Thrift Shop Camaro

[Flash68]

Originally Posted by Payton King

Plan on running the car everywhere I can. Carolina Motorsports Park is 1 hour from here, Road Atlanta is 3, VIR is 2. I am close to some nice tracks.

...But it will be tagged for the street too! Vanity plate "ECBMF" East Coast Bad Motor Finger

I can get an out-of-date NASCAR bladder for $200. Per rules they can only race with them for 3 years, but they are good for 10 to 15 years. So as stated above, will have a bladder along with foam. Will be using a CTS-V pump with the help from Carl at Vaporworx.

It is an 18 gallon cell.

LOL... if anyone's car is a little bro to the other... it's me to you!

So one CTS-V pump is good enough for 800 hp? I know jack about the LS EFI stuff..

[Payton King]

So you heard about my mid-life crisis / daily driver/ tow vehicle?





Skulls on the dash





And the plate that sums it up.

[intocarss]

Great Build And Congrats On The Truck

[Flash68]

The truck is a BEAST.... your wife must be proud.

[Sieg]

Originally Posted by Flash68

The truck is a BEAST.... your wife must be proud.

Around here those are known as prostetic enhancements.

[Ron Sutton]

Hey Guys!

For those not familiar, this is an offset, decoupled three link. The reason to offset the top link is to counteract the torque transmitting through the rear end housing.

With all 4-link, centered 3-link, truck arm, torque arm, leaf spring style rear suspensions there is a significant amount of torque steer. The friction of the bearings & gear mating surfaces in the rear end cause power loss ... in the 7-12% range. Due to the friction drag, that 7-12% power goes into rotating the rear end housing down onto the left rear tire & up off the right rear tire. This causes uneven tire loading. The LR tire gets 7-12% more loading ... and therefore 7-12% more grip ... than the RR tire. This causes cars to have more grip on the exit of LH corner & less grip on the exit of RH corners.

With a 3-link ... if we offset the top link to the passenger side the correct amount ... we neutralize the torque steer. When done correctly, the car now has the same torque applied to both rear tires for even grip on corner exit, regardless if LH or RH corner. We can't do this practically with other styles of rear suspensions.

The decoupled part is ultra bad ass. Because it is the only rear suspension version where we can have it all ... almost.

In all 4-link, centered 3-link, offset 3-link, truck arm, torque arm, leaf spring style rear suspensions ... the instant center (swing arm pivot point) defines the anti-squat for corner entry handling & corner exit handling. If you move the instant center to increase anti-squat for increased corner exit grip ... you are affecting the corner entry handling ... the opposite direction ... moving it toward loose handling on corner entry.

With any 3-link or 4-link track car, we're typically adjusting the top link(s) down at the front chassis mount ... bit by bit ... to increase grip on corner exit ... until the car starts to get loose on corner entry. Then we adjust the front of the top link(s) back up just enough to not be loose on corner entry. It is always a compromise between corner entry grip & corner exit grip. This is the case with any rear suspension model, except a decoupled version. FYI: There are decoupled torque arms, but they don't have the advantages of the 3-link. So I only focus on decoupled 3-links.

With a Decoupled 3-Link ... we have a dedicated top link for acceleration & a separate dedicated top link for deceleration. For short, we call them the "Accel Link & "Decel Link".

The Accel Link only loads up under acceleration. You can see the blue bushings in the Accel Link photos. Under acceleration, the top of the rear end housing rotates back & pulls on the Accel Link ... and compresses those bushings. The instant center formed by that Accel Link determines the anti-squat ... and therefore the tire loading & grip ... on corner exit. Under deceleration, the top of the rear end housing rotates forward & pushes on the Accel Link ... and releases the load on those bushings. The shaft inside the Accel Link "free slides" forward on deceleration ... to the point there is gap between the bushings ... and therefore no load on that link.

Under deceleration, just before the load is fully released on the Accel Link bushings ... the load is engaging the red poly bushings in the Decel Link. Under hard braking, the top of the rear end housing rotates forward and compresses the red bushings in the Decel Link. The instant center formed by that Decel Link determines the anti-squat ... and therefore the tire loading & grip ... on corner entry. This is completely independent of the Accel link.

Under acceleration, as the top of the rear end housing rotates back & pulls on the Decel Link ... this releases the load on those bushings. The shaft inside the Decel link "free slides" back on acceleration ... to the point there is gap between the bushings ... and therefore no load on that Decel Link.

It sounds complicated, but frankly it is pretty simple. I'm sure whoever came up with the original idea had sleepless nights figuring out. But once it is installed, it is simple to tune ... and bad fast. We typically set the Decel Link at 12°-15° uphill (to the front) and start with the Accel Link forming its instant center directly under the CG of the car.

I love this next part ...
Set the Decel Link as close to 15° as packaging will allow ... and forget it. From there we tune the Accel Link for optimum corner exit grip with no concern about how it affects the corner entry ... because it doesn't.

Tuning:
Need more corner exit grip? Place a 1/2" ratchet into the top of the adjuster cone you see in the photos & rotate clockwise to lower the front of Accel Link. Adjust it until you have optimum corner exit grip. If you go too far (getting "greedy" I call it) the car will push on corner exit. Simply turn the adjuster counter-clockwise until the push goes away. Easy-peasy.

In summation ...
In my experience, the offset, decoupled 3-link is the ultimate track car performance rear suspension. It allows the optimum grip on corner entry & corner exit, no torque steer & no impact on mid-corner handling. No other rear suspension can do all that. But there is a down side. It rides rougher on the street, as the poly bushings in the Decel Link add spring rate. I have some clients that run this set-up as a simple offset 3-link on the street, and swap in the Accel & Decel Links for track days. The 3 bolts & swap takes about 10 minutes.

IMHO this is not a suspension for most ProTouring cars. For 95% street use, little to no fabrication and keeping the rear seat ... I prefer a Torque Arm or Triangulated 4-link rear suspension. If done right ... 3-links, Offset 3-Links & Offset/Decoupled 3-Links are for hardcore cars that prioritize track performance over everything else. But these require professional fabrication, roll bar or cage & eliminating the rear seat.

Originally Posted by Payton King

[Flash68]

Originally Posted by Ron Sutton

The decoupled part is ultra bad ass.

Bringin the tech!!

Seriously Ron, this thing is so wicked cool. Thanks for bringing it.

[fleetus macmullitz]

Wow, nice mann rigg Payton!

That's why yer still the King.

[Beach Cruiser]

Good Stuff Payton! That's a whole lot of truck, you'll need a step stool to get in that thing! Just signed up for the USCA event in Charlotte in July, I'm sure I'll see you there!

[srh3trinity]

So where does the GoPro mount for the rear suspension? I want to see it in action. Cool stuff and one of these days I want to dig deeper into the tech stuff.