Apart from the weight difference, is their any difference to their spring rate (lbs/in)? Who could possibly know for sure?
STD Cup - 42N/mm Ohlins (Trophy&Cup-S) - 47N/mm Ohlins Composite (Trophy R) - 48N/mm Ohlins Steel (Trophy R) - 50N/mm
Thanks a lot. .....BUT in renault's press release , they formally mention spring rate 15.3mm/100kg for 250cup model front springs, which means 64N/mm. Also, you mention steel springs for trophy R. I don't think there is such an option Are you sure on the above? Where did you find the values?
The values in the press release may also include the bump stop or have some marketing influence. The values I have are measured ones. The Composite springs are part of the nurburgring pack along with the bi-material disks, Li-on battery and tyre bags. The steel spring is used for the none nurburgring pack cars. Edit: STD Cup PN: 54010 0108R if you can confirm this part number you'll know for sure the vehicle. HTH
An update on the Trophy-R composite spring. Yesterday we removed the springs, dampers and bump stops from the car, front and rear before deciding what to do next. I’ll update in the projects area on what we are doing but meanwhile, here is what we found. But to give a hint, we are changing geometry, spring rates and damper settings on my Trophy-R whilst retaining the excellent Öhlins dampers which are so much better than the aftermarket coilover kit. The Allevard composite spring is not linear. It starts off linear at 48N/mm as stated above and it is linear in droop and at right height. But as you move into bump, The rate rises steadily in a straight line such that by the end of the travel the rate is 57N/mm. by the time you get towards the end of the travel however, the quite large bump stop has come into play. We tested the elastic deformability of the bump stop and found that whilst it starts very soft, as you would expect its resistance increases dramatically as it squashes up. Superimposing the spring rate effect of the bump stop onto the rising rate spring means that the springroad rises steadily and then very rapidly as the deflection moves towards the limit in bump. But there is more! Stripping down the Ohlins dampers, this is all done by a specialist Ohlins damper shop by the way, we discovered that the internal spec of the Road & Track DFV damper, at the front, is not typical. It contains an extra stage at the end of the shaft which is effectively an additional bump stop. It has a valve piston that runs into an end cap. We discovered this only on stripping down the damper naturally and so haven’t tested the effect of it all sorted to construct the superimpose curve of spring plus pump stop plus bumpstop affect from the damper. Suffice to say though that it’s quite complicated and looking at the behaviour of the system it seems that whilst it is designed to provide significant roll resistance, another major objective was to allow the set up to be made very compliant for road driving on compromised services. Given the number of cars that are sold in the UK I suppose this is not surprising. Another thing that jumps out is that the balance between the damper’s resistance and the spring’s resistance means that the damper can and does dominate the behaviour of the spring over most of the range and, depending on the damper settings, all of the range. So the setup has been designed to be very damper adjustable, even changing its fundamental behaviour through damper settings rather than merely fine-tuning.
Reposted with fewer typos! Would someone be so kind as to delete the previous version? An update on the Trophy-R composite spring. Yesterday we removed the springs, dampers and bump stops from the car, front and rear before deciding what to do next. I’ll update in the projects area on what we are doing but meanwhile, here is what we found. But to give a hint, we are changing geometry, spring rates and damper settings on my Trophy-R whilst retaining the excellent Öhlins dampers which are so much better than the aftermarket coilover kit. The Allevard composite spring is not linear. It starts off linear at 48N/mm as stated above and it is linear in droop and at ride height. But as you move into bump, the rate rises steadily in a straight line such that by the end of the travel the rate is 57N/mm. By the time you get towards the end of the travel however, the quite large bump stop has come into play. We tested the elastic deformability of the bump stop and found that whilst it starts very soft, as you would expect, its resistance increases dramatically as it squashes up. Superimposing the spring rate effect of the bump stop onto the rising rate spring means that the effective spring rate rises steadily and then very rapidly as the deflection moves towards the limit in bump. But there is more! Stripping down the Öhlins dampers, this is all done by a specialist Öhlins damper shop by the way, we discovered that the internal spec of the Trophy-R Road & Track DFV damper, at the front, is not typical. It contains an extra stage at the end of the shaft which is effectively an additional bump stop. It has a valves piston that runs into an end cap. We discovered this only on stripping down the damper naturally and so haven’t tested the effect of it or sought to construct the superimposed curve of spring plus bumpstop plus bumpstop effect from the damper. Suffice to say though that it’s quite a complicated, three part, rising rate spring set up and looking at the behaviour of the system it seems that whilst it is designed to provide significant roll resistance, another major objective was to allow the set up to be made very compliant for road driving on compromised services. Given the number of cars that are sold in the UK I suppose this is not surprising. Another thing that jumps out is that the balance between the damper’s resistance and the spring’s resistance means that the damper can and does dominate the behaviour of the spring over most of the range and, depending on the damper settings, all of the range. So the setup has been designed to be very damper adjustable, even changing its fundamental behaviour through damper settings rather than merely fine-tuning.
That's a great write up, thanks. Is it possible to share the spring and damper graphs? I really want to convert my Ohlins to 2.5inch linear springs but I need to redesign the rear bump stop. I'm not convinced the conversion by RSC addresses this properly. I know Renault had problems with the composite spring sagging more than the steel equivalents. I can share the technical drawing with you if you need it. Sent from my iPhone using Tapatalk
Yes! But I haven’t got hosting sorted. Pm me an email, I’ll send all the before and after graphs I’ve got. Anyone know what free hosting there is because the photobucket seems to have changed for the worse.
And whilst I do not have the graph of the Allevard spring I can reproduce it pretty accurately by hand and photograph that and send it through. Spent ages looking at the shape of it because it’s so interesting!
Flickr is pretty good for hosting photos, Id be interested in seeing what you have got as well, Purely to satisfy my curiousity haha
Here goes: 1. This is the stock front Öhlins R&T Trophy-R from Renault, we have not changed it IMG_0225 by 2. And here is the way we changed the rear Öhlins R&T damper: we are comparing the original click zero with the new click zero. The envelope has widened: compression and rebound are always greater at every point on the curve IMG_0227 by 3. Here are the new settings on the rear IMG_0226 by 4. Approximation of the Allevard Spring allevard by
Would be great to see the technical drawing of the spring and get your thoughts on call overs et cetera
