New MEV Exocet Kit car

[Munter]

singlecoil said:

Munter said:

singlecoil said:

Anyone know why Mazda chose to have a framework linking the engine and rear axle?

Edited by singlecoil on Tuesday 20th July 20:34

No idea. But I wonder if it's part of adding "stiffness" to a cabrio. I see they carried it over to the MK3 from the photos above.

I'm not very familiar with MX5 bits, but if it connects power unit (which I'm prepared to bet is isolated from the bodyshell with rubber mountings) then it cannot contibute to the bodyshell stiffness.

You raise a very good point. So now I'm buggered if I even have an idea what it could be for.

[JonRB]

Munter said:

You raise a very good point. So now I'm buggered if I even have an idea what it could be for.

Well, plenty of convertibles in the past had a backbone chassis. All TVRs have and a lot of other British sports cars did too, so I just presumed the MX-5 does too. It has to give some measure of stiffness, surely?

[singlecoil]

JonRB said:

Munter said:

You raise a very good point. So now I'm buggered if I even have an idea what it could be for.

Well, plenty of convertibles in the past had a backbone chassis. All TVRs have and a lot of other British sports cars did too, so I just presumed the MX-5 does too. It has to give some measure of stiffness, surely?

As someone said, though, if it's bolted to the engine, and the engine is not rigidly bolted to the bodyshell, how can it possibly contribute to the stiffness?

[antnicuk]

Mazda RX7s FD3s since 1992 and all rx8's also use power plant frames. The rear of the diff mounts to the subframe at the top but the nose of the diff bolts to the PPF. The PPF doent touch the chassis, only the diff and the gear box. Im not sure of the technicalities of it but it is supposed to keep the drive train in sync and prevent tramp, make for less movement and smoother drive. The rx7s only have mounts at the rear of the engine, the gearbox isnt mounted to the chassis, the rx8 and mx5 are the same iirc.

You can buy uprated PPF for the rx7 as the high power drag cars break them.

Also, when they do a V8 conversion on the rx7, the use a torque tube instead which attaches to the diff to do a similar job i think.

[cymtriks]

Munter said:

singlecoil said:

Anyone know why Mazda chose to have a framework linking the engine and rear axle?

No idea. But I wonder if it's part of adding "stiffness" to a cabrio. I see they carried it over to the MK3 from the photos above.

It has absolutely nothing to do with adding stiffness to the chassis.

Firstly, it isn't part of the chassis, it's part of the driveline. Secondly, the PPF is a C section beam with lots of holes in it, a design which has inherently poor torsional stiffness.

Other performance cars have this feature. The corvette, the Porsche 928 and the front engined Ferraris have a similar system, at least on some models.

Apparently it is there to make the drivline feel better, I'm not sure exactly how.

[stig mills]

Some very interesting pictures and explanations there.
The simplist way to describe the PPF feature is to imagine the diff trying to rotate as you pull away rather than the wheels turning. Instead of relying on mountings they just anchor the diff to the box with the beam, simple, clever, stiff and light. You can see why we chose this donor, I can't fault any of the components we are using. Rear tracking is adjustable and after market dampers are available for those with larger budgets who require damping adjustment. There are tons of tune up parts available too. As you can see from the pictures it is so easy to build the Exocet. We don't remove the engine, just lift off the body shell. It could be possible to run it on the donor registration and avoid IVA claiming that it is a body conversion on an un modified chassis. It might work. Is the PPF a chassis? The MX5 has just won the JD power sports car of the year competition. Apparently over one million have been made in the last 20 years. The engines seem to go for ever. One guy came to me from Brighton to pick up MX5 body spares that I had left from my donor. He had done over 250,000 miles in his Mk1 and it was not showing any signs of wear. I have just completed the body mods and I am very pleased with the new front. I will have pics on our site soon, a little paint now required. Still thinking of red, will need to decide in the morning.
Regards Stiggy

[fuoriserie]

A few more interesting drawings ....

[fuoriserie]

singlecoil said:

Anyone know why Mazda chose to have a framework linking the engine and rear axle?

Edited by singlecoil on Tuesday 20th July 20:34

Info written on the book I have on the MX5

: MAZDA MX5- MIATA Design & Development the Inside story:

http://www.amazon.com/Mazda-Miata-Roadster-Toshihi...

Page 100:

The transmission and differential gear casing were connected by an aluminiom powerplat frame(PPF) toform a highly rigid , single drivetrain. This drivetrain system reduced the wind-up effect, vibration caused by resonance of rear suspension and differential gear case, rear suspension pitching and power trasmission time lag, that were all common in traditional FR cars.

The PPF eliminated the phase lag in handling and stability and improved handling.

Page 107:

Adoption of the PPF was to further enhance the basic performance of the car. The PPF stops the relative movement (wind-up) of individual components as torque is transmitted through the powertrain from transmission to differential and gives direct throttle response for the driver.

PPF Structure
When a car accelerates a reaction force from wheel torque tries to turn the differential case in the opposite direction to the wheel, raising the front of the casing. Only after all possiblie movement is taken up is the traction fully transmitted to the ground: this movement causes a small time lag between application of the throttle and the start of the acceleration..............


The explanation continues for 5 pages..... but I'm sure this brief explanation was enough to understand why......

Edited by fuoriserie on Wednesday 21st July 09:52

[JonRB]

Just a small point, Stiggy, but I presume you've thoroughly researched how far the trademarks on the word "Excocet" extend and whether you're infringing or not?

[Sonic7]

Just a quick post to make you all a little jealous, and because I‘m genuinely excited.

