TMB
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| posted on 15/8/23 at 07:42 AM |
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Lighten crownwheel, propshaft, CV joints etc.
For some time ago I read about a man who lighten the crownwheel in his differential.
It might not be a lot, but it’s moving mass.
Anyone who experiences crownwheel failure on the ford cosworth diff?
I’ve got a lathe, and was thinking about taking off a 0,75-1pound.
I’ve tested with taking off some weight of the outer stub axle. It’s quite heavy and I didn’t need the abs ring gear.
The CV joints could also be lighten, but only 0,05pound.
I’ve know the bolt on flanges are heavier than the push in shafts.
But could it be made lighter? Hollow shafts?
Anyone done that?
And you ask why?
My calculations says that my seven will be rear heavy…
I’ve have to move the fuel tank to compensate, and it will make problems for my long legs.
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Mr Whippy
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| posted on 15/8/23 at 11:49 AM |
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Hmm. What is going to be your measurement that you have not weakened it? Most manufactures will be working to quite close to the limits just to save
money. It sounds like your going down the route of removing metal that's holding your car together. Unless you are able to model the part and
loads using something like FEA I suspect it will all be guesswork.
Personally I would not be to concerned over losing an amount weight just having a good dump would achieve.
[Edited on 16/8/23 by Mr Whippy]
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nick205
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| posted on 15/8/23 at 01:18 PM |
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Agree with Mr Whippy - don't mess about with what you can't be certain isn't going to affect the safety of the car and just break.
Having your differemtial lock up on you because it's broken (or your drive shafts/CV joints) will cause damage to the vehicle, probably throw you
off the road and quite possibly injure driver/passenger.
Focus on reducing the weight at the front of the vehicle with lighter (not lightened) parts to balance the front/rear weight.
What car are you building?
What engine are you using (can you move the engine further back in the engine bay)?
Will fitting a roll cage help with weight balance (and increase safety)?
[Edited on 15/8/23 by nick205]
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coyoteboy
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| posted on 16/8/23 at 10:24 AM |
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Rotating weight loss of the transmission parts is relatively ineffectual unless you're already at the lightest end of everything. Diff rotational
speeds are lower than other parts and a relatively low diameter. Of course it will have an effect, but it will be immeasurable on your average dyno.
Can you chop a lot out of the average diff - probably. massive cast iron lumps mass produced from castings designed to cover a range of sizes and
loads - I imagine you could cut quite a lot out without negative effects. But it would be nice to simulate it first. Worst case you mash a diff or
lose a shaft and have to repair the ensuing crash I guess.
You could probably get bigger gains by finding lighter wheels and tyres. Or going two piece brake rotors if you don't already have them.
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Dingz
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| posted on 16/8/23 at 01:39 PM |
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If its just weight/lack of, your after look at fitting the rear end from the early 1.3 1.6 Sierra, the shafts are smaller and the rear drums are
8" not 9"
Phoned the local ramblers club today, but the bloke who answered just
went on and on.
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adithorp
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| posted on 16/8/23 at 07:26 PM |
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quote:
Originally posted by Dingz
If its just weight/lack of, your after look at fitting the rear end from the early 1.3 1.6 Sierra, the shafts are smaller and the rear drums are
8" not 9"
Mated to an early Freelander. The Freelander inner joints fit the Sierra shaft splines.
When you say rear heavy, what sort if front/rear split do you expect?
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TMB
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| posted on 17/8/23 at 08:54 PM |
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quote:
Originally posted by adithorp
quote:
Originally posted by Dingz
If its just weight/lack of, your after look at fitting the rear end from the early 1.3 1.6 Sierra, the shafts are smaller and the rear drums are
8" not 9"
Mated to an early Freelander. The Freelander inner joints fit the Sierra shaft splines.
When you say rear heavy, what sort if front/rear split do you expect?
The engine is a Yamaha 5vy, frame is a DAX rush mc round tube.
Does the freelander diff comes with a good lsd?
I’ve got the cossi 4x4 lsd in now.
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adithorp
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| posted on 17/8/23 at 10:34 PM |
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No but you can get a quaife for it.
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coyoteboy
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| posted on 21/8/23 at 10:14 AM |
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Freelander (2?) chewed up and spat out diffs on a weekly basis, IIRC they even admitted to design issues with it and did repairs for free. Are you
thinking Freelander 1?
[Edited on 21/8/2023 by coyoteboy]
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adithorp
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| posted on 21/8/23 at 01:10 PM |
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Yes, Freelander mk1. Their problem wasn't the diff but the viscous coupling (often "cured" by removing the rear prop). It's light
and compact. Down side is only one ratio 3.21:1 and they have quite a lot of 'lash in them from new.
Mk2 did away with the coupling and had drive selected in the diff electronically. Diffs were chocolate, larger and heavier anyway even if you could
make it work.
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