snot
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| posted on 24/11/05 at 05:28 AM |
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AWD using Subaru????
Hi all,
Just found this forum/website and did a quick scan of it and found some like minded stuff.
For a while (3 years!)I have been pondering an AWD , wide nose ,7 replica using Subaru running gear( its cheap here in oz,bolt on HP
upgrades,adjustable front/rear center diff,low c of g).I seen that comments that the weight balance is nose heavy etc but the rally cars and track
cars do all right...??
My thoughts are to use the complete front and rear alloy sub frames/mounts on a 7 style frame but due to the engine config I would have a wider track
and a more 'elongated oval' nose.To minimise front overhang I'd run only front mt intercooler and rear mount radiator.
Has anyone already done this?
There is a guy in NZ with the same deal in a mcycle quad frame!Uses it on hill climbs I believe.
Penny for you thoughts.
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kb58
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| posted on 24/11/05 at 05:55 AM |
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While it's possible, it won't work in a Seven type car. The Subaru engine is way forward of the front axle, exactly the opposite of what
you need.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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snot
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| posted on 24/11/05 at 06:10 AM |
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True about it being way forward especially with the Subaru Liberty engine (see attached pic of the "quadzilla!),from what I can see the Impreza
is shorter and less over the front.
I thought the aim of the seven type was to get as close to 50/50 weight and an open wheel type design.Some of the sevens seen to have a nose cone that
extends 500mm past the front edge of the wheels and still look proportional but I guess that wouldn't have much weight of course.
I had the thought that if 75% of the engine is ahead of the axle and 25% + the gearbox behind then that would be the load on the front axle.Then to
balance that out and achieve same weight on rear axle I'd have battery,fuel ,radiator behind rear axle and try to keep seats as much to the rear
as possible.Keep it comin!
 
Rescued attachment Copy of sti_atv.jpg
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Messenjah
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| posted on 24/11/05 at 08:10 AM |
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doesnt the radiator need to be somewhere at the front where lots of air will hit it  as opposed to behind the rear seats in a relatively sealed
position and sheilded form airflow
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NS Dev
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| posted on 24/11/05 at 08:45 AM |
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quote:
Originally posted by snot
True about it being way forward especially with the Subaru Liberty engine (see attached pic of the "quadzilla!),from what I can see the Impreza
is shorter and less over the front.
I thought the aim of the seven type was to get as close to 50/50 weight and an open wheel type design.Some of the sevens seen to have a nose cone that
extends 500mm past the front edge of the wheels and still look proportional but I guess that wouldn't have much weight of course.
I had the thought that if 75% of the engine is ahead of the axle and 25% + the gearbox behind then that would be the load on the front axle.Then to
balance that out and achieve same weight on rear axle I'd have battery,fuel ,radiator behind rear axle and try to keep seats as much to the rear
as possible.Keep it comin!
.............unfortunately that then makes the car have a very high polar moment of inertia which will make it handle pretty poorly, think of a
dumbell.
[Edited on 24/11/05 by NS Dev]
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David Jenkins
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| posted on 24/11/05 at 08:48 AM |
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quote:
Originally posted by NS Dev
...think dumbell.
"How rude!" I thought, calling him a dumbell - then I re-read it and understood...
David
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NS Dev
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| posted on 24/11/05 at 08:57 AM |
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In fact, let me be honest and frank!!
The front of a traditional 7 is no place for the subaru engine, that is a silly idea!!!
I can't be bothered to explain all the reasons why not but suffice to say it is an engineering bodge of some proportion, it is just
fundamentally wrong!
The way to use that engine, should you choose to, would be to design a mid engined car and attach the subaru engine to a vw transporter/hewland
transaxle.
Other thing is the Subaru engine is not the picture of perfection that many people seem to make them out to be. Bottom end failures are VERY common on
even fairly mildly tuned examples. My mate who runs a breakers yard usually has a lovely shipping container full of engines for a core collection
company, and there is always a big pile of subaru engines with failed bottom ends. Yes, it is a good engine, but not quite as good as some make out!
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snot
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| posted on 24/11/05 at 11:10 AM |
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now thats the sort of info I'm after!I am concerned about that whole front bias thing but noone seems to be able to tell me for sure.I have
this thing about a 4wd 7 and the cosworth is the ideal choice (and done before) but rare as rocking horse.... here.Maybe Audi?or has anyone used any
of the constant 4wd stuff out of (dare I say it...) a Daihatsu or Suzuki but of course not the suspension?