To explain I currently own a MEV Sonic7, and had mentioned to Stuart Mills of MEV that I may be looking at starting a new project this winter as the good lady has been getting a little fed up riding shotgun and now want’s something of her own to drive.

So

I’ve just been invited by MEV to be one of the first people to get to test drive the Exocet on the weekend after next, at the MEV Owners 1st Annual Mogger’s Meeting http://www.mevowners.proboards.com/index.cgi?board...

I will do my best to report back here on my driving experiences after the event.

nigel

[Iwantoneofthose]

How much different is a UK spec MX5 to a grey import?

Would using a grey import as a donor effect the insurance at all?
After all, it's going to be quite different from the standard UK spec MX5, so you'd be looking at specialist insurers from the start.

Also, it would be nice to have a side profile photo of the Exocet, married up against a MX5 (wheel to wheel) to get an idea of scale.

cheers.

[Munter]

Iwantoneofthose said:

How much different is a UK spec MX5 to a grey import?

Would using a grey import as a donor effect the insurance at all?
After all, it's going to be quite different from the standard UK spec MX5, so you'd be looking at specialist insurers from the start.

Also, it would be nice to have a side profile photo of the Exocet, married up against a MX5 (wheel to wheel) to get an idea of scale.

cheers.

No idea on the insurance.

The main differences are trim levels. Imports are more likely to have leather, "wooden" steering wheel, aircon, and seat speakers. Things like ABS move the washer bottle from the bulkhead into the front beside the rad. That's a minor consideration though.

The main oily difference that'll interest I suspect is 1.8 imports tend to come with a TorSen LSD. UK MK1 1.8 is an open diff. The UK MK2 1.8is comes with the TorSen.

Some import special editions have lighter flywheels and different diff ratio.

Your problem finding a donor might be that the ones failing MOTs due to rust are more likely to be UK rather than imports.

[covmutley]

Mine is a eunos. Don't think it is much different to uk cars. Imports are often better spec- LSD as standard. Mine has a/c (which would go) and a LSD. The basic LSD is viscous and they are known to fail but still work just becoming locked. The specials etc have better lsd's I believe. Loads of tuning potential too- have a look on mx5 nutz.

[stig mills]

Hi, our demo Exocet car will be available for test rides this weekend, sporting it's new style GRP. It will be at the MEV OWNERS GROUP track day at Litchfield (Curborough) Admmision is £10 if you book on line via paypal or £15 on the gate. You will get a ride in a car for that too, also includes tea or coffee and you will get a refund if you place a deposit on a car/kit. We will have all seven vehicles in the MEV range on the track plus several members of MOG with their own cars. Come and see the Rocket, Missile, Exocet, ECO-EXO, tR1ke, Sonic7 and Atomic in action. If you have a MEV it's the cheapest track day ever at only £40 inc driver and car if you book or £60 on the gate. Please book today.
http://www.mevowners.proboards.com/index.cgi?board...
See you there! Regards Stiggy

[rickbrown74]

covmutley said:

Mine is a eunos. Don't think it is much different to uk cars. Imports are often better spec- LSD as standard. Mine has a/c (which would go) and a LSD. ...... Loads of tuning potential too- have a look on mx5 nutz.

^^^ What he said ^^^

I would be SERIOUSLY tempted by this if I hadnt just spent £800 doing up my low mileage Eunos. Got it for £1800 with a roll cage (sold of £100), a hardtop (worth 3-400) adjustable shocks and strut braces. There's plenty of cheap MX5/Eunos's out there. This kit is a serious bargain and I would not hesitate to build one if I had seen this 4 months ago!!!

[covmutley]

I paid £950 for mine. Given me a good couple of years of fun and trouble free motoring and have done 2 track days in it. Some rust on one rear arch that is now fixed but it will be an issue again next winter somewhere on the car ,probably sills. 3 panels suffering from peeling laquer. Its begging me to free it from its ageing body.

Mine is 1.6- I wonder if that could be the engine of choice? I understand it is a fair bit lighter than the 1.8 and 'revvier' than the 1.8, but the 1.8 benefititng from more torque. Presumably torque is less of a benefit in and light car driven relatively hard?? Im happy to give you my mx5 and, say, £1k if you want to find out for me Stuart

I look forward to reports and photos of the weekend...

[Kev M]

Make sure you get some photos up pretty sharpish of the new bodywork after the trackday (please tell me you're not taking inspiration for the colour scheme from the Opal Fruits lottery again ) I'd have come along for a proper look if I wasn't stuck working.

Edited by Kev M on Tuesday 27th July 15:30

[Munter]

stig mills said:

My exhaust sounds too quiet as it is the standard MX5 one but apart from that I am delighted with it.

Good for getting on track days without problems though. Every cloud has a USP.

[stig mills]

Colours are a personal taste thing, I feel now though that one colour on a black frame works best on the Exocet. I have chosen red with a black stripe to compliment the black frame/side panels etc.
I reckon most Exocets are going to be built with the 1.6 engines. Can't quite get down to £1000 but thanx for the offer. I have finished the GRP now, I have also driven the car in anger for a couple of days. The wiring was so easy I enjoyed it. Just plug and play. My exhaust sounds too quiet as it is the standard MX5 one but apart from that I am delighted with it. Just the lights to connect. I have gone for slightly larger headlights as I felt the headlights that were smaller than the indicators looked wrong.
Apart from that I have now fitted the reclining MX5 seats and was delighted to find headrest speakers. Ipod amp on order. Pics soon, regards Stiggy

[Kev M]

What's the score with IVA then Stig? Does the Exocet need it or is it exempt? Apologies if you've already answered the question and I've missed it.