[GunMetalGrey]

Originally Posted by Msquared

I think the question remains: how do you know the car's geometry needs "corrections" just because you lower it slightly? And if so, what will you correct, and how will you know what to correct? Don't forget, if you increase the effective spindle height (which is what the "roll center correction" shims achieve), then that has other implications for geometry, such as where the RC moves and how quickly as the suspension compresses and rebounds. The existence of these parts implies that "RC correction" is needed, but has anybody really quantified that? Again, I don't think Chevy does anything to correct it for the different ride heights of the various Camaro models.

Good question, I have no idea, But if I had to guess I would think that changing one thing would generally mean changing something else to keep everything in balance. But I can’t prove that at all.

Yes there’s definitely trust that SPL knows what they are doing but I don’t think it’s a far-fetched assumption either.

They also said that their tension rods would give me the ability to increase caster, independently of camber, to somewhere between 8.5 And 9.5 which is what they claim a lot of guys tracking the Camaro are at. Apparently without this product the caster is tied to the camber which is why I am now at 7.6 up from my original 6.9 because I’ve increased the camber to -2.5

[GunMetalGrey]

Originally Posted by kropscamaro16

spl parts just announced they will be doing a black friday sale 20% off if anybody wants to grab some!

Excellent, Where did you see this? And what dates of the sale for? I don’t see it on their website

Is there a code or something?

[kropscamaro16]

i saw it on facebook they said keep posted for more details

[TrackClub]

Originally Posted by GunMetalGrey

Good question, I have no idea, But if I had to guess I would think that changing one thing would generally mean changing something else to keep everything in balance. But I can’t prove that at all.

Yes there’s definitely trust that SPL knows what they are doing but I don’t think it’s a far-fetched assumption either.

Either way I’m willing to take the risk.

That would presume that they sell different control arms depending on how much the car is lowered. Id check with them this is indeed the case, lest you could go too far the other way and create a completely new mess geometry wise.

[GunMetalGrey]

Originally Posted by TrackClub

That would presume that they sell different control arms depending on how much the car is lowered. Id check with them this is indeed the case, lest you could go too far the other way and create a completely new mess geometry wise.

The arms are apparently adjustable depending on how much the car has been lowered.
He said he would send me and/or my alignment shop the specs on how much adjustment was needed.

[TrackClub]

Originally Posted by GunMetalGrey

The arms are apparently adjustable depending on how much the car has been lowered.
He said he would send me and/or my alignment shop the specs on how much adjustment was needed.

I suspected as much.

[Msquared]

Originally Posted by GunMetalGrey

Good question, I have no idea, But if I had to guess I would think that changing one thing would generally mean changing something else to keep everything in balance. But I can’t prove that at all.

OH, there's no question changing some things affects others. Ride height and RC are inextricably linked to one another, for example. That's not what I'm questioning. What I question is whether or not the RC needs to be corrected after a Camaro is lowered. I'm not aware of such a need, and Chevy obviously doesn't see one. That doesn't mean it wouldn't be a good idea. I'm just saying that we don't know.

They also said that their tension rods would give me the ability to increase caster, independently of camber, to somewhere between 8.5 And 9.5 which is what they claim a lot of guys tracking the Camaro are at. Apparently without this product the caster is tied to the camber which is why I am now at 7.6 up from my original 6.9 because I’ve increased the camber to -2.5

Well, let's unpack this a bit. Caster isn't adjustable on a stock Camaro at all. At least some camber plates allow caster adjustability, like the Vorshlag units. But the two are independently adjustable. One can limit the other: for example at max camber on the plates you probably have to give up some caster, and vice versa. But within those limits you can absolutely set whatever caster and camber you want, independent from one another. I don't know what caster range the Vorshlag plates give you with no other mods: you might be able to get the 8.5-9.5 you want just from those.

Using the stock adjustment, I don't see how setting camber using the factory adjustment could change caster. That doesn't really make sense. On my 1LE, going from the as-delivered -1.4/-0.9 (left/right) camber to -2.7 on both sides using the stock camber adjustment didn't change my caster one single bit. It read 7.6 and 7.3 before and after the camber change. That's what we'd expect.

Also, it's not clear that normal alignment machines can accurately read caster or steering axis inclination because there is no single pivot point defined by a single lower ball joint. Instead, there are two ball joints (one for each link) and a virtual pivot point defined by their instant center. But the problem is that as the steering is turned, that virtual pivot point moves...a lot. We could define static caster using the virtual pivot point. However, an alignment machine infers caster from the change in camber as the steering is cycled through its range, and that would not be accurate for our cars because that pivot point is moving.

This all boils down to: I'd be interested to know the basis for measuring the caster that track drivers are using. I'd also be interested to know why more is better. Typically, the benefit of extreme caster only matter with extreme steering angles, such as autocross use. More than 7.5 or so is starting to get into the extreme range. So what benefit does 8.5-9.5 give on a road course?

