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We are Team Bugsplat, We take part in the Scumrun rally and run the official Scumrunvideo youtube channel

5 Apr 2013

Bug to Superbug - Part 1 - Choices and a rather kind offer


Bug to SuperBug – Part 1 – Choices and a rather kind offer...

So I’ve always had big plans for the little MX5 which is affectionately known as ‘The Bug’ (team bugsplat derived, nothing to do with the bubbly air cooled rear engine Herby lookalikes). The grandest of these plans always involved some kind of engine conversion.



The choice was not as simple as I first thought. Many people when opting for more power go down the route of Forced induction...that is to say find a way of ramming more air into the engine by effectively bolting a hair dryer to the engine (or other more refined applications).

This option alone gave multiple choices... Do you go turbo, or supercharger, there are kits for both, and for a while the plan was to find the supercharger from the new mini cooper and bolt that on. Then I had a 180 and decided the FI route wasn’t the way to go and started looking at Bike throttle bodies, there is a developing trend of bolting GSXR throttle bodies to the block to unleash some potential.

Then I changed tack once again and decided Turbo was the way to go...but sticking to the teambugsplatscumrunarian way of things I wasn’t going to just go out and splash the cash on the infamous ‘Flyin Miata’ hardware that claimed 200 odd ponies of power and awesomeness. So I started collecting second hand parts. Turbo from an 80s mazda 323 turbo 4x4, injectors from a 1.8 mx5 etc etc.
It was about a year ago today that something happened to change all that...

It was something no less innocent than I slight facebook comment. Mentioning I’d been looking at options for more power for the bug. I jokingly put that I should whack a whopping great V8 or V12 in the thing and be done with it...
Bit of context...On the Scumrun there are many types of people, some relatively normal, others not. All share one thing in common though, a distinct love of either cars or driving or both...some take this to the level of tinkering around with spanners at home, some pay others to do it, but Mr Kevin Marshall takes this to a new level. He is in the interesting position of working at a College which has a huge automotive engineering training department, with some serious workshop equipment to boot. Sir Marshall as he shall now be known to me innocently comments on said Facebook that he’d do the work...I stated not to taunt me and he said ‘who’s joking, find me a donor car’... I should point out here purely for context that Kev was completing the 2012 Scumrun on a 50cc moped...



It was at this point that the obscene descent into insanity began...after a little more probing on the very generous offer from Sir Marshall it was clear that he was serious and that after the 2012 rally all I needed to do was give him the bug, a relevant donor vehicle and then let them do their stuff...So I started hunting around for donor cars.  The limitations on the donor vehicle were as follows...
Kev said It needed to be rear wheel drive and front engine in order for the drivetrain to be more easily transferable
I said It needed to have enough ponies to warrant the work
I also said it needed to be something ‘a little bit different’ but a fairly modern engine.
Most people who go down this ‘lets shove some cc’s into an mx5’ route go to a trusted source...US V8s
They stick a chevy short block in with a massive carb on it and join a fairly small club of small car big power enthusiasts.



This is going to sound altogether wrong to those who have seen my previous rally activity but I wanted something a little more refined, and ideally with electronic injection. But I don’t mind admitting the draw of a V8 was calling...
When you throw in the need for a little representative patriotism and the fact that the car had also been known as the spitfire for a while due to the noise of the exhaust I hit on one word...
Jaguar...
I will momentarily digress to another conversation with Sir Marshall that I will somewhat paraphrase but you’ll get the idea...
Me – “how about a Jag V8, will it fit?”
Kev – “be a squeeze, but anything is possible with a grinder”
Me – “erm....ok then”
So I did what any sensible chap would do and went and bought a Jaguar XJ Sport.



“What! Not the 460hp XJR” I hear you cry...”only a piddly 3.2 v8” I hear you moan...
Let me explain...quite simply...I want it to actually be driveable. Yes I did consider the 4.2 V8 also, but alas I decided that the 240hp produced by the 3.2 was a good compromise between refinement and ludicrousness. There is clearly little point in creating something with more power than 1.the chassis can cope with and 2.won’t be able to get it onto the ground anyway, and I don’t have plans to fit 435 width tyres on it...
So we had our donor vehicle. It had no tax or mot but was in good condition apart from a damaged front wing (didn’t need that bit anyway) and the engine only had 81k on it. So I got it trailered up to Kev’s empire and then post Scumrun drove the Bug up there also.
The scale of the task was immediately clear when we put the cars up next to each other in the workshop...the engine was big...really big, the mx5 was small...seemingly smaller than I first imagined (comparatively)...



We all laughed at it and the noises from the mechanical nutters in the workshop were positive about the possibilities but I left them with no illusions as to the scale of the task they had undertaken!

The Plan...

Well, to be fair that might be putting it a little grandly, again back to our good social medionic friend and enabler of all things motor enthusiast communicative, Facebook, Kev and I discussed thinking on what might be involved in making such a machine of rareness and wonder.

The first realisation / insight was that we could not find evidence on the web of anyone else having completed such a transition, there was 1 jag V12 miata in the states we found but other than that it would appear that V8s used were either the chevy one or the LS lexus v8.

So Kev would be pioneering (again) in his endeavours...

We realised that the most important part of the plan was not to have too strict a plan, Sir Marshall has a certain way of working, it’s something akin to scrapheap challenge with a smidge of the Krypton Factor and a dash of genius. The bottom line was...leave it to them and they’ll figure it out.



One thing that was clear was 3 key bits that definitely needed swapping...Engine, Gearbox and Differential. Everything else had a ‘let’s figure it out as we go’ tag over it.
This was no better demonstrated than when people asked “I hope you are going to fit bigger brakes?” , the response being “we’ll worry about stopping it once we’ve got it going”
Initial thinking was the whole rear end (sub frame and all) from the jag might need to be used and it would end up with some 50 50 chassis of the 2 cars... It became clear later on that that wasn’t the right approach but for a while I imagined a rear end with a 28cm wider track than the front...



The other big question was electronics...use the Jag loom? Or go for external...cost said we should try the Jag one before opting for the expensive alternatives but this one’s still being worked on as I write so watch this space.



What I didn’t realise early on (although no doubt they were well aware) was just the number of parts they had to custom fabricate themselves! Engine mounts, gearbox mounts, oil cooling, diff fittings all totally fabricated by the welding skills of Kev, his team and his students. Fair play.
The engine mounts alone looked like they could hold a Jet engine onto a 747!



The guys view of these things was nicely summed up with a recent conversation with Kev where he said “oh we’ve just been doing a few little jobs”, “few little jobs?” I enquired, “yeah we just had to fabricate an oil cooling system for the gearbox”....he cracks me up.

So anyway, things have progressed further now but I will save that for the next update...Continued massive thanks to all the people working on the car!

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