorsport Park where we're up from a starting point of about 160 km/h, we were up about
17 km/h.
That is huge.
The other advantage is braking distances are reduced, we can brake later and carry more
speed into the corners so all things being equal, I think the aero alone, and it's hard
because we're not in a position where we tend to make just one single change but if I
could do a best guess, I think the aero alone was good for about a reduction of 1.5 to
2 seconds per lap, around 1:40 lap so that's definitely a significant improvement.
And you can see the aero working not only in the increased cornering speed but of course
it does come at a cost which is drag and when we're down around about 7 km/h in top speed
down the fastest section of the front straight so despite that reduction in top speed we're
also significantly faster.
That being said, we did still have some work to do and we'll jump across to my laptop screen,
it's a little hard to get a sense of all this but I'm going to try and talk you through it.
This is the view of the rear diffuser, sorry yeah rear diffuser that is at the back of the car,
obviously there's a hint there because it's a rear diffuser, not a front diffuser.
Clearly it's at the back of the car.
And the problem with this as it's installed at the moment, and this was always going to
be a temporary measure, is that you can see it's got essentially nothing to guide airflow
onto it, we've got this square upright lip at the front edge of it.
So essentially we've got the air flowing from the front to the rear of the car in the direction
I've just put that arrow and there's nothing really to just guide it onto that diffuser and
what we really want the airflow to do is kind of stick to the underside of the surface there
and it gives the downforce as a result of this and the pressure differential of that is created.
Now not an aerodynamicist just to be clear here, I'm just sort of giving a really high level view of
what this does.
But for it to be effective, we really need that air to be guided nicely onto the diffuser,
we're going to instead have a whole bunch of turbulence caused by this flat face that
the air's going to be hitting.
Plus we don't really have nice smooth flow of the air under the car anyway due to the fact it's going
to be bouncing off all of the componentry under the car.
Now if we look at the front, so now we're looking from the rear of the car forwards and this is
obviously one of our brake cooling ducts just to give you a bit of an idea and this is the Top Stage
Composites front splitter.
So again we've got this little lip here which is designed to sort of incorporate to a flat
floor section and again we always intended to get this flat floor into place but priorities,
it just hasn't been something that we've been able to spend time on.
One of the things we were quite careful of with when we were installing these components
and we were backwards and forwards talking to Freddy from Top Stage Composites over in
Australia about this, these aren't just off the shelf eBay special components, these are
actually designed with CFD so they're a step ahead of the eBay rear wings that you see
around and these are proper components and Freddy's able to give us actual data on the
sort of drag and down force that they will produce.
So one of the elements we talked quite closely to Freddy about, aspects around the height of the
diffuser and the splitter off the ground and basically making sure that when we were
installing these components, the likes of this front lip here at the back of the splitter
and that flat section of floor at the back that we just looked at with the diffuser at the
back were in a line so that was really important so we can integrate a flat floor.
Anyway moving forward, we finally got the opportunity to do this.
So it's not an easy job, there's actually a bit more to it than I think we had originally
considered and it starts with this aluminium frame here that you can see that Jimmy and
Brandon fabricated up.
This bolts to the underside of the car.
Actually spaces down off the underside of the car quite significantly, also what we can
see here, and I'll talk a little bit more about this shortly is we've got a little cut out on
each side there for our air jacks and we've also got these two NACA ducts, again I'll
discuss those in a bit more detail.
So this basically bolts to the underside of the car and it connects the front and rear.
Now I haven't got a picture of the whole thing installed.
It's so reflective it actually is just about impossible to get a good photo of it but
with the floor standing up, that's what basically the underside looks like now.
So perfectly smooth, perfectly flat.
And of course we're expecting that this should help our aero performance.
Now a couple of things about this because I know a lot of you will be thinking or asking
what the material is that we've used here.
So it's a material called Aluplast.
And the hint in its name there is two very thin layers of aluminium sandwiched with
plastic in the middle.
It's not the best product because it is unfortunately quite heavy.
This whole contraption including the flat floor and the alloy framing that we made is somewhere
in the vicinity of about 16 kg, what's that, about 32, 35 pounds, sorry I can't do the math in my
head there but yeah it's quite heavy but I'll get into how we're going to sort that shortly.