Any other north-south engined sources?
Have thought about Nissan skyline stuff- but the six is two long and the trans too wide....
Keep it comin!
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NS Dev
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| posted on 24/11/05 at 01:07 PM |
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You could use the ford 4x4 system (which is the most "7 friendly" but with an alternative engine.
Take a look at Liam's archive on here for some inspiration.
Certainly the ford sierra/scorpio 4x4 system is the easiest to use.
An option that I had considered due to having a few of them laying around was using the Vauxhall XE engine (200 hp naturally aspirated std engine on
throttle body injection) mated to the early type 9 gearbox based ford 4x4 system, using an off the shelf long input shaft caterham type bellhousing.
This will work using all off the shelf bits, and you can uprate to a quaife set of internals for the box and a turbo calibra engine in the future!
The audi unfortunately uses similar engine positioning to the subaru in terms of it being far forward.
[Edited on 24/11/05 by NS Dev]
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kb58
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| posted on 24/11/05 at 04:45 PM |
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quote:
Originally posted by snot
I had the thought that if 75% of the engine is ahead of the axle and 25% + the gearbox behind then that would be the load on the front axle.Then to
balance that out and achieve same weight on rear axle I'd have battery,fuel ,radiator behind rear axle and try to keep seats as much to the rear
as possible.Keep it comin!
As I recall that quad had 75% front wieght bias. Truely terrible for anything of the sports car variety.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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Mad Scientist
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| posted on 24/11/05 at 10:02 PM |
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Whilst the Scoob engine isn't going to work in a 7 type arangement, I feel I must defend it! Yes, a lot go bang due to poor moddifications etc,
but the world record holding scoob for top speed (211mph I think) is both British and still a 2litre.............................with around 600
proven horses! Thats around 300bhp per litre! Personally I think thats quite impressive.
Pete
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kreb
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| posted on 25/11/05 at 03:58 PM |
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It's interesting that Subaru engines seem to be much more maligned in the UK than in the states. In my experience with an Impreza retrofitted
with a WRX turbo driveline the weak point is the gearbox, not the engine. While I agree that the weight distribution and Polar moment are horid,
it's hard to argue with the racing succes that those cars have had.
That said, while I'd consider a Subbie H-4 for purely RWD application (It'll fit in a plus $' chasis), I agree that the Ford seems
to be the way to go.
Bear in mind that although the enhanced ability to get power to the ground has a lot of appeal, it is a harder car to drive at the limit. A
traditional seven is tremendously forgiving. Ask Dax about their experiences with a awd. Forgiving is not a term they'll use.
https://www.supercars.net/blog/wp-content/uploads/2016/04/1966_FiatAbarth_1000SP1.jpg
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quattromike
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| posted on 25/11/05 at 10:28 PM |
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Yip I agree with all what everyone is saying about the engine being way too far forward but if you think back a few years the Audi A4 was pretty
succesful in the btcc.
Mike
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phelpsa
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| posted on 27/11/05 at 04:40 PM |
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The subaru engine bottom end failiures are to do with big ends, which let go at anytime for no real reason (speaking from experience, happened to our
scoob at 12000 miles). Yet some cars manage to run 400+bhp out of it with no problem at all!
Adam
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snot
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| posted on 27/11/05 at 09:37 PM |
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Thanks people.Interesting about the AWD dax being a handful- I would have thought the AWD would be less of a handful than a rear wheel 200hp+ ,
especially in the wet??I wonder if the dax experiance had anything to do with the center diff power split?As people have said - the soobies ,skylines
and audi have all had some good race track sucess (also especially in the damp) -certainly a different technique to driving em.I remain uncertain!
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NS Dev
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| posted on 28/11/05 at 08:33 AM |
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quote:
Originally posted by snot
Thanks people.Interesting about the AWD dax being a handful- I would have thought the AWD would be less of a handful than a rear wheel 200hp+
You are quite right, it depends on the power level applied, and the dax had (if we are talking about their old demo car which got crashed a lot!)
around 400hp!
A 200hp 4wd seven will be VERY stable indeed
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