What is everyone doing for suspension upgrades?

[BaylorCamaro]

Curious what everyone is doing with their suspension in terms of upgrades? I've currently only done sways on my ZL1 and I'm having issues putting the power down for corner exit. I'm going to do front radius arm inserts and solid sub frame bushings. However, there's a ton of other bushings and I'm wondering what else I should upgrade, especially when I have the rear end out?

When it comes to Polyurethane vs. Delrin I see a lot of debates across the web. Some swear that Polyurethane is too soft and will give over time and the firmness of Delrin reduces wear. But then on the flip side people say the hardness and lack of give in Delrin takes a toll on your suspension components.

[Crash76]

I haven't tracked yet ... But going on the car as follows

From Peagasus
Camber plates, solid subframe bushing, delrin diff bushing, and outter rear trailing arm bushings

From JDP
I ordered their ZL1 Track Package minus the stuff that I got from Pegasus

Detroit Speed Egineering Components

DSS Aluminum 1 Piece DS

Stock ZL1 Wheels with Toyo 888s

[Crash76]

Hopefully that takes care of any suspension issues...

Plan is to run Thunderhill on Feb 13 stock since it will be cutting time short to get everything on the car and then throw the stuff on it, run MRLS Sonoma and more thunderhill throughout the year

[X25]

Originally Posted by BaylorCamaro

Curious what everyone is doing with their suspension in terms of upgrades? I've currently only done sways on my ZL1 and I'm having issues putting the power down for corner exit. I'm going to do front radius arm inserts and solid sub frame bushings. However, there's a ton of other bushings and I'm wondering what else I should upgrade, especially when I have the rear end out?

When it comes to Polyurethane vs. Delrin I see a lot of debates across the web. Some swear that Polyurethane is too soft and will give over time and the firmness of Delrin reduces wear. But then on the flip side people say the hardness and lack of give in Delrin takes a toll on your suspension components.

I presume you have Detroit Speed sways? I don't know much about them, but if it's anything similar to Pedders' 32mm solid rear sway, then they will be too stiff. The reduced articulation due to that might severely reduce your corner exit traction. I used the BMR sways, and they were OK. They are hallow, though, so they're nowhere as stiff, even though all these aftermarket sways usually have similar diameter.

Again, I don't know much about their sways, but some sway bars are indeed a bit too stiff. By the way, FYI, stiffer shocks/springs with softer sways is what the Z/28 package is all about.

[Crash76]

Yep DSE sway bars ... JDP seems to have a ton of track experience in their shop car... Went with their recommendation...

See how it goes ... Be a while before I know the proper way around a track anyhow...

[BaylorCamaro]

Originally Posted by X25

I presume you have Detroit Speed sways? I don't know much about them, but if it's anything similar to Pedders' 32mm solid rear sway, then they will be too stiff. The reduced articulation due to that might severely reduce your corner exit traction. I used the BMR sways, and they were OK. They are hallow, though, so they're nowhere as stiff, even though all these aftermarket sways usually have similar diameter.

Again, I don't know much about their sways, but some sway bars are indeed a bit too stiff. By the way, FYI, stiffer shocks/springs with softer sways is what the Z/28 package is all about.

DSE sways are fairly large, but they are hollow. The problem with the ZL1 and its weight was it not wanting to rotate and had noticeable understeer in areas. The sways bars have definitely helped that.

Right now by biggest dilemma is to go with polyurethane or delrin on bushings.

[SPCBA]

The tips about at least the rear bar are still mostly valid with your response. I don't follow your car specifically what tires and alignment? Tire pressures and maybe some tire wear pics would be sweet as well. (There are some good ol boys here that can dissect that)

As per your bushing question each have pros and cons. Check the melt point for those materials and keep in mind your hobby of driving this heavy Chevy 90%!!

Some bushing upgrades really can help with eliminating some wonky and or unpredictable deflections all going their own ways. They can makes the car easier to drive but much less forgiving with the loud peddle and good ol snap steering hehe.

my car is a completely hodgepodge set up that works great for me I'm on stock sways and old geometries so specfic experience with your set up I lack.

[X25]

From my build thread regarding our discussion about the same topic:

I have not yet tried my solid subframe bushings or the solid bushing at the knuckle at the track, so we'll see about that. I did, however, change my differential to address the traction issue. I don't know how the OEM ZL1 differential fares (and I'm sure it's a beefier unit), but the OEM SS differential literally 'opened-up', not locking when needed. The helical differential I installed should always lock (as long as I do not screw up the fluid) when needed, and should not lose its locking capability since it is now gear-driven.

There are so many things that contribute to better traction off the corner: Soft/compliant suspension (ZL1's magna ride would provide it, but stiff sway bars might impede a bit), good differential, good alignment (don't recommend too much toe; you can't get too much negative rear camber on these cars), good weight on rear tires (don't replace your battery with a Li-Ion :P), less body flex, less overall weight, aero, etc.

[h018871]

I'm running a fairly simple setup for the moment
Rear cradle bushing inserts
Front radius arm inserts
Rear 32mm hollow bar
Camber plates
Alignment changes (this is still a work in progress)
Other than that, stock 1le gear (at the track 10x20 rims on all corners)

EDIT truetrac differential also

[KaBoom1701]

[E. Bryant]

Originally Posted by BaylorCamaro

DSE sways are fairly large, but they are hollow. The problem with the ZL1 and its weight was it not wanting to rotate and had noticeable understeer in areas. The sways bars have definitely helped that.

The issue with high-power front-engine/rear-drive cars is that you typically can either tune the rear roll stiffness for neutral handling characteristics on corner entry and mid-turn, or you can tune it for good power application on corner exit, but it's extremely difficult to do both (especially with the constraints of a typical limited-slip diff).

I've eventually come around to accept some moderate understeer in exchange for better power application on exit. If that's not acceptable, the ultimate fix is either to move the engine closer to the rear axle or to put some torque to the front wheels. Those are difficult modifications to perform on a budget

[BaylorCamaro]

Originally Posted by SPCBA

The tips about at least the rear bar are still mostly valid with your response. I don't follow your car specifically what tires and alignment? Tire pressures and maybe some tire wear pics would be sweet as well. (There are some good ol boys here that can dissect that)

-2 degrees camber in the front with a little bit of toe out. Rear has some slight camