MX5 throttle body conversion update

MX5 throttle body conversion

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about my throttle body setup and it occurred to me that the most recent post and photos that I uploaded here are quite out of date.

Black crinkle paint for the cam cover
Black crinkle paint for the cam cover

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.

Nangkang NS2R
Nangkang NS2R

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…

Slip slidin' away
Slip slidin’ away

 

CartoDB and track days

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.