DDK - Die Deutschen Klassiker

interesting thread on pelican regarding torsion bar sizes

http://forums.pelicanparts.com/showthre ... oni&page=2




I'm going to do something with my suspension this winter, but as my car is pretty much all street, I'm thinking of leaving torsion bar sizes alone & just changing my shocks & lifting the ride height.

The type of shock I go for will depend on what struts I have, as until I remove them I don't know if they are Boge or Koni.

Interesting find that James - a complete minefield

Tuthills suggested stock front and 26mm rear, whilst others have advocated 21/27 and 22/28.

I guess it all comes down to TB size, damper rating, tyre size and rating that all add up to zilions of combinations.

Having looked at my Donington track day pictures, and experienced the car through the corners, I am pretty happy as it is, but could do with a little more brakes - now there's another whole upgrade in itself.

FWIW - I has assumed as you have an 'S', it would be Koni or Bilstein struts.

Ian

Mike Bainbridge advised me to stick with stock front TB's & maybe go to turbo rears ... sounds like Tuthills recomend the same.

I imagine a tarmac 'rally' set up will work well on our country roads.


My car deffo does not have Bilsteins ( no roll pin). The strutts have a thin coat of black paint like Boge , but might have been blasted & painted in teh past?, & have the 3.5" caliper spacing for S calipers. I won't know what they are exactly until I open them up.

Ian, another interesting read on TB sizes from the IB lads, this time based on UK experience

http://www.impactbumpers.com/forum/inde ... topic=4618


and this thread ( especially nearer the end of the thread )

http://www.impactbumpers.com/forum/inde ... topic=4724

Good IB threads, with again a number of different combinations on offer.

Simplest is to go to 26mm rears first, and see how that works - that was the recommendation from Tuthills, along with their Rally Spec. rear shocks and a revalve up front.

TBH - I suspect I will not really notice the difference the way I drive - note to self - need to be more aggressive and see that wheel in the air approach to cornering

I will be calling Tuthills soon....

Now I just need to decide in which bushings - stock, superpro, elephant etc.

Ian

There was an excellent quote from Steve Weiner (ex-RSR racer & owner of Rennsport Systems) in a thread on suspension settings on the Early S Registry :

"...There are MANY things that affect perceived ride quality and before engaging in a protracted discussion, one must understand that the operative word here is; "perceived", which means its all subjective. Aside from color, I cannot think of another aspect of ownership where "One man's tea is another man's poison", is more meaningful..... One should never get caught up in aquiring fancy technology due to peer pressure or appearance.

IMHO, the components that have the greatest effect ride quality are (in order):

1) Shock valving
2) Tires & pressures
3) Bushings
4) Spring rates (torsion bar sizes)
5) Swaybar diameters & adjustment (where applicable)

Obviously, this doesn't account for local road conditions since thats a variable that nobody can control.

Needless to say, every modification one does to their car becomes a compromise of sorts and an individual decision based on what one does with the car and how its driven. Its simply a question of degree.

I would conclude by offering that suspension upgrades are not a one-size-fits all proposition. Everyone's needs and expectations are different and people in my business ought to listen carefully to their customers so that the end result will meet or exceed each individual's objectives..."

Ian - I had Bilstein Sports F&R on my black RS-engined Targa above.

I also have experience of a 21/28 mm torsion bar combination - my 2.8 twin-plug car had the following set-up:

21mm (F) + 28mm (R) torsion bars
3.2 Carrera Bilstein front struts with 'Sports' inserts
Bilstein Sports rear shockers
Factory 16mm (F) + 18mm (R) antiroll bars
Turbo tie-rods
3.2 carrera F&R brakes
Lowered (significantly - too much ?)
Corner balanced
205/55 & 225/50 x 15" tyres on 7 & 8 Fuchs

I found the overall compromise of comfort/roadholding/handling ideal for my use/style which is why I went for a very similar set-up on my silver 911R-inspired car - the only difference being I opted for 22mm Weltmeister antiroll bars F&R.

The silver car was already lighter (grp front wings & rear bumper + carbon fibre engine lid) than my black 2.8 but I am in the process of lightening it further so it may be that some of these settings prove too harsh ...

Ian, I'd be interested to know the tuthill costs .. pm me if you want to keep it private.

I'd also be interested in how it handles afterwards too. Are you doing it soon?

interestingly, Chuck @ Elephant racing has advised me to go for 21/27 combo with Bilstein HD's. Car has stock 'S' roll bars, ER polybronze bushes & I'm raising the suspension to 25.5 fr , 25 rear.

Mike bainbridge, tuthills & others it appears recomend 19/26 combo

Any comments etc ? I don;t want the car oversteery to the point it becomes a liability if I'm not concentrating

Shame you are so far away as I am running 21/27 and you are welcome to drive my car to get a feel for the set up.

Alan

Alan, how do you find the handling ? Neutral or a little bit under steerey?

Hi,

I find the steering pretty neutral, but I think handlng interpretation varies based on the driver. Also at the moment it is hard to 100% tell as the car is too low which is making the car very hard/stiff, but it corners very well.

HTH

Alan