The Fastest Accelerating Westfield in the World?
by Graeme Finlayson & Dan Johnston
Is the future electric? It's beginning to look that way, with over 100,000 plug-in vehicles (including petrol and diesel/electric hybrids) currently on the road in the UK; but many enthusiasts may look on that future scenario with dread.
Won't an electric car be boring and dull? Well, Westfield Sports Car Club member Graeme Finlayson, currently resident in Barbados (it's a tough job, but somebody has to do it!) has set out with Dan Johnson to build an electric car that is definitely neither of those things.
Below is the first instalment of Graeme’s Build Diary of the Megawatt electric Westfield, first printed in Westfield World, the magazine of the Westfield Sports Car Club.
The fastest accelerating Westfield in the World? A bold claim? Yep. A true one? Oh yes, it will be.... over 1000 bhp/tonne and around 2000 ft lbs/tonne should be enough to see to that.
Those who know me on Facebook have seen hints about this, but now the car is effectively finished, time to detail it.
So, to do an introduction to this build diary. My good friend Dan Johnson has been coming out to Barbados helping support us ever since we used to rally the Westfields out here 15 years ago – he got hooked, has been coming back two or three times a year since, even selling up and moving here for various six month stints.
I recently rebuilt a Hayabusa turbo Westfield out here, which Dan helped with and got into the drag racing scene on the island. Currently, my car holds the outright 2WD record. But not for much longer...
A professional mechanic/motor engineer by trade, Dan re-caught the Westfield bug, having previously built a MegaBlade kit about 10 years ago, and so, with one eye on creating a mobile CV and one eye on a worldwide record, he bought Martin Atwell’s old MegaBird on the island in December 2015. A car we used to rally with and know inside out, but since then it had been sold on and fallen into a terrible state. In the UK it would probably be scrap, but not here, it’s duty paid and registered/licensed so time to resurrect!
I mean, the thing was in a state. It had been left outside for some time in this climate, chassis rust, bodywork a mess, all nuts and bolts rusted solid, engine dead, all the work that had been done on it since it left Martin seemed to be a total bodge job. Just awful. And so the strip and debuild begins.
In it’s happier days, setting times up among the WRC cars and tearing round the rallysprint track here is the car in it’s original setting.
Weight before debuild 515kg dry (Blackbird engined, no dry sump anymore, *rolls eyes*), full CDS cage (T45 was against the rules out here back then), lightweight bodywork, heavy wheels with road tyres, allu uprights and hubs, Outlaw 4 pots, alloy Avo shocks).
Dan finished the teardown in his first three month stint from January-March, taking slightly longer than normal due to some rum soaking, seized bolts, more rum soaking, a trip to Trinidad Carnival (which will now become a yearly pilgrimage), building a work bench, a little more rum and extracting from Bridgetown Port a rather large shipment of carbon fibre rolls of various weight along with associated strange pumps and materials (more on that later...).
On stripping the car the state of the chassis became apparent – a couple of bars were rusted through and needed replacing (including those adjoining the rusted bars to be safe). The car really was moments from disaster.
The diff area, a consistent weak point, had been bodged fixed previously and aside from being absolutely hideous rat**** welded, it hadn’t worked.
The diff carrier had multiple cracks and required a lot of work. Knowing the amount of torque that is going to be put through this car (in the region of 1000 ft lbs) this is one of the key areas that needed work.
The existing basic diff carrier area cracks/issues were fixed, bars replaced, bars were sleeved with an extra welded right angle of steel, all corners gusseted top and bottom, an extra mounting point added and then multiple triangulation bars were added.
Will it be enough? Time will tell, but it will require a lot of monitoring. Countless hours, weeks even, were spent on this area, but it will still require constant checking.
The car is running a 7" Sierra LSD diff, which is another area for monitoring. Initially we’ll run this, but as the torque is ramped up, the worry is the whole rear end might need replacing with something substantially stronger (perhaps even 4-link).
Jumping ahead a little, here is the diff carrier at various stages through the build:
Diff is debushed and hard mounted with an extra mounting tab (at the bottom).
