irstang(on the old forum) wrote:

Daze gave me some numbers on his LCA's. They are 18.25 center to center and the coilover attachment is 12.375 out on the arm. His LCA ratio is .678. The LCA ratio before he shortened them 2.125 would have been .711. So shortening of the LCA did not make a big difference. What one has to be real careful of with JAG IRS is the coilover angle.. The ones in this diagram are somewhere around 20 degrees off vertical. This is the maximum I would want to go when we already have a marginal LCA ratio to start with. Angles down around 10 degrees are going to have very little effect. Cos10 degrees = .985 Motion ratio would be .668

Cos20 degree = .94, Motion ratio .637

Cos30 degrees= .866, Motion ratio .589

Cos 35 X .678 = .55 With this low of a ratio Spring rates have to be double the rate at the wheel. Loads on the body go way up when we start looking at high spring rates, even with the Jags two coilovers per side.

I would like to see some numbers from Daze with his shocks as vertical as his mock up will allow. Something around 15 degrees would be nice.

We need to keep the motion ratio as much above .6 as we can.

Mocked it up with the upper shock mount at the furthest hole out.  Resulted in the coil overs being about 13º off of vertical.  with the weight of the car on the suspension the coil overs only compressed about .25" and the wishbones were angled down about 10º  and the ride height was way off. I then moved it to the next hole about 18º off of vertical and the coil overs compressed about .5"  the wish bones were angled down about 5º and and the ride height was at the extreme end of acceptable.  I ran out of time before I could move to the middle hole it should result in about a 23º angle off of vertical and I would guess the ride height will be about right.  The  over all suspension felt fairly good when I was pulling on it so I am thinking it might just be about right.  more details to come.