Stu16v
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| posted on 19/12/06 at 06:50 PM |
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quote:
Originally posted by C10CoryM
Anyone know how much weight IRS saves overall? Obviously the unsprung weight is the primary reason, but wondering how much heavier a solid axle would
be.
Cheers.
An 'average' Sierra based IRS setup is actually heavier than an Escort Mk2 live axle...
Dont just build it.....make it!
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robertst
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| posted on 20/12/06 at 12:45 AM |
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quote:
Originally posted by Stu16v
quote:
Originally posted by C10CoryM
Anyone know how much weight IRS saves overall? Obviously the unsprung weight is the primary reason, but wondering how much heavier a solid axle would
be.
Cheers.
An 'average' Sierra based IRS setup is actually heavier than an Escort Mk2 live axle...
yes but its not unsprung mass just like a live axle is... so theoretically an IRS based car handles much, much better than a live axle one.
the bad thing about IRS is the camber change in bumps and the sheer difficulty in setting it up....
thats why De-Dion is the way to go in my opinion...
Tom
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C10CoryM
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| posted on 20/12/06 at 01:31 AM |
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Are the sierra diff and uprights aluminum or iron?
My viable options are a 7.5" ford axle (very similar to a capri Id guess), or a custom SLA with MX5 miata diff/uprights.
I like the 7.5" in that I am familiar with a 4link setup and won't take a lot of time to deal with, but it is heavy (component, and
unsprung weight). Other choice is to spend countless hours obsessing about the geometry of a SLA setup. I figured the mx5 stuff would weigh in a
little lighter over all, but never actually verified that. Only real goal Ive set on my budget build is a curb weight limit. Everything else is
secondary.
De-dion isn't commonly used here. I would personally opt for IRS or live axle but lets start another topic if its going to end up a can
o' worms  .
Cheers.
"Our watchword evermore shall be: The Maple Leaf Forever!"
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smart51
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| posted on 20/12/06 at 07:57 AM |
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The sierra diff is in an alloy casting but the uprights are in cast iron.
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Stu16v
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| posted on 21/12/06 at 10:26 PM |
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quote:
Originally posted by robertst
yes but its not unsprung mass just like a live axle is... so theoretically an IRS based car handles much, much better than a live axle one.
Thing is, in theory a bumble bee cant fly...
A well set up live axle car will still hold it's own against a well set IRS equivalent.
A badly set up live axle car will pi55 all over a badly set up IRS equivalent!
P.s. my car has dedion!!!  
Dont just build it.....make it!
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cossey
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| posted on 22/12/06 at 08:46 AM |
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on a smooth road a live axle works very well it just when it gets bumpy that the irs really start to show an advantage. there are alot of very capable
live axle racers out there
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G.Man
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| posted on 22/12/06 at 07:23 PM |
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I lost 13kg's this year....
Cheapest performance upgrade I have ever made...
Opinions are like backsides..
Everyone has one, nobody wants to hear it and only other peoples stink!
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atomic
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| posted on 26/12/06 at 08:17 AM |
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Well I don't know about others but here is what I did
Magnesium Alloy Wheels with Toyo R888 tyres
Carbon Fibre Propshaft
Titanium Drive Shafts
7" Sierra Diff rather than 7.5"
Carbon Fibre Seats
Alloy Brake Callipers all round and front dics's with alloy bells
Exedy Hyper Carbon Fibre Clutch,Light Weight Flywheel and Alloy Cover
Braille No-Weight Racing Battery
Electric ceramic Heater.
Titanium exhuast with Carbon Fibre can.
As I'm sure you can tell this has turned out to not be very locost. Would I do it again..short answer is no.
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DIY Si
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| posted on 26/12/06 at 11:54 AM |
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That's the problem, you rapidly get into diminishing returns on stuff like this. Yes, the first 15-20kgs can be saved with different component
choices when building, but most extra stuff starts to cost loads of money! To start with, ally panels and light wheels are easy to sort, and save a
reasonable amount of weight, but using Ti bolts and shafts, CF prop etc, these things do save weight, but not much compared to their cost! Sub 500 kg
is plenty for a road car, otherwise just lose some weight, I know I need to. That's 20 Kg for free, and the lady's will like you more too!
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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