The goal was to have the chassis finished so it could be sent off for powder coating while Dan was back in the UK. However, the arrival of the motors was delayed which pushed the entire time-frame back. There were still vast amounts of other jobs to complete, not least the stripping, cleaning, checking of all the parts that came off to see which were suitable to go back on!
So the powerplant, this is where my knowledge gets a little iffy and Dan’s ingenuity completely takes over so forgive me if the details are not 100% and my technical knowledge is a little lacking.
Anyways, yep, it’s going electric. I know it’s been done, but so far, the one’s we have seen were kinda tame and nothing stupid. So Dan decided to go full retard.
Twin series-wound DC motors, good for 500 ft lbs of torque each, potentially more if you want to push them. Going to be run in series, straight through to the back.
Not bothering with 4WD, just means more weight and complexity, hell, the quickest drag cars in the world are 2WD right?
The aluminum discs and bar you see are the raw materials to machine the joining plates from – to pair the two motors in unison and enable the mounting of them to the chassis – as ever, all Dan’s design.
And then the delivery of batteries arrives...
384 lithium cell batteries, 640kw power – about 50 times more power than a Tesla battery and the most you can legally import by air (99.9Wh). The battery pack will be a small lightweight ‘drag’ pack for the car, high power/low range. But easily swappable so can run a longer range pack, or, simply just add more packs as required.
And so now the chassis modifications begin in earnest. Bodywork off and with time limited on the first visit the bodywork was transported to a local fibreglass specialist – safety first during transport! Or maybe not...
The tyres for drag are 10" wide full Hoosier drag slicks, so the arches are considerably widened. I measured my ultra-wide arches as 10" from edge to the first lip, these are 12" now, who knows just how wide the rubber will have to go to keep this stuck... Fibreglass, for now...
All holes and cracks filled in, no need for exhaust hole now of course!
And so back full on to the chassis, still replacing chassis bars that are looking dodgy while continuing with the motor mounts...
With the aim of getting the weight as central as possible and no gearbox being used, one motor is going in the tunnel, one visible in the engine bay. The motors are joined by the CNC machined aluminum plates, spaced with the aluminum bars. These also provide additional mounting points onto the chassis. The tunnel is widened and the mounting points beefed up by doubling up the bar there.
Front motor top and bottom X-braces in place, next up time to do the bars that join the two braces.
With the chassis complete and all holes plugged, it was time for that to go off for powder coating
Along with various other components off for soda blasting, shot blasting, powder coating, etc. etc. No point putting on rusty old parts, everything has to be as new now.
With the body away for repairs, adjustments and then painting, along with the chassis away for powder coating, now time to focus on the various components.
It became clear, very early on, this wasn’t going to be straight-forward. Due to the state of the car, every component that came off needed repair/refreshing; every–damn–component.
Take a brake caliper off? Seized, so needs a full strip and rebuild.
Rack comes off, too much play - strip, rebuild. etc. etc.
Down to individual threads and bolts that had seized, sheared, or in some cases even had the incorrect bolts used. Every single nut, bolt, component came off to be checked individually and in 90% of cases repaired/rebuilt.
Rear hubs? Cracked. Needed repairing, new bearings...
Front hubs? New bearings, new joints, time to fabricate some custom super lightweight cycle wing brackets as well – after unseizing the bolts of course...
Driveshafts? Remove sheared bolts, replace all joints, rebuild, regrease, etc...
Diff? Drain, retap all holes, check, new seals, etc.
The car had the original Westfield race seats, albeit without covers (long since melted). But again, seats needed blasting, fibreglass repairs, sanding and painting.
Ideally these will be replaced with carbon seats in the near future but in the current timescale just a refresh on the cards.
Everyone loves a detachable steering wheel, so a tidy Rapfix q/r boss (lovely piece of kit) and with the steering wheel being quite a major ‘face’ of the car, time for a new smaller Momo to be put in place.
This is where you take your life into your own hands with your welding...