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 Post subject: Re: AWD Locost?
PostPosted: Fri Nov 26, 2010 5:16 pm 
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I'm just curious, and maybe there is an obvious reason, but why has the Impreza drivetrain not been mentioned?

Oh and fwiw, when I was still in the UK in the late 90's, a colleague of mine had a 4WD Westfield(I think). This was using the Sierra Cosworth 4x4 setup. That's all I know about it. It's also the same setup that was squeezed into a Mini.

Tom...


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 Post subject: Re: AWD Locost?
PostPosted: Fri Nov 26, 2010 6:09 pm 
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I believe it has to do with where the engine sits relitive to the front wheels, from my understanding most awd cars hang the engine out front of the front axle or mostly out that way, where a 7 the engine is almost completely behind the front wheel center line.


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 Post subject: Re: AWD Locost?
PostPosted: Fri Nov 26, 2010 6:59 pm 
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Exactly, the transfer case must go behind the engine in a Locost, which means using off-road 4x4 parts to keep the price down. And it'll be heavy.

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 Post subject: Re: AWD Locost?
PostPosted: Sat Nov 27, 2010 11:25 am 
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dilbert wrote:
I just imagine 4wheels locked going the exact same speed. Thats where I'd think you'd end up constantly doing a 4wheel drift!


No, thats an assumption and incorrect.

The Subaru RX's when setup for rallying are notorious for hanging the rear out with a rear LSD and front open diff when you break traction under power because both rear wheels are spinning together along with the de-weighted inside front whereas the outside front is not driving and is only prone to lateral forces.

For the same reasons in a corner you can actually spin just the front and rear inside tyres on a 4WD when the front and rear diffs are open - have you seen an older 4WD bogged in sand? It just spins up one front and one rear wheel.


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 Post subject: Re: AWD Locost?
PostPosted: Sat Nov 27, 2010 11:31 am 
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KB58 wrote:
Exactly, the transfer case must go behind the engine in a Locost, which means using off-road 4x4 parts to keep the price down. And it'll be heavy.


The Mitsubishi L200 4WD has a neat Chain drive which sidesteps to a dummy shaft and is about the simplest and lightest of the lot.

But yes there is a weight penalty and one has to balance the advantages against that weight increase. Not much will beat you from a green light thats for sure and powerful light cars can be a pain in the ass on a wet road but who wants to drive a Locost on a wet day by choice anyway ....


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 Post subject: Re: AWD Locost?
PostPosted: Tue Nov 30, 2010 3:14 am 
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What about using the drive train from an e30 BMW 325 ix? I realize you would end up with an oversize frame but I don't see any reason you wouldn't be able to extend the front drive shaft forward to place the front diff in front of the engine as opposed to having it directly below the oil pan. Then you could run either a S14 or M42 to try and keep the length some what under control.


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 Post subject: Re: AWD Locost?
PostPosted: Tue Nov 30, 2010 1:53 pm 
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Tom17 wrote:
I'm just curious, and maybe there is an obvious reason, but why has the Impreza drivetrain not been mentioned?


The problem with an Impreza drive train is the transmissions layout. The front diff is placed just behind the bell housing hanging the engine out over the front wheels which is the exact opposite of the lotus 7 layout where the engine is placed behind the front wheels center line. This would lead to massive under steer not to mention one ridiculous looking design that has at least a 3 foot long nose. Its too bad though cause the Impreza's drive train is wonderful. I currently have an 02' wagon and its once of the best cars I have owned between being easy to work on (I can already feel the flaming about valve adjustments and spark plug changes coming) and drive ability.


Last edited by worthingtontw on Mon Dec 06, 2010 7:40 pm, edited 1 time in total.

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 Post subject: Re: AWD Locost?
PostPosted: Tue Nov 30, 2010 5:42 pm 
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Location: Georgetown, KY
Hasn't this been posted on here before?

http://www.bxv.co.nz/


750 Kg with weight dist of 60% front 40% rear

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 Post subject: Re: AWD Locost?
PostPosted: Thu Dec 02, 2010 12:16 pm 
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worthingtontw wrote:

The problem with an Impreza drive train ..... would lead to massive under steer .


Not true, while front overhanging engines certainly don't help the cause, in a Locost the seating position, battery, fuel tank and other items are so far back that the overhang is balanced out and nullified.

In my mind the problem with the Sub drivetrain is where to put an intercooler and still have a decent looking car.


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 Post subject: Re: AWD Locost?
PostPosted: Thu Dec 02, 2010 1:20 pm 
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Right, I now see the issue with the scooby drivetrain. Ouch, I never thought it would be like that.

I was wondering what could have been so different about a Sierra 4x4 that allowed it to fit into a friends Westfield back in the early 90's. Then I finally looked around and realised that there is a take-off on the side of the gearbox, with a shaft running forward from there to a diff up near the front of the engine. From there, one driveshaft went to the right wheel, the other went THROUGH the sump and on to the left wheel.

Now I am wondering if there is anything current/good/North American like this...

I guess i'm finally just catching up with all your thought processes on this :)

Tom...


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 Post subject: Re: AWD Locost?
PostPosted: Thu Dec 02, 2010 1:34 pm 
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It's nice having the front and center diff in the subaru transmission, though. All that symmetry gets me excited. I've owned two STIs. Changing the clutch out on jackstands it a lot of fun.s
Image

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 Post subject: Re: AWD Locost?
PostPosted: Sat Dec 04, 2010 8:50 am 
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Tom17 wrote:
From there, one driveshaft went to the right wheel, the other went THROUGH the sump and on to the left wheel.

Now I am wondering if there is anything current/good/North American like this...
Tom...


The already mentioned BMW driveline and Nissan GTR ...

BMW ...
Attachment:
BMW 4x4.JPG
BMW 4x4.JPG [ 148.7 KiB | Viewed 1398 times ]


Making up a center diff for a L200 or similar driveline isn't the world's hardest prospect either.


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 Post subject: Re: AWD Locost?
PostPosted: Mon Dec 06, 2010 7:35 pm 
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cheapracer wrote:
worthingtontw wrote:

The problem with an Impreza drive train ..... would lead to massive under steer .


Not true, while front overhanging engines certainly don't help the cause, in a Locost the seating position, battery, fuel tank and other items are so far back that the overhang is balanced out and nullified.

In my mind the problem with the Sub drivetrain is where to put an intercooler and still have a decent looking car.


This is not strictly true either because admittedly it would not create massive under steer, but the key thing about a Locost is that you have everything less the fuel tank between both the front and rear wheel center lines. When retaining the the same seating, battery, and chassis lay out with a Subaru drivetrain you move the entire front portion of the drive train on and in front of the front wheel center lines which would throw off the balance entirely as your moving a 300-400 lbs mass 3 feet forward.


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 Post subject: Re: AWD Locost?
PostPosted: Mon Dec 06, 2010 10:08 pm 
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The 325ix (as I posted ages ago) is probably the easiest available vehicle to use in the US... Every thing is there for you, I understand the front uprights are a tad tall, but otherwise, good donor...


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 Post subject: Re: AWD Locost?
PostPosted: Tue Dec 07, 2010 1:39 am 
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I've added links to every AWD / 4WD related thread I could to my initial post in this thread. It's tough not being able to search for "AWD" & I know that if we could we would probably see fewer of these kinds of posts. Hopefully linking all the existing info helps.

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