Upgraded torsion bar adjustment for correct ride height

[PkF]

My front suspension is about 40mm too low. I appear to have upgraded torsion bars from Xk Engineering which are 23.65mm thick (about 0.93mm) Standard height is around 16 13/16" and Jag I have seen a recommended 16 1/4" but no indication of torsion bar thickness was mentioned. Can anyone suggest the correct measurement I should use on set up?

[mgcjag]

Far better to introduce yourself in the welcome section.....and give us some background info.....please try to put your name and car model in the signature area.....all ride height details per model are detailed in the Jaguar service manual......i have no idea where your getting the 16in from.....the ride height should be the same whether your torsion bars are upgraded or not.....however if the 16in is refering to the setting link then this will be dependant on your torsion bars......but i have no info of setting link measurements for other than standard torsion bars.....Steve

[PkF]

All done Steve.
I have seen the technical manuals and supplements that you mention
I could use the recommended settings but when there is weight on the wheels there will be less droop with stiffer TB's and ride height will be too high, so was hoping for a suggestion as there where to start

[mgcjag]

So what your after is the length of a front ride height setting link when useing uprated torsion bars.....Steve

[bitsobrits]

Doubt you will find anyone with that information, as it's too dependent on who actually made the bars and their specific characteristics. What I did when I installed uprated bars was to make up an adjustable setting link from a turnbuckle with eye hook ends, then started with something like 1" shorter to the factory setting tool spec and installed the bars, rolled the car to settle the suspension (nuts loose on the A arm bushings). Ride height was off from my target, so made a guesstimate to my adjustable setting tool to lower the car a bit, and reset the bars. That second time I was a bit too low, so third time's a charm as they say.

So a long winded way to say that if you are using non stock bars it will take a couple three tries to get it where you want it.

[PkF]

I understand. Will try the manufacturers for advice.
Failing there we will just have to try the hit and miss

[PkF]

Right. Standard link setting is about 452mm, upgraded at 413mm. We stripped and measured the existing setup which was at 410mm. Using Tom's suggestion of 75% of the revised our height adjustment of 30mm we added 22mm to the 410 getting 432mm for the setting link. Thereafter Xk Engineering called back with the correct measurement of 432. Now to reassemble and hope all is good. Many thanks for the assistance