CT5-V Blackwing: Slight Yaw/Rotation under hard throttle

[BWDudeBro]

Coming from a Mustang GT PP2 with light suspension mods. I had ~20 track weekends under my belt with that car. I am decently comfortable with how the limits feel but I too was surprised how much wiggle I get in my 4BW, since I always heard how amazing the alpha platform was.

Mine feels like a noticeable twitch in the rear as a response to any input whatsoever. A little disconcerting, but not totally alarming. I'll keep playing with it and maybe try some PTM experimentation.

Or maybe an alignment is due.

 

[BimmerFan]

Interesting thread. I've noticed the same thing, but thought it was over-application of throttle and lots of torque on cold/wet tires.

I'm still not sure about this PTM stuff and just what it's doing, where and when.

 

[TheShark]

Interesting thread. I've noticed the same thing, but thought it was over-application of throttle and lots of torque on cold/wet tires.

I'm still not sure about this PTM stuff and just what it's doing, where and when.

I agree with @pkincy - it's the e-diff doing it's thing. The rear feels like it is swaying back and forth (well, it is, but just the body) as the tires do not break traction

 

[Throat Yogurt]

Interesting thread. I've noticed the same thing, but thought it was over-application of throttle and lots of torque on cold/wet tires.

I'm still not sure about this PTM stuff and just what it's doing, where and when.

You need to get yourself to Spring Mountain, post haste!

 

[BimmerFan]

You need to get yourself to Spring Mountain, post haste!

I'm waiting for the 2024 schedule! I was hoping for a Winter event, when it's not so hot.

 

[SS_Shooter]

WANTED TO BRING THIS THREAD BACK UP...

After 10,000 miles, my CT5V is experiencing severe rear end wiggle when you jump on the throttle at higher speeds in 3rd and 4th gear.

There have been pretty significant discussions on this issue on the Blackwing Facebook Group and people have tracked it down to a couple of issues:

- Wheel alignment: Evidently the rear wheel alignment can fall out of spec and cause this issue

- Rear Toe Links: The reason the wheel alignment gets out of spec is due to the stock toe links not being strong enough.

In cross-discussions with the ZL1 Camaro guys, the Facebook posters found they were having identical issues with rear-end squirrelyness, and they had replaces their toe links with the SPL versions and it corrected the issue. One of the CT5V guys replaced his toe links and reported the car is much more solid now and the rear end doesn't kick to the side when he goes WOT at speed.

I attached a screenshot of his post which shows the stock toe arms and the SPL toe arm links side-by side.

The part they are recommending is: SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+
Part Number: SPL-RTAEL-CAM6

link to the part is below:

SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+

Check out the deal on SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+ at Evasive Motorsports

www.evasivemotorsports.com

Here's what it says about those toe arms: "The stock eccentric bolts that allow for small toe adjustments tend to slip under high cornering loads, causing changes to the rear alignment. SPL Parts Eccentric Lockout (EL) kit eliminate the stock eccentric bolts to keep your rear alignment where you set it. SPL lockout plates are CNC machined from 6061-T6 Billet Aluminum and supplied with Zinc plated grade 10.9 hardware for absolutely zero-slip."

Please let me know your thoughts.

 

[Champale]

WANTED TO BRING THIS THREAD BACK UP...

After 10,000 miles, my CT5V is experiencing severe rear end wiggle when you jump on the throttle at higher speeds in 3rd and 4th gear.

There have been pretty significant discussions on this issue on the Blackwing Facebook Group and people have tracked it down to a couple of issues:

- Wheel alignment: Evidently the rear wheel alignment can fall out of spec and cause this issue

- Rear Toe Links: The reason the wheel alignment gets out of spec is due to the stock toe links not being strong enough.

In cross-discussions with the ZL1 Camaro guys, the Facebook posters found they were having identical issues with rear-end squirrelyness, and they had replaces their toe links with the SPL versions and it corrected the issue. One of the CT5V guys replaced his toe links and reported the car is much more solid now and the rear end doesn't kick to the side when he goes WOT at speed.

I attached a screenshot of his post which shows the stock toe arms and the SPL toe arm links side-by side.

