I’ve had a few comments and questions sent to me recently about my throttle body setup and it occurred to me that the most recent post and photos that I uploaded here are quite out of date.
There’s not a great deal to add, but I’ve now fitted an airbox (Pipercross 600 series) over the throttles, tidied things up a little, given the cam cover a lick of black crinkle paint and refined the fuel and ignition maps plenty more.
I was having some issues with rough running at very low TPS and RPM values, I think the very short intake trumpets I’m running due to lack of space was causing turbulent airflow at low revs. The airbox appears to have the effect of lengthening the intake tract and smoothing things out a little. The car definitely runs a little smoother with it fitted, although that great ITB sound is muffled a little unfortunately. Whether it robs the car of any power at the top end is up for debate. Perhaps a bhp or two, but I can live with that.
I’m also running some more aggressive, track-biased tyres now. As the car only gets used in the dry or for the occasional track day, I figured I may as well get something suited to those conditions. In the dry they’re great, plenty of grip and very controllable at the limit. I wasn’t so keen at Snetterton circuit earlier this month though in cold and soaking wet conditions. Part of the problem was that I forgot my tyre pressure gauge and was running far too much pressure. Either way, there was lots of this going on…
This weekend I completed my first trail marathon. To cut a very long story short, it ranks as one of my favourite running experiences ever. Amazing Lake District scenery, interesting trails, great organisation, perfect running weather and a totally relaxed atmosphere amongst both the organisers and competitors.
Some observations I made throughout the day:
- Standing around chatting in the race HQ tent with other runners, looking at your watch and saying “ooh, the race starts in less than two minutes, we’d better wander over to the start line” is the most relaxed I’ve ever been about a race. What a brilliant way to start the day, it couldn’t be further from the sort of tense atmosphere you experience on the start line of a big city race like the London Marathon.
- I’ve never seen so many smiling and chatty runners around a race course before. Even after 20+ miles, everyone I came across was happily trotting along and appearing to enjoy themselves. Where were all the people bent double at the side of the road at 22 miles looking like death that you usually get at a marathon?
- Treading knee deep into a peat bog is a good way to lose a shoe.
- Running downhill over tricky terrain is tougher than it looks, but loads of fun.
- Having tricky trails to concentrate on, great scenery to admire and no mile markers or target pace to worry about makes the time and distance just zip by.
The one overpowering vibe that came through all day though was what a positive bunch of people everyone involved were. There were no charity runners, no stag parties, hen dos, people dressed as rhinos or telephone boxes or people that had been roped into corporate teams. Just runners whose only reason to be there was their love of running.
All in all, a great day and finished off with an obligatory burger and beer before the four hour trek back to Milton Keynes. I shall definitely be back for more of this nonsense in the future.
Here’s a few laps of the Snetterton 300 track from a couple of weeks ago in the MX5. As usual, the video makes it all seems a lot slower and more sedate than in real life.
Here’s a very quick and dirty attempt at taking some data logged (on an iPhone) at a track day I did a while back and using CartoDB’s excellent web mapping tools to create an interactive visualisation of the data. Hover over the points to view speed, lateral g (cornering) and lineal g (acceleration/braking). Click, drag and scroll as usual to pan and zoom around the map.
Note that the iPhone can only gather GPS information at 1Hz, which is why the data is pretty coarse. I’m at Snetterton in a few weeks so I’ll do a bit more data logging and analysis then.