[khcoaching]

Question(s) regarding the direction I want to go with suspension for my 2021 SS 1LE....

Context -

The car will be used almost primarily for track time and I am not concerned about general streetability. Lap times are honestly the goal, though consumables are also important.

- I probably only will do 5-7 days total this year with the car. (I'll be coaching in client cars most of the other time and might get to do a session or two per day at a few of those days, in conjunction with the standalone days)

- There is a budget, but it is fairly tight.

- I plan on leaving the engine stock for at least the first year.

- I have sponsorship with EBC and Continental, though I may not run their products on this car, as it is my personal car.


The plan -

Having driven my car absolutely stock, it works pretty well, but it also easy to understand the shortcomings. I can easily do the strut mod or camber plates, but at the level I want this car to perform, I think the stock MRC will be a limitation, fairly quickly. I've driven a ZLE and it worked pretty well, for sure a step up than the standard SS 1LE, suspension wise.

So....

- My thought is to replace the stock MRC with a takeoff ZLE DSSV system, along with the ZLE adjustable swaybars and front control arms.

- Rear SPl/BMR toe links

- Typical track alignment

- Square setup 305/30/19 with a normal 200tw tires.

- Brake upgrade will the normal fluid, brake lines, Ferodo 1.11 pads and Ti shims.

Edit - Rear cradle ZLE bushings

My thought is that this is a good or closer step to a full aftermarket coilover setup, at a fraction of the cost and a step up from the stock MRC.....

Thoughts?

Ken

[carguy55]

The largest single gain I've found for better lap times is the 305/30/19 square G3R tires. This has resulted in 2-6 sec per lap gains, depending on track. Everything else supports this mod and only adds small fractions of time. I would add rear cradle lock out, racing seat, 6 point harness to your list.

[khcoaching]

Originally Posted by carguy55

The largest single gain I've found for better lap times is the 305/30/19 square G3R tires. This has resulted in 2-6 sec per lap gains, depending on track. Everything else supports this mod and only adds small fractions of time. I would add rear cradle lock out, racing seat, 6 point harness to your list.

Yes, I forgot to add, rear cradle ZLE bushings...

[kropscamaro16]

just added a full spl parts kit to my car ! car felt way more stable and you could feel the inputs alot better and car was super flat on track way less body roll also!

[khcoaching]

Originally Posted by kropscamaro16

just added a full spl parts kit to my car ! car felt way more stable and you could feel the inputs alot better and car was super flat on track way less body roll also!

Great info!

All of the rear bars?

[kropscamaro16]

full kit front and rear

[khcoaching]

In order to see what the DSSV system gains actually are, I'm going to track it all stock next week, so I have a base point of reference to use. In order to get the best results, I had an alignment done and it appears I am one of the unlucky ones, that is limited on alignment -

This was all we could get out of it....

After this phase, the DSSV is going on, along with FEA sway bars, front control arms and solid crate mounts.

Ken

[Alpha1BC]

Carguy is pretty spot on IMO. Check this thread where GM kinda answered your question on an SS: https://www.camaro6.com/forums/showthread.php?t=542333

Tire will be the single best bang for your buck by a pretty decent margin. Doesn't even need to be 305 19" square. I'd personally go with 3Rs in standard SS 1LE sizes. That way they'll play nicer with PTM/ABS/eLSD cals if that's useful to you.

If using more aggressive pads I'd suggest looking into ZL1 calipers/rotors. Even with Ti shims and extra cooling there's potential to overheat stuff (i.e. seals) to failure once more aggressive pads are used in the right conditions.

From there, cradle lockouts are probably the next best gain followed by bars/DSSV dampers. From what I've seen elsewhere there's not a ton of time to be found with these component swaps though, mainly just driver feel preference and driver confidence.

Lastly, I wouldn't trust that alignment shop did everything they could. Should be able to get -2 deg camber front and -1.5 rear no problem, the unlucky ones are limited to that from what I've seen. My guess would be the shop didn't get the strut bolt spline fully disengaged or was hung up in some other way. Jouncing the car with those bolts loose and pushed out past the splines should help there. Front toe looks good.
Not sure what happened with rear camber and toe, but those values also seem like there should be more to achieve to be closer to the track alignment. Mind snapping a pic of the eccentric camber/toe bolts on the rear cradle to show where they're at? I'd also double check that they didn't manage to get the washers on those over the guides on the cradle. There's an eccentric washer on the front and back, and I've seen the front washer slip up over the guide bump on other vehicles and get tightened like that before at least.

[khcoaching]

Originally Posted by Alpha1BC

Carguy is pretty spot on IMO. Check this thread where GM kinda answered your question on an SS: https://www.camaro6.com/forums/showthread.php?t=542333

Tire will be the single best bang for your buck by a pretty decent margin. Doesn't even need to be 305 19" square. I'd personally go with 3Rs in standard SS 1LE sizes. That way they'll play nicer with PTM/ABS/eLSD cals if that's useful to you.