The part they are recommending is: SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+
Part Number: SPL-RTAEL-CAM6

link to the part is below:

SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+

Check out the deal on SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+ at Evasive Motorsports

www.evasivemotorsports.com

Here's what it says about those toe arms: "The stock eccentric bolts that allow for small toe adjustments tend to slip under high cornering loads, causing changes to the rear alignment. SPL Parts Eccentric Lockout (EL) kit eliminate the stock eccentric bolts to keep your rear alignment where you set it. SPL lockout plates are CNC machined from 6061-T6 Billet Aluminum and supplied with Zinc plated grade 10.9 hardware for absolutely zero-slip."

Please let me know your thoughts.

This is great information. I have posted elsewhere about noticing this phenomenon in 3rd and 4th and it definitely can be disconcerting. I may start with the SPL arms and see if I need to go any further.

@WONT TAP - any thoughts on this issue or these arms?

 

[AC2024]

Maybe i am over simplifying-hard to “feel” a feeling through words, but what youre describing sounds to me like n LSD hunting for grip in a high tq/hp car…. Which is even a bit more stnthetic feeling since its an ELSD.

While i would totally buy rear control arm bushing wear as making this feeling worse-not on a car this new. Regarding alignment-maybe. When the car squats under load it drives a bit more toe-out dynamically. But thats easy enough to check-go get an alignment and dial in some negative camber while you're there.

 

[5VBW Nick]

WANTED TO BRING THIS THREAD BACK UP...

After 10,000 miles, my CT5V is experiencing severe rear end wiggle when you jump on the throttle at higher speeds in 3rd and 4th gear.

There have been pretty significant discussions on this issue on the Blackwing Facebook Group and people have tracked it down to a couple of issues:

- Wheel alignment: Evidently the rear wheel alignment can fall out of spec and cause this issue

- Rear Toe Links: The reason the wheel alignment gets out of spec is due to the stock toe links not being strong enough.

In cross-discussions with the ZL1 Camaro guys, the Facebook posters found they were having identical issues with rear-end squirrelyness, and they had replaces their toe links with the SPL versions and it corrected the issue. One of the CT5V guys replaced his toe links and reported the car is much more solid now and the rear end doesn't kick to the side when he goes WOT at speed.

I attached a screenshot of his post which shows the stock toe arms and the SPL toe arm links side-by side.

The part they are recommending is: SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+
Part Number: SPL-RTAEL-CAM6

link to the part is below:

SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+

Check out the deal on SPL Parts Toe Arms with Eccentric Lockout (Rear) - Chevrolet Camaro 2016+ / Cadillac CT5 Blackwing 2022+ at Evasive Motorsports

www.evasivemotorsports.com

Here's what it says about those toe arms: "The stock eccentric bolts that allow for small toe adjustments tend to slip under high cornering loads, causing changes to the rear alignment. SPL Parts Eccentric Lockout (EL) kit eliminate the stock eccentric bolts to keep your rear alignment where you set it. SPL lockout plates are CNC machined from 6061-T6 Billet Aluminum and supplied with Zinc plated grade 10.9 hardware for absolutely zero-slip."

Please let me know your thoughts.

Seems like a simple/inexpensive mod that is worthwhile

 

[BimmerFan]

You guys must be on the track, because I can't imagine doing any kind of WOT in those higher gears, that's mandatory jail time around here!

OK, yeah, if you get caught, if they can catch you, yeah, I get it.

 

[hawk02]

I'm came to my 5BW from a 2017 m6 ZL1 (not the 1LE). I never noticed the rear-end wiggle under hard acceleration with the stock Goodyear tires that came on the ZL1. It was only after I swapped out the Goodyears for the PS4Ss. I thought maybe it was the softer sidewall of the 4S that contributed to the backend moving around. I also noticed that the rear-end movement seemed to get worse as the 4Ss aged.

The 4Ss are superior to the Goodyears in the rain and cold but I'm not convinced they're the ideal performance tire for the ZL1 and 5BW. The softer sidewall might be fine on the lighter Corvette but on a heavier car like the ZL1 and 5BW there might be too much flex.