70 S2 0044Q

[BDA]

As I understand it, caster is not relative to the center line of the car but I think I see where you're headed - you're interested in positioning the front wheels first, right?

I think you can put the car on stands and measure between the bottom suspension pivots. It might also be useful to drop a plumb line from each front suspension pivot and mark the floor and measure the half distance and mark the floor there. Maybe you could also put some tape outward from the plumb mark on both sides and graduate them so that you can measure the distance from a plumb line say from the end of the spindle to the inner suspension pivot to get them the same distance.

Does that sound helpful?

I was trying to remember what I did with my Lola T492 race car since it would be a similar situation. I don't think I really bothered with caster at all and figured, probably incorrectly, that Lola set that when the car was built. I never noticed any tendency to pull one way or the other so either it actually was set correctly enough or I wasn't sensitive enough to notice it wsa off or both!

[TurboFource]

The brake caliper mounting bolts on the stock spindles look to be in line with the ball joint and trunnion pivot line. You could take the caliper off and just put a level against the bolts I think, and get a very accurate reading.

[jbcollier]

By caster (tilt of the steering axis forward or back), do you mean camber (tilt of the wheel in or out from vertical)?

[Sandyman]

John, once I set the camber, I need to set the caster. The car does not track well in a straight line. In a corner I can let go of the steering wheel and the car continues to travel on the same arc it is on.

[BDA]

I think the trunnion will limit the  amount of adjustment available. I tried to adjust my caster one side. Of course, I had to use washers. I got a small change at first but then new washers didn’t seem to change it at all. The consensus on this forum was the trunnion was limiting any adjustment. It seemed reasonable to me when I thought about it. On the other hand, the specified caster is very small so it might work for you.

What is the caster angle currently?

[Sandyman]

BDA, I first need to find the vertical centre line, once I get the car level in both side to side and front to back. Coffee almost done. Heading out to garage soon.

[jbcollier]

Yes, unfortunately, you can’t adjust caster with the stock upright.  There is no provision for the connection to the lower arms for the upright to pivot fore and aft.  Your upper arms make it look like you can but it’s not possible.  You can put the upright under tremendous strain and get a bit of adjustment but that’s a bad idea.

You can do it if you convert to the Canely uprights with the spherical lower joint.  Not cheap but they work very well.

It is somewhat normal for the steering not to return to centre automatically.  It can be improved somewhat by making sure you have as little stiction as possible in the steering mech.  Check your rack’s pinion adjustment is not too tight and lube the rack with gear oil rather than grease.  If you changed the steering column’s bushing, this is another source of stiction.  The new bushings are a bit snug and take a long time to bed in.

Again, though, there is not a lot of self-centring force designed in.  Nature of the beast.

[Sandyman]

What a day! 3 of the 4 corners done. Either my fault or bad design but the upper bushings drifted out of position. There is no provision in the original design to hold them in place. I widened the space and fitted 2 washers to hold the bushings in place. Right front corner tomorrow morning. I also fitted a new rear screen behind the license plate as I no longer need the exhaust pipe hole.

[Clifton]

I used string on both sides to find my center line. I cut the back of the frame off, tubed it and made my own rear double a arms.  You can find perfect center. I have made a few posts on straight line stability and alignment on these. I won't go into that again but I found removing the spring in the rack allowed the steering to return to center on slower speed turns. I cheated a little more caster in it but the rack still had too much drag with the spring. Just not enough weight on the front to over come it. It takes 2 minutes to remove, drive and see if it returns better.

[Sandyman]

WOW! The Europa is much better behaved as I get closer to the suspension settings. I widened the area either side of the upper spring mount bushings and inserted washers to hold the bushings in place. PITA. Has anybody swapped the sides of the turn signal stalk and the dimmer switch? How did it go?
Sandy

[jbcollier]

The suspension bushings are supposed to be bonded.  Some aren't and can "slide out".  I had the same thing happen to me.

Here are the bushings that separated:

https://jbcollier.smugmug.com/Lotus-Europa/i-W7cTbNb/A

Here's a side by side comparison:

https://jbcollier.smugmug.com/Lotus-Europa/i-dCM2Bf6/A

The good bushing (left) has rolled edges and the rubber looks like it has been poured in.  The poor bushing (right) doesn't have rolled edges and the rubber looks like it has been pressed in.

[BDA]

JB has a solution. I had the same problem with my bushings (see attached photo) and just put washers on either side which you can barely see in the other attached picture. If  you're buying new bushings, get the rolled kind and use washers for the belt and suspenders approach!

[Sandyman]

Thanks gentlemen, I am unsure if Spyder glued the bushings, if so the glue failed. I added washers.

[Sandyman]

I discovered that the wire from the fuel gauge to the tank had an open fault. I replaced the wire only to find that the voltage stabilizer had stopped working. Replacement on its way. While doing my most hated job (electrics) I decided to drag the old girl into the 21st. century by adding 3 more fuses and a more reliable ground/earth system. This is so I can add a GPS speedometer for kilometre per hour driving, a charging port for cell phones and power for a washer unit to be installed soon. My artiest brother has done a mock up of the door decal. I will take it to graphics company once I find a match for the gold stripe.
Sandy

[BDA]

Great stuff, Sandy!