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WCA G46 - The slow build (MX5 donor, customer chassis)
Don't worry. It is staying stock motor for the moment. It is just the thought of sticking a 1200bhp supercharged V8 under such a delicate looking car makes me smile. My pockets aren't that deep (yet).
The beauty of the custom chassis and standard MX5 internals is that I can gradually replace and improve parts as and when I find money down the back of the sofa.
To begin with I am going to be struggling to find the money for paint, let alone a £12,000 motor.
Let's start with reality and then work towards the dreams ;-)
Well I have been back down to look at the G46 and measure up a few bits.
The MX5 will fit if we move the front wheels forward 9-10 inches. I am planning on keeping the drive train and engine in the original position (see pics on first page) but was worried this would put the gear lever too far back in the cabin.
After much measuring and comparing photos (using the wheels to gauge scale) I have concluded that the gear stick will be fine. It appears to sit a little further back from the steering wheel than in the MX5 but it should be bearable. I might stick a bent (swan neck?) gear lever to move it forward slightly but let's see when it is together.
Still looking for the <£500 MX5 donor at the moment
I got a partial built Mev exocet - its plonked onto the mx5 power frame as you illustrate on p1 - if you want any specific measurements ill try and oblige - im away from it for 2 weeks currently though.
The mev exocet forum (http://www.mevowners.proboards.com/index.cgi?board=exocet) has a lot of builds detailed on it with frames in bits thats well worth a look for a few MX5 powerframe pointers , cheapest polybush sets , tips on removing the chassis etc
Where are you based in the country? I wouldn't mind having a look and a chat. I am kind of new to this kit car scene so interested in finding out about other peoples experience.
I have had a look around the Exocet forum, I think I used a few of the pics there to work out the sizes.
Apparently the gear lever is reasonably easy to move so that is a problem that should be easy to get around but if you are near to Southampton I would be happy to meet.
Even today the old Scimitar is a pretty quick car in its own right and there's loads of tuning options if you must have more power.
It shouldn't be too difficult to find a tax free donor and the G46 was designed to fit the chassis, saving a lot of trouble modifying the Mazda.
I could understand it if the MX5 was that good a car, but I've got to say that when I had a mk1 1800 I found it rather soulless. I know they've sold a hell of a lot of them but McDonalds sell a lot of boring burgers.
Sure it was quick and it was easy to catch the massive tail slides you got on every roundabout, wet or dry (so long as you didn't hit the truck alongside you first), but it lacked any sense of occasion driving it. Think of the Scimitar as chicken jalfrezi and the MX5 as a quarter pounder, without cheese and with the dill pickle deleted, and you wouldn't be too far off the mark.
The most damning thing I can say about the MX5 was that, when the first road tests came out, Mazda made a big noise about how they'd recorded the exhaust note made by dozens of different British classic sports cars, played them all into a computer and then tuned the MX5 exhaust to emit an average British sports car sound. The result, to my ears, sounds exactly the same as my Zanussi washing machine on a medium spin. Swishy and boring.
Anyway, best of luck with whatever base you choose, just have a drive of a Scimitar before going with the Mazda.
I have driven and old Scimitar and a mid 90's MX5.
I agree that the Scimitar is noticeably more 'period' in it's handling and performance. I like the extra tourque of the 6 pot (192 vs 114) but I don't ever remember the Ford Essex engine being described as particularly tuneful. The power from the two units is similar with the Scimitar edging it at 138bhp vs 132bhp. I don't think the G46 is all about raw power though and these figures can be addressed later with a simple bolt on supercharger.
MX5 vs Scimitar
Soul or Souless? Always hard to define. It is the faults that make the soul but too many faults remove the pleasure. Engine sound and the feel of the revs rising. The poise and balance as you power through a corner. That nice 'rightness' as the turn in is sharp and you feel the controlled balance as the rear chirps messages of grip to you. The ability to tweak and improve the car over time.
Lets give them points on each item
Either build will have faults due to inexperienced builder which will add character or be fixed.
1 point each.
A six pot normally sounds 'nicer' than a four pot.
Point to Scimitar
Modern 1.8, revs faster and more smoothly than old Ford 3 litre.
Point to Mazda
Modern tuneable suspension will handle better than old suspension just through design improvements.
Point to Mazda
Front mid-engined car (remember I am moving the front sub-chassis 10 inches forward of the engine in the space frame) will encourage better turn in and balance.
Point to Maxda
Either car can be tweaked but there is a large market of off-the-shelf tweaking for the MX5 using new equipment rather than the reconditioned Ford tuning.
Point to Mazda
No need to IVA the result.
