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Motorsport Wheel Alignment: 1. Setup Suspension Components

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1. Setup Suspension Components


00:00 - The first step in our process here is to take all of our new suspension components and get some baseline settings on them so that we can install them into the car.
00:08 Now we've got some advantages here because our other Toyota 86 has the same SPL suspension arms in it.
00:16 We've already got an alignment on that car that we know is working.
00:19 So we can take some baseline settings off the existing arms on our other car and apply these to our SPL arms.
00:26 That might not have us exactly where we need to be but it's going to get us into the ballpark pretty quickly.
00:33 Of course, if you don't have the benefit of another car that's already properly set up, a good place to start with adjusting your aftermarket suspension arms is to simply measure the length of your factory arms and replicate that.
00:46 You know therefore you're going to at least be in the ballpark with the stock alignment and you can make your modifications from there.
00:53 As we discussed in the introduction, the MCA coil over suspension is already adjusted as delivered so this should pretty much be a drop in replacement and it should already get us to our desired ride height.
01:05 Of course we will still be measuring that.
01:08 The camber on the other hand, particularly with the front MacPherson strut, will need to be adjusted to get us where we want to be.
01:14 So we'll start by adjusting our new SPL Parts rear lower control arms.
01:19 The measurement that we've taken off our existing car gives us a centre to centre length for the arms of 448 millimetres, so we're going to start by adjusting the new arms to match that measurement.
01:31 Of course, we don't need to be millimetre perfect here and we will be able to make further adjustments on the car once we're actually making our alignment checks.
01:40 However, again this is going to get us into the ballpark.
01:43 So we've got our SPL Parts lower control arm and before we make any adjustments, what we want to do is loosen off all of the adjusters so that it's going to be easy for us to adjust the overall length.
01:55 It's also a good idea to make sure that the rod end and the adjuster are both at their minimum travel.
02:00 What this means is that as we extend this out to get our arm length where we want it to be, we're going to be making equal adjustments to both the rod end and the adjuster where it threads into the CNC machined body of the suspension arm.
02:14 So let's start by taking a baseline measurement and seeing where we're at now.
02:22 OK so as delivered there, at their minimum length, these are around about 416 millimetres centre to centre so we're obviously going to need to extend those out, let's go ahead and do that now.
02:43 OK we've got our first arm adjusted there.
02:45 And it is important when we are adjusting any aftermarket suspension arms just to be aware of how much engagement we've got with our threads of both the rod end as well as the adjuster.
02:57 Now we've got some recommendations inside of the course that we want to make sure that we've got at least 1.5 times the diameter of the thread engaged.
03:05 There's also some recommendations that come from SPL so we want to heed those warnings as well.
03:11 Just to make sure that we've got adequate strength in these components once they've been adjusted.
03:15 Now that we've got our first arm adjusted, rather than going through the same performance with the second arm and adjusting the overall length, what we can do is use our vernier calipers to measure the extension of that rod end and we can then match that to our other arm.
03:30 When we are using vernier calipers to make this measurement, we do need to take a reference point on our rod end that we can then replicate on our other arm and the point I'm going to be using here is just at the end of the rod end, where the thread meets the body of the rod end.
03:45 So we're just going to extend our vernier calipers out to that point here.
03:49 And we can see, once we're at that point, we're measuring about 54.5 millimetres.
03:56 So this is the measurement that we're going to then replicate onto our other arm.
04:00 It is important to mention that we can get away with this because we are using CNC machined arms.
04:06 So the body of the two arms are exactly the same, they're just a mirror image of each other.
04:12 Of course if you are doing this with fabricated arms, you'd want to be checking the overall centre to centre length, as we've just gone through.
04:19 Now that we've got that measurement, let's go ahead and we'll apply that to our other arm.
04:30 With our rear lower control arms now adjusted, we can repeat the process on our traction arms or rear trailing arms as they're also known.
04:38 Now again these are a component that we've sourced from SPL parts and we've started by loosening off the adjusters so that we can get our length correct.
04:46 Now the measurement that we've taken off our other development car is a length of 294 millimetres centre to centre.
04:54 So again we're going to use our steel rule and we're going to measure our existing length and adjust this to suit.
05:03 As you can see at the moment with the arms as delivered in their minimum length position, we're at about 252 millimetres so we're going to need to extend this a fair way, let's go ahead and do that now.
