Welcome to ChargedPat's MX5 based Westfield site!

On this site, you can follow the building process of one of the very first Westfields, based on the first generation Mazda MX5 (also called the MX5 NA)
The prototype was based on a 1.6 but the 1.8 can be used as a donor as well.  The first couple of frames didn't accept the larger differential of the 1.8 MX5 (the Westfield prototype was based on a 1.6) but Westfield quickly solved that problem.  All frames are the same now (1.6 and 1.8).
When it comes to performance, the 1800 engine produces more power than the 1600 (130hp as opposed to 116hp) but it also comes with a weight penalty, resulting in a kerb weight of 585kg compared to 545kg for the 1600 car.  Also the 1.8 has a lower max rpm and doesn't like high revs that much.
We'll be building the 1.6 version with a 1.8 Torsen differential.   These are a lot stronger than the standard 1.6 differential and have a slightly longer gearing (4.10:1 <=> 4.30:1).
With it's 116hp, the 545kg Westfield has a power to weight ratio of 212hp per tonne.  To give you an idea of its performance, a Porsche 911 Turbo has a power to weight ratio of 246hp per tonne, so even in standard trim, the Westfield should be very quick. 
ChargedPat wouldn't be ChargedPat if he didn't want a supercharger.  So, we'll try to install a supercharger on it.  More precisely, the Eaton M45 @ 10psi.  Out of the box with standard pulley layout at 6 psi, the Eaton delivers about 45 extra hp, bringing us at about 160hp.  Combined with a bigger cranck pulley, a smaller supercharger pulley and with a Link engine management system, we should be able to find another 30hp or so.  We'll have to put it on the dyno to get real numbers.  
To quote Steve Allen of Westfield about our plans: "the car should be rather rapid".  
The power to weight ratio will be 360hp per tonne.  This is the same than the 490hp Ferrari F430 with it's sub 4sec 0-60mph and max speed of 196mph.  
The Westfield will top out at around 240kph (150mph) because of the short gearing, but that's plenty fast.  We have no idea about its 0-60mph performance, but it'll be pretty darn fast.  We'll see .

Preliminary measurements show that there isn't enough room to fit the supercharger.  We'll just have to find a way to make it fit, won't we!

Once Patrick's Westfield is built, plan is to build a 2nd car for Frank.
Here's our donor car by the way.

The first pictures are online in the photoalbum.
Read the latest news here.