Point to Scimitar
No need to restore the starting chassis.
Point to Mazda
General feeling of predudice against the car you don't like and for the car you do like.
+30 for the car of your choice
I guess there are plus and minus points for each but I would say that complaining the MX5 was a bit souless when you drove it would have similar relevance to a G46 build as saying you didn't like the boot line on the Scimitar.
The basic reason I am going the MX5 route is that I want to build a sports car, not restore one. I have never done this before so I want to keep it simple at first. Once I have completed this I will decide whether I enjoyed it. If I did enjoy it I can then continue to evolve the car and the space frame chassis approach gives maximum flexibility.
I used the same approach on a number of other 'hobbies'. For photography I bought and borrowed a few bits to see if I liked it. After a month I decided I didn't really enjoy it but I hadn't invested much so that was okay. For mountain biking I bought a cheap bike and rode it for a while. I really enjoyed it and over the years I have spent an obscene amount on bikes and bits.
I want to spend as little time and money as I can while still getting a good result on this first build and getting to understand the skills and tricks required. If at the end of this I am fully enthused then I am sure I will spend more time and money, if not, then I will have a nice simple fun car. Either way, I look forward to joining the Sammio tribe and continuing the fun of the forum.
from a £500 MX5, I thought it was the Cologne V6 that wasn't that tuneable?
Big car needs a V6 when you open the bonnet! not a load of plastic.
Come on, you know the Scimitar will be far more exciting...layball:
I agree the Scimitar route would be fun, just the MX5 route would be easier and more upgradable later. I will be removing as much of the plastic engine covering as I can.
£500 for a 1.8 MX5 is relatively easy to find. Stick a supercharger on there and power is 200bhp and ~200lb.ft torque. That is before you do any real tweaking and tuning.
The space frame chassis, instead of the Scimitar chassis) makes it far easier to drop in other engines and drive trains.
Dropping a turbo Supra engine is quite straight forward with gives a nice noise and up to around 600bhp reasonably reliably. Of course, an LS7 or similar from the Corvette will give 600bhp out of the box and go up to silly numbers but a 1,200 bhp G46 would just be silly, possibly less exciting that a Ford 6 pot* and clearly have no soul ;-)
* I thought the Scimitar started witht he 3 litre Essex. Was the Cologne used on later models or am I wrong (again)?
I thought they raced the Essex's in Mk.1 Capris and a Cologne is what my brother used in his pilgrim Sumo... with side pipes and sounded more like an old aircraft! I've seen the size of the bonnet on the G46 and i think you would be embarrassed to open it with the Mazda engine.
Just double check with the wife Supra engine, space frame chassis just don't tune all the fun out of it! or it will be another track car... you want to think when driving it round a hairpin, not just turn the wheel and it sticks to the ground... (BORING).The colour, you can have blue, just one that others would want! It's a classic shape, simples! you can't get away from it.
As I keep saying. I want to start with it simple and CHEAP. Basic 1.8 MX5 donor and as simple as possible while I learn my skills.
It is just the comments on here about the size of my engine that make me feel I need to brag about what I 'could' put together.
Chances are it will stay relatively standard for a while. Just tweaks to improve what I have done and correct mistakes I have made.
I am tempted to turn up at one of the get together with it wrapped in metallic pink vinyl sporting a big V12 plastic engine cover, jacked up rear suspension and drainpipe sized false exhausts sticking out the back just to provoke comment. ;-)
There's no rush, Get the MX 5 sell the engine etc... How much is a Supra engine.You don't have to lash something together, just to be out in super quick time... Get it right, first time. What am i saying, don't worry about the MX5, start with chassis, just like JMC does, maybe buy a Supra instead? Use all the bits etc...
Mx5 powerframe I think is balenced so the engine sits on its mounts on the front suspension frame - i dont think separating engine from these mounts would be good karma.
extending the prop , and RSJ type support onto the rear would be more mechanically sound me thinks.
Also extending the steering column ( its a brakeable one ) might be a nause.
The Electrics are degree level to get your head round.
Last and most important one - MX5 is classed as a monocoque , removing the body = removing the main part of the car and its registration - Therfore you would need to IVA the new build..............
Ill PM my contact details if you still want to look
Gary - Get behind me you devil! I will not be tempted. ;-) I really want to build the cheap and simple (not quick lash up) to learn what I can and cannot do. One car, one chassis and one body. IF I enjoy it then I might start playing and spending more money but for the moment this is a trial run.
Red5 - The engine sits on the subframe that holds the suspension but can easily be separated. The front subframe will be moved forward 10 inches with the wheels and suspension attached while the engine stays where it is with new mounting points built into the chassis.
I agree the engine could move forward to but one choice is extending the prop shaft and the other is extending the steering column and the prop takes a lot more torque.
Leaving the engine where it is, relative to the rear end means that everything mechanical (other than the steering column) is bog standard MX5 so if anything on the drive train breaks it can easily be switched out.
I know about the IVA but again, keeping it standard MX5 makes that easier. First check of the body shell (without screen) looks like it should pass and the stretched chassis gives even more crumple zone so hopefully I should be in good shape.
Sherbourne is a bit far at this point unfortunately but I may look you up again later,.
Now there's a novel idea. You could try asking Gary J if he could knock up a one-off body to fit a single donor that wouldn't need much modding. A Triumph Herald or Vitesse, for example?
How about the 3 series Beemer? You'd have a lot more engine/drivetrain choice there and I've seen a few Cobra alikes that use 5 series mechanicals, so it's clearly possible.
The reason that I am using the Miata parts for my Sammio is because the availability of Heralds in the US is pretty limited!
I think that it is the perfect choice for the Sammio here. The wheelbase is almost identical. The body needs to be widened by 6 inches to fit the width of the Miata. I actually think that the added width will be a great look. And, the added cockpit width will be welcome by us "supersized" Americans!
The Miatas suspension cradles will bolt into my stiff and light space frame. (The Miata is a unibody and can not be used in the same way that the Gary uses the Herald.) By keeping everything in the same position as the Miata all suspension drivetrain parts, steering, pedals ect will be used in their stock location. The left over Miata parts can be sold for what most people will pay for the car to begin with.
There are several forums in the US dedicated to the MX5. There is a huge aftermarket supply of performance parts. All of which can be used on the Sammio MX5 Spyder.
I don't know about the "Soul" of the car. But, for sound, an aftermarket exhaust with a more aggressive sound is easy. Even a simple "Cherry Bomb" glass pack can give you a great rumble. The suspension on the Miata is a true double Aframe. Which is FAR superior to the swing arm designed used on the rear of the Triumph. When a Swing arm moves the tire contact patch lessens because the tire is moving in an arc. This causes snap oversteer. With a double wishbone design the tire moves more vertically allowing larger contact patches. And with this design the car is more predictable and control able. Hence, the great "power slides".
In the Miata, the scrub radius, ackerman, bump steer, roll center, brakes, steering are all better than on the older Triumphs. Nothing against the Triumphs. Just the natural progression in Engineering.
I think that Gary has done a great job to enable a cool car to be built and registered economically. But, for here in the US the Miata, I believe, is a better choice.
jmc - The G46 is all of the above without the need to get the body widened as it fits just fine. Stick the G46 onto of an Mx5/Eunos/Miata and you have a great car with the advantage of more flexible space than when it is on the Scimitar.
I have used Google Sketch to try and create a 3d model of what I have planned. It is not great as I am new to the software but if you dowload the free SketchUp software and then search the 3D warehouse for Sammio you will see what I have done so far.
Feel free to improve on it and load your own version up. Tag it as Sammio so we can see what has been done. The dimensions on my model are VERY approximate.
The reason that I am using the Miata parts for my Sammio is because the availability of Heralds in the US is pretty limited.
I think that Gary has done a great job to enable a cool car to be built and registered economically. But, for here in the US the Miata, I believe, is a better choice.
Yes I totally agree with the comments you've posted JMC, and I completely understand your problem in not having a ready supply of old Triumphs in the 'States. Of course the Miata is a suitable alternative donor due to their plentiful and cheap availability.
As a retired military engineer, however, I just love the older machinery: carburettors that you can balance; gears that you can hear meshing; oily smells that permeate the interior; proper, age-old dirt that gets ingrained into your palms while you fix broken parts at the roadside; and horse 'n' cart suspension that actually discourages you from crashing.
By all means build your Sammio on an MX5 platform. One day you may even go blasting past me as I slow for a slight bend in the road, but as I double-de-clutch my down-change (while holding the lever in place to stop it jumping out of third) and listen to the raucous roar of my ancient straight six on the overrun, you know who'll have the bigger grin on their face.
layball: 
Supra engine, space frame chassis just don't tune all the fun out of it! or it will be another track car... you want to think when driving it round a hairpin, not just turn the wheel and it sticks to the ground... (BORING).The colour, you can have blue, just one that others would want! It's a classic shape, simples! you can't get away from it.
What am i saying, don't worry about the MX5, start with chassis, just like JMC does, maybe buy a Supra instead? Use all the bits etc...
