So, despite following all the advice I could find, this exhaust is a bit on the loud side. I'm going to have to take it a part a again and have another go at repacking it. There is was no way I was going to be allowed out on the track with a car making that much noise. Ironically, three guys came up to me after this session and told me how fantastic it sounded. Fortunately, I'd stuck my old Yamaha R1 silencer in the boot and I'd also left the original mounting bracket on the car just in case. This is a standard 2003 exhaust with catalyst.
Whilst the second session of sighting laps went on, I whipped the sidepod off and swapped over the exhaust. I've done this so many times now, I can do it in about 5 minutes. The downside was that this silencer doesn't have a full tail pipe, so it wasn't really venting out through the side pod, something that was ultimately going to limit my track time.
We had been very lucky with the weather this weekend. It was a cool, autumnal morning with a lot of dew on the ground but no rain. The track was damp and with cold tyres, the back end stepped out on the exit of every corner. As the tyres warmed up grip got better and better. Having put in a good number of laps I came back into the pits to check the car over.
The exhaust gases had started to damage the heat reflective mat in the side pod and were heating the rear tyre up too, resulting is some unpredictable handling. The course was mainly right-hand corners so the left tyres were going to be warmer but the rear left tyre was noticable warmer and the pressure was 5psi higher when measured in the pitlane.
I rigged up a temporary tail pipe using the materials to hand, which wasn't much. I went back out on track and things were much improved. The track was also starting to dry in the sunshine . The rear was a lot more planted but I was still getting the back end out on accelerating out of the corners. The power and torque was overwhelming the rear tyres. I think some of this was down to them being about 2mm off the wear indicators. Eventually my improvised DIY attempt at a tail pipe gave way and the aluminium simply melted. It was now time for an early lunch break.
Instead of eating lunch, I popped out to the nearest tyre and exhaust place I'd used before (Melton) and they let me go through their skip to find a suitable piece of steel pipe and sold me an exhaust clamp to fit. I popped home and cut it down with an angle grinder to fit. I was back at the circuit 15 minutes before the afternoon session was due to start. Fitting it proved harder than I planned (sidepod off again) but it did the trick and I got to do a lot more driving in the afternoon and even took out a few passengers. It was shocking how big an effect a passenger had on braking. I could really feel the extra momentum and had to press the brakes a lot harder. There was never any doubt that they would stop the car though but, that was to be expected having taken a no-compromise approach to the braking system.
On a side by side drag down the main straight with Daz there was nothing between our cars in speed. On the one occasion I actually looked at the speedo on the main straight it read 132mph. I honestly don't know if the car would do more as I was too focussed on the track ahead. I must remember to look at the maximum figures stored by the Digidash2. On a few occasions the displayed OTA (Oil Temperature Alarm) but this is not unusual as I have it set to alarm at a relatively low 100°C. Flipping the fan switch was enough to make it go away but, I generally used this as justification to come in and give the car and myself a rest and an opportunity to let the car cool down.
It is amazing how much gravel and rubber finds a way over the aeroscreen and into your lap! On a fairly twisty circuit like this the standard cars seem to expose their mass and momentum. Following mainstream cars (BMW, Nova, Supra, 200SX, TVR, etc.) it was clear that a lot more effort was being required to keep them on course and they braked so much earlier. Some of them were turbo/super charged and quite powerful though and staying with them on the straights required good gear choice. The lighter kit cars made it all look so much more effortless, taking faster and straighter lines through chicanes and simply looking more composed. I'm a total believer in the 'less is more' philosophy of Colin Chapman. If I ever get a dedicated trackday car, it will be a single seater weighing sub-350Kg. That said, you can't argue with the guys that turn up in £1000 hatchbacks and have huge fun on a budget. Pretty much any car is fun in such an environment.
All in all, I didn't really get to test out the car as I'd planned though, I did finally get enough tarmac to explore its full potential. I spent too much time messing with the exhaust and too little time focussed on my driving and my lines around the track. Looking back at the video I took in-car, I was braking far too early and changing up far too early. It was great fun though, if not without its stressful moments. The exhaust issue being the primary reason for this but, the rear tyres also seemed to be well down on grip. I went out with Daz later on and his car seemed to have much more grip on exiting corners. He's obviously a better driver than me but, I put some of this down to his car being properly set up and corner weighted. He looked to be the quickest thing out there on the day. Compared to a Striker though, my Fury felt properly refined with its tall aeroscreen. I was reminded why I didn't built an open-wheel car and the wind buffeting made it feel like you were going much faster. At about 3.30pm Daz's exhaust note changed and his exhaust started to get louder over the next hour. He was eventually black flagged as he failed a drive-by noise test.
