LOL!
Update: "Journey to Ruin"
This weekend was, through a play of fate, a jam-packed one for racing, with Shelsley Walsh Hill Climb on Saturday and Rushmore Sprint on Sunday.
Things did not go entirely to plan...
The drive up to Shelsley on Saturday was pretty uneventful. It is around 120 miles from me, and nearly 90 of these are motorway, which gave me plenty of time to consider the now much lower 5th gear. I need a sixth gear now! But then, even with the standard gearbox, you need a sixth gear for long motorway drives - except that now, with the lower final drive ratio and the lower fifth gear ratio, 70mph is now at an indicated 3,600rpm. At least that engine speed is outside the usual exhaust resonance frequency. Slightly annoying, but tolerable. I haven't worked out the fuel economy, but the impact of the higher engine speed was not particularly ruinous or noticeable to be honest.
One side effect of the higher continuous engine speed is a higher oil temperature. Whereas under similar conditions, the same engine would register a temperature of around 90C and not budge, this transmission and higher engine speeds result in an engine temperature of whatever that intermediate marker between 60 and 120C on the oil temperature gauge actually signifies? 90C? I don't think that this is a too-big-a-deal. An oil cooler is planned for the next engine upgrade, so certainly manageable.
The Torsen diff makes no impact upon normal driving. What you would hope for and think to be honest.
The new (to me) gearbox felt good. Initially changes in first and second were pretty notchy, but soon eased up with use: this gearbox has sat for some years without oil waiting to go into the car, so no surprise there and no concerns now.
Apart from the excessively light clutch pedal, there were no concerns.
Shelsley Walsh, like all events starts with practice runs and then timed runs. We were scheduled, and got, two practice runs and then two timed runs.
At this point all seemed well. There is a tyre warm up area then the start line. I decided to go full "ASBO" on the tyre warming - lit up the rear tyres, and drove to the start line in first practice. The car got off the line fine, again with wheel spin - but then the clutch started to slip. BADLY. By the finish straight after the "Esses", the car could barely manage 25mph - just like a clutch failure.
Cutting a long story short, this persisted all through the day. Because the clutch pedal was so light, the perceived wisdom was that there could have been some dirt or air or what ever in the system, acting like a valve preventing the release of the clutch disengagement causing the clutch to slip. This led to much disassembly between runs and even had me taking the slave cylinder apart and shortening the return spring to give more-than-usual clutch movement. After much bleeding, the mother load of black gunge and seemingly some water, came out of the hydraulic line the upshot of this was a clutch pedal weight that finally felt normal! But this did not help stop the clutch from slipping.
Total failure to record any times whatsoever (or at least no meaningful times) - so the benefit of the close ratio gearbox and Torsen diff could not be realised. The engine spins up super quickly on the starter motor and revs really quickly and nicely with the lightweight flywheel though!
I was able to drive the Shed home without problem that evening - gentle driving through the back roads, motorway and then through north London traffic. No clutch slip at all.
With Rushmore the next day, I was wondering what best to do. Three options I considered were (1) to bale out and not do the event and sit around sulking, (2) to go with my other MGF and simply have some fun or (3) risk it with Project Shed. I went for option (3), primarily because the start line at Rushmore is downhill and the rest of it is on the flat - so much easier on the clutch than Shelsley would be.
This proved to be the right decision: starting gently, and getting more aggressive on the clutch throughout the day, I had no further clutch slip! In a mixed class of modified vehicles, I won second in class behind a very well prepared Ford Escort that I recon probably over 60 (probably 100) bhp advantage on me, with a car that probably weighs under 800kg. So I am not worried he was 6 seconds faster.
So what could the clutch problem be? I did some research on line before Rushmore and discovered that these clutches need to be bedded in - 200 miles was what was suggested on one Saab forum. So I wondered whether I had glazed my clutch by over exuberance on the Saturday?
This morning, I was on the phone to the clutch supplier, Black Diamond. I explained the problem but did not voice my suspicion, and they told me that the stage 2 clutch, by dint of its construction material, needs 600 miles of bedding in before working as it should. Apparently this is clearly stated in the installation instructions - instructions that were not passed on to me. I wonder whether the mechanic even read the instructions? He was a man after all...
So yes, Simon from Black Diamond thinks that the clutch was likely glazed on Saturday.
Simon suggested three options going first. Worst case, I could return the clutch to them and they could re-surface this for me. Second, I could remove the clutch and get some emery paper and remove any glaze and ensure that the bearing surfaces are all showing even witness marks. Third would be to bed in the clutch with frequent gear changes and hopefully the clutch will just work.
Given that the clutch now seems to be working okay, I'll go with option 3 for now and see how we go, but if problems persist, I'll need to get the clutch out of the car to restore it.
Fingers crossed that I'll get away with the unintended (intended) abuse!