Ride Height

[Steve_Lindford]

I was going to set my ride height based upon information on this forum - front ride height measured at the body behind the front wheel should be 5 3/4" and the rear ride height measured at the body in front of the rear wheel should be 6 1/4". BUT I already have 7" at the rear with existing non adjustable shock absorbers. I have new adjustable AVOs on the front - so do I aim for 1/2" less at the front making it 6.5"??

I have 185/70 13 on rear and 175/70 13 on front - standard TC car.

Steve

[EuropaTC]

Hi Steve,

The problem with going off the body for ride height is that it's not an easily transferable datum because I very much doubt every car was identically mounted on it's chassis. Nothing dramatic but not as easily identifiable as the backbone chassis itself.  I use the points you've mentioned but only as a comparative for my own car, I wouldn't suggest anyone else treat my numbers as gospel truth.

To illustrate the point, with my car unladen I have 15cm underneath the front chassis cross member, 15.5cm just before the start of the engine bay fork and 22cm underneath the rear hoop where the gearbox mounts. So the chassis has a very slight forward tilt, somewhere around 0.5cm.

If I go off the bodywork alone the floorpan just behind the front wheelarch is around 12.5cm and 15cm just in front of the rear wheelarch (which almost corresponds to the 15.5cm point). So it would look like a 2.5cm tilt on the car, which it clearly hasn't got.

As you can't do anything at the rear I'd suggest you try for an imaginary horizontal line between the outboard (brass trunnion) bolt head and the inboard chassis mount bolt. Due to the bend on the lower wishbone this isn't as clear as on conventional wishbones but it's a reasonable start.  I used a DIY laser level that casts a horizontal line, the sort you use to get wall tiles nice and level but there's no reason you can't use a normal spirit level/ruler.

Then I'd see how the car drives and raise/lower to get the sort of balance you like.

Brian

[Steve_Lindford]

Thanks Brian - sounds like every car is probably set up differently - so the settings aren't too critical. Your figures give me something to go on. Presumably there is no point using a laser unless the garage floor is level. This car will behave so differently from my normal (Peugeot 206sw) car that it won't be easy for me to assess how it handles - but hopefully it would be obvious if it was very wrong. Do you try and aim for the same number of threads showing on each side below the shock absorber adjuster??

[EuropaTC]

Do you try and aim for the same number of threads showing on each side below the shock absorber adjuster??

Technically you should go on corner weights which would probably mean the platform height will be slightly different on either side, but I'll come clean and admit that I did pretty much what you've suggested.  I used simple calipers to measure the thread showing and both sides look similar but unfortunately I don't have measurements to hand.

I initially set the front end about an inch lower than it now is. The car looked great but on the first run out it felt twitchy on where the road wasn't so smooth and I wasn't convinced that was just down to higher spring rates.  I can't recall the numbers but remember there was a greater slope forward on the chassis spine. By gradually lowering the rear and raising the front to the current measurements I convinced myself it was an improvement.

I guess what I'm trying to say is "don't be afraid to experiment"   

[Steve_Lindford]

Not many smooth roads in Surrey or Hampshire - but it gets better into Sussex - so it is a nice drive to Goodwood! Also lots of speed bumps round here - some 50 yds from where the car is kept - and I'm not sure I can get over those without a scrape. I will apply some of your logic and see how it goes...

Steve

[Steve_Lindford]

I put a similar slope on the chassis as you have - and as the back is fixed the front was a turn out dimension. I think mine might be approx an inch higher than yours - which sounds a lot. The lowest part is the bottom of the shock absorbers - which is just 3.5 inches. I could grind off the bottom half inch of spare thread - before the road does.

This photo was taken after my FIRST drive in the car - just 30 feet in reverse! - and I had to get my glasses to see the diagram on the gear knob to find it. I have now done 0.8 miles in a friend's garden. MOT next week.

Steve

[BDA]

I would say just by looking at that picture, your ride heights don't seem out of whack. Good luck with your MOT!

[EuropaTC]

and I had to get my glasses to see the diagram on the gear knob to find it.

   you're lucky, I used to be stirring the stick for ages before I found reverse, and then, to prove it was still there,  sometimes I'd find it going down from 3rd......

Quite honestly, it looks about right from the photo. I wouldn't get too hung up on measurements until you know what it drives like. (going forwards that is    )

I think I posted this somewhere before but can't find the thread, so here's another shot. It's from contemporary road tests and compares the dimensions of the S2 & TC when new and they have bumper height measurements which might confirm where you are.

Brian

ps - best of luck on the MoT, let's know how you get on. Adjust the handbrake the night before.....    it's traditional.

[Steve_Lindford]

Thanks for all the help - I will probably need more. Will let you know about the MOT...

Steve

[Steve_Lindford]

MOT - fail - but not too terrible at all! Passenger door won't open from outside - I knew about this but didn't think it was urgent. And front wheels on the wrong way round so the tyre faces the wrong way. Handbrake OK!

Also they advise:

The lower nyloc nut on shock absorber - thro wishbone - the nylon part doesn't touch the thread - either because the bolt is too short or the nut too long. The next size down for the nut is 8mm high - so I will see if they are happy with that.

Rear brakes out of adjustment - different readings for both sides.

Handbrake lever not releasing easily.

Also - not anything to do with MOT test - big gearbox leak at the clutch end. This was not apparent to me when I filled with oil and the car was static. I also have small leak at both driveshafts which I knew about...

Steve

[Bainford]

All in all, not a bad report. Good news about the handbrake.

[BDA]

Boy, they're sure thorough over there! I'm glad it went relatively well for you. Those problems should be pretty simple to resolve. The gearbox leak sounds like a bit more work, though.

[EuropaTC]

That's what I call a good MoT test Steve, anyone who picks up on a nyloc not having full thread is a good guy in my books.  I didn't even know that the passenger door opening was part of the MoT these days, I can see the logic but it's still surprising.

Some things like rear brake imbalance is very hard for us DIY guys to pick up on until it gets serious enough to pull the car during braking. I had a similar thing on the Elan last year, the car didn't move during the traditional "hands off" braking test but my local garage picked up a small imbalance and warned me about it.

All in all I'd class that as a good result. So when's the re-test and that magic bit of paper ?   

[lotusfanatic]

Hello Steve,

that's a very good MOT indeed, worth the fee alone as the tester spotted the nyloc nut thread not being engaged on the bolt.

Best of luck with the work and the re-test 

Mark

[4129R]

The irony is to get the brakes to work properly, you have to use them hard to bed them in equally. To do that, you have to drive and use the brakes a lot, and you cannot drive without the MOT test certificate.

Time for a long track day to bed the brakes in, I think.

Alex in Norfolk.