Where to mesure Ride height..pic

The Oily Bits S1 Specific Topics
1

[image]http://img.photobucket.com/albums/v709/niceguy28/ResizeofRearWheel.jpg[/image]

I assume This is the correct place to mesure the ride
height on the rear…





ON the front Im not so sure…

[image]http://img.photobucket.com/albums/v709/niceguy28/ResizeofFtrontWheel.jpg[/image]

here?

[image]http://img.photobucket.com/albums/v709/niceguy28/ResizeofFront2.jpg[/image]

or 1 of thease…???

2

behind the front wheel from the sill to the floor and from the front of the rear wheel from the sill to the floor

3

behind the front wheel from the sill to the floor and from the front of the rear wheel from the sill to the floor

And I suppose that is where the tube is on the pic?? or the vernie?? (front wheel)…

4

You can just see a little bit of the chassis in the wheelarch on the third picture - that’s pretty much where you measure.

5

So this must be the correct place to measure the front ride height…?
[image]http://img.photobucket.com/albums/v709/niceguy28/ResizeofBilde013.jpg[/image]



Im a bit in doubt about the rear… … I have removed the undertray on this pic … But should I use point 1 or 2 here or none.??

[image]http://img.photobucket.com/albums/v709/niceguy28/ResizeofBilde022.jpg[/image]

Hope the pic makes sense…

6

front one is right
rear one, sorry but I can’t make sense of the picture
basically if you measure inside the wheel arch from the chassis to the floor

7

front one is right
rear one, sorry but I can’t make sense of the picture
basically if you measure inside the wheel arch from the chassis to the floor

ok…:slight_smile:
The “paint brush” pic is inside/close to the wheel arch… You can see the tire to the right… The hole you can see on 1. is used for the undertray…

8

yes measure from there

9

niceguy

you measure the ride height on the chassis rails, not on the bodywork.

You have the front one about right (as per Azreal) i think, and the rear one should be the equivalent point at rear of car.

10

From RUSSELL G, it’s the same as the “A” and “B” jacking points on the car, which is unsettling at first since point A is relatively far from the “rear” of the car:
JackingPoints-RideHeight

“you need to measure the ride height from point A and B as this is the chassis,although you should measure at each axis but on a Lotus you can’t as the fixture of sub-frame can vary,so 100 mm at front and 110mm at rear but you can go lower than this say 98 front and 108 rear it’s up to you,what ever feels best on track”

Note these heights are for TRACK-ONLY cars.

11

Remember that if you get the relative ride heights wrong, you change the angle of the rear wing…

So if you want to go for a maximum speed run, you could try lowering the rear, but dont blame me if you start to surf!!!

I think this happened on Matt Cummings race car a couple of seasons ago at Thruxton - Matt came back from practice saying that the car was all over the place in the corners, and felt really weird - we checked the tyres etc and then we checked ride height - it was running higher at the front than at the back - god knows how that happened!!

When we reset the heights the car was totally different… (and of course much faster)

12

Thanks for lots of info… . but I must say its a bit confusing…

I can use the A jacking point to measure the rear, but then at “1” at my last pic it will be some mm lower compare to A.
For me this point looks to be at the same level as A and B but just closer to the rear (if you remove the undertray)…

I have understood the ride difference is ok if its between 6-10mm from front to rear… So then I will prop aim for 10mm lower at “1” compare to the front, and if this is all wrong the hight from A will some mm less then 1… But at least it will be within the 6-10mm difference.

13

Ride height is very complex - all the other suspension adjustments are affected by ride height changes - I found castor to be quite painful to change on the Exige.

As Mike Lane said, keeping rake as close to spec (10mm) is crucial. Therefore, you want measuring points that don’t require the removal of the undertray, coz modifying the weight distribution will change ride height! Keep the tank half full (or whatever level you run at the track), put some representative weight in the driver’s seat, make sure your tires aren’t overly worn, and fill those tires to hot pressures - forgetting to do any of these things will screw up your height measurements…incorrect rake will be the first thing you notice in the form of too little or too much downforce on the fixed rear wing cars.

Does anyone own (or have fabricated) setup wheels for the Exige? At the bottom of a To Do list somewhere I have a note to create square setup wheels.

Opposite to Mike Lane’s story, I had too much rake while at Road America, a track with three very long straights - cars that I normally keep behind me were passing me at the end of the straight - I was losing all kinds of speed! Before I discovered the rake issue, I thought my Rover K was near death!

Notice how adjustable rear wings are very handy because they help mask a ride height mistake when there isn’t enough time to fix it at the track.

14

Notice how adjustable rear wings are very handy because they help mask a ride height mistake when there isn’t enough time to fix it at the track.

Would it be possible to get some simple tool fabricated allowing us to use a spirit level to measure fixed wing angle?

I am thinking of some sort of wedge that hooks over the wing at the opposite of the 11 degrees. YOu could park the car on a pre-checked level surface and then check teh level of the top…

or am I losing it???

15

Would it be possible to get some simple tool fabricated allowing us to use a spirit level to measure fixed wing angle?

Plumbob, string and a protractor - if you are on a level surface, would work wouldn’t it.

Otherwise, a large builders right angle (large enough to reach the top of the wing) and a protractor?

But what about downforce at speed - is thaty going to alter the relative ride height of front of rear and so the angle of attack?

16

Yes it would, and so would tyre temp and pressure, and fuel load, and the burger you had for lunch as well I suppose !!