Doug68
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| posted on 17/1/12 at 07:41 AM |
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The flipping of gearboxes is common in mid-engine land, particularly for GT40’s and the like, commonly done with Porsche units such as the G50 as they
are the strongest ‘reasonably’ priced units available. So I would be surprised if the Subaru unit would not work acceptably in this config. Of
course an adapter plate will be required, which’ll stuff up the use of the standard flywheel I expect.
Refer to www.gt40s.com and search in the transmission section for help on the above.
Doug. 1TG
Sports Car Builders WA
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chimney sweeper
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| posted on 17/1/12 at 07:48 AM |
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Only the drive train is fliped not the engine.
Some one told me that honda engines spin the oposite way to other engines? if that is true I would not have to flip diffs and boxes with eather drive
train would I.
If it isn't broken fix it till it is
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owelly
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| posted on 17/1/12 at 07:51 AM |
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No, but you'd be having 5 reverse gears......
http://www.ppcmag.co.uk
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chimney sweeper
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| posted on 17/1/12 at 08:32 AM |
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Looking at it B,D and H Honda motors spin the other way so no diff flipping needed with the above mid or rear engine set ups, May make things easyer
If it isn't broken fix it till it is
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TheGecko
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| posted on 17/1/12 at 10:57 AM |
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quote:
Originally posted by chimney sweeper
Looking at it B,D and H Honda motors spin the other way so no diff flipping needed with the above mid or rear engine set ups, May make things easyer
You might want to read up on axial thrust in helical gear sets before you think too much about running a whole gearbox/drive train backwards.
It would destroy itself eventually because all of the thrust didirections are reversed.
D
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coyoteboy
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| posted on 17/1/12 at 02:50 PM |
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Yup, running it in reverse will trash it in a matter of miles.
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chimney sweeper
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| posted on 17/1/12 at 03:11 PM |
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I kn ow alot of the 4x4 of road racer guys do it with out a problem but I have wondered about it.
Have also seen an MGB with honda engine and fliped rear axle that had done over 30,000miles without problem. I am sure I could find plenty of people
who have had a problem as well, this is the reason I am posting on here.
If it isn't broken fix it till it is
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daviep
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| posted on 17/1/12 at 03:36 PM |
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quote:
Originally posted by chimney sweeper
I kn ow alot of the 4x4 of road racer guys do it with out a problem but I have wondered about it.
Have also seen an MGB with honda engine and fliped rear axle that had done over 30,000miles without problem. I am sure I could find plenty of people
who have had a problem as well, this is the reason I am posting on here.
When you flip an axle or diff they are still turning the input shaft the correct way but because the pinion is on the opposite side of the crown wheel
only the output direction is reversed so the whole assembly is still working as designed.
Reversing the input shaft direction of a gearbox means all the gears and bearings are running the opposite direction to how they were designed.
Davie
“A truly great library contains something in it to offend everyone.”
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chimney sweeper
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| posted on 17/1/12 at 06:34 PM |
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Very true never thought of that, rules out the Honda engine then
If it isn't broken fix it till it is
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Ninehigh
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| posted on 17/1/12 at 06:55 PM |
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Couldn't the gearbox be slightly modifed to reverse the direction at the point where the engine enters the box?
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coyoteboy
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| posted on 17/1/12 at 07:00 PM |
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I suppose you could interface a simple 1:1 reversal box right off the crank to get it back to gearbox input direction, but you're adding
complexity, weight and failure modes left right and centre.
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Ninehigh
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| posted on 17/1/12 at 08:58 PM |
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I'm thinking that on the input shaft, thus no need to add anything more than one shaft, the 1:1 gears and the fittings to hold said shaft down
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JC
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| posted on 17/1/12 at 09:51 PM |
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How about a FWD engine, gearbox and driveshafts, turned through 90 degrees so the driveshafts run fore/aft, connected to 2 more diffs for the front
and rear axles? Ratios might be a problem...?
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chimney sweeper
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| posted on 17/1/12 at 09:59 PM |
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Ruled that idea out due to your last coment, I want to use this car alot not top out at 6000rpm at 55mph
[Edited on 17/1/12 by chimney sweeper]
If it isn't broken fix it till it is
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coyoteboy
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| posted on 18/1/12 at 02:05 AM |
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quote:
I'm thinking that on the input shaft, thus no need to add anything more than one shaft, the 1:1 gears and the fittings to hold said shaft
down
Yup, that's what I was thinking but that still means a secondary gearbox, new (offset) bell housing, possibly clutch and fly arrangement.....
[Edited on 18/1/12 by coyoteboy]
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TQ_uk
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| posted on 19/1/12 at 01:26 PM |
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In your 'thinking/driving' post you mention now losing the rear seats and going midengine.
In which case I think I'd go back to the Scooby scenario, & going 2WD, i.e losing the original rear prop output and using the transaxle to
drive the rear wheels (if you follow)
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chimney sweeper
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| posted on 19/1/12 at 03:44 PM |
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2WD is an option but think it would be easyer to go with Audi engine and box as I think an Audi 2WD box would be easyer to find so would not have to
spend time and money modding a Subaru box, I aim to build it for as little money as posible but be a good looking semi daily driver.
I could hunt down a passat vr6 like the cheep one that I just missed on EBay for engine and box, then I just need to think about front and rear
uprights, I have an old BMW 728i on the drive that no one wants to buy so I could use the uprights of that if not going 4WD and I have some BMW PCD
wheels tht i want to use as well.
If it isn't broken fix it till it is
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violentblue
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| posted on 19/1/12 at 03:45 PM |
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http://www.members.iinet.net.au/~ttriebler/
you can get reverse cut ring gears for the subaru box, simplifys everything.
I'm planning on doing an all wheel drive beetle eventually.
a few pics of my other projects
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chimney sweeper
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| posted on 19/1/12 at 06:39 PM |
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Will have to find the price of reverse gears for the subaru box, will more than likely be over budget especially with shipping as this is a budget
project like all my past projects
If it isn't broken fix it till it is
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coyoteboy
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| posted on 20/1/12 at 01:32 AM |
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Just don't under-estimate the cost of screwing around with the rest of it though, or the cost of not having what you want. I like to make
everything, but sometimes you can't beat paying a bit and not having to mess about endlessly.
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chimney sweeper
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| posted on 20/1/12 at 07:40 AM |
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I know what you mean mate I like to do everything myself but have had to pay someone to do some welding on my race car because in the run up to xmas I
have no time and did not want the project to stall, also want it finished by the first race in April.
You do have to weigh up cost and time
If it isn't broken fix it till it is
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JoelP
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| posted on 20/1/12 at 10:44 PM |
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I doubt you need to pay $1500 for that reverse ring gear. Look on HPC gears website, maybe call their technical line, im sure if you can send in the
original then they can make a mirror image (assuming thats all it is).
Beware! Bourettes is binfectious.
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coyoteboy
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| posted on 21/1/12 at 01:57 AM |
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We've been looking at a small project involving an off-the-shelf worm and gear system for low torque use (around 12Nm) and the cheapest quote we
have so far is £100 delivered, for a couple of bits no more than 3" diameter.
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