I what sense Ed?
Road use? Competition?
Standard? Coilovers?
I'd assume most if not all people use whatever damper rate is given by the manufacturer and don't change damper rates springs are much the same I presume
The bc coilovers i've seen are fixed b/r ratio
This is where I complicate it a litte bitWell, the application is designed towards rally but was trying to get an overview. It doesnt need to exact but more of a general idea.
Rocks are the main culprits for bending emWell, the idea is to simulate hitting a rock or similar (which is when I assume the wishbone would fail), so forest rally I guess.
What would be the softest damper rating (in bump) that you could expect to run? (softer damping means less force on spring and therefore more force on wishbone).
I had a feeling you may be able to help me on this one Andy
Some rough calcs for a damping ration of 0.6 has come up with a damping ratio about 1470Ns/m sound anywhere near right?
Good figureI am estimating 400kg over that wheel btw.
Compression vs Rebound I assume in which case I'd use 0.6 as a control figureFrom damping ratio that most road (passenger) cars run AFAIK.
No sorry, ration of damping/critical dampingGood figure
Compression vs Rebound I assume in which case I'd use 0.6 as a control figure
Have you any hertz ratios?
Found some data I'll add it in a mo
You've lost me a bit here,205 GTi
Front 643.5kg (50/50)
Rear 411.5kg (50/50)
Spring rates 160lbs/in all round (2.86kg/mm)
Dampers
Hertz F - 1.4 R - 1.6
C/R - 1.473 progressive (kgf/mms)
cheers frankjust checked the k11 and corsa rears ed, both 1:1 ratio
Ah I see. Makes sense nowNo sorry, ration of damping/critical damping
You've lost me a bit here,
What is a Hertz ratio?
And C/R?
(assuming linear damping in my model btw )
1:1?just checked the k11 and corsa rears ed, both 1:1 ratio
there are 2 damper rates on every shock tho i believe ed, a fast rate and a slow ratecheers frank
Measuring rate is tricky though eh as force is dependant on the speed at which you move the damper, springs are much easier.
aye, equal compression and rebound andy, where-as the k11 and matiz fronts were 1:2 and 1:41:1?
And they're standard items?aye, equal compression and rebound andy, where-as the k11 and matiz fronts were 1:2 and 1:4
there are 2 damper rates on every shock tho i believe ed, a fast rate and a slow rate
(assuming linear damping in my model btw )
Ah I seeguestimated innit there is a huge ratio difference between front and rear tho
i doubt that would be realistic personally ed, it does,nt take much of a bump for the high rate damping to come into effect(assuming linear damping in my model btw )
I suppose we can create a dual linear line to represent a rough digressive ratei doubt that would be realistic personally ed, it does,nt take much of a bump for the high rate damping to come into effect
I could write an expression for damping but would need at least a damping curve in order to do this. The simulation is an impact so would just use the higher rate otherwise.I suppose we can create a dual linear line to represent a rough progressive rate
Like the one I just put up?I could write an expression for damping but would need at least a damping curve in order to do this. The simulation is an impact so would just use the higher rate otherwise.
arrr, yes, that looks good. what damper is it?View attachment 28503
This might help a tad more :/
Its a force vs velocity graph
Goes up in lbs
And across in inches/second
Compression top left
Rebound bottom right
Its a typical road car/tarmac rally setup
Rotate (not flip) 180deg to get an idea of a forest rally setup
Shows you how much compression is added (jacking up setup) along with spring rate
Thats a custom bilstein b4 or 7 iircarrr, yes, that looks good. what damper is it?
Do you have any exported data from it? .csv? or excel format? or matlab? anything with numbers in really
Yes please mate! email would be great. Ill pm you my email address nowThats a custom bilstein b4 or 7 iirc
No idea that's all computer stuff. I load the program and it shows me that
I can get print outs etc. I'll email it to you?
Force vs Velocity graph with every single adjustment testedWhat monstrosity is that!?!
Im out!
mostly two stage bump and linear rebound eh? that what they call '3 way adjustable'? I may be wrong but it looks like the thing being adjusted is the speed at which the shock goes from low to high rate? and the low speed rate, but not the high speed rate?Force vs Velocity graph with every single adjustment tested
That's a 3 stage shock that one you can see in the rebound. The low speed is pretty similar throughout. Linear then digresses to a 3rd linear linemostly two stage bump and linear rebound eh? that what they call '3 way adjustable'?
Also, andy, what would an average spring rate be for a forest micra rally set up?