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Chevette or Viva Upright geometry
Paul TigerB6 - 9/9/08 at 01:19 PM

Does anyone have any information as to the geometry / suitability of the above uprights for use on a se7en at all?? Just looking at alternatives to the use of Cortina uprights which i understand arent perfect due to the small kpi / large scrub radius etc which does nothing for self centring ability.

Just interested in the concencus of the LocostBuilder massif so let the debate begin.

britishtrident - 9/9/08 at 01:38 PM

On Viva uprights the discs are tiny unless you get the 10.2" setup off the 1600/1800/2000/2300/Victor FD.

Vauxhalls of this era tended to rely on KPI rather than caster for self-centering.

ISTR there was some other reason why they never became popular.

Paul TigerB6 - 9/9/08 at 01:48 PM

Brakes wont be an issue as i will be using 4-pot calipers / 265mm disks. The uprights i am looking at are Chevette geometry rather than actual chevette ones.

Memphis Twin - 9/9/08 at 01:58 PM

Actually Viva uprights are very good, and are still used by many oval racers, f750 racers, Classic Clubmans etc.

Paul TigerB6 - 9/9/08 at 02:37 PM

quote:
Originally posted by Memphis Twin
Actually Viva uprights are very good, and are still used by many oval racers, f750 racers, Classic Clubmans etc.


Anyone used them on a road based car at all?? Just concerned about self centring ability etc. I'll be fabricating wishbones to suit but keen to know the basic gemetry is suitable before going too much further with this

JimSpencer - 9/9/08 at 02:51 PM

Hi

The early Sylva Strikers used Chevette uprights, mine has them and they seem fine to me - plus not heard of strikers ever being shabby in the handling department.

Re the brakes - what on earth are you stopping to need those

Paul TigerB6 - 9/9/08 at 03:01 PM

quote:
Originally posted by JimSpencer
Hi

The early Sylva Strikers used Chevette uprights, mine has them and they seem fine to me - plus not heard of strikers ever being shabby in the handling department.

Re the brakes - what on earth are you stopping to need those



Sounds like i'll have to go for them then!! Will do all the sums to accurately work out the kpi / scrub radius etc once i have the uprights, and work out wishbones etc from there.

As for the car.... a Tiger B6 with ZX10R bike engine....... probably look to use slicks for sprinting hence the decent brakes (the Cortina solid disk kit from Rally Design looks favourite at the moment although i may look at similar options yet.

JimSpencer - 9/9/08 at 03:14 PM

quote:
Originally posted by Paul TigerB6
...... probably look to use slicks for sprinting hence the decent brakes (the Cortina solid disk kit from Rally Design looks favourite at the moment although i may look at similar options yet.


Ahh - yup can see that then, you can use a lot of initial bite on sprint & hillclimb slicks, so well worthwhile - solid disks sound like a sensible approach too.

Should be seeing you at a track soon then as you'll be playing in the same area as me by the sounds of it - good stuff!

Paul TigerB6 - 9/9/08 at 03:22 PM

quote:
Originally posted by JimSpencer
Ahh - yup can see that then, you can use a lot of initial bite on sprint & hillclimb slicks, so well worthwhile - solid disks sound like a sensible approach too.

Should be seeing you at a track soon then as you'll be playing in the same area as me by the sounds of it - good stuff!


Well i'm not so sure it will be soon i'm afraid Jim. Maybe get the car built for season after next at the rate i'm going. My kit is currently in storage till i move house so i'm doing what i can to prepare for the build. If i can sort the uprights / brakes now, i'll be in a position to design the wishbones and chassis mods ready for when i get a new house with garage.

Having been around Curborough several times in a 400bhp twin ZX12R Tiger Z100WR, i kinda got hooked on the idea of competing there (circuit racing too expensive for me)

zilspeed - 9/9/08 at 04:01 PM

Just so happens that Ye Olde Zylva has Viva front uprights.

Give me a couple of hours and I'll get you some numbers.

(Mine are off the car just now).

Paul TigerB6 - 9/9/08 at 04:07 PM

quote:
Originally posted by zilspeed
Just so happens that Ye Olde Zylva has Viva front uprights.

Give me a couple of hours and I'll get you some numbers.

(Mine are off the car just now).



Fantastic - that would be superb. Would be interested in knowing what castor, kpi etc you are running there. Any information you feel relevant would be great.

t.j. - 9/9/08 at 05:13 PM

I can have a look for the Chevette (opel kadett) ones if you want, send me a U2U and i will have a look in the manual.

t.j. - 11/9/08 at 06:37 PM

Hi,

Here you will find the data from the manual:

Camber:

Unloaded:
Ascona-B and Manta-B: +0`20' till -1`10'
Manta-B/GT:+0`30' till -1`
Kadett-C: +0`15' till -1`15'

Castor:
Ascona-B: +3` till +5`30'
Manta-B: + 3` till 6`
Manta-B/GT: + 3` till 6`
Kadett-C sedan: +2`30' till + 5`
Kadett-C coupe: +2`45' till + 5`15'
Kadett-C caravan: +2` till + 4`30'

Toe-in:
Ascona-B: 0`30' till 0`50'
Manta-B: 0`30' till 0`50'
Manta-B/GT: 0`20' till 0`40'
Kadett-C sedan: 0`40' till 1'
Kadett-C coupe: +0`35' till + 0`55'
Kadett-C caravan: +0`20' till + 0`40'

wheels (4, 5.5 or 6 J) (kadett C only 4J)
ET 37 +- 1 mm

Too bad no KPI

[Edited on 11/9/08 by t.j.]

MikeRJ - 12/9/08 at 11:32 AM

quote:
Originally posted by JimSpencer
Hi

The early Sylva Strikers used Chevette uprights, mine has them


It was the rather short lived Mk3 that used Chevette uprights (with out board suspension) IIRC? The the earlier (and later!) Mk2 used an Escort strut.