Seymour Snerd
Lifetime Supporter
I think there is a pic of a gold MK11 at le mans? in the gallery somewhere with a placard beside it with the spring rates on it
Just looked, couldn't find it. Might it be somewhere else?
I think there is a pic of a gold MK11 at le mans? in the gallery somewhere with a placard beside it with the spring rates on it
Tom,
Yes, technically speaking you're exactly right - the amount of pre-load doesn't affect the point of coil bind. However, practically speaking you (and anyone who knows the minimal basics) knows that it does. Why? When a guy winds up the adjuster on the spring perch so that there's less working travel in the spring (commonly done to lower the car....), and re-uses the same spring, then the likelihood of hitting the point of coil bind is much higher. That's how it works practically speaking.
I think everyone understands that. And I think you understand I wasn't suggesting otherwise.
I'm not entirely sure of the relevance of what one particular spring rate would be unless you knew the rest of the setup and the track it was configured for. I can't tell you how many times I changed spring rates for various tracks all on the same car. Right hand turn bias vs left hand, high bank and smooth vs. flat and technical, high speed vs. medium speed, aero no aero, etc.. Would we not have expected the same differing setups of these original cars and teams?
I think there is a pic of a gold MK11 at le mans? in the gallery somewhere with a placard beside it with the spring rates on it
Exactly,
thats what i pointed out also. One have to find the springs for his driving conditions. Of course if you are not fighting for the last 10th , the spring rates for a givven car will be not to far of from one car to the other.
Hey Randy, think this is a interessting discussion, but don´t want to completly destroy Carlos´s Thread. What about asking an admin (wink) to relocate those post to a new tread?
TOM
don´t want to completly destroy Carlos´s Thread.
I think Jac already did that...![]()
I'm not entirely sure of the relevance of what one particular spring rate would be....
and I was looking for a quantity to attach to that qualitative statement.most of our beloved GT40s replicase are undersprung because of the comfort desire of all us old farts driving them. Face it, they are racecars and its supsension is concepted like a racecars, short strokes, heavy springs, at least on the front, The rear is much more forgiving
Dear Cliff
if i understand you correctly than you talking about the spring taking a set ( which most springs will do to more or less extend, depending on the quality and springlayout). Practically speaking , this set will not be depending on the preload, it will be depending on the total load put on the spring and its capability to withstand. What you end up is a spring with a different unload lenght ( shorter) and more relative spring winds on this new length ( spring winds per inch will increase) and therefore you get a spring with a lower spring rate.
TOM
That's OK. Here's the relevance. Tom said and I was looking for a quantity to attach to that qualitative statement.
to be honest, i´m suprised by this values of the mk11. Front could be ok, but the rear seems to be quite soft, especially taking in account the weight of the big block engine.
Dear Cliff,
Thats exactly the missinformation most people have.
Some of it is true what you say. Under a certain condition some spring coils will bind up but not by adding preload only.
Just think about it. As long as the shock still has some way to move out, turning up the lower spring perch will only change the level of the car. The spring still gets the same load and will not change his length, only it will be positioned higher in relative position to the shock.
What you say is true, if one turns up the lower spring perch to a point that the shock can no further extend anymore ( because it is bottomed out). But as soon this point is reached the height of the car can not be changed any more and any further turn up will only further compress the spring ( and finally lead to coil bind ). But this a absolute no go scenario anyway, because than the shock is way to short.
So again the amount of total load to the spring for going coil bind is not different than without preload. ( as long as your shock has still some negative way to bottom out in rideheight)
Increasing compression dampening to avoid this. I know that people are doing this , but this is not a very good solution for a spring dimensioning issue and will defenitely compromise the sensitivity of a cars suspension. The tire than would need to take over some of the dampening function and in competition will heat up more and have more tire wear.
TOM
<<Spring coil
Front - 505 lb
Rear - 336 lb>>
Perhaps they've increased the rate in the front to reduce suspension-rise-induced aero lift, and they've put a larger anti-sway in the rear for more adjustability.
I suspect that they keep the overall suspension rates pretty low for driver comfort and chassis longevity. It's a long grueling race, after all.