Harewood 29th August 2004
Back to Harewood again and as I now feel I am quite consistent here it was time to try a few suspension tweaks.
The course is 1448.25 metres long. The map is from www.harewoodhill.co.uk
Set Up: I decided to try stiffer springs for this meeting. I was concerned that the soft springs I was using may be allowing too much body roll using up suspension travel (actually going onto the bump stops) and causing the wheels to go into positive camber. So I fitted 200 lb springs on the front (170 LB before) and 250 LB to the rear (200 LB before) These were not the ideal springs to use but it is all I had. The idea is to maintain the front to rear ratio of wheel rate. Ideally to get 25% stiffer I should have used 213 LB front springs. Hopefully by running the front anti roll bar stiffer I can still maintain a balanced vehicle.
One problem of fitting the stiffer springs is that the ride
height is increased. I could lower the spring seats but this would mean that
the spring would rattle loose on full droop, which is not good. So the front
is 16mm higher and the rear 12mm too high. I adjusted the pushrods to lower
the vehicle but they are their shortest adjustment so this did not gain much.
The fronts were wound two turns which is 5mm lower. (1/2" UNF x 20 TPI
I took the car on a test run with my video camera on the rear
coilovers so I could observe how much suspension travel I was using. Under
hard cornering under power there was about 15mm of travel left before the
bump stop came into play (the bump stops are soft and progressive). However
on bumpy roads the bumps really came into use.
Graham Blackwell was also at Harewood in his Sports Libre Zetec powered Fiesta on slicks. I walked the course with Graham and tried to explain the correct lines up Harewood.
1st Practice Run Grahams
2nd Practice Run Grahams
3rd Timed Run
Notes: Track dry, but a big oil spill around Farmhouse Bend about 15 cars before I ran. Graham went home before this run. I went as fast as I could until Farmhouse Bend then took it easy so the first 3 splits are true, splits 4 and 5 are slow due to me backing off.
Summary: The car was slower today even though I felt I was driving as fast as previously. So this could be caused by me not driving consistently, the track being slower or the springs making the car slower. It was good to have Grahams times to compare against. I am loosing a lot of time between split 2 and 3. Willow bend is fast with no run off plus if I take it in 3rd gear I am just off cam coming out, but 2nd gear feels too low.
These are the split times from this meeting arranged in a table for easy comparison.
Split1: 64 ft, Split 2: Entrance to Country Corner, Split 3: Exit of Orchard Corner, Split 4: Exit of Farmhouse Bend, Split 5: Finish line.
M Geen is on road tyres in a modified 1.4 litre Peugeot 205. He is the class record holder. P Short is in an extensively modified Mini 148bhp on wide slick tyres. Phils time was from the 1st August meeting. These times are for comparison.