CSG and RCE tag-team suspension Q&A thread! Ask us anything!

[DoomsdayJesus]

Originally Posted by strat61caster

From everything I've read, warped rotors haven't happened since the 60's, uneven pad deposits is likely what's being felt and why turning them down helps.

I also haven't seen anyone but a vendor recommend anything other than OE replacement blank rotors. Centric gets a bunch of love and is cheap available on Amazon.

https://www.amazon.com/Centric-Parts...centric+rotors

Thanks, probably just saved me a lot of money in unnecessary upgrades. Nice to know slotted/crossdrilled rotors are unnecessary.

[peaches]

Hey guys, wanted to get your thoughts on my new setup.

* KSPORT coilovers
* dropped the car 1.25"
* Sparco Asetto Gara 17x7.5 + 225/45/17 Kumho V720
* drive on street, doing HPDE and looking to get into TTD

Looking at this thread I was expecting the rear camber to settle at around -2.2 with that drop, not sure why the big difference between left and right (see below). I measured the coils like 5 times, both sides are the same length. I was told the machine was set to high sensitivity, saw the toe numbers fluctuate from what you see to zero so I'm not too worried about that.

Right now it feels very good on the street and on on\off ramps, can't go back to the track till Sept.

Alignment



How it sits now

[solidONE]

Originally Posted by peaches

Hey guys, wanted to get your thoughts on my new setup.

* KSPORT coilovers
* dropped the car 1.25"
* Sparco Asetto Gara 17x7.5 + 225/45/17 Kumho V720
* drive on street, doing HPDE and looking to get into TTD

Looking at this thread I was expecting the rear camber to settle at around -2.2 with that drop, not sure why the big difference between left and right (see below). I measured the coils like 5 times, both sides are the same length. I was told the machine was set to high sensitivity, saw the toe numbers fluctuate from what you see to zero so I'm not too worried about that.

Right now it feels very good on the street and on on\off ramps, can't go back to the track till Sept.

Alignment

They could not reduce the camber on the RR wheel? The amount of camber you're running is pretty aggressive and should work well on the track. Only way to know for certain if to run it and check the temps across the tread. Until then you'll likely get a lot of camber wear, particularly on the RR tire.

[Tokay444]

I didn't think tires got camber wear anymore with current technology, and people generally mistake toe wear for camber wear.

[peaches]

Originally Posted by solidONE

They could not reduce the camber on the RR wheel? The amount of camber you're running is pretty aggressive and should work well on the track. Only way to know for certain if to run it and check the temps across the tread. Until then you'll likely get a lot of camber wear, particularly on the RR tire.

Don't have LCAs, hence why I dropped it 1.25" expecting it to settle at around -2.2. Again not sure why the difference between left and right.

I'll take temps next time I'm out, should it be too much camber then I'll see about LCAs or raising the car a bit.

Originally Posted by Tokay444

I didn't think tires got camber wear anymore with current technology, and people generally mistake toe wear for camber wear.

A friend who works at KENDA told me on Friday that there is a tire out there that was designed to be run with aggressive camber, producing an optimal contact path under high loads. Not sure if the V720 is it.

[solidONE]

Originally Posted by peaches

Don't have LCAs, hence why I dropped it 1.25" expecting it to settle at around -2.2. Again not sure why the difference between left and right.

I'll take temps next time I'm out, should it be too much camber then I'll see about LCAs or raising the car a bit.



A friend who works at KENDA told me on Friday that there is a tire out there that was designed to be run with aggressive camber, producing an optimal contact path under high loads. Not sure if the V720 is it.

I think it's pretty common to see lop sided camber on this car. Whether you get one that's lop sided or closer to even from the factory is a crap shoot. Mine had as much as .5* difference left to right on both the front and rear corners with more camber on the passenger sides IIRC.

[renfield90]

Originally Posted by Tokay444

I didn't think tires got camber wear anymore with current technology, and people generally mistake toe wear for camber wear.

Not true but it depends how you're using the tire. If your camber is too low for the amount of time the car spends cornering (or too high and you spend too much time driving straight), you absolutely will get camber wear regardless of toe. Just ask any stock class autocrosser.

