Yeah I'm guilty of calling every circuit "my favourite", but Donny is very much up there!
Anyway, onto Saturday and a visit to my favourite circuit ( ) - Blyton Park
It was a Javelin day, so was expecting some crowding but I had a few friends travelling over in their Lotus' and I'd arranged a friend and fellow enthusiast to join me for the day for some tuition. I did the same a couple of years ago and my tutor for the day (Ishy) really helped me move my game on along both with Blyton circuit knowledge but also technique knowledge that I could carry through into future trackdays. Unfortunately a year of no tuition thanks to COVID meant I'd regressed a bit so I was looking forward to a refresher session.
For a Javelin day it was very quiet right from the get-go. Paddock seemed busy enough, but for some reason the track never seemed to get busy. I wasn't queued up a single time and I got loads of clear laps in, perfect.
First session was just me finding my feet and remembering where the track goes, second session Ishy took the car for a few laps as I wanted him to give me some direction on damper tuning and whether the car had any obvious scope for improvement.
One thing jumped out in that the car would push a little bit in slower corners which is fairly standard behaviour for the S2 Elise/Exige platform, but where he expected this understeer to continue through to higher speed stuff it didn't, and instead the front of the car came to life and the rear got a little bit loose.
This was knocking my confidence a little bit in the quicker stuff because I wasn't sure the rear of the car was going to live with a higher speed turn-in (you can tell on my recent videos that this manifests of turning in way too early to almost all corners, and of course carrying less speed). We discussed a couple of theories for it, one being the extra camber I've added to the front potentially unbalancing the car a bit in conditions where that camber really comes alive (the faster/higher load turns) and the other simply being damper tweaks. I
I've always had a very simplified view of damper and/or ARB changes in that:
- If the front lacks grip, then soften the front or stiffen the rear
- If the rear lacks grip, then soften the rear or stiffen the front
Ishy explained the logic behind that, and why I may actually want to consider the opposite. I probably won't do his description any justice but he put it in terms of the car generates most grip whilst the suspension is compressing. Once it's maxed out it's compression, then grip stops increasing. With that in mind, softening a car can help because the compression will effectively start with less weight transfer so the theory I worked to has some sense.
The counter theory he put to me is that my car is generating enough grip that the range of compression is actually running out, and perhaps by adding some damping we could prop up the spring rates a little bit to delay this limit from being reached - at the trade-off that my transition between grip and no grip would become narrower.
Going forward Ishy would be making some 'blind' tweaks to the car so that I could give unbiased feedback, a little unnerving at first but this worked really well and I think between us we got the car into a much better spot. I don't actually know what damping settings I ended up with, I need to go into the garage and document them - so reminder to myself. We did end up going stiffer over all which brings my dampers very close to their stiffest settings, so I'm running out of adjustability and some slightly stronger springs may be worth consideration.
We had 3 or 4 sessions on the run up to lunch, car (and me) got faster and faster. Particularly around the Port Froid high speed chicane type thing which is the type of corner that has been bothering me all year. Jim Clark Esses (Croft) and Craners at Dony have all exposed my lack of confidence in the car - but we were gathering pace through Port Froid at a pretty impressive rate. Ishy suggested just before lunch that we'd be taking it flat by the end of the day...
Unfortunately, we never got to find out. The car was on fumes at lunch time so I limped it into Gainsborough for a fill up of Jet Super (97). The usual favourites of Shell and Tesco (Momentum) are really hard to get hold of around Blyton so I've always used this Jet over the many trackdays I've done there. The pump seemed very lethargic in delivering its fuel, took ages to give me the 35litres.
Got back to the track, had a quick brief with Ishy and they we headed out to keep on pushing... but the car had called it a day It wouldn't rev above 3k, was heavily missing and sounded really lumpy at idle when we brought it back in.
Laptop out and I could see it was running very lean, at idle it was only making around 1.4 Lambda (target of 1.0) and you could hear it struggling as a result. Blipping the throttle would lead to heavy misfiring and an attempt at stalling. On the road I could creep the revs above 3k if I was VERY gentle on the throttle, but any sudden load or requirement for fuel and the car would stutter like mad.
I suspected dodgy fuel, and still do. Investigations still ongoing but it was a disappointing early finish to the day. Track continued to get quieter and the weather was perfect. I made the most of the day, had my first ever track experience of an S1 Elise (from the passenger seat) and that was eye opening. Braking distances are another league completely, it felt like an absolute hoot despite its 140bhp.
I limped the car home, whether that was a mistake or not is yet to be discovered. I could see some knock events in the ECU logs after I got home, all at very low ignition advance and low load (sub 30% throttle etc) so hopefully it's not "dangerous" levels of knock - but still very much lends to the theory that the fuel I've put in is complete garbage.
I've not done much so far, just taken charge cooler off for access and pulled the injectors for a look of anything obvious.
Injectors were next up on the roadmap for upgrade anyway, so they might get swapped out whilst they're accessible just to rule them out. I've also spoken to Spitfire who make my fuel pump who have given me some metrics to gauge how well the pump is (or isn't) working once I can drain it into a bucket so the plan is to disconnect the fuel rail, set the pump running from my ECU and drain it all out - put it all back together and stick 20l of v-power in and see if it magically comes back to life.