emilio700

iTrader: (3)

MCS and gen 2 Xida are not similar. The plot in your example is a gen 1. Xida. Force values at key points are near opposite ends of usual scale. The MCS have very little low speed compression or rebound. This make it possible to have very little hysteresis and tends to ride really well on rough pavement. The tradeoff is less control of body movements with high grip tires and high spring rates. The sofest "street" settings of Xidas are similar to the MCS full range but it sorta stops there. Don't just look at the shapes of the curves but pay attention to the actual force values, particularly on the stiffer settings used on track.

Junkwhale

I thought that was a gen 2 they dynoed earlier in the thread? The rear was this one (was going on front and rear based on the labelling of long and short):

Edit: this post says gen2 xida were the ones he was dyno'ing https://www.miataturbo.net/race-prep...5/#post1259054

And yes I agree it's the forces that matter (although the forces at all speeds is what results in the curve shape, so we're talking about the same thing) - that's what I'm interested in working out: a good baseline curve (and forces of course!) for the budget bilstein crowd and say 700/400 springs or similar. The MCS and Xidas are a useful starting point for the range of forces involved.

If I could afford it atm I'd definitely get the Xidas - I'm not trying to compare them to say one is better or worse. However I can get my bilsteins revalved for $400 which is more my budget than importing a set of Xidas for something like 2.5k shipped + tax/customs (I'm on the other side of the world).

I'm looking at something like Bilstein 290-100D valving (from their circle-track manual) which translates to roughly this (blue line for the compression):

mekilljoydammit

Have you seen a source for shock dynos of the various Bilstein valvings? I know the linear valving works out to approximately pounds of force at 10 in/sec, but not how to work out the valving codes on the digressive side. Honestly I should just sit down and plug it all into Restackor.

Actually, is there a thread for more general valving discussion / theory? There's some great info in this one but it seems weird to sidetrack it further and further away from MCS.

Junkwhale

Don't have a source for actual graphs, but the nomenclature is the same as linear valving in terms of working out the high speed - eg 200-80D is 2000N @ 0.52m/s rebound, 800N@0.52m/s comp with the 'D' indicating a digressive piston (and shimstack). The bleed (shim with ports/holes), and digression point (pre-load & cover plate shim) determines the low speed shape.

Yeah, I'll post up what I know in the better bilstein/ebay coilover thread. I only posted in here as my original question was: is the MCS shock dyno shown in this thread for a front or a rear shock?

mekilljoydammit

Yeah, but specifying the high speed force of a digressive piston is pretty unhelpful. Ah well, Restackor to the rescue I suppose.

turbofan

iTrader: (1)

Indeed, confirming those are Gen2 Xidas in the dyno posted above -- my set, in fact, which I personally handed to Martin to do those tests.

Emilio's comment above is the first time I've heard linear VS digressive broken down like that. That (at least partially) explains why Ryan's MCS-equipped car bounced around less than mine on the incredibly bumpy autocross course on Sunday.

Anyway, Sorry, I don't have the answer to your question about which shock was being dynoed.

Junkwhale

Will continue the discussion here: https://www.miataturbo.net/suspensio...2/#post1347603