You can see it's 4 mm thick so one of the nice aspects about this with the construction,
it is actually quite rigid, it's got quite a lot of strength to it and obviously that's important
because we don't want the risk of this coming loose and ending up under a tyre or
something of that nature, that's not going to end well.
So it's important to have something with a reasonable amount of rigidity on the car.
Now we've had two opportunities to shake the car down with the underfloor on it and
unfortunately at the moment we haven't really been in a position to get good solid data.
But I just wanted to talk about the plan of how we go about this.
First of all, before I talk about that, I just want to talk about one of the concerns we had which
is around the heat generated with that flat floor.
And obviously we've got the exhaust system running under the car through the transmission tunnel,
we've got our Hollinger SG3 transmission in there, the diff at the rear and because this car is used
for sprint and endurance events, heat control is something that we very much do take quite
seriously.
So by basically enclosing that underfloor, we're not allowing airflow through the transmission
tunnel or at least nowhere near as much airflow as we would normally get and the other aspect there
is we've got no easy way of getting the air in and out.
So what we've done, just to try and alleviate some of that, or get some airflow in there is
to add a couple of NACA ducts to the underfloor.
So you can see one there in close up and if I just go back a little bit, you can see we've got one
at the front, actually that's the front there, and one at the rear.
So that's just about getting some airflow around that exhaust.
Now again a little too early in the piece to really have solid data on this.
What we intended to do is actually temporarily fit a temperature sensor in the transmission
tunnel, do some runs around our local track with and without that flat floor and just see how
they compare, however I do have some data that's of some value here so did a little club sprint event
at Highlands Motorsport Park on the weekend and it was only around a very short section of the track
so not a good test but what we can monitor here, this is our transmission worksheet and we've got
transmission and diff oil temperature and we do run an oil cooler for the Hollinger transmission
and you can see that through this section here which is lap 11 of 13, our transmission temperature's
sitting at 78°.
That's a little hotter than we've previously seen, previously on some very long runs around
about 30 minutes of racing in very very high ambient temperatures, certainly higher than we
were seeing on the weekend, the highest we'd seen was about 75, 76 so to be able to get up to
78 under short run like we've got here, albeit running quite a higher power setting,
it suggests that we do definitely have a little bit more heat that's getting into the transmission.
That being said, 78° is still incredibly cold and I wouldn't be concerned running that transmission
temperature up around 100° so we've got no problem with that as it sits.
So little bit more testing to go, if we come back, I think my fastest lap of the session,
was lap 7 and we can see that transmission temperature staying pretty consistent,
76° there and I did slow down and do a cool down lap but in the final lap I think the highest
we saw was yeah 80° was our peak temperature so certainly nothing to worry about, looking
reasonably good so far.
Alright so, how do we validate if these components work?
And we're obviously not in a position where we can put the car in a wind tunnel,
to the best of my knowledge there's no wind tunnels in New Zealand so that's not a relevant
technology.
So one of the ways we can go about this is that we do have shock travel or damper position
sensors on the vehicle.
So obviously when we create downforce at speed particularly, what that tends to do is it compresses
the car into the ground.
So we can do some rough calculations and admittedly they are quite rough, that's all they're
good for, based on the spring rates, the wheel rate of the car more particularly and we can do
what's called a coast down test.
So that's where we'll get the car up to a reasonably high speed where we know that the
aero's going to work, I can get up to around 210, 220 km/h in the fastest section of the track
and basically disengage the clutch, put the clutch in and just allow the car to coast and gather data.
So what we can do there is basically go to the track and gather data in that way with the
flat floor then without the flat floor and then we also actually want to remove the rear diffuser
entirely and just see what each of those components is doing.
Now again for the aero buffs out there, I know this is not a foolproof solution but it is
reasonably effective for our particular application in so much as we're at least getting some idea.
And just to see what those sensors look like, if we jump back over to my laptop screen,
this is our right rear here and you can see we've got a Penny and Giles linear travel potentiometer
there that is located between the bottom and the chassis.
One of the aspects when you're configuring and installing these you do need to keep in mind is
the motion ratio.
So that's our inner pivot there, this is our outer pivot here, obviously out of shot somewhere
over here we've got the centre of the wheel and what we're really interested in here is
the wheel travel.
So here we've got our linear travel potentiometer and then we've got our shock or damper itself.
