carlknight1982
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| posted on 1/4/08 at 03:36 PM |
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IRS conversion
live axle to IRS
well ive decided to go for IRS and ive got chris's book im just wondering cause my chassis is narrower than the haynes roadster, do i need to
shorten my driveshafts or can i get away with it?
also i have to rebuild the back end of my chassis from seat back, back so that i can mount the diff etc, any advice?
cheers guys
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Mr Whippy
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| posted on 1/4/08 at 03:40 PM |
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personally I'd rather widen a plastic wing than shorten a driveshaft 
not wanting to use Chris's rear wishbone sizes? Just build the back as per the book and weld it on to your chassis.
[Edited on 1/4/08 by Mr Whippy]
Fame is when your old car is plastered all over the internet
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Mole
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| posted on 1/4/08 at 04:03 PM |
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I believe the roadster needs shortened driveshafts any way.
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MikeR
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| posted on 1/4/08 at 04:14 PM |
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i think that was a mistake that made it into print.
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carlknight1982
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| posted on 1/4/08 at 04:41 PM |
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i do have a set of cateram wide arches, so i think with chris's wishbones i should be ok.
thanks guys,
now just got to remanufacture the back end
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alistairolsen
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| posted on 1/4/08 at 05:02 PM |
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anyone know what the track difference is between the locost and the roadster?
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Mole
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| posted on 1/4/08 at 05:06 PM |
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quote:
Originally posted by MikeR
i think that was a mistake that made it into print.
As I recall the book makes no mention of shortened driveshafts but I remember reading on the forum that it does (or the bones need to be two inches
longer). The roadsters is two inches wider than a locost. Flakmonkey hosts Rorty's plans for IRS on his site. That may be worth a look.
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Mole
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| posted on 1/4/08 at 05:10 PM |
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Yeah definately needs shortened driveshafts. http://www.haynes.co.uk/forums/showthread.php?t=20 from the man himself.
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chrisg
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| posted on 1/4/08 at 06:26 PM |
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Ah yes, about that.
This should explain it better.
Roadster wishbones
The modified wishbone drawings are on there too.
All the little, erm, adjustments to the book are here
I'm only human although I am stunningly attractive 
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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mookaloid
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| posted on 1/4/08 at 07:25 PM |
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If I understand correctly you already have a live axle installed?
If so I would stick with it Before I sold my Indy I was giving very serious consideration to converting to either de dion or a live axle.
At the risk of being chased off the forum - I believe the live axle is better - it is well known that the live axle can be quicker from a standing
start as it puts the traction down better and is better out of corners. also the camber change is less than with independant and hence handling can be
more predictable.
Just my 2p worth.....
Cheers
mark
"That thing you're thinking - it wont be that."
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Myke 2463
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| posted on 1/4/08 at 07:56 PM |
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Ready Built Rear End
Check out casava custom conversions on his e bay shop, ex Luego man and well respected.
Good Luck Mike 
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chrisg
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| posted on 1/4/08 at 08:27 PM |
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quote:
Originally posted by mookaloid
If I understand correctly you already have a live axle installed?
If so I would stick with it Before I sold my Indy I was giving very serious consideration to converting to either de dion or a live axle.
At the risk of being chased off the forum - I believe the live axle is better - it is well known that the live axle can be quicker from a standing
start as it puts the traction down better and is better out of corners. also the camber change is less than with independant and hence handling can be
more predictable.
Just my 2p worth.....
Cheers
mark
I'd agree, up to a point.
A good reference for this would be Herb Adams' "Chassis Engineering" in which he says
"Major disadvantage of an indeoendent rear suspension is its ability to deliver power to the ground. The basic geometry of an IRS is such that
only small amounts of anti squat can be used, so high powered cars without a rear weight bias will have problems getting optimum performance and
handling"
Now I'd agree with that until the last word.
I believe that the advantage an IRS has in ride and ultimate roadholdng mean that for a road car that won't be doing full power standing
starts, IRS is the superior system.
For a track or race car the superior traction of the live axle may swing things in it's favour, particularly on smooth tarmac surfaces.
The reduction in unsprung weight offered by the dedion might be an advantge.
In the end it's a matterof opinion, after all it's your car and your decision.
Cheers
Chris
Note to all: I really don't know when to leave well alone. I tried to get clever with the mods, then when they gave me a lifeline to see the
error of my ways, I tried to incite more trouble via u2u. So now I'm banned, never to return again. They should have done it years ago!
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lsdweb
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| posted on 1/4/08 at 08:58 PM |
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Casarva
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les g
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| posted on 1/4/08 at 09:09 PM |
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halfshaft lengths
quote:
Originally posted by carlknight1982
live axle to IRS
well ive decided to go for IRS and ive got chris's book im just wondering cause my chassis is narrower than the haynes roadster, do i need to
shorten my driveshafts or can i get away with it?
hi 3ge components make the bones to fit a standard driveshaft web-site listed on haynes forum
any help ???
cheers les g
also i have to rebuild the back end of my chassis from seat back, back so that i can mount the diff etc, any advice?
cheers guys
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MikeR
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| posted on 1/4/08 at 11:34 PM |
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if your thinking of de-dion be careful, see my recent thread. Unless youre careful you can end up with a system with only slight improvements over a
live axle.