05:28 We've got our first arm adjusted to the correct length and again we need to be mindful while we're making these adjustments of our minimum engagement length with our threads.
05:37 Now a convenient option with the SPL Parts arms is they do have a machined slot so you can actually visually see how much engagement you've got with the threads.
05:46 Now again just like with our rear lower control arms, we're going to now measure the length that we've extended that rod end using our vernier calipers and apply that to our other arm, so let's go ahead and do that now.
06:10 Last but not least, we've got our front lower control arms to set up and adjust.
06:13 Now there's two adjustments on these arms.
06:15 We can adjust the track width of the car and independently we can also adjust the caster.
06:22 Now here, again we've got the benefit of having the exact same arms in our other development car so this simplifies things, particularly when we are adjusting the track width.
06:34 Rather than needing to measure the overall length of the arm, between the lower ball joint and the inner pivot point.
06:38 What we're going to do is just match the extension of the inner rod end.
06:43 In this case, on our other vehicle, we've measured that to be 70 millimetres, so we're going to match that.
06:50 Adjusting the caster arm is a little bit more involved and here we've chosen to take a centre to centre length from our other car, we've measured that at 305 millimetres, we'll be applying that to our new arms.
07:02 So let's go ahead and we'll get our first arm adjusted and ready to go.
07:06 So we'll start by adjusting our rod end and we're going to be looking for a measurement with our verniers of 70 millimetres.
07:14 So we'll just extend that out and get that set up.
07:28 With our first adjustment made, we can now go ahead and measure and adjust our caster arm.
07:37 Now we're looking for a measurement of 305 millimetres centre to centre and at the moment we're measuring about 282 so we've got a little bit of extension required there.
07:52 Alright we've got our first front lower control arm adjusted, we're just going to repeat that process now on our second arm.
08:14 So at this point we've got all of our new suspension components adjusted and we've got a baseline setting there, ready to install into the car.
08:21 You'll note that at this point I haven't tightened up any of those adjusters, we're going to be leaving those loose for the moment because we're expecting that further adjustment will be required once we get stuck into actually doing our alignment.
08:34 Of course it is important to mention here that we must make sure that all of those adjusters are correctly locked up before we actually try driving the car for the first time.
08:45 Now the only arm that I haven't made any adjustments to here is the new rear toe control arms and there's not a lot of point trying to match the measurements on these toe control arms to our other car.
08:55 As their name implies, these will be adjusting the toe so we're simply going to be adjusting these on the car to the correct length in order to get our toe at the rear of the car where we need it to be.
09:06 Now, we can go out into the workshop and we'll install all of our new components onto our car.
09:12 We've got our car up on the hoist and we're going to start by replacing the components at the rear of the car.
09:17 We're simply going to remove our existing suspension arms and the coil overs that are in the car right now and we're going to be fitting our aftermarket MCA red coil overs and our SPL Parts suspension arms.
09:29 And one thing that I did just want to mention here at the rear of the car, is that in stock form, the rear toe is adjusted using an eccentric bolt on the subframe side of the toe control arm.
09:42 Now we're going to be replacing this with an eccentric lock out kit.
09:45 This simply consists of a pair of thick square aluminium washers which positively locate on the inner mount on the subframe.
09:53 This removes the eccentric adjustment because we're not needing that anymore, given that we're using our SPL toe control arm.
10:01 This eccentric lock out kit just ensures positive placement of that inner link on the subframe, making sure there's no chance of it moving out on the racetrack and it also means that if we do need to drop that inner link off the subframe at any point, we can be sure that we're going to get it back in exactly the same position, meaning that we don't need to double check our toe.
10:22 So let's get stuck in and we'll start swapping out those parts.
10:59 With our rear components complete, it's time to move on and deal with the front of the car.
11:03 And we're going to start by removing and replacing our existing lower control arms.
11:07 Now once we've got our lower control arms out of the way, we need to remove the lower ball joint or the stud in our case from the hub assembly.
11:15 Now this can be quite tricky because the stud is tapered and it sits in a taper inside of the hub.
11:23 So in order to do this, we need to free it out of that taper by hitting the lower part of the hub assembly with a hammer.
11:30 This can be quite a time consuming process and it does require a reasonable amount of car so that you can free the stud out of that taper, without doing any undue damage to your cast hub assembly.
11:42 In stock form, the Toyota 86 chassis is fitted with a large diameter stud which locates the front of the lower control arm.