So my plans are now are:
Had a look over the car today to see how things looked after the track day. It had collected a lot of gravel. The side pods have taken a bit of a battering on the undersides but other than that, the bodywork has stood up well. The fibreglass where the exhaust exits (or rather it didn't) has been slightly heat damaged. I need to replace the heat reflective matting in one place too.
|I opened up the exhaust to find this. Not enough Basalt so it has moved to the ends and allowed the wire wool to move in one place too. My first attempt was pretty rubbish then!|
Repacked the exhaust again but with more Basalt this time. I've a feeling this won't be the last time either .
Uploaded a couple of videos from the trackday. My driving was rubbish. I was changing up far too early, I was lifting off the throttle far too early and I was braking far too late. My only excuse was the distracting 'technical issues' and the worn tyres. More focus and more courage required next time!
Ben (one of my friends from work who was there in his MR2) sent me some pictures he took on the day. Very handy as I was keen to see how it looked on cornering. I must return the favour next time. I didn't have the foresight to pack a camera as well.
|The pictures were taken whilst I was giving a passenger ride.|
|This picture tells me two things. My roll hoops are too short and I need to get the geometry set up properly. The is a lot of negative camber on the inside wheel. This maybe OK but I don't know enough to be sure. But I know a man who does!|
To answer a question I posed earlier, the maximum oil temperature recorded by the Digidash2 was 101°C, the maximum water temperature was 103°C and the maximum speed was 135mph.
With 2769 miles on the clock, I've ordered four new Yokohama A048R tyres (185x60R13) in a medium compound. The fronts won't last much longer and the back tyres are down to the wear indicators and are nice and evenly worn. I really must try harder next time . That's 13p per mile just on tyres! Money bloody well spent!
|Created a template from cardboard for my new side pod bracket and then cut it out in 1.5mm aluminium. This bracket will hold the sidepod more firmly in place and with an added difuser, will direct the air heated by the exhaust silencer out and around the rear tyre.|
Picture of completed item to follow ...
Also made a few changes to the Digidash2 configuration following the trackday. The main one is to shift the oil level pressure warning light as it kept coming on at junctions and traffic lights when idling. I've moved it to below 20psi above 3000rpm. Lowered the water temperature alarm from 110ºC to 105ºC. Moved the fuel level alarm up from 5% to 8%.
Went out for a quick drive as it was a nice sunny day. I'd assumed the trackday speedo reading of 135mph was optomistic because my gearing calculations show I would need to be doing over 12,000rpm in 6th to reach this speed. I used my GPS device to check the speedo today and sure enough it was reading about 78mph at a GPS 70mph. This makes my 135mph a more realistic 121mph, about what I'd expect given that I wasn't actually trying to reach the top speed. I reckon a real 125mph is probably the maximum. There is little point in trying to correct this until the new tyres are on the car as the extra diameter of the new rubber will make a large difference. The speedo was calibrated using new tyres and the SVA rolling road, so it will be interesting to see how accurate is becomes with new tyres on.
The surface at Woodbridge Airfield must be fairly slippery because once the tyres were up to temperature, it was a real struggle to get the rear end to break free, despite them being at the end of their life and me showing them no mercy. Another thing I noticed is that I'd left the Nitrons up three clicks at the front and the back and it shows on the road.
Gear changes seemed to be a bit of a stuggle and as I got nearer to home, it got to the point where I could only change up and down when accelerating. A quick check when home showed that the clutch cable had slipped slightly. Easily fixed.
Oh, and the repacked exhaust? The car is louder than it has ever been . Even I'm shocked at how loud it is. I guess I'll have to take another look inside.
Spent a large chunk of the morning integrating the accessory wiring and in-car video behind the dash.
Took the car out for a spin this afternoon, to see if the clutch action had improved. There was a huge difference, enough to encourage me to extend my drive, something I soon regretted. As I pulled onto the A14 towards Felixstowe, the clutch stayed down with a shift up to 4th. My first thought was that I had locked the clutch out, as I had done once before, by allowing too much movement on cable. My second though was one of panic as I realised that the car was stuck in 4th gear, heading towards Felixstowe with no where to stop the car safely. The mild panic increased somewhat as a 'Police Accident' sign loomed up ahead!
