The back of #118 rides very low indeed, and while I know that they're all low, it's increasingly noticable. It's definately dropped a little as the tailpipe scrapes slightly leaving the garage recently. The leaf springs look pretty flat and i suspect i will need to replace/refurbish them.
Ground to the tip of rear fin is 29.25", with the center of the rear wheel at 12". Could someone measure theirs and let me know for comparison, please?
Just had most everything in suspension redone. Tip of fin 32 3/4"", top of headlight 32". Center of wheels just a hair above 12". You are low for sure.
Thanks Steve. I have 29 3/4" to the top of the headlight/wing so the overall car is lower and it's tilted down not up from front to back.
As it was raced in the 80s perhaps it has modified springs all around. I'd never really contemplated that.
Be careful taking measurements off the body, it's the part of the car that tends to be dimensionally challenged, especially at the front.
Original springs are likely to be well shot by now, originals will have a flat plate as the lower spring leaf. TR3 replacements (even uprated ones) are a bit soft for the car and ride very low, an extra leaf and +1 1/2 inches is about right for road use.
If there's about half an inch clearance between the de-dion tube and the lower bump stop on the chassis, then it's about right.
Running a little lower is OK, it allows the car to roll a little further in the corners before lifting the inside rear wheel and loosing traction.
When racing. these cars slide around, more grip is not necessarily a good thing.
I think that TR3 front rebound stops (Moss part 10175) were the original fit, when I rebuilt my chassis I fitted a captive nut and used Bump Rubber (MOSS part 106845) which will then be adjustable.
Whilst you are doing all these adjustments, be aware that the way that the car drives is far more affected by the front ride height, because this changes the camber of the front wheels. So as you jack one rear corner the camber on the opposite front corner changes. Be prepared for the chassis to have some "twist", either as constructed or due to accident or repair. Remember all those period reports about "goes better round left hand bends"....
My advice is to set the car up "from the front". Ignore any measurements against the GRP body, this is just along for the ride and to keep the rain off. Get the front suspension angles and ride heights the same by adding or subtracting spring spacers, or swapping springs L to R. Once this is right, set the rear up so that the front angles are maintained, and then set the bump stops under the rear springs the same distance below the de-dion tube. As in previous messages, a lower rear is better, you get more roll before the inside rear wheel lifts and you loose traction.
If you were going racing, you'd do all this with the weight of a driver in place, and then you'd fine tune using corner weights, it depends how serious you want to get.
Quite a few trials, getting the correct (for the car) spring rating and use or not of a bottom spring that can effect the ride height significantly. Worth it in the end though.
I'm just in the process of re-fitting my re-set rear springs.... try saying that three times quickly!
The old measuring stick for the rear springs (That I know too) is six of your English inches between a line drawn through the centres of both eyes of the spring and the top of the first leaf (at the point where it
locates the De Dion Tube).
does that make sense?
The ones that I have had reset measure a little over that but they will settle down. I will take pics and report back.
I do remember (a long time ago) when I first fitted these (50,000+ miles ago too!) that I had to stretch the springs flat to get them in and connected, then removed the stretching device....will photograph this cunning plan too!
Nige, that does make sense. Making a stretching device also makes sense, but was not what I was considering I'd have to do - though clearly I'll have to
Soooo, I've finally had a little time to get the rear springs on (well just for a dry run before stripping it down again!) and my thoughts on the stretcher were put into action and it worked!
Picture paints a thousand and all that....
one piece of 2x1 measuring 38" in legth, cut in half, (with both end faces slightly rounded to aid the rolling motion) side timbers screwed on to stop the hole thing getting out of line.
another piece of 2x1 screwed on the top as a stop when in the straight position.
held the spring in a vice and then pushed down (with all my weight....steady!) on the centre. when locked in a straight line I screwed a 4" wood screw in.
this allows you to wind it out with a battery drill when fully fitted in the car.
You could do all sorts of over engineering along these lines but hey, it worked and it only took 10 minuets to make.