Sunday, 1 March 2009

Suspension upgrade part 4 - Test drive

As the work on the DHC has taken up most of my spare time it took me slightly longer to fit the new (front) suspension. But after bleeding the brakes Wednesday evening, I found a free hour Thursday afternoon to take ‘t Kreng out for a short spin. As she had been standing dormant since November last year, she was rather reluctant to fire up, but she did splutter to life at the fifth attempt. This first trip was mainly used to blow the engines cobwebs away and to settle everything gently and get an overall feel of the new setup. First impression was rather positive though.

Today I took the car for a longer spin over some of the more demanding roads around here. Due to the fact that the front springs are quite a bit stiffer now (remember I went from 225 to 336 lbs/inch) the car feels slightly bumpy on uneven surfaces, but without being harsh and only when the speed is slow. As stated earlier the dampers are at their softest setting, which probably helps here. This all changes significantly once the loud pedal goes down a bit more. The front is much firmer, more precise then my last setup and overall grip at the front is much improved. So much that I managed to get the coolant light on in a long and fairly fast right hand corner ...
But where it really excels is in its ability to absorb bumps and ruts at speed. Even on two really vicious bumps here in my neighbourhood the new front doesn’t lose its poise. Even at well over 70 mph it doesn’t bottom out or crashes, but feels completely in control.
First impression with the current damper settings is that it needs to be stiffened up slightly, but as the weather was rather nice today there were loads of walkers, cyclists and cars on the road making it impossible to do some decent comparison tests. So tweaking the dampers will have to wait a bit.

Every pro off course has it’s con, most notable being the difference between front and rear now. With the old (front) setup the rear felt pretty good, but not anymore. Although far from being sloppy it really isn’t good enough. With the current rear springs it needs pretty firm damper settings to keep it more or less in control, but compared to the front that is not good enough. So next stage will be fitting the rear coil-overs, but to fit them I need to adapt the rear suspension turrets slightly. So that will have to wait till after the ”Nacht van het Oosten” the first rally of the year in two weeks time.

Remains the front ride height, which has gone up a bit. It is now 630/635 mm (L/R) with the lower spring seats at their lowest possible setting with the current springs (they were 610/625 mm respectively). So not yet sure what I’ll do here, if room allows I will probably add helper springs to give me more freedom with the adjustment. But for now the cars stands pretty good, so I’ll leave it for a while;

As you can see the car stands nice and level with the lower rear links nicely horizontal. Will need to get front alignment checked/adjusted in the next few weeks.

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