Spindle Angle
- Thread starter MAS
- Start date
MAS
Member
So say I roll the scales at 470 lbs what’s the benefit or negative impact to each?
flattop1
Dawg 89
Just so i understand , the 10* spindle has more camber gain then a 15* degree spindle ?
Along with that more weight jacking ?
XXX#40
2A supporter
Yes on the RS, on the Left opposite
alvin l nunley
Site Supporter
This picture shows a 15° kingpin inclination spindle. If I turn the spindle right or left, 45°, you can see that the tip of the spindle is forced down .377". It's the same on both ends. You can see the arc of the redline. In fact, any jacking affect of kingpin inclination is canceled out as you turn from right to left. Many years ago it was used in automobiles to help vehicle tracking as it traveled down the road as the steering would move to the high point of the arc. I've built karts with no kingpin inclination that handled really well. It is my belief that karts have no need of kingpin inclination. My experience leads me to believe that.
XXX#40
2A supporter
And if you had oval experience you'd see it does matter
alvin l nunley
Site Supporter
Would I now? And what makes you say that? I'd like to hear about your experience with, and without, kingpin inclination! On the same kart, on the same track, with the same engine.
XXX#40
2A supporter
Never have had a kart with zero KPI see no need to, I have changed from 10 to 15 degree RF spindle/L blocks at the track and accomplished what we were looking for which was faster lap times, less tire over working, same kart, same driver same engine, same track
and your picture is wrong, it shows no kpi, nor caster in the spindle, and for the RS the axle will be pointed up not down
alvin l nunley
Site Supporter
Pictures would be nice. I've never seen a front end arrangement where you could change the L block camber angle at the track. One of the disadvantages I see with the Heim joint is when you change the camber angle, you also change the kingpin inclination angle. Sorry if I'm being a little confusing.
alvin l nunley
Site Supporter
I'm sorry if the drawing is confusing. There is 15° of kingpin inclination. Look closely and you'll see it.
alvin l nunley
Site Supporter
Sorry again, there's 12° kingpin inclination, not 15°.
racing promotor
Moderator
Not confusing we can see it, Jamie is pointing out it's pitched down, it should pitch up to be correct for the RS which is where you would use the higher degree.
alvin l nunley
Site Supporter
Sorry "Pitched"? Here's another view.
flattop1
Dawg 89
Roger , I might be starting to understand a little.
Al : the modern lto chassis has had different kpi via the L-blocks for at least 14 years .
The drawing shows the rise and fall of the axle . When you introduce the caster , the amount of movment may not change but the relationship too the ground does
Al : the modern lto chassis has had different kpi via the L-blocks for at least 14 years .
The drawing shows the rise and fall of the axle . When you introduce the caster , the amount of movment may not change but the relationship too the ground does
flattop1
Dawg 89
I would like to see this arc with 12* of caster .
See if what i picture in my mind is correct .
Couple of things to clarify.
When talking about KPI, we are actually considering the angle from perpendicular to the centerline of the spindle. This angle never changes when we adjust static camber.
Although it is easier to show the movement of the end of the spindle, the chassis never actually sees this movement. To see the actual effect, we must consider what the chassis sees, which is movement at the centerline of the contact patch. (not the centerline of the tread)
I think if you accurately depict how we use caster, camber, and KPI in a lto chassis, relative to the tire contact patch on both sides, you will better understand why we use KPI.
Also will have a better understanding of how the chassis works the tires.
The goal of a straight rail, sprint type chassis is completely different.
I feel like we have covered this same ground before.
When talking about KPI, we are actually considering the angle from perpendicular to the centerline of the spindle. This angle never changes when we adjust static camber.
Although it is easier to show the movement of the end of the spindle, the chassis never actually sees this movement. To see the actual effect, we must consider what the chassis sees, which is movement at the centerline of the contact patch. (not the centerline of the tread)
I think if you accurately depict how we use caster, camber, and KPI in a lto chassis, relative to the tire contact patch on both sides, you will better understand why we use KPI.
Also will have a better understanding of how the chassis works the tires.
The goal of a straight rail, sprint type chassis is completely different.
I feel like we have covered this same ground before.
alvin l nunley
Site Supporter
I can easily do that, but I'm wondering, what it is that you're thinking? The arc itself will never change, regardless of how much castor is put into the spindle! If I take the kingpin inclination out, and only use castor, that arc goes away.
Since you are suggesting KPI is not needed, you could also show how to achieve the same things, using zero KPI, as the chassis is designed to have the tires worked by front end settings in this manner.
Or, show us the changes in the rest of the setup to achieve even lower lap times?
Or, maybe, show your zero KPI setup vs a standard KPI/caster setup from the same time period? Maybe see what you were missing by not running KPI?
Or, show us the changes in the rest of the setup to achieve even lower lap times?
Or, maybe, show your zero KPI setup vs a standard KPI/caster setup from the same time period? Maybe see what you were missing by not running KPI?
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