Last update was december 2008, I took a long break but have some time now (April 2009). I did some things in the meanwhile. The rear side windows are bothering me, I think I will make plexi windows with aluframes that will be bonded in with a polymer or urethane kit, more flush with the body. The inner glass window will be left out and the window surround smoothed. Then a small door for the fuel filler cap. Another future project.
Work continued on the brakes install. Made the definitive brackets out of 6 mm thick 40x40 mm angle steel. The holes for the caliper are threaded but there will be counter nuts also. It takes extreme precision to fabricate these as I didn't want to use shimms later to properly align the caliper in the 2 dimensions.
Seen here with temporary suspension arms. The calliper sits very close to the spokes of the rim and that was what I was aiming for. I think 16 inch wheels would still fit depending on the spoke design or I could have used 330 mm discs instead of 310 mm. These discs are large enough though and already quite heavy. Also the calliper adapter is shorter and stiffer this way and it shows more brake calliper on the outside, good looks is also important! I need to get shorter bolts for the adapters.
I was thinking alot about what to do with the front suspension. I wanted to get rid of spacers and not use extreme wide wheels. I thought about making subframes that bolt to the existing suspension pick up points where then the original suspension A-arms could be bolted to but rejected that as a poor looking solution and it also would introduce bumpsteer. I decided on longer A-arms but then the leverage of the spring/damper would be longer resulting in softer suspension and a too low front. I made an extender for the upper shock mount that bolts to the original mount and moves out the shock 60 mm. It fitted but looked awful.
I rejected the previous solution and started thinking about buying longer aftermarket adjustable shocks with adjustable spring seats, the QA-1 from the USA seems to be very popular among 308 owners though there are many more to choose from. But I already have new original shocks and the uprated springs from Superformance. I started doing calculations and found then that an increase in A-arm length of 55 mm only had a 6% negative effect on leverage or springrate. That is OK as my new Superformance springs are supposed to be 25% stiffer than standard. I only had to find out if the shock was long enough and that too was OK, wheel can move out 50 mm from my desired ride height before the shock is fully extended.
This means I can use the original Koni dampers and the uprated Superformance springs. However, I did swap the front and rear springs. The springs are similar front and rear but the rears have 1 extra wind making them a bit softer. The rear of the car was too high with the new rear springs but perfect with the shorter front springs so I fitted the front springs in the rear. Because of the longer lower front A-arms I needed a longer spring, perfect, the longer rear springs fitted though I needed to make extra 10 mm spacers for under the springs to get the proper ride height. The front is now softer sprung compared to the rear but this is good. Because I now have a longer wheelbase there is more weight transferred to the front and softer springs prevent extra understeer. Only when all is ready and driving the car I can tell if all is well and when the budget permits I might buy aftermarket shocks and springs after all.
I had started building new A-arms but these were intended to be used with the upper shock mount extender that I later rejected. Also I didn't like the welded angles in the upper A-arm, the welds might break after a while of alternating loads (metal fatigue) so I didn't use these, only for measuring puposes.
Checking spring rate. Not very accurate, spring is 3 kg, 5 mm travel for 22.6 kg weight is 45 kg/cm or 250 lb/inch. Original front spring is about 180 lb/inch, good.
