WCA G46 - The slow build (MX5 donor, customer chassis)

[garyh]

Morning WCA, I have no limits... if it stops you using that Mazda blue! Get something with a bit of pedigree

[jmc14]

The brilliance of Gary's designs is that they have the look of the 50"s. But, are not recreations of existing cars. If you do a recreation you are pretty much locked into building the car to match the original, drive train and all, or it just isn't "quite" right. Using the Sammio, or the G46 gives the builder the freedom to do it "their way". There is no right or wrong. So we are fee to be creative, have fun, and keep the cost down. Now, Gary, I need my body!!!!!

[WorldClassAccident]

Just got back from talking with Mark at Dreamshack about the chassis build. He assures me it is al possible and I like the look of the other stuff he has been doing. Looks like I will be starting this thing for real in the new year.

Talking with Mark was great for checking out ideas as to what was possible, easy, difficult etc. He also offers to do as much or little as needed. I guess I will be going for a rolling chassis with the engine fitted but not plumbed in. This will leave me plenty to get on with but mean the difficult chassis building bit will be done properly.

Definitely going for the standard MX5 engine and drive train. As Mark said, I can always change and upgrade it as and when I get the money and enthusiasm. He reckons that it would be fairly straight forward to drop a LS7 V8 engine in there and they are good for an easy 5-600BHP with tuned versions going over 1,000!

Perhaps a bit much for my first build but later...

[Mister Towed]

Supra Turbo?

Cooper S Supercharger?

General Motors LS7 Supercharged V8?

Given your moniker, wouldn't a Sammio Chevaux 600cc twin be safer?

Oh, and the LS7 is priced from £8,400 + £735 for the alternator and power steering pump + £580 for the ECU + VAT + Delivery.

That's £11,658 plus delivery.




You're going to need mighty deep pockets.

[jmc14]

I have 500hp LS6's in my cars. My cars weigh 1900lbs. Believe me this is WAY MORE THAN ENOUGH TO BE SERIOUSLY FAST! The problem is if you were to put big power with the Miata suspension, brakes, and diff you will have to spend serious money upgrading them to handle the extra stress.

I am sticking with the Miata drivetrain. I don't race on the street so I am looking for a fun little ride. It's pretty easy to get 190hp with an inexpensive supercharger. This won't over tax the Miata parts and in an under 1500 lb car, will be plenty fast.

It is fun to think of all of the possibilities, isn't it. You will have fun and I am sure the end result will be great. John

[WorldClassAccident]

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 ;-)

[Mister Towed]

Phew, I thought you were going for the land speed record.

Posthumously.

[WorldClassAccident]

What could possibly go wrong?

[WorldClassAccident]

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

[red5]

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/i...i?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

[WorldClassAccident]

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.

[Mister Towed]

Why are you so set on an MX5 base?

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.

[WorldClassAccident]

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.

:-)

[garyh]

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...

[WorldClassAccident]

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)?

[garyh]

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.

[WorldClassAccident]

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

I could always fit two...

[garyh]

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.

PS. are you at work today, having all this time


http://garyssammiospyderbuild.blogspot.com/

[WorldClassAccident]

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. ;-)

[garyh]

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...