Having successfully negotiated the accident which was still being cleared up, I had a little more time to evaluate my options. I could slow down and even brake or I could go faster. No clutch means stopping is not really an option. Simply turning off the engine is going to have consequences and I don't know what the result would be in a bike engined car. It's not something you do very often!
Another attempt to shift gear found 5th rather clunkily. My panic eased slightly. This was good. This meant the clutch was not locked out. Something else was wrong though. It didn't take long to realise that the only other thing that could be wrong was a snapped clutch cable. But, it must still have some connection if I can change gear. I tried again. The resulting thunk was the last strands of the cable giving way . Bugger!
It's a well known fact that you can change up a gear on a motorbike without using the clutch, so long as you are accelerating quite hard and then ease off the throttle as you change. It's a less known fact that you can change down under the same conditions. It's a bit noisier though! Having successfully negotiated the Trimley roundabout without needed to change out of fourth or touch the brakes, I took a familiar slip road to Levington, which has a nice long layby half way down it's length. I managed to get down through the gears and into neutral and pulled the car up. This was a big relief.
I now had time to ponder my predicament. Ordinarily, these are the kind of engineering challenges I relish but, this was bad timing and I wasn't really equipped for the task. Kind of like Scrapheap Challenge using the contents of your glovebox alone. It wouldn't make for interesting TV. A quick call to my wife set her mind at ease (I was only supposed to be gone for 30 minutes), whilst I thought about how I could get myself and the car home.
I carry an emergency toolkit in the Fury, in an old wash bag. It's minimalist to say the least but, it contains a small socket set, three spanners (8mm, 10mm and 13mm cover 95% of the nuts in my car), a few odd nuts, bolts and washers just in case, some tiewraps and a puncture repair device. No clutch cable though . And in this situation not enough washers. Oh, and a drilled 6mm cable clamp bolt would have been handy too.
Having removed the footwell plate, I could see the nipple had detached itself from the cable, resulting in a cable that was now too short to be much use. I unclamped it at the engine end and used every last millimeter of spare cable to get some spare cable that might possibly be clamped to the pedal. I don't think you could solve this challenge, if you hadn't built the car in the first place but, I found the means to clamp the cable to the pedal, by stealing bits from other areas of the car. The parts where there is an element of redundancy and not by disabling essential functions or safety features . In less than 15 minutes I had clutch pedal action, so I set off rather nervously, with a plan to minimise the number of gear changes required just in case my improvised fix should fail. The consequences were going to be a lot higher as I headed back onto the busy roads that led to home.
I still can't quite believe it but 200 yards down the road, I passed another Fury. The first I've ever seen on the road in this area. I was probably a bit too enthusiastic in greeting my fellow owner but, round these parts Ferrari Enzo's and Audi R8's are a more common sight!
I made it home, put the car in the garage and had a well deserved beer. A proper fix can wait for another day.
Popped home at lunchtime to replace the clutch cable and pick up the car to get the tyres changed after work. I fabricated a bracket to fit to the pedal, which should keep the cable run straight and avoid it wearing through in the future.
At 3pm it rained rather hard, leaving the seats filled to overflowing and the harnesses soaking wet. I did my best to remove the water but I had to drive the car home in the rain and I needed a complete change of clothes by the time I'd got home. I did finally get to the tyre fitters after work, only to find my tyres hadn't been delivered yet .
Got my new tyres fitted on the second attempt. It took them two attempts to get the balancing right though but, this was one of the reasons I used a local supplier.
|Spent some time looking at a possible airbox design this morning. I've got room for quite a large one but it will be very close to the bonnet. This is a cardboard template I made to see what was possible. The actual airbox will be made from fibreglass.|
I then engineered a better clutch cable mount, one that doesn't wear through the cable! It made an amazing difference to the weight and feel of the clutch pedal, it just seems to run more smoothly now and I'm sure the cable won't wear through now.
Out for a drive this afternoon as the weather was so good. Followed a Noble M12 GTO 3R for a while which was interesting. It was quite nippy and I could even hear the dump valve over my rather loud exhaust. We were going different places though. The car is running well bar the extreme noise levels. I hope to swap over to the R1 exhaust next week so I can investigate the current one further.
Finished painting the exhaust side pod bracket/difuser.