A question on KPIs.
Do HR,HK,HT,HG,HQ,HJ,HX,HZ,WB LC,LJ all have a KPI of 7 degrees?
Do LH and LX have a KPI of 9 degrees?
Do any of the KPIs vary from drum to disc stub axles in the same models?
No guessing please.This could make a valuable sticky in its own right if somebody has definitive answers.
KPI variations in ball joint Holdens.
Started by
wot179
, Dec 31 2011 10:42 AM
62 replies to this topic
#1
wot179
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Posted 31 December 2011 - 10:42 AM
#2
TerrA LX
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Posted 31 December 2011 - 10:53 AM
1973. what do I win?
#4
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Posted 31 December 2011 - 02:04 PM
1973. what do I win?
thats it,
mike missed this in his extensive reasearch.
bathurst balls joints,
me thinks the 2 researchers, smoked to much joints.
hey craig,
i had no idea about this,so it will be interesting to see where this goes.
Edited by 73BATHXU1HTBATH350, 31 December 2011 - 02:05 PM.
#5
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Posted 31 December 2011 - 02:21 PM
Lol. Bathurst ball joints 
I would think an old wheel alignment spec book would supply this info.
The two and four wheel aligners I was fixing in the late 80's - late 90's all measured king pin inclination - a useful reference to determine mechanical integrity of the vehicle.
Maybe someone like Chopper has some old reference books??
I would think an old wheel alignment spec book would supply this info.
The two and four wheel aligners I was fixing in the late 80's - late 90's all measured king pin inclination - a useful reference to determine mechanical integrity of the vehicle.
Maybe someone like Chopper has some old reference books??
Edited by CraigA, 31 December 2011 - 02:23 PM.
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#7
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Posted 31 December 2011 - 03:36 PM
Do the cars when complete and original actually have a different KPI?
Or is it just the actual geometry of the different front ends means the stubs are slightly different (as we know they are) to achieve the approx same KPI between them? So putting HK-WB stubs on al LH-UC changes the car's KPI but when the stubs are on their original cars the KPI is always around 7deg 30min?
Or is it just the actual geometry of the different front ends means the stubs are slightly different (as we know they are) to achieve the approx same KPI between them? So putting HK-WB stubs on al LH-UC changes the car's KPI but when the stubs are on their original cars the KPI is always around 7deg 30min?
#8
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Posted 31 December 2011 - 04:57 PM
To my knowledge... vague as it is
LH-X-UC all had the 9"
Not 100% sure on the LC-j ... but heard rumour they are the same stub
And just to confuse things.. .Rodtech actually state the Big HOldens to have a 7.5 deg not 7 deg stub
Which seems you can buy undrilled to mount your own brakes
LH-X-UC all had the 9"
Not 100% sure on the LC-j ... but heard rumour they are the same stub
And just to confuse things.. .Rodtech actually state the Big HOldens to have a 7.5 deg not 7 deg stub
Which seems you can buy undrilled to mount your own brakes
#9
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Posted 31 December 2011 - 05:37 PM
LC/LJ steering axis inclination (with factory specified camber settings) should be within the limits of 7deg 42' to 8deg 42'.
#11
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Posted 31 December 2011 - 05:44 PM
To my knowledge... vague as it is
LH-X-UC all had the 9"
Not 100% sure on the LC-j ... but heard rumour they are the same stub
And just to confuse things.. .Rodtech actually state the Big HOldens to have a 7.5 deg not 7 deg stub
Which seems you can buy undrilled to mount your own brakes
Hey Datto
LC/LJ stub axles carried over to LH Torana and HG stub axles carried over to HQ.
#12
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Posted 31 December 2011 - 06:55 PM
Maybe someone like Chopper has some old reference books??
Yes I do and the important one is in front of me now. I see confusion has already crept into this discussion and I will now clear that up. The original question is about the KPI ( King Pin Inclination ) of certain vehicles.
Do all HR-WB and LC/LJ have a KPI of 7 degrees? NO!
Do all LH/LX have a KPI of 9 degrees? NO!
Does an HQ have the same KPI as a WB? NO!
Here is the detailed explanation.
STEERING AXIS INCLINATION
Steering Axis Inclination (SAI) is also known as King Pin Inclination (KPI). When viewed from the front of the vehicle, SAI is the angle between true vertical and a line drawn through the centreline of the ball joints ( or king pin ) WHEN MEASURED AT THE FACTORY SPECIFIED CAMBER ANGLE. So if you alter the camber angle, you alter the SAI. So what you really need to know is the Included Angle. The Included Angle is SAI + the measured camber angle. The Included Angle is therefore the angle between the stub and the line drawn through the centreline of the ball joints ( or king pin ).
In short, all HR-WB stub axles have the same included angle. All LC-UC stub axles have the same included angle.
The included angle was something I very rarely checked in my 50 - 70 thousand alignments I've done over 30 years. it was only checked if something was suspected of being damaged ( ie: panel shop cars ). it is generally accepted that the Torana stub axles have an included angle of 9 degrees. I have seen included angle figures of either 7 degrees or 7.5 degrees for HR-WB stub axles. I can't recall the last time I checked the Included angle on a shimmed Holden, nor do I remember what the figure was. All I remember is that they are normally within 0.2 degrees of each other. As most machines were set to display camber and castor to 0.1 degrees, the difference in most cases was probably a rounding error.
#13
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Posted 31 December 2011 - 11:53 PM
I decided to check through my many reference books earlier. Most of the reference books have copied the info from the book that I view as the most reliable source of info. Some of them have made errors in copying info, others seem to have copied it quite well. The main problem is that my most reliable book not only has what appears to be mis-leading info, it also has errors. So after sorting through the lot, I am reasonably confident that the factory spec of the included angle for Torana stub axles is 8.7 degrees. I'll be chasing down another reference book or two to see what I can find out about the included angle spec for HQ stubs.
