Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: raf2379 on March 10, 2012, 09:04:29 PM

Title: Coilover mounting angle...... body roll
Post by: raf2379 on March 10, 2012, 09:04:29 PM
Just wanted to share some Tech info for those interested in installing coilovers or air shocks. What I want to touch on is the angle of coilovers or air shocks. The mounting angle is critical when body roll is a concern. the goal is to have the shock perpendicular to the axle at full flex, meaning one side of the axle is at full compression and the other at full droop. When the one side is at full compression this is where you want your coilover or air shock to be 90* to the axle without braking over. The reason is that if it breaks over you are no longer building spring pressure and the chassis will tend to flex that way without any roll resistance, causing major body roll. If you ever watch videos where you see some rigs have massive body roll during turning or small off camber terrain, its possible due to bad installation angle. If you install the shock at 90* to the axle at ride height, as soon as you hit a bump the angle is braking over almost immediately causing body roll. I know that you can install sway bars to help with body roll resistance, but that’s a band-aid to poor shock installation, now if space is a concern then you kind of have no choice and use a sway bar.

thought it would be good info to discuss in the tech section.

here are a few pictures to show you what i'm talking about, you can see that the angle at compression breaking over the ideal 90* angle
Title: Re: Coilover mounting angle...... body roll
Post by: SwampSinger on March 11, 2012, 08:11:33 AM
this is real good info...I have not started researching about this yet. It makes total sense.

Thanks Raf!!

What happen if the top of the shock is a bit more kicked in at full compression like....  //__\\  ?  I'd see it would not be the perfect angle to get the maximum travel out of your CO but the lost of travel would me minimal.  

If the top of the CO if a little kicked in at full compression; would it increase stability?...I assume it would not make much difference then if it was at 90* at full compression but it's better then the example in the pictures where it's kicked out if you have no choice.

A "few" years back my football coach was always saying "wide and low is always more stable"  ;D

Title: Re: Coilover mounting angle...... body roll
Post by: raf2379 on March 11, 2012, 09:44:46 AM
Coilovers being Angled in at compression would work, I dont think they will increase in stability, it would still have the roll resistance and do its job, you may loose travel as you mentioned. the only real concern is when the shock breaks over 90*
Title: Re: Coilover mounting angle...... body roll
Post by: Rubi03 jef on March 11, 2012, 12:16:43 PM
Good info  my fronts are set up //_\\ like that at full bump and still look like that at rode height
I have the top mounts in towards the engine and the diff mounts sit on top of the C's so it gives me the stance for the coilovers

The rears Are going to be similar   Should see how it all turns out
Title: Re: Coilover mounting angle...... body roll
Post by: raf2379 on March 11, 2012, 04:07:31 PM
since My frame is 36" wide i will have to do something similar to the picture bellow in order to have the correct angle.
Title: Re: Coilover mounting angle...... body roll
Post by: TL-Iguana on March 11, 2012, 08:27:56 PM
I dont see how painting it orange will improve things Raf. Your XJ is red. Get over it. :)
Title: Re: Coilover mounting angle...... body roll
Post by: Bnine on March 12, 2012, 08:04:30 AM
You have to watch your uptravel with something like that. A mount that high would put 14's out your hood. You can try a couple tabs on the inner C, but even that is fairly high.

Title: Re: Coilover mounting angle...... body roll
Post by: raf2379 on March 12, 2012, 08:11:12 AM
You have to watch your uptravel with something like that. A mount that high would put 14's out your hood. You can try a couple tabs on the inner C, but even that is fairly high.



 I will have to find a solution, I might have to do something with the frame it self.