[GunMetalGrey]

Originally Posted by Msquared

OH, there's no question changing some things affects others. Ride height and RC are inextricably linked to one another, for example. That's not what I'm questioning. What I question is whether or not the RC needs to be corrected after a Camaro is lowered. I'm not aware of such a need, and Chevy obviously doesn't see one. That doesn't mean it wouldn't be a good idea. I'm just saying that we don't know.

We agree on most of that, but I don't understand why you are saying Chevy does not see the need to adjust anything due to ride height.

Originally Posted by Msquared

Well, let's unpack this a bit. Caster isn't adjustable on a stock Camaro at all. At least some camber plates allow caster adjustability, like the Vorshlag units. But the two are independently adjustable. One can limit the other: for example at max camber on the plates you probably have to give up some caster, and vice versa. But within those limits you can absolutely set whatever caster and camber you want, independent from one another. I don't know what caster range the Vorshlag plates give you with no other mods: you might be able to get the 8.5-9.5 you want just from those.

Using the stock adjustment, I don't see how setting camber using the factory adjustment could change caster. That doesn't really make sense. On my 1LE, going from the as-delivered -1.4/-0.9 (left/right) camber to -2.7 on both sides using the stock camber adjustment didn't change my caster one single bit. It read 7.6 and 7.3 before and after the camber change. That's what we'd expect.

Also, it's not clear that normal alignment machines can accurately read caster or steering axis inclination because there is no single pivot point defined by a single lower ball joint. Instead, there are two ball joints (one for each link) and a virtual pivot point defined by their instant center. But the problem is that as the steering is turned, that virtual pivot point moves...a lot. We could define static caster using the virtual pivot point. However, an alignment machine infers caster from the change in camber as the steering is cycled through its range, and that would not be accurate for our cars because that pivot point is moving.

This all boils down to: I'd be interested to know the basis for measuring the caster that track drivers are using. I'd also be interested to know why more is better. Typically, the benefit of extreme caster only matter with extreme steering angles, such as autocross use. More than 7.5 or so is starting to get into the extreme range. So what benefit does 8.5-9.5 give on a road course?

Interesting, I'd like to know as well.
I'm quoting what the guy from SPL said, so I can't comment on whether or not he is right. My track has 19 turns in a 1 minute and 20 second lap so it is corner heavy and technical.

This could all be a waste of money but only one thing is for sure, he definitely wants mine!

[TrackClub]

Originally Posted by GunMetalGrey

We agree on most of that, but I don't understand why you are saying Chevy does not see the need to adjust anything due to ride height.



Interesting, I'd like to know as well.
I'm quoting what the guy from SPL said, so I can't comment on whether or not he is right. My track has 19 turns in a 1 minute and 20 second lap so it is corner heavy and technical.

This could all be a waste of money but only one thing is for sure, he definitely wants mine!

Please re read my post #30. "Some guy" telling you that "some track guys" run high caster without understanding just how fast they are in the first place and what other mods they may have in a second place is just plain noise best not to pay attention to.

PS GM sells a lowering kit for a non 1LE SS without any specs re changing caster.

PSS By design, the more caster the less responsive steering, the less responsive car = the more understeer.
No race cars run such high caster, unless they are mid/rear engine cars. To the contrary, they usually run less than our stock caster to make them as responsive as possible.

[GunMetalGrey]

Originally Posted by TrackClub

PS GM sells a lowering kit for a non 1LE SS without any specs re changing caster.

PSS By design, the more caster the less responsive steering, the less responsive car = the more understeer.
No race cars run such high caster, unless they are mid/rear engine cars. To the contrary, they usually run less than our stock caster to make them as responsive as possible.

Ah yes, good point!

And good to know! Thanks

They also offer a rear Toe lockout kit that apparently stops the alignment from getting out of whack and causing premature tire wear

[kropscamaro16]

Originally Posted by GunMetalGrey

Ah yes, good point!

And good to know! Thanks

They also offer a rear Toe lockout kit that apparently stops the alignment from getting out of whack and causing premature tire wear

thats the only spl part i have so far but will be getting more in future!

[Msquared]

Originally Posted by GunMetalGrey

We agree on most of that, but I don't understand why you are saying Chevy does not see the need to adjust anything due to ride height.

On this I was referring specifically to the spindle height and roll center. Chevy makes a range of ride heights on various trim levels of Camaros, and to my knowledge they don't do anything to correct the changes in RC that occur with the varying ride heights.

[GunMetalGrey]

Originally Posted by Msquared

On this I was referring specifically to the spindle height and roll center. Chevy makes a range of ride heights on various trim levels of Camaros, and to my knowledge they don't do anything to correct the changes in RC that occur with the varying ride heights.

Gotchya.

I also forgot they offered lowering kits from factory without roll centre correction.

[GunMetalGrey]

Originally Posted by kropscamaro16

thats the only spl part i have so far but will be getting more in future!

I will be getting the front lower control arms so that I can increase camber. That’s the only part I’m getting for sure