Wednesday 28th August 2002
To help myself understand the dynamics etc of the brakes on the car, I've written a new page, brakes which explains how I've modified the brakes on the Fiesta, and the steps taken to improve the rather dead pedal that I've so far experienced. I've still not driven the car since modifying the linkage bar, but hopefully the next opportunity should occur in following weeks. I'll add to the page as I develop the brakes, and I'll go in to theories etc of how you calculate fluid pressures over the next few days, as I get an opportunity to document all my work.
Sunday 25th August 2002
Made a slight modification to the brakes in an attempt to make them work better. The brake transfer bar that runs across the bulkhead, has two 60mm long levers welded one on each end. I've now shortened the lever that connects to the brake bias box assembly, by 30mm, therefore giving me a mechanical advantage of x2. So, for 200 lb of force on the brake pedal, the overall ratio of the linkage assembly has gone from 3.571:1 to 7.142:1, which means for the same amount of effort, I now have twice the amount of force applied to the bias box, ie 1400 lbs of force which should make a 100% increase in the braking performance. Of course, the bias bar then divides this force by 2, which results in 700 lb of force on each master cylinder, and other physics like the size of the master cylinders and the slave cylinders, all comes in to play. But its the only no-cost tweak I can think of at the moment, that doesn't involve some huge amounts of re-engineering etc etc. I just need to find a piece of land where I can test this theory out.... Now, if I could only fit a tow rope and get the wife to take me for a few laps of the dual carriageway.
Sunday 18th August 2002
The RSOC National show was massive this year, with hundreds of awesome Ford Cosworths, and a single red Fiesta XR2 in the paddock! I was amazed how much interest my little car generated. Thousands of people must have come across to the Performance Ford stand during the course of the day, and most of them came over and peered in to the engine bay, some with open mouths as they tried to comprehend the 2.0 Zetec conversion. It was a shame I couldn't get any track time (no places left). I'd like to have driven the Fiesta around Donington, particularly as it was such a nice day, just a couple of brief rain showers in the morning. Perfect conditions for some quick laps of the circuit. Theres always next year.
Here are some photos from the event for those of you who couldn't make it.
Wednesday 14th August 2002
I will be at the RS Owners Club show at Donington Park race circuit on Sunday 18th August, on the Performance Ford stand, if the tickets arrive in the post in time. If you're at the show, please come by and say hello. If I get a chance, I'll sneak the car on the circuit for a quick play! So the crash helmet and racing gloves are definitely coming with me... So far, the car has been to Mallory Park, Silverstone Circuit and now Donington Park. Thats not bad, 3 different national race circuits in under 2 months.
Saturday 10th August 2002
I've downloaded and analysed the data from the ECU for the 2nd run in the wet. Click the graph icon to display the output, showing engine RPM and throttle position. Looks like I should be revving the engine a bit harder, I've changed early on some of the gear changes, certainly before the 6750rpm shift light came on anyway. Maximum rpm is 7250, and I never approached that figure, which is good for the engine, but not for my laptimes. Mental note: Drive it like you've stolen it!
The Engine UDP has arrived from Kurts Kustom Motorsports, I'll try to get it fitted in the next few weeks. Its a replacement crank pulley, which is 25% smaller, and 75% lighter than the original, and it saves horsepower, by turning the water pump and alternator slower. Many thanks to Warren Kurtz for donating it to the project. Even though the pulley came from Kansas in the USA, it arrived on my desk at work in just 2 days, courtesey of UPS. Amazing!
A short (3MB) MPEG video clip of a portion of my first timed run is available for download. Click the icon to view the car in action, with sound too.
Monday 5th August 2002
Well, I'm very pleased to say that we had an excellent run at Stowe Circuit on Sunday. No problems with the car, aside from the brakes still not working properly. The Silverstone Stowe circuit is fun to drive on, if a little short at 0.8 miles per lap. My first practice I trundled round at 97 seconds for the 1¾ laps, having a quick play at getting the braking points and turning-in points right.
My first timed run I posted 90 second's, which was only 7 seconds slower than a modified 3200cc Porsche 911. Having then psyched myself up for the second and final timed run of the afternoon, it started raining, and by the time I got the green light, the track was very wet and I had the windscreen wipers on. This time I recorded 97 seconds again, but the best news was that I was only 1 second slower than the Porsche. Rain is a good leveller isn't it
In all, we didn't disgrace ourselves. Another 10 laps and I'd be down in the low 80's in the dry. I really underestimated the levels of grip from the sticky Yokohama tyres. I should be carrying a lot more speed in to the corners, braking much later, turning in later on some of the 45° corners too. I need to get some more testing under my belt. Really learn how to chuck the car round corners, get some more confidence in how she reacts.
My times weren't too bad compared to other cars. I was faster than a group of Peugeot 205 1.9 GTI's, a Lotus Sunbeam, Lotus Elan etc. I should be running rings round them, and with some more practice I probably will be. I'd like to get some slick tyres for the car, and get the front brakes working properly for next season. The Hawk Ferro-Carbon blue pads still don't stop the car. I guess theres just not enough hydraulic pressure for the HiSpec calipers to work properly. I spoke with the owner of a Triumph TR8, and he said he had exactly the same problem, and he cured it by fitting a remote servo. I think I may do the same.
Jez of www.drivetrainuk.com says that there's a new test venue near Coventry, owned by Prodrive, and very twisty, a really good place to learn the handling of the Fiesta. I've run out of holiday at work, so I need to beg some time off to go and play on the test track.
Friday 2nd August 2002
I am car number 45 on Sunday. Up against a Radical Clubsport, which is a spaceframed 1100cc Kawasaki engined race car that does 0-60 in 3 seconds, and two Caterham 7's, so I guess I'll be 4th in class then. Doesn't matter really, I'm there to gain experience of competing again, as its a long long time since I competed in a sprint. And its the first event for the Fiesta, so I'll be learning how she handles, particularly if it's raining on Sunday.
Fellow Nottingham Sports Car Club member Stephen Miles will be there in his Van Diemen Dunnel-Zetec, so it'll be nice to have some familiar faces around us.