Reduced droop shock length

[vstibbard]

I’m having a set rear Koni’s reconditioned for S2 Elan project.
As they will be apart I wanted to have the rods reduced in length to allow use of TTR rear driveline or CV joints. I’ll use the car for track days and fast road use.
Few questions:
1. Does anyone know how much shorter the rods are?
2. Anyone of the Australian forum members had their Koni’s rebuilt and modified length? If so can you recommend who did the work?
Thanks in advance
Vaughan

[rgh0]

"Top Performance Products" are the Koni distributor for Australia and can rebuild the shocks I believe.

I have TTR supplied reduced stroke Koni shocks fitted to my Elan rear with CVs and with no binding issues on full droop and I will check measure the length for you over the weekend.

cheers
Rohan

[Lotusian]

I had my Koni dampers reconditioned by S P Suspension in the UK. They are Koni approved reconditioners.
They suggested reducing the droop by 50mm to suit CV joints and I accepted their advice.
I think they fitted sleeves internally, rather than reduce the rod length.
Ian

[vstibbard]

Thank you both, Rohan I look forward to the measurements, 50mm seems a lot but then there is a lot of travel.
What height spacer do you use with the aeon bump stop?
Cheers
Vaughan

[ericbushby]

Kelvedon in the UK suggest a 25mm reduction in droop for their CV shafts.
My shock absorbers looked to be in as new condition, and as I could not find how to get into them to fit spacers, I shortened the shafts by reducing the diameter at the top and fitting a tubular spacer under the nut.
Eric in Burnley
1967 S3SE DHC

[vstibbard]

Thanks Eric
I’ve three sets of Koni’s to choose from, one had thread damaged in past. So maybe an option. From your post sounds like you did not strip the shock down.
Cheers
Vaughan

[rgh0]

https://www.youtube.com/watch?v=q01k3xLvmy0

Hi Vaughan
This is a link to Ric Kemp who gave a presentation of the Victorian lotus club recently. He used to be a race suspension engineer in Europe and Australia with Koni and now runs his own suspension tuning and shock building service. he can probably help you out also. I used to race against him in marque sports cars back in the 80's, he had a pinto engined Lotus 7 and was much much quicker than me
cheers
Rohan

[ericbushby]

Hi Vaughan,
I could not find any way into the Koni shock absorber to fit a spacer. Please realise that this is the first time I have worked on one.!
We did two cars. My friends had quite soft shafts so we shortened them, recut the thread and sawed and filed the end bits (sorry) and a new cross drilling for the pin.
Mine was too hard for screw cutting, so we turned the shaft down for 25mm, cut the flat with an angle grinder fitted with a diamond wheel, finishing with diamond files and abrasive paper until satisfied with the finish.
A 25mm tubular spacer was made to fit under the nut thus lifting the whole assembly 25mm.
The lathe was not happy turning the hardened shaft down, but with a tipped tool and 10 thou` cuts it got there.
The shock absorber body end of the shaft was held up at the tailstock end by a lathe steady during turning.
It took some time and a lot of planning and care but it worked and it cost nothing.
However I would suggest that you listen to Rohan who knows far more than I could ever know about work on Elans.
Eric in Burnley
1967 S3SE DHC

[fatboyoz]

Hi V,
Had my limited droop, TTR Koni serviced by this chap a couple of years ago. Recommended by Koni.
https://www.smoothsuspension.com.au
Cheers,
Colin.

quote="vstibbard"]I’m having a set rear Koni’s reconditioned for S2 Elan project.
As they will be apart I wanted to have the rods reduced in length to allow use of TTR rear driveline or CV joints. I’ll use the car for track days and fast road use.
Few questions:
1. Does anyone know how much shorter the rods are?
2. Anyone of the Australian forum members had their Koni’s rebuilt and modified length? If so can you recommend who did the work?
Thanks in advance
Vaughan[/quote]

[vstibbard]

Thanks All, Rohan,I’ve just finished listening to Ric and will reach out to him as he’d be good with Elfin and Rennmax shock rebuild as well and set up as both have historic Koni’s.
Cheers
Vaughan

[vstibbard]

Thanks Colin, I'll also reach out to them as well.

Cheers

V

[GreyElan]

An alternative could be using Elan Trik Bits shafts and you don't have to modify anything! Perhaps too straight forward?

[vstibbard]

Good suggestion and timing, I reached out to Col yesterday and will buy a set of his cv axles and a frame toe adjusters while I’m at it, I still need to have one of the sets of shocks reconditioned which is an easier problem to solve. :
Cheers
Vaughan

[661]

An alternative could be using Elan Trik Bits shafts and you don't have to modify anything! Perhaps too straight forward?

^^^ This.
I've just fitted a pair of Col's CV's to the road car ( albeit with TTR shocks anyway)
I understand there would be no binding with these with normal full droop shocks.
They are exceptionally well engineered.
( I've also got fully adjustable A frames with polybushes)

[vstibbard]

Thanks Graeme,
How are you doing? The last few years must have been tough with the waves of covid impacting patients and health system.
I had a great chat with Seb who we played water polo with a few days ago, he’s set up and group headmaster of a private equity funded group of schools in Chelsea area, who said recent policy settings have the schools making the hard decisions.
How’s the GTS going?
Cheers
Vaughan