Considering building new dampers, need advice

[PeR4]

I've found a local company that can build dampers for my Atom 2, dampers that will function with the new needle roller susp. bellcranks that this winter are replacing the (sticking) originals.

I've understood here that only the stiffest adjustment on the 5 way adjustable Bilsteins will function when the bellcrancks are changed, because the friction is reduced alot.

Will it work if I dynotest the Bilsteins set with the stiffest adjustment, and then shim the new dampers based on these compression/reboundcurves?

[PhillipM]

No, what you want are the very low speed characteristics from the Bilstiens to match the reduced bellcrank friction and then bring the high speed settings back to match the springs.

However, dynoing the Bilstiens on a force graph and using that as a base will tell you very little using a normal sinusoidal damper dyno compared to a completely different unit - even if you matched the traces they would perform very differently. That's only really any use for setting the same units up together, or changes from a baseline on the same damper.

I would expect any company building dampers worth their salt should be able to work out what you need themselves.

[PeR4]

OK and thanks for quick reply PhillipM 
As you understand I don't know much technical about dampers yet.. In a few months

[HenryJS]

PeR4:

great to hear you have upgraded to the needle roller bellcranks, you'll feel a huge difference with these alone!

Remember to grease them a couple of times a year (especially if its wet a lot when you're driving) to keep them running super smooth. I would recommend Silkolene Pro RG2 grease.

RE the Dampers, have you considered having your current dampers serviced? rather than spend (what i can only guess) would be a quite a lot of money on new dampers to see if that helps first?

[PeR4]

Thanks for advice!

Then reshimming is part of the service? I haven't (yet) found information on this forum about reshimming/servicing the 5-way adjustable Bilsteins.

I will be mainly be using it on track and together with tuned Elise, Exige and similar. Today I'm left behind in the corners . It is smart to brake early because of a tendency to lockup entering the corner, as well I loose meters due to lower grip in the corner and struggle sideways(not efficient time wise, but fun..) trying to keep up out of the corners. Much of this due to sticking suspension which is not the case soon

I would like the damperadjustment range to be wide, and as well keep suspension friction down. I think the Atom because of low weight, especially in the front, could advantage from good very adjustable low friction suspension. This is also based on my reading on this forum.

Im looking at Ohlins (ttx36) now, main reasons beeing earlier good experience using Ohlins, positive remarks here from Atomdrivers and, very important, expertice within 1,5 hours driving from where I live.

[911tom]

Anyone which Ohlins the factory fit? Or is that top secret information 

[HenryJS]

Hi PeR4

It can be shimmed to how you like it, it you would like it harder that is no problem. We also offer harder springs as well. The rear springs can be moved to the front, and a firmer spring fitted to the rear. If you want it to be harder again i recommend fitted a very lightweight assister spring.

The adjustment range i do not think can be changed unfortunately, not without having pretty much all new internals!

The TTX36 Ohlins has proven itself to be very good on Race Tracks, you have a wide range of adjustment, and a wide variety of spring rates available to you.

Alternatively you could look at the Ohlins dampers we fitted to the Atom Cup Cars - these come presest for maximum track performance.

You can make changes to the setup of your car  to make it better round the track too - increasing camber and decreasing the rear ride height (I assume you have 16" rear wheels). However this will put more stress on all of your components, wheel bearings, engine and chassis.

If you would like some prices - please get in touch at:  henry@arielmotor.co.uk

[PeR4]

[quote="911tom"]
Anyone which Ohlins the factory fit? Or is that top secret information 
[/quote]

Factory kit for the road and track is based on the ttx36.

[PeR4]

[quote="HenryJS"]
Hi PeR4

The TTX36 Ohlins has proven itself to be very good on Race Tracks, you have a wide range of adjustment, and a wide variety of spring rates available to you.

Alternatively you could look at the Ohlins dampers we fitted to the Atom Cup Cars - these come presest for maximum track performance.

You can make changes to the setup of your car  to make it better round the track too - increasing camber and decreasing the rear ride height (I assume you have 16" rear wheels). However this will put more stress on all of your components, wheel bearings, engine and chassis
[/quote]

My choice for ttx36 damper and spring set up would be one that suits the Nurburgring. If You know of anyone with this, I would like a copy

How are service intervals for the Atom Cup Ohlins, in track distance? Any adjustment to these dampers?, between wet and dry..?

Yes, 16"x8" rear. Corner weighting and adjusting the set up against a mild track orientation will be done coming spring.
If I stay with the tuned Exiges w this I'm happy.. or

[HenryJS]

PeR4,

Having never been to the Nurburgring, but having listened in on many a conversation about set up -

I have been told the Nordschleife is very bumpy and struggles if set up too hard. Im sure someone with more experience may be able to help with that question. Setting the car up softer in this instance would give you more performance to deal better with the lumps and bumps.

A difficult decision as many racetracks as a general rule are smooth.

The service intervals on dampers varies, if you were doing 1000's of miles a year on the race track i would suggest a service every year. However if you only do a few track days every year, and you keep the car nice a clean i would say once every 4-5 years would be fine.

A mild track setup would be 1 degree negative camber front and rear. Reducing the rear ride height by perhaps 5mm.

[PeR4]

Thanks Henry, then maybe the softer road setup is better for me..
I already got som info from Ariel with prices. Probably I'll decide what to buy and where next week.

[HenryJS]

[PeR4]

Today I ordered the factory Ohlins set based on the ttx36 damper, and the Atom 3 Bell Crank – race. These give even less friction than the standard Atom 3 bell crank, and the factory think they are ok for many miles, road and track use. I hope that the tendency with sticking suspension will be cured.

[PeR4]

The garage used 7 hours today adjusting camber and toe, in advance they estimated 3 hours.. They did not want to do the job again, especially the rear was time consuming.

I understand the US-Atom is easier to adjust, what is different from the UK version?

[Oli1122]

My Garage checked all my rod ends (replaced 2 of it), did corner weighing, the geo alignment and safety wired the big rod ends in under 5h.
They were not really pleased with the effort needed but had a lot of fun doing it on a unusual car instead of boring 911 gt3's 

I guess your garage is not used to it... I'm only judging it by reading 7h.