If using more aggressive pads I'd suggest looking into ZL1 calipers/rotors. Even with Ti shims and extra cooling there's potential to overheat stuff (i.e. seals) to failure once more aggressive pads are used in the right conditions.

From there, cradle lockouts are probably the next best gain followed by bars/DSSV dampers. From what I've seen elsewhere there's not a ton of time to be found with these component swaps though, mainly just driver feel preference and driver confidence.

Lastly, I wouldn't trust that alignment shop did everything they could. Should be able to get -2 deg camber front and -1.5 rear no problem, the unlucky ones are limited to that from what I've seen. My guess would be the shop didn't get the strut bolt spline fully disengaged or was hung up in some other way. Jouncing the car with those bolts loose and pushed out past the splines should help there. Front toe looks good.
Not sure what happened with rear camber and toe, but those values also seem like there should be more to achieve to be closer to the track alignment. Mind snapping a pic of the eccentric camber/toe bolts on the rear cradle to show where they're at? I'd also double check that they didn't manage to get the washers on those over the guides on the cradle. There's an eccentric washer on the front and back, and I've seen the front washer slip up over the guide bump on other vehicles and get tightened like that before at least.

Thanks for the info and link!

The only time I ran it on track was with in Race mode with everything off and I don't see me running it with the PTM modes engaged, unless maybe it is wet out.

HA! I just found a used set of ZLE calipers and rotors that will go on during the DSSV swap.

While I do think the the stock MRC is very good, for where I want the car to be and how I think I can perform with it, the MRC will be limited. (I thought about the DSC controller, but the reviews are quite mixed) I mainly run at smooth tracks where where I think the DSSV will be at an advantage. I'll start with the stock FEA bars and I can always use my old FE4 bars if I think I need more. I did drive another 1LE with the square setup and loved it, plus I want to be able to rotate.

The alignment is a bit baffling.....I was there and we did knock the bolt past the splines to make sure it was all we could get. I had thought about opening up the hole before I went, but since I will only be doing 1-2 days on it before the conversion, I left it.

Good catch on the rear, I had to leave when he was starting it and I'll check tomorrow!

[khcoaching]

Pic of the rear adjustment....

[Alpha1BC]

Gotcha. And to clarify, the 19" wheels won't break any of the car features by any means, they just won't be as optimized as the 20" diameter stuff, specifically for eLSD and ABS when all other systems are off on track, which may or may not be leaving measurable time on the table if that's more important that being able to rotate. Seems like a preference thing either way though.

Yeah, for the front you shouldn't need to open the holes up. Might even require getting the front wheels off the ground and physically holding the tire (pulling out on bottom and pushing in on top) to get it, but it should be able to get past -2° on each side.

As for the rear, they definitely didn't use the whole range on those bolts pictured. The camber bolt is right in the middle of its adjustment range and the toe bolt is about 3/4 of the way to its max toe-in capability. Should be plenty of room to get to the -1.5° camber and 0.1° total toe in if the other side's bolts are roughly the same.

[khcoaching]

Originally Posted by Alpha1BC

Gotcha. And to clarify, the 19" wheels won't break any of the car features by any means, they just won't be as optimized as the 20" diameter stuff, specifically for eLSD and ABS when all other systems are off on track, which may or may not be leaving measurable time on the table if that's more important that being able to rotate. Seems like a preference thing either way though.

Yeah, for the front you shouldn't need to open the holes up. Might even require getting the front wheels off the ground and physically holding the tire (pulling out on bottom and pushing in on top) to get it, but it should be able to get past -2° on each side.

As for the rear, they definitely didn't use the whole range on those bolts pictured. The camber bolt is right in the middle of its adjustment range and the toe bolt is about 3/4 of the way to its max toe-in capability. Should be plenty of room to get to the -1.5° camber and 0.1° total toe in if the other side's bolts are roughly the same.

We did pull on the wheel, but maybe not enough!!

My fault on the rear, I told him I wanted to keep it .5-.75 less than the front.

Ken

[Alpha1BC]

Originally Posted by khcoaching

We did pull on the wheel, but maybe not enough!!

My fault on the rear, I told him I wanted to keep it .5-.75 less than the front.

Ken

Gotcha, yeah you'll definitely want to get the toe set to somewhere between the track settings and 0. And even if the front is staying where it's at I'd still throw a little more camber at the rear. Camber is probably decent enough where it's at, but I usually treat it as a ratio instead of a straight delta with the stock tire sizes: every ~0.2° the front differs from the track alignment have the rear also adjusted from the track alignment by 0.1°. For example, instead of -2 front and -1.5 rear, if you could get -2.4 on the front I'd set -1.7 on the rear. I bet that'll switch to being a pure delta once you get a square setup, though. Either way, probably not off enough to completely kill lap times, just will wear outside edge a smidge faster and might not be as optimized for lap times as it could be.

[kropscamaro16]

i just got my full spl parts kit on and was able to get -3 front and -2.2 rear with no camber plates