thread on coilovers?

[Tim.duncan]

Hey

just wanting to know on a set of custom "height adjustable coil overs" are the height adjusting threads multi start threads or just single start?

also what material are they normally made from?

and while we are going what material are the "perches"(not sure on correct terminology) normally made from? if they are aluminium is it a hader grade ali?

[Konakid]

Aluminium perches.

Steel threads.

Single start 99% sure.

[Tim.duncan]

I have never used a set of coil overs before so bare with me

when you are making adjustments how many times do you need to turn the perch to change the height say 10mm? would a twin start thread be benifitial for quicker adjustments?

Also when measuring corner weights how much adjustment is made to tune the suspension? would having a twin start thread be a pain if only minor height changes are needed

[takai]

You want single thread for the strength of the contact. Speed of adjustment is a moot point compared to the strength that you want out of them.

[Slimer86]

Guesstimate.
A friend had some in his A31 Cefiro with the AE92 TRD yellow shocks.
Tube is MS, thread on the tube is single start, M56x3p.
Twin start thread is not recommended, and also, once it is threaded, it doesn't make any difference. Don't forget the perch isn't at the start of a thread, its sitting around the middle/lower third in most cases.
Also, with regency, screw adjustable perches are not legal unless fully locked in position so they cannot be moved. This can be averted by having Circlip adjustable perch heights as is the case on Bilstein MX5 coilovers.
When plating the steel, please use Trivalent plate not hexavalent chromium.
Triv is up to the standard of hex now, however a little more expensive, but much more environmentally friendly. :O) (scientist hat now off)

Lead in is 20mm long from the tube end to start of thread and 50.8dia.
Overall thread length 127mm
All threaded collars and perches are aluminium. (6061 T6(treatment) probably) Sorry I can't test the hardness for you, as I no longer have access to a Brinell tester.
Top perch (Meets the cambertop) has a press fit MS insert.
Tim, your welcome to come have a look at them. SMS me

[takai]

Yeah, i would concur with 6061 T6, based on how they machine.
FWIW, if you need an external oil seal then use a 52mm not a 53 or 54mm unit, fits a lot better.