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MK bones - book chassis?
Avoneer - 14/12/04 at 07:22 PM

Will normal MK bones fit on a standard book chassis, all be it with the brackets in slightly different places?
Cheers,
Pat...


James - 15/12/04 at 09:42 AM

Snoopy,

I think Pat wants to use Sierra uprights though! So he's gotta use the Indy length ones.

Pat,
I'm pretty sure that other than the bush tubes being further apart the Indy wishbones would be ok for you- you'll just need to move the rear 4 wishbone brackets back a bit!
Just make sure you keep the 25° castor!

HTH,
James


Avoneer - 15/12/04 at 11:53 AM

Cheers James,
No problem moving the back brackets.
So the key is the 25 degree castor angle?
Basically, I've a book chassis, book bones and Sierra uprights.
So...I either need some cortina uprights, which is a bugger as I have just bought some new discs for the Sierra uprights, or some new bones for the Sierra uprights.
Getting new bones allows me to go wide track though.
Just wanting to work out the cheapest options.
Cheers,
Pat...


indykid - 15/12/04 at 12:15 PM

bugger me, 25 degree castor?

you sure about that james?
I thought 5 ish degrees was the norm

tom


ludsonline - 31/12/04 at 08:29 AM

25º Castor seems a bit excessive. I would of thought between 4º and 6º would be ok for a road car.


Northy - 31/12/04 at 01:06 PM

Pat have you looked at Darren's site (GTS), there's all sorts of bones on there.

Did you buy those Cortina uprights from the guy I put you in touch with?

Cheers


britishtrident - 31/12/04 at 02:10 PM

At least 5 degrees castor ---- 25 is silly most I can recall on any car is 11 degrees on the Hillan Limp
Another can of of very old worms

Using too much caster introduces many side-effects in the geometry using too little givse little or no self centring. Cars which have little weight on the front wheels require more caster.
Caster angle you can use on a given suspension is closely related to the King Pin Inclination (KPI) -- as when the steering is turned he combination of the two angles has a major effect on camber angle.

If the Caster angle is greater than the KPI by a few degrees it boosts the negative camber on the outside wheel in turns. This was really noticeable on the imp front suspension which had a KPI of 7 degrees and Castor of 11 degrees.

Here are a few typical caster anglesof older models lifted from one of Fred Phuns excellent books.
73 Volvo 146 1.5
73 Capri 1.75
68 E Type 2
68 XJ6 2.25
72 TR6 2.5
73 MG Midget 3
72 GT6 3.5
72 Spitfire 4
70 914 "Poorsche" 6
73 911 Porsche 6.5
71 MGB 7

[Edited on 31/12/04 by britishtrident]


James - 31/12/04 at 03:28 PM

Balls!

Sorry everyone- typo there!

It's 25mm castor- not degrees. 22mm for Cortina and 25mm for Sierra IIRC.

Sorry!

James leaves the room, red faced...