a whacky idea

[Martin]

I saw someone post a thread about putting a subaru engine into a porsche (or maybe the other way around into an 818). It got me thinking. When the 818 was originally announced, I thought it was going to remain as an AWD car. A rear engined 2WD car isn't what I was expecting, but I think FFR have done a great job of the car and won me over. But I still think a bit about the AWD concept.

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Anyway, I saw the picture above (it's a BRZ, but you get the idea), and thought it would be great in an Ariel Atom exo-skeleton car. Put a tube frame on it, a big rear wing and something on the front to balance it out and away you go. It seems like such an obvious thing to do, but that is just showing my ignorance because nobody has done it as far as i can tell.

Thoughts? How hard would it be? (it's out of the question for me, but others with skill might have some thoughts).

Martin

[longislandwrx]

I'm not sure what are you looking for, an AWD exoskeleton car?

there's probably a reason it hasn't been done extensively... a front opposed engine like the ej doesn't really lend itself so sleek narrow front ends like the atom or tr42 have.

[Martin]

I was more thinking of a minimalist awd kit car. Doesn't have to be exoskeleton. Obviously, this means a narrow front end won't work, but an awd rally or prototype car might work?

[longislandwrx]

I was more thinking of a minimalist awd kit car. Doesn't have to be exoskeleton. Obviously, this means a narrow front end won't work, but an awd rally or prototype car might work?


The Murtaya is probably the closest you are going to get... there's not much too them and the sky's the limit if you want to customize. They're right in your backyard too.

[Martin]

I don't think the Murtaya has been engineered to be a race car as such, I see it more as a body kit. As a company, they've had a lot of problems/owners as well which doesn't instill much confidence.

For the subuaru folks, is there any reason why it couldn't be done properly? I guess, my question is really why nobody has successfully done it before? The Murtaya has subaru parts, is easy to build, is awd, looks OK, but the last time I looked at them they had sold <5 cars in total. I wonder if someone gave it the FFR treatment and built a proper chassis for it, would it have great success, or is the whole idea fundamentally flawed?

Martin

[billjr212]

The problem (challenge?) is, with the Subaru engine and AWD configuration the motor has to hang out in front of the front axle. Not a huge issue in a 3,500 pound street car, but if you slim it down to exo car weight levels, you would end up with some terrible weight distribution.

There was someone on here trying to make the 818 into an AWD hybrid by using electric motors to drive the front wheels. Not sure what the latest on that project is.

[Martin]

The problem (challenge?) is, with the Subaru engine and AWD configuration the motor has to hang out in front of the front axle. Not a huge issue in a 3,500 pound street car, but if you slim it down to exo car weight levels, you would end up with some terrible weight distribution.

There was someone on here trying to make the 818 into an AWD hybrid by using electric motors to drive the front wheels. Not sure what the latest on that project is.

Now that makes sense. I always assumed the drivers being over the back axle would balance it out. Shows how little I know!

Martin

[billjr212]

Now that makes sense. I always assumed the drivers being over the back axle would balance it out. Shows how little I know!

Martin

If you put the driver/passenger far enough back to balance the motor, you end up with crazy proportions and a high moment of rotational inertia (I know I'm not using the right term here). Basically, you want the weight near the center between the front and rear axle for best handling - think Porsche Boxster (or FFR 818!).

[Hiryu]

I think that by the time you get to a lightweight car, a lot of people would rather have centered weight than AWD. If you're going to go with AWD and want a mid-mounted engine, you need to figure out how to arrange it. Boxer engines would have to be raised up since the driveshafts couldn't go around the engine like they can in V-type engines, and then you have a higher center of gravity, which is undesirable (which is probably one reason Subaru just put the engine in front of the front axle instead of behind and above). If you have a mid-mounted V engine with AWD, you either have to shift the engine to a side or move the driveshaft over (usually both), in which case you lose any symmetric AWD and have slightly off left-right weight balance. At least this is how I understand it, and why I assume they've only sold a little over 40 Murtayas (at least before the recession helped kill the original company). BTW, the Murtaya isn't a body kit; it uses a completely custom monocoque body and spaceframe for the engine. They've had many different versions for different types of races (autocross, drag, off-road rallying, etc.). In fact, one of the UK distributors races a Murtaya against Caterham 7s, etc..

[Martin]

Thank you for a detailed explaination. Very much appreciated. Glad there are professionals for this sort of thing!

[DodgyTim]

A work colleague has built an AWD kit car using the Mitsubishi Evo running gear.
Motor/gearbox is transverse in the rear (atom like) and drive shaft has been redirected forward to run the front wheel drive
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He ran the completed car last year and his times were pretty good. It is street registered but track focussed

[Evan78]

A work colleague has built an AWD kit car using the Mitsubishi Evo running gear.
Motor/gearbox is transverse in the rear (atom like) and drive shaft has been redirected forward to run the front wheel drive
He ran the completed car last year and his times were pretty good. It is street registered but track focussedWhat kit is it?

[DodgyTim]

Here's part of the time card from last years Leyburn Sprints
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It's listed as an Sylva AWD Riot (Glen Hooper #159)
Looking up their website, they list a Sylva Riot, but it isn't AWD, so I don't know whether they are producing the kit commercially
http://southam.com.au/riot.html

[Frank818]

There was someone on here trying to make the 818 into an AWD hybrid by using electric motors to drive the front wheels. Not sure what the latest on that project is.

Gary Livinsgton? http://thefactoryfiveforum.com/showthread.php?15883-Gary-s-818SEx4
It's not hybrid, it's full electric.