Toe just tends to speed up the wear - unless it's really excessive, then you get the funny wear patterns.

Originally Posted by peaches

Don't have LCAs, hence why I dropped it 1.25" expecting it to settle at around -2.2. Again not sure why the difference between left and right.

I'll take temps next time I'm out, should it be too much camber then I'll see about LCAs or raising the car a bit.

A friend who works at KENDA told me on Friday that there is a tire out there that was designed to be run with aggressive camber, producing an optimal contact path under high loads. Not sure if the V720 is it.

Dropping it 1.25" is a bit much for not having camber correction in the rear. The TRD springs were 0.75"-1" and rear camber looked to be almost perfect, maybe a touch too high. I wouldn't go past 1" without having correction available.

Depending on your sway bar and tire selection it might work for you, but IMO your rear camber numbers are too high. I haven't heard of tires made for "aggressive" camber. Really there's two schools of thought for tire construction: 1, we build a tire that works best when it's fully square on the road, and the end user is responsible for figuring out the correct camber that achieves that for their particular setup; and 2, we build a tire that cares less about camber so that the extremely camber limited user doesn't have such a sucky life.

In fact some past models have tried so hard to service school of thought number 2 that they come beveled to make up for the lack of camber, so at max body roll the tire carcass is bent over but the tread face is square with the road. But I digress. The school of thought number 1 is that anyone with too much camber didn't get there without the ability to dial it back.

[peaches]

Originally Posted by renfield90

Not true but it depends how you're using the tire. If your camber is too low for the amount of time the car spends cornering (or too high and you spend too much time driving straight), you absolutely will get camber wear regardless of toe. Just ask any stock class autocrosser.

Toe just tends to speed up the wear - unless it's really excessive, then you get the funny wear patterns.


Dropping it 1.25" is a bit much for not having camber correction in the rear. The TRD springs were 0.75"-1" and rear camber looked to be almost perfect, maybe a touch too high. I wouldn't go past 1" without having correction available.

Depending on your sway bar and tire selection it might work for you, but IMO your rear camber numbers are too high. I haven't heard of tires made for "aggressive" camber. Really there's two schools of thought for tire construction: 1, we build a tire that works best when it's fully square on the road, and the end user is responsible for figuring out the correct camber that achieves that for their particular setup; and 2, we build a tire that cares less about camber so that the extremely camber limited user doesn't have such a sucky life.

In fact some past models have tried so hard to service school of thought number 2 that they come beveled to make up for the lack of camber, so at max body roll the tire carcass is bent over but the tread face is square with the road. But I digress. The school of thought number 1 is that anyone with too much camber didn't get there without the ability to dial it back.

Sway bars are stock, sticking with the V720 for now. Eventually I'll get another set of wheels with slicks, Hankook or Hoosier not sure yet.

[ajc209]

I have a question regard corner weight/balancing.

The suspension in question is the Ohlins road and track MI20 kit.

The coilovers are shock length and preload independently adjustable.

When corner weighting i've heard people banding around that you should adjust the shock length rather than spring preload to add weight to a corner(s).

I've done quite few measurements to calculate bump travel.

Here are my corner weights (setup using shock body length adjustment to balance and NOT preload)

Front left: 370kg Front right: 410.5kg
Rear left: 282kg Right Rear: 317kg

Now with fixed spring preload of 2mm on all corners, its easy to see the corners with more weight will have less bump but more droop travel.

I have calculated that bump travel (before bumpstop engagement) based on those weights and is as follows:

Front left: 32mm Front right: 25mm
Rear left: 24mm Right Rear: 15mm

The drivers side has a fairly significant reduction in bump due to driver weight.

So my question is this. Is it not better to add preload on the drivers side to even up bump travel, then adjust shock lengths to balance the cross axis corner weights?

