track and flange to flange

[Dominik]

Posted by mickmate on 02-25-2005 09:01 AM:

Try these

Front rim 7.5" measures 8.5"/2=4.25"-2.75"=1.5"x2=3"
Track is 53.96"-3"=50.96" is my new flange to flange!
Comments....................

__________________
mickmate

Mick,

the 6-pin wheels have another offset, almost 1,5" towards the outside.
they stick about 3/4" more out of the fender than a 5-pin TRIGO or vintage.
give me some days and I provide the flange to flange (without disk) measurement.

keep an eye on that when using original control arm lenghts, but with 5-pin wheels.

Dom

[mickmate]

I'm still fiddling with the rear but it's the same topic. Vintage rear wheels measures 10 9/32" on ouside of rim. They are 9 3/8" on inside of rim. They measure without the adapter at 4 1/16" backspace. That makes an offset of 1.078". I have a bunch of numbers which I'll regurgitate shortly. I'm working off a 56" track which is what every piece of litereature but one says. I think the flange to flange is listed as track on the odd one out at 55 1/8" racing. Still looking for comments and opinions. I will do my maths on the rear hub offsets for these wheels after I quadruple check my numbers you soon will be.

[Dominik]

here are the measurements to get to the flange to flange distance:
25.4mm = 1"

the values stand for:
hub + gap to upright + upright + balljoint mount + control arm + length to chassis CL (no disk!)
the 6-pin wheels stick about 20mm more out in front than the 5-pin (TRIGO), so using the TRIGO one could make the front control arms 20mm longer, AS WELL AS the tie rods of the steering!
(depending on the body to use)

front lower:
8.5mm + 20mm + 53mm + 15mm + 277.25mm + 330mm = 703.75mm x2 = 1407.50mm (55.41")
front upper:
8.5mm + 20mm + 53mm + 55mm + 252.5(?)mm + 311mm = 700mm x2 = 1400mm (55.11")
(we want a little less for the upper to get about 1 deg neg camber, see below)

upright height = 230mm (but add balljoints), KPI 9.8 deg
where is the vertical distance from UCA (upper control arm) to LCA to get a feel for IC (intant center) and RC (roll center)?

I am not sure about the length of the UCA, because I do not have the length of the camber adjusters, so I calculated it using all other values.


rear lower:
8.5mm + 10(?)mm + 101mm + 315mm + 234.15mm = 668.65 x2 = 1337.30 (52.6")
rear upper:
8.5mm + 10(?)mm + 93mm + 290mm + 260.8mm = 662.30 x2 = 1324.60 (52.1")

the uppers add up to about 6mm shorter than the lower, which is 1 deg negativ camber at the wheel, because the upright is about 315mm high.
the 10mm gap hub to upright rear is a guess, because I haven't finished one to orig specs yet.

Dominik

[stevehaygood]

Anyone have the design numbers when using a 1973 Jag sedan wishbone set up on the front??? I need some help.. I have read several books on the topic, but domeopne with the knowho and practical experience willing to part the info would be greatly appreciated.. I have built my basic frame (scratch built with 2x4" rails so the seat will sit down on the body pan for greater leg room. U hgacew builr and welded all of this myself. The fron and reat clips have me stymied. anmy help would be appreciate!

Many thanks!

[Dominik]

hi Steve,

I don't have any design numbers, but there are plenty of british built cars which used XJ6 control arm.

you could contact the british club http://www.clubcobra.co.uk/

or place your wheels mounted to the hubs, with upright and control arms and weld the missing chassis brackets.
get your lower control arm level at ride height (or rather the line through the chassis mount and balljoint center) and angle the upper slightly down.

we can discuss your instant center now (and the corresponding roll center), but if you want to go fancy make upper control arm brakets to be able to slide them up and down to change roll center.

you also want to be able to change camber there and castor.

does that help?

dominik

[stevehaygood]

Dear Dominik,

I tried the website address, but iit was a "Dance Club" website. got anymore sites for me to check out??
Thanks!
Steve

[Dominik]

oups,

now we must find the correct link via the UK chapter in this forum.
there is a UK cobra club, I tried google but to no avail.

dominik

[mickmate]

OK I have the bottom pivot point of my upright tacked in place. I have 55.125" for a track (from Steve Volks (SAAC)numbers) and that just fits nicely inside my 4000 body with 295 tyres. That gives me a 52.815" flange to flange with a 4.0625" wheel backspace. That is pretty close to Dom's rear lower at 52.6"..................

[roadsportusa]

I am working on my front and rear track width plan

I will be using a mustang II front suspension set up from speedway motors
using the Narrowed arms 56.75 in hub to hub, with wilwood vented rotors.
My body front fender center to front center fender is 52 inch. have not built the inner fender walls. will be using 15 in wheels. I need help with back set width size of wheels. wheel width 7.5 .

I will be using a solid 9 inch ford rear end assembly with vented rotors.
Planning on track width of 54 in . I am thinking straight about this?? size of wheels 15X8

I have read that rear track width should be narrower than the front for road racing applications.

[verticalroll]

Could somebody please show a picture of the wheel width design in cad or a drawing so I can visualize what everybody is talking about. I understand each wheel has an offset and that determines where the wheel will be inside the body. If we can see this it helps at least for me LOL!!

thanks
Andy

[strictlypersonl]

Rear (same as original 427): http://www.erareplicas.com/427man/wh...27pd_wheel.pdf

Front (I think that the stock backspacing on an original wheel is 3.25", not the 3.4" shown.)
http://www.erareplicas.com/427man/wh...27pd_wheel.pdf