DIY Coilovers

[rs200]

nice work man.. I realy like it..
now I'm in middle of DIY coilovers for my S8 by using bilstein B6 and Eibach springs.
but have one little problem, and it is choice of material.
please can you tell me what kind of material you use on your coils?
my English is not so good , and don't know the name of following part on picture. here is your picture.



what kind of materials is 1. & 2. part ?
tnx
Igor

[Rusty]

1 stainless steel
2 anodised aluminium or stainless

Mild steel will corrode too much.

Spring length depends on spring rate, as stiffer springs will sag more. Stiffer springs also require shorter shocks as the overall spring height when off the car will be shorter and that difference needs to be accounted for.

Simply F=k.x where

F is the axle weight: 4500-5000N front, 3000-3500N rear per spring (1500kg-100kg) total

k = spring rate in N/mm

Giving x, sag in mm

The Avant rear suspension may require a scaling factor though, as it's not a simple MacStrut. This could be estimated by comparing the spring rate of the front and rear springs, as they will be roughly similar (within 10%) based on the coupe. Another option is to ask someone with KWs.

[bambridge]

The threaded tube is made from mild steel and then plated, the adjuster ring is aluminium and hard black anodised.

Brian Tonks is also fitting a set of these next week or so:

Cheers

Kev

[A80Avant]

hopefully there will be a write up soon. Once we get our head around the height of the springs required!!

[rs200]

can I buy somewhere this part "2" ? it could be good that I can buy it for example: 30cm long , inner diameter 4cm.
or have to made it in machine shop?

[Rusty]

I attached a spring rate and length calculator to this thread a while back. It works out stack height at rest and when compressed. If you have a specific question then I'll do my best to help.

[rs200]

tnx my friend..
I calculated everithing what I need , but don't know where to find this part No "2". can I buy it somewhere or have to made it from aluminium? did they must be anodised aluminum? is there some different between anodised alu and non anodised alu?
isn't aluminum little too much soft ? my fear is ..
when I want to put car higher, and screw must go up.. and spring will go stiffer, can screw kill part 2?
what is english name for part 2?
thanks ..

[Error404]

I guess it's is called a threaded sleeve
I'm sure you can buy them from Bambridge or Compbrake, but I'm sure the Bambridge items will be much better quality (compbrake ones don't have very good tolerances on the threads) HTH

[Rusty]

Kev, an idea on costs for the coilover kits?

[A80Avant]

Rusty that is good idea but for some reason even a specialist spring shop got it wrong for us and gave us springs that made the car sit like a Porsche cayenne. So we have now considered with Brian an 8inch spring to make it able to sit with the coilovers from stock to lower setting by 20mm

Lbs wise, the fronts stock being 211 and rear 300 I'm going to go for 275-325 and I am a bit apprehensive of if the car will become too stiff

sent with Nokia 5110

[Rusty]

Sounds like the specialist spring shop need a lesson in simple physics

Stock springs are 330mm front, 300mm rear free length but with sports dampers then HnRs at 310mm and 280mm respectively are only just under tension and are dual rate to give the drop in rideheight, which is essential for increased stiffness springs. Dropping to a 200m spring will leave a gap of 110mm and 80mm that needs to be taken up by shortening the dampers considerably, to avoid the spring falling off the seals under full extension or even a large bump in the road!

As for stiffness, the small upgrade that you mention isn't a good idea in terms of the balance front to rear. You should really increase both by the same % and for the understeering (R)S2, a slightly stiffer rear setup (by 5-10%) will make the car handle much better (similar to fitting a big RARB but with better axle articulation). As for whether it's worth all the effort to get car to sit and ride basically the same as it would on a set of HnRs (similar spring rates to those you mention and marginally lower, I'd say not. If you want to lift the car over HnRs then fit some small spacers between the top strut and top mount - much cheaper.

[A80Avant]

I'd like to keep the car in the same stiffness overall but I am told that if the car drops, it need slightly stiffer springs. So hence the fact of building the coilovers with Bambridge and Brian and then fitting the correct springs to match. I'm happy to use 250 front and 325 rear as I feel the rears are already stiff from stock, and using up to 20mm drop which isnt that big anyway should be ok hopefully.

I'm using the pro mounts in front and those have lifted the front end by 2mm anyway so currently the car sits higher in front than rear

sent with Nokia 5110

[rs200]

I know that here is all about s2/rs2, but I have S8 , for now on the car is Eibach spring. if that will knot be good for some reason, than will go in Zagreb, there is one guy who will calculated what kind of spring will be the best for my car, than they will produce spring for me .
I know that is the best choice, because they made springs for my friend (s6 aan) and that is best handling car I ever drive.
hard & steady in corners, soft enough on bad roads.. with this springs, the filling of hard braking is like nothing. he i specialist for springs and car handling.
I also have to said that set of this springs cost half of price than H&R set.. LOL

[terrybullwon]

Has any one that has made a set of these yet put them on a damper dyno to see if your not completely in balancing the car?

[Error404]

That's why I didn't bother building my own, works out too expensive to do it properly, getting the shocks dyno matched etc you spend a grand on it to do it right. IMHO of course.