Many thanks for your time

@Racecomp Engineering

[Shankenstein]

Originally Posted by ajc209

I have a question regard corner weight/balancing.
...
Front left: 370kg Front right: 410.5kg
Rear left: 282kg Right Rear: 317kg
...
So my question is this. Is it not better to add preload on the drivers side to even up bump travel, then adjust shock lengths to balance the cross axis corner weights?
Many thanks for your time
@Racecomp Engineering

Based on the method outlined in Autocross to Win (LINK to FarNorthRacing's site), you'd benefit from slightly raising the Front-Left and Right-Rear corners. Considering that you only need to add 3 kg to each wheel, and a healthy human can lose ~3 kg in water weight during a track day... I'd enjoy this as a learning exercise, rather than something that will meaningfully change the car's behavior.

As a side note, it would take a 91 kg weight shift (front-to-rear) to reach a 50/50 weight balance. Others can probably chime in about how much weight they can move using ride height and preload. Based on my calculations, that would require 17 degrees of rake (front-to-rear angle of tilt)... which is probably more than Ohlins designed for.

[ajc209]

Originally Posted by Shankenstein

Based on the method outlined in Autocross to Win (LINK to FarNorthRacing's site), you'd benefit from slightly raising the Front-Left and Right-Rear corners. Considering that you only need to add 3 kg to each wheel, and a healthy human can lose ~3 kg in water weight during a track day... I'd enjoy this as a learning exercise, rather than something that will meaningfully change the car's behavior.

As a side note, it would take a 91 kg weight shift (front-to-rear) to reach a 50/50 weight balance. Others can probably chime in about how much weight they can move using ride height and preload. Based on my calculations, that would require 17 degrees of rake (front-to-rear angle of tilt)... which is probably more than Ohlins designed for.

Thanks for taking the time to reply. Im not trying to get 50:50 weight distribiton.

Also the corner weights I posted above were after I did the corner weight setup to balance cross corner weights BUT I used the shock length ride height adjustment and as a result I have differing bump travel on each corner. What im suggesting is using the preload adjustment (so adding preload and reducing shock length) to add more bump on the driver side which is the heavy side. The actual corner weight numbers should stay the same but bump and droop should be fairly evenly match on each corner.

[Racecomp Engineering]

Originally Posted by ajc209

I have a question regard corner weight/balancing.

The suspension in question is the Ohlins road and track MI20 kit.

The coilovers are shock length and preload independently adjustable.

When corner weighting i've heard people banding around that you should adjust the shock length rather than spring preload to add weight to a corner(s).

I've done quite few measurements to calculate bump travel.

Here are my corner weights (setup using shock body length adjustment to balance and NOT preload)

Front left: 370kg Front right: 410.5kg
Rear left: 282kg Right Rear: 317kg

Now with fixed spring preload of 2mm on all corners, its easy to see the corners with more weight will have less bump but more droop travel.

I have calculated that bump travel (before bumpstop engagement) based on those weights and is as follows:

Front left: 32mm Front right: 25mm
Rear left: 24mm Right Rear: 15mm

The drivers side has a fairly significant reduction in bump due to driver weight.

So my question is this. Is it not better to add preload on the drivers side to even up bump travel, then adjust shock lengths to balance the cross axis corner weights?

Many thanks for your time

@Racecomp Engineering

I'd consider using the perch for a few mm of adjustment via preload. Ohlins unfortunately just don't have a ton of travel.

We generally stick with single height adjustable coilovers with helper springs. Makes this a lot simpler and they generally have a lot more bump and droop travel.

- Andrew

[ajc209]

Originally Posted by Racecomp Engineering

I'd consider using the perch for a few mm of adjustment via preload. Ohlins unfortunately just don't have a ton of travel.

We generally stick with single height adjustable coilovers with helper springs. Makes this a lot simpler and they generally have a lot more bump and droop travel.

- Andrew

Thanks for that Andrew.

Yeah Ohlins have 80mm up front and 60mm rear free travel excluding bumpstops. At the rear they are very limited and the progressive bumpstop is almost engaged at static height. The same is true of the S2000 ohlins. They've obviously done a good job with the damping though as you can hit stuff surpringly hard before it feels like your teeth will come out.

Sent from my SM-G935F using Tapatalk

[Bramick]

Does anyone make a replacement for this OEM part that is separate or part of an aftermarket sway bar setup? (I have a BRZ, but I'm assuming the FRS has the same part.)

Item #8

http://oemtoyotaparts.riverviewtoyot...omponents-scat