ckowalc

So I was looking at this a little bit more and Sakebomb's chart says every 3mm of preload added raises ride height ~1.77mm (~0.07 in). This seems to be preload multiplied by motion ratio or 3 * 0.578 = 1.73mm. However, wouldn't it be preload divided by motion ratio or 3 / 0.578 = 5.19mm?

Isn't adding 3mm of preload just like adding 3mm of shock length? Doesn't the change get "magnified" by the length of the control arm?

Maybe I'm having a brain fart?

bgoetz

Are you saying 3mm length change (+or-)=~5mm height? I am just asking because I am trying to figure where mine need to be to get the right height

ckowalc

Yes, what I'm saying is if you increase preload by 3mm -OR- increase damper length by 3mm, you will increase ride height ~5mm. That is not what Sakebomb's chart is saying but I've thought about it over the weekend and still come to the same conclusion.

andrewhake

Yeah makes sense, the amount of change at the actual wheel will be different compared to the amount of change at the damper mounting point. No need to just stick to theory very easy for anyone to test this for themselves.

B serious

The shock moves less than the wheel at a ratio of 1.73:1.

1.73" at the wheel/hub is 1.00" at the shock.

So....yes, the ride height should change MORE than the damper length change.

SakeBomb Garage

Good catch, we made a standalone version of our calculator to be able to create this chart and it looks like I fat-fingered it a bit. I will get the the chart updated as soon as I get a chance. Either way the trend is correct, basically a drop of about 3/4 of an inch is possible with our recommended pre-load settings.

bgoetz

Has this been updated to reflect the correct calculations yet?

JamesD89

Bump

bgoetz

For what it is worth I tossed on 10k springs and 8mm preload and am at 13 inches fender to wheel center in the rear. I think that equates to a 1.25" drop, which was actually .25" more than I was after, so I am adding 3mm preload.

bgoetz

I added 4mm length in the front and 4mm preload in the rear. So total I am 12mm rear preload with 10k springs. Final ride height is 13 1/8" front and 13 1/4" rear. The car feels perfect, it couldn't feel better. I will say allowing the shocks more travel really made a massive difference. In my case it was a combination of not scraping fenders in the front and scraping fenders/hitting bump stops in the rear.