So there's a motion ratio related to each of the mounting locations of those so there is a bit
of calibration that is required in order to get actual useful data.
Now segueing nicely into our latest podcast release and I did get the opportunity to talk
to Andrew Brilliant from AMB Aero who is a very well regarded aerodynamicist in the
motorsport industry, particulary on this side of the world, he's been involved in a couple of
really high profile World Time Attack cars as well as numerous others that I won't
go into but in our interview with Andrew we did actually talk about this exact technique.
And to validate the data, that's really the key here in terms of getting an indication for how
many millimetres or inches of compression, what that actually relates to in terms of the load
being applied by the aerodynamics and he is an advocate of the test he calls the pile on test.
So I dug in a little bit on that because obviously I was interested and turns out that the pile on test
is simply where you get a bunch of your mates and get them to pile onto the car and then you
know the weight that is being applied to the car and you can measure or correlate that to the
compression of the suspension so sometimes you don't need to be spending millions of dollars on
research and development, there are some techhniques that for a modest cost will get
you at least part of the way towards knowing what's going on so there you go, we'll give you
some more information on that as we actually get the opportunity to do those coast down tests.
But as I mentioned, segueing into our podcast, if you've been living under a rock, you may be
interested to know that High Performance Academy now has our very own podcast that is the
HPA Tuned In podcast.
And we'd love it if you could go along and have a listen and if you like what you're hearing,
leave us a rating and leave us a review, we always love to hear what our listeners are liking, disliking
for that matter and what other guests you'd like to have along so as I mentioned we've got Andrew
from AMB Aero joining us this week and just to give you an idea, there we go, if we jump
across to my laptop screen, couple of the cars that I mentioned there, he's involved with at
the World Time Attack event which we're actually off to in a few day's time.
This is the Scorch Racing S15 and as you can see, lot of stuff going on there, it's pretty far removed
from a factory Nissan S15.
Another car that he's well known for is the Life Motorsport R35 GTR which did do an
appearance at World Time Attack and was also racing, I think it's the Grid Life events
in the US among others such as Pike's Peak.
So really interesting to get an idea from Andrew on what goes into the design and
development of aerodynamic components for cars, how he goes about it, what his philosophy is.
The fact that downforce is not everything when it comes to the development of these components
as well and how to design so that the team that own the car are actually able to produce these
parts because there's no point designing the most intricate components in the world that
require pre preg layup and the use of an auto clave in order to actually produce a
finished item so yeah there's a lot of great information in that podcast and I would urge
you to go along and check that out, remember you can check that out at hpa-tuned in and you
can listen to it or find it anywhere that you currently listen to podcasts.
Now on that note, I just talked about the actual production of parts and if we come
back to the flat underfloor, I mentioned that the aluplast that we're using at the moment is
reasonably heavy, that whole unit's somewhere around about 16 kg at the moment and that is
quite a bit of weight to be adding to the car which obviously weight is the enemy, we don't
want to do that.
This is simply a test and if we do find out that that flat floor, first of all doesn't cause the car
to overheat and burn to the ground, that would be number one, would also be really nice.
And also gives us a nice bump up in terms of an improvement in downforce, a reduction in
drag or potentially even both.
Then what we will do is we will be redesigning that component and constructing it out of a carbon
Nomex honeycomb core and we'll be vacuum bagging that.
So with that, we're expecting that should get us somewhere around about a 1-1.2 kg per square metre
so probably the whole thing there, around about 3.5 maybe 4 kg plus the weight of that aluminium
frame which is around 4 kg so from 16 we should be down to around 8, so around half, so quite a
significant saving.
And on that note, I'd like to ask you a favour.
We have always, we always are looking at new course ideas and for those who have been
following recently, you know that we've branched out into fabrication, we've just released our
Fabrication Fundamentals and TIG Welding, Practical TIG Welding courses.
Another area that we're really interested in developing and we're considering doing some
courses and material around is composites for motorsport.
So basically how to make components out of kevlar, carbon fibre, fibreglass etc, how to make moulds.
And with a really specific slant around motorsport components there.
So let us know in the comments if that's something that you would be interested in.
We'll gauge the interest out there and it's something that we may well develop in the
near future.
Alright enough with our pre show, I do appreciate you tuning in and watching.
Give me a few moments and we'll get started with today's lesson.
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