NB: Just because some companies are making stub axles for Holdens with different included angles, doesn't mean they are making them to the GM-H spec.
NB: Just because some companies are making stub axles for Holdens with different included angles, doesn't mean they are making them to the GM-H spec.
#14
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Posted 01 January 2012 - 08:24 PM
But isn't KPI built into the angle between the stub and the ball joint tapered pin centres and/or king pin (KP) centre to the stub?
Therefore, the KPI wont alter with alignment? I know what your talking about Chopper, but KPI can't be altered from what I know?
And that was the OP's Q?
Therefore, the KPI wont alter with alignment? I know what your talking about Chopper, but KPI can't be altered from what I know?
And that was the OP's Q?
Edited by rodomo, 01 January 2012 - 08:25 PM.
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Posted 01 January 2012 - 10:12 PM
But isn't KPI built into the angle between the stub and the ball joint tapered pin centres and/or king pin (KP) centre to the stub?
Therefore, the KPI wont alter with alignment? I know what your talking about Chopper, but KPI can't be altered from what I know?
And that was the OP's Q?
G/day Rob
I agree, each stub axle is made with a set angle so therefore changing the camber angle will change the SAI.
Extract from the LC Torana Workshop Manual.
Since camber is the angle of the wheel in relation to the vertical plane and steering axis is the angle of the turning axis in relation to the vertical plane, it can readily be seen that camber cannot be changed without changing steering axis inclination. If, with the camber correctly adjusted, the steering axis inclination does not fall within the specified limits 7deg 42' to 8deg 42', the knuckle is bent and should be replaced. If a new knuckle is installed, caster, camber and toe-in must be readjusted.
Edited by S pack, 01 January 2012 - 10:13 PM.
#16
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Posted 01 January 2012 - 11:30 PM
But isn't KPI built into the angle between the stub and the ball joint tapered pin centres and/or king pin (KP) centre to the stub?
Therefore, the KPI wont alter with alignment? I know what your talking about Chopper, but KPI can't be altered from what I know?
And that was the OP's Q?
I believe this was the original intention of the question
Regardless of wheel alignments
He's asking about the angle of the stub... assume its bare and sitting on the bench
#17
wot179
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Posted 02 January 2012 - 08:18 AM
OK. Rodomo and Datto have the intention of my question correct.
BY KPI,I meant the angle of of the stub axle.
The angle created by drawing a line through the horizontal centerline of the stub and another line through the centerline of the balljoints,as viewed from the front.
If I have incorrectly named this the "KPI" instead of "included angle" I am happy to be corrected.
The question remains the same,
Are my questions correct?
I forgot to include UC in my original question,I assume they are the same as LH and LX.
BY KPI,I meant the angle of of the stub axle.
The angle created by drawing a line through the horizontal centerline of the stub and another line through the centerline of the balljoints,as viewed from the front.
If I have incorrectly named this the "KPI" instead of "included angle" I am happy to be corrected.
The question remains the same,
Are my questions correct?
I forgot to include UC in my original question,I assume they are the same as LH and LX.
Edited by wot179, 02 January 2012 - 08:21 AM.
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Posted 02 January 2012 - 11:06 AM
So,its definitely the included angle I am lookin for.
Are the numbers right?
Are the numbers right?
#20
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Posted 02 January 2012 - 11:51 AM
As I explained in a detailed manner, KPI (SAI) is the SUM of the vehicles camber and the angle between true vertical and a line drawn through the centreline of the ball joints.
The angle between the vehicles stub and a line drawn through the centreline of the ball joints is the included angle. Which on a Torana stub axle is likely to be 8.7 degrees.
The KPI (SAI) of 7deg 42' will be correct at a camber of +1.0
The KPI (SAI) of 8deg 42' will be correct at a camber of zero.
The angle between the vehicles stub and a line drawn through the centreline of the ball joints is the included angle. Which on a Torana stub axle is likely to be 8.7 degrees.
The KPI (SAI) of 7deg 42' will be correct at a camber of +1.0
The KPI (SAI) of 8deg 42' will be correct at a camber of zero.
Most people get this wrong.If I have incorrectly named this the "KPI" instead of "included angle" I am happy to be corrected.
#21
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Posted 02 January 2012 - 12:23 PM
Is that on all Toranas Chop?
#22
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Posted 02 January 2012 - 12:26 PM
LC-UC stubs are the same. HB may be different.
#23
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Posted 02 January 2012 - 12:28 PM
Thank you chop.
Can anyone give a definitive answer regarding other balljoint Holdens?
Can anyone give a definitive answer regarding other balljoint Holdens?
#24
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Posted 02 January 2012 - 12:38 PM
I will be starting to look into that on the weekend. Finding the data could take some time.
PS. That should've been all LC-UC except L34 and A9X.
PS. That should've been all LC-UC except L34 and A9X.
#25
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Posted 02 January 2012 - 01:30 PM
Thank you chop.
Can anyone give a definitive answer regarding other balljoint Holdens?
Ok, this is from the LC Torana and HQ GMH workshop manuals.
LC Torana (6cyl) and therefore LJ Torana (6cyl) LH & LX + UC? bare disc and drum stubs. SAI (KPI) = 9deg 0' +/- 0deg 10'
HQ Holden and therefore HJ and HX + HZ? bare disc and drum stubs. SAI (KPI) = 7deg 30' +/- 0deg 10'
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