11:49 In this case, that's going to be used to locate the caster arm for our SPL parts lower control arm assembly.
11:56 In this case though, SPL parts actually require us to remove that stud and instead it's going to be replaced with the bolt.
12:03 You'll also note here, there are a couple of braces that go from this bolt forward to the lower part of the subframe.
12:10 It's important that these are reinstalled, otherwise we could end up twisting and damaging that bolt and this will also affect our alignment.
12:19 With the stud removed, we can now complete the installation of our new lower control arms, but we also need to give some consideration here to our roll centre height.
12:27 The SPL parts lower control arms come with a set of spacers that can be used to space down the outer, lower ball joint in order to adjust out roll centre height.
12:38 Here, we're simply matching the installation on our other car, and we'll be using all four of the roll centre spacers that are included in the SPL Parts kit.
13:14 With our lower control arm installation complete, we can move onto replacing our existing struts.
13:19 This is a relatively straightforward process, there's two bolts that connect the bottom of the strut to our hub assembly and we simply need to undo and remove those bolts and then there are three, 12 millimetre nuts that attach to our top hat where it goes through the top of the chassis.
13:35 With all of that undone, we can remove the strut out of the car.
13:53 Before we can install our MCA coil overs though, we need to install a sleeve through the upper hole in our hub.
14:00 In stock form, this hole is larger in diameter than the bolt we're going to be using and it's used for camber correction using an eccentric camber bolt.
14:09 With our MCA coil overs, rather than relying on an eccentric camber bolt, the struts are fitted with specially designed camber washers.
14:18 These are available in a variety of offsets and they positively locate in the strut assembly and are held in place using a small cap screw.
14:27 This ensures that they're not going to rotate and it means that any time we remove the struts, we can be pretty certain we're going to be getting everything back in exactly the same location.
14:40 With the sleeve installed in the hub, we can now simply install our MCA coil overs.
15:07 Once we've got our struts installed, we can now temporarily refit one of the wheels and check the clearance between the inside of the wheel and tyre and our strut assembly.
15:17 What I'm trying to do here is maximise the camber using our off washers, but of course we need to make sure that we maintain sufficient clearance between the wheel and tyre and our strut assembly.
15:30 By adjusting our negative camber in this way, it means that we don't need so much adjustment from our suspension top hat.
15:36 And really this is just a balancing act between the two areas we can make that adjustment.
15:41 Now that we've got all of our suspension components installed, we can refit the wheels to the car and it's a good idea at this point to just have a quick visual inspection of our toe on each corner of the car.
15:52 Given that we've changed just about every component in the car, there's a pretty good chance that our toe is going to be all over the place.
15:59 And while we're not trying to get everything absolutely perfect right here, it's a good opportunity to just make a quick visual adjustment so that at least the car will push off the hoist straight.
16:11 With our component installation complete, we can now refit the wheels, lower the car off the hoist and push it back into our workshop so that we can measure our ride height.
16:21 Now when we're doing this, it's always a good idea to make sure that we push the car backwards and forwards a few metres, turning the steering wheel and allowing all of our suspension components to settle so that we're getting an accurate measurement of our ride height.
16:34 The MCA coil overs that we've fitted to the car come preset so theoretically there should be no need to make ride height adjustments, however in this case we are going to be lowering the car slightly below MCA's recommendation of 350 millimetres.
16:49 Now that recommendation of 350 millimetres is between the centre of the wheel and the underside or lip of the guard on both front and rear so what this means is that if we are measuring ride height in this manner, it doesn't matter if we're running on a 16 inch wheel or an 18 inch wheel, our ride height still remains the same.
17:08 Now it can be quite tricky to make that measurement between the centre of the wheel and the lip of the guard accurately so my personal preference is to take the overall diameter of our wheel, which in this case is 249 millimetres, we divide that by two.
17:23 So that's giving us the dimension between the centre of the wheel and the top of our wheel lip.
17:30 From here, we can simply measure between the top of the wheel lip and the lip of our guard and we add 249 millimetres to this and it will give us our ride height to the centre of the wheel.
17:41 It might sound a little bit complex but once you understand how to do this, it's quick and easy and it gives us a much more repeatable and accurate way of measuring our ride height.
17:51 So in this way, we can measure between the top of our wheel and the lip of our guard on the front right corner of the car and we can see that this is 80 millimetres.
17:58 Adding in our 249 millimetres to that, we end up with a ride height at the front right corner of 329 millimetres.
18:08 In this case, our desired ride height at the front of the car is 330 millimetres and while we are one millimetre too low on the front right corner, I'm not going to be splitting hairs over one millimetre.
18:19 By going around and measuring the ride height at the other three corners of the car however, we find that the rear of the car is six millimetres too high, so that's going to need to come down and our front left corner is two millimetres higher than the right hand side, so we are going to make an adjustment here.
18:36 To make those adjustments, we need to get our car back onto our hoist and get the wheels off.
18:41 We'll start our ride height adjustments on the left rear corner of the car and there is a little bit of complexity when we are making adjustments on a multi-link suspension system.
18:52 This is because there is a motion ratio associated with a multi-link suspension design which means that in order to make a six millimetre adjustment at the wheel, we need to make less of an adjustment at the strut because the strut is located further inboard on the lower control arm.
19:08 We can work out that motion ratio relatively easily.
19:12 We simply need to measure the overall length of the lower control arm between the inner and outer pivot points and then divide this by the distance between the inner pivot point and the point where the strut locates on the lower control arm.
19:26 In the case of our Toyota 86, this motion ratio works out to be about 1.3.
19:32 Now in order to make a six millimetre adjustment at the wheel, we simply divide that by 1.3, our motion ratio and this gives us a change in strut height that we need to make of about 4.6 millimetres.
19:47 Before making any adjustments we need to loosen the locking screw inside of the lower spring platform.
19:54 This can be simply done with a small allen key.
19:57 Now we can use our vernier calipers and measure between the lower spring platform and a reference point on the body of our strut.
20:03 In this case, we're measuring 73.8 millimetres and remembering we want to take 4.6 millimetres off that, this would give us a target of 69.2 millimetres.
20:14 Now again, we're not trying to split hairs and we'll just set this to 69 millimetres.
20:18 We can not screw down the lower spring platform until we achieve our new target ride height and then we can lock off the adjustment screw.
20:27 Once we've done this, we can repeat this process on the other rear corner of the car.
20:31 With the rear complete, we can now move onto our front left and you'll remember that this was two millimetres too high.
20:37 The process is essentially identical here, however with a MacPherson strut our motion ratio is 1:1 so in order to effect a ride height change of two millimetres, we need to make a two millimetre adjustment to our spring platform.
20:51 The process here is again to loosen off the locking screw in our lower spring platform, measure our existing ride height between the spring platform and the strut body, which in this case measures 15.1 millimetres, remembering we're trying to reduce our ride height here by two millimetres, so we're going to screw that spring platform down until we reach a ride height of 13.1 millimetres and finally we can re tighten the locking screw.
21:16 Making ride height adjustments like this is an iterative process so the chances are that you're not going to get it perfect on your first set of adjustments.
21:24 However we're simply going to repeat that process until we've got our ride height exactly where we want it.
21:30 With all of our components installed and our ride height set, our job's really done here with our Toyota 86 project car.
21:37 However before we move into the next steps of the process, I did just want to revisit our roll centre adjustment kit and talk about that in a little bit more detail.
21:46 Now in our case, as I've already mentioned, we're simply replicating the setup that we've got on our other Toyota 86 racecar.
21:54 So in this case we're simply replicating the roll centre adjustment and ride height that we've got on that particular car as we know it works well for our purposes.
22:03 However if you're starting from scratch and you've got no information here, you do need a bit of an understanding of what you're trying to achieve with that roll centre adjustment kit.
22:12 It's a really good idea here to inspect the angle of the front lower control arms in stock form before you pull your car's suspension apart and start adding your aftermarket parts.
22:24 In most instances with a stock standard car, you're going to find that those front lower control arms point downhill from the inner pivot point on the suspension to the bottom ball joint on your hub assembly.
22:36 And this is all about controlling the roll centre of the car.
22:40 Of course, when we lower the car we can get into a situation where those arms actually start pointing up hill from the inner suspension pickups on the chassis towards our lower ball joint on the hub assembly.
22:52 And this can end up with our roll centre below the ground level.
22:56 This makes the car roll more in the corner because our roll couple or roll moment is increased.
23:03 So what we're going to be doing is using the roll centre adjuster to try and get our lower control arm angle back to replicating factory.
23:11 In our case, as we can see here, we've got the arm pointing slightly downhill by about 1.2 degrees and we know that this is going to give us pretty good results when we hit the racetrack.