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carlknight1982
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| posted on 2/4/08 at 03:49 AM |
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not quiet, I brought an abandoned project, well basically an incomplete chassis, everythings done except for the suspension mounts, but nothing is
installed, i have the sierra running gear but no live axle just the IRS, since its just a case of "adjusting" the wishbones to suit its
not a problem.
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rusty nuts
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| posted on 2/4/08 at 06:58 PM |
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Not sure if I will get to the Baldock meet on sunday but if I do your welcome to take a few measurements of my rear end (excuse the expression) I have
I.R.S on my Luego locost.which has narrowed drive shafts. I believe that the Velocity uses standard length shafts for comparison ?
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carlknight1982
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| posted on 3/4/08 at 12:16 AM |
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that would be really helpful to just see one in the flesh (metal?)
cheers
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britishtrident
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| posted on 3/4/08 at 06:36 AM |
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quote:
Originally posted by carlknight1982
not quiet, I brought an abandoned project, well basically an incomplete chassis, everythings done except for the suspension mounts, but nothing is
installed, i have the sierra running gear but no live axle just the IRS, since its just a case of "adjusting" the wishbones to suit its
not a problem.
If you mean using the Sierra rear trailing arms --- I strongly advise against. a double wishbone IRS is a different matter.
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britishtrident
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| posted on 3/4/08 at 06:46 AM |
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quote:
Originally posted by MikeR
if your thinking of de-dion be careful, see my recent thread. Unless youre careful you can end up with a system with only slight improvements over a
live axle.
Why the fixation with unsprung weight, it isn't the primary advantage of the De Dion (or for that matter IRS).
Its the location of the mass on the live axle thats the big problem. Because of the big lump of mass in the centre of the axle in a single wheel
bump more disturbance is transmitted to the opposite wheel and the body/chassis.
Then of course you have the drive torque effects, that all live axles have that IRS and De Dion are immune from.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 3/4/08 at 07:24 AM |
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quote:
Originally posted by chrisg
quote:
Originally posted by mookaloid
I'd agree, up to a point.
A good reference for this would be Herb Adams' "Chassis Engineering" in which he says
"Major disadvantage of an indeoendent rear suspension is its ability to deliver power to the ground. The basic geometry of an IRS is such that
only small amounts of anti squat can be used, so high powered cars without a rear weight bias will have problems getting optimum performance and
handling"
Now I'd agree with that until the last word.
I believe that the advantage an IRS has in ride and ultimate roadholdng mean that for a road car that won't be doing full power standing
starts, IRS is the superior system.
For a track or race car the superior traction of the live axle may swing things in it's favour, particularly on smooth tarmac surfaces.
The reduction in unsprung weight offered by the dedion might be an advantge.
In the end it's a matterof opinion, after all it's your car and your decision.
Cheers
Chris
Your source of info on live axles is wrong, so wide of the mark that it is not worth attempting to use logic to counter it.
It equivalent to saying having a full set of healthy teeth is a disadvantage because you can't have dentures.
In the US in some classes of Oval racing live axle work very well indeed because the tracks are suited to the live axles and because they have had
more than 70 years development for that very limmited situation, usually these cars are set up using tricks like weight jacking and other
asymmetrical bodges.
Live axles have traction problems because unlike IRS and De Dion the axle has to deal with drive torque couples in 2 axis.
In the UK Clubmans formula cars used a variety of live axles, double wishbone IRS and De Dion. IRS and De dion had little to choose between them and
the live axle B class cars which used very sophisticated axle linkages development by the late Major Authur Mallock were close behind in cornering
power. However remember this is on smooth track surfaces not typical roads.
[Edited on 3/4/08 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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procomp
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| posted on 4/4/08 at 07:16 AM |
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Hi and after all of the years of trying IRS dedion and live axle. The latest Mallock MK35 went with what.
Cheers Matt
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wilkingj
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| posted on 4/4/08 at 02:51 PM |
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quote:
Originally posted by Myke 2463
Check out casava custom conversions on his e bay shop, ex Luego man and well respected.
Good Luck Mike
I'll second that. Matt welded up all the Luego Chassis's. He's now making goodies and suspension parts.
Also The Luego Viento rear wings are fairly wide.
EDIT:
Will try to make Baldock as well with the Viento, but have a 470mile run to do on Sat, so it will depend on how tired I am!
Geoff
[Edited on 4/4/2008 by wilkingj]
1. The point of a journey is not to arrive.
2. Never take life seriously. Nobody gets out alive anyway.
Best Regards
Geoff
http://www.v8viento.co.uk
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rusty nuts
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| posted on 6/4/08 at 09:16 AM |
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I wont be at the Baldock meet today but if you are going to be in Cambridge anytime let me know , you are more than welcome to have a look.
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wilkingj
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| posted on 7/4/08 at 10:43 AM |
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quote:
Originally posted by rusty nuts
I wont be at the Baldock meet today but if you are going to be in Cambridge anytime let me know , you are more than welcome to have a look.
I didnt get there either, Same goes for me if you are in the Cambridge area, I live about 10 miles from Rusty nuts on the other side of town
(Bedford side).
Cheers
1. The point of a journey is not to arrive.
2. Never take life seriously. Nobody gets out alive anyway.
Best Regards
Geoff
http://www.v8viento.co.uk
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