Myself and Kitch (a member of the forum) are about to embark on individual projects to build an MX-5 based car but before we do I have a question.....Which chassis design is better, the Saturn or the Vodou?

We'll be scratch building the chassis as we have the services of an incredibly good professional welder at our disposal, so what we produce should be something rather special, but which design is inherently lighter, stiffer or just regarded as better?

One concern is that good bodywork is available to fit either design with no issues, nothing worse than a car that's had money and time thrown at it that ends up looking like shit. As myself and kitch are both mechanical engineers by trade so we want to create something that from all angles looks every bit as good as a factory built Caterham so want the best platform to build around.

Thanks

GM

[Edited on 3/1/12 by Gear Monkey]

I'm unbiased on this one

I think both designs are based heavilly on the original haynes roadster design but have been modified for front suspension pick ups and accomodating the rear diff.

I very much doubt there would be much weight saving between the designs as the basic chassis is pretty similar, but I'd look at both (I think the drawings were available from voodu and Spud probably has pictures of his Mx5 chassis), and see which one you think is better designed as there will be differences, not forgetting you'll need there wishbone designs to and again there are differnces between the two.

Bodywork, I think dimensionally bodywork should be tranferable across the chassis, voodu's bodywork is meant to fit the haynes roadster and I think Saturns does to and I think MK Indy stuff fits to as per the original Haynes build and theres another company offering bodywork for haynes so you should have four to choose from

the voodu bodywork I think will be combined nose & bonnet and may have some neat touches, but is yet to materialise. Where as Saturns is well turned out and the company has a good reputation for customer service and delivery.

Talon is making chassis to the Voodu design so PM him on the haynes forum for any advice on that one. Spud is friendly and can point you to owners using his design.

I'm not sure if a finished example of either car has actually been completed and on the road, Saturn is probably closer with Voodu close behind (but they have seem to have gone quiet on the forums in the last month.)

Hope this helps

Mike

I have used saturn and there body work is good quaility

Dont MNR do an MX5 donor based kit? Any reason for not looking at them?

Thanks Guys,

Does anybody know if much if any modification will be needed to fit an engine from a MK2.5 MX5? The engine and gearbox I have is the 1.8 with VVT and the 5 speed box. At a glance at the engine bay this looks the same as the MK1 engine so hopefully no mods will need to be made. I should have my engine and box before I start the chassis so shouldn't be a problem to make any changes if need be.

GM

Do MNR have plans to download?

GM

quote:

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Originally posted by Gear Monkey
Do MNR have plans to download?

GM

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quote:

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Originally posted by Gear Monkey
we want to create something that from all angles looks every bit as good as a factory built Caterham so want the best platform to build around.

Thanks

GM

[Edited on 3/1/12 by Gear Monkey]

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I,m with James here, mine is based upon the original book, if I made again I would make based upon pre-litigation westfield size and chop down the long sierra driveshaft.

Main bodywork is easy to make apart from the nose cone, the panels are either flat or only bent in one plane as easy to form in ali which gives a better finish that plastic/fibreglass and is much cheaper.

Wow guys alot of negativity here for the roadster, mines built and finished its physically similar in size to a rush or an Indy and not far off my mates Westfield
As for Ali sides being nicer than fibreglass I think that's purely a personal decision as I prefer FTP to Ali I think it looks more complete.

I actually have built a car many years ago in the late 90's based on the 1st edition of the champion book with escort parts and found that rather cramped. I also have a part build chassis based on the 2nd edition of the champion book and after ten+ years of working out I'd need to lube up just to squeeze into the thing so maybe the wider haynes based design is the way to go.

@carlknight1982, Your car looks great, nice work!


GM

Thank you

is there any particular reason for it to be an mx5 build? if you want something small and light then aries motorsport do a great chassis and bodywork. nice guy to!

The Aries car does look really nice but I need to build the chassis myself and from what I can tell they don't provide plans unlike saturn and vodou.

GM

if you call him and ask im sure he'd supply it flat pack. if you look at the photo gallery on there website the yellow one with the black front wings and nose band looks very caterham. the brittish racing green one looks nice also!

I looked at both Saturn and Vodou. Having consulted an engineer we decided the Vodou was a better more resolved design. The wishbones and diff mounts are far better.

Having said that I found the support and back up to be much better from Saturn. The guys behind Vodou have gone very quiet since November due to personel issues I believe.

If you pop over to the Haynes forum there is some talk about some very nice bodywork for the Vodou too. There haven't been any pictures though yet.

In the end I went in a different direction with the chassis as I was always going to use an enclosed body. I bought the 2 together from the body manufacturer.

As for the MX5 engines they will all fit the chassis. It is a good bit larger than the original Locost, MK, MAC#1 etc.

The only real difference between mk1 and 2 mx5's is the front uprights are slightly different with the hight of the steering arms 7mm ish higher on the mk2.

Mk1 1.6 has smaller diff, thinner driveshafts, prop and smaller brakes. All mk2's are the same with the running gear. The MK2.5 had VVT but it doesn't really increase engine power.

The wheel base on the roadster and the indy are identical. What are you lot on about. The roadster is 2inch wider than an indy and 4inch longer in the chassis but the wheelbase has been kept the same. Having driven several indys and 3 roadsters including my own they feel near identical to drive. The newer indy r is better on the limit than both the roadster and the old indy.

Now on to the mx5 versions of the roadster. There are pros and cons to everything. But I can't and won't comment as neither company have a road legal car as far as I am aware. Time and time again it has been proven just because it works on a computer screen doesn't mean it will work when it comes to real life.

The sierra based roadster and locost have been over time been proven as working designs. Realistically all you need is the diff rear driveshafts/carriers and front uprights off a sierra or axle and front uprights off a cortina and the other bits can come off any car.

Personally I would go with a sierra rear end and mx5 front uprights if I wanted the best of both.




[Edited on 4/1/2012 by ashg]

Evening Ash, how are things! Your rocket car doing OK and how is the magazine build going, I don’t get the magazine sorry.

On the Roadster verses other cars, was it not the same person that did the Indy did the Roadster chassis in all reality, or have I got that wrong.

Back to the Op's question and points. Bodywork and finish is down to time and effort I think in all cases, to the finishing of edges and trim. Fibreglass is probably easier to make look nice, aluminium can look stunning if done by a master craft person such as TrevD.

I would tend to say stick with the basic chassis and try for a land rover diff that I believe is lighter and there are lighter uprights that can be used from the likes of Rally design or others.

Or better still wait until after shows like Stoneleigh and see what is available and see them in the flesh before making a decision.

Adrian

How Timely,
I'm in the midst of making this decision right now. I think I'm going to go Vodou because they say the outer dimentions are the same as the hayes chassis, and they plans look more polished. Although I did see that there's no lower shock mount on the rear wishbone assemble. Hmm.. I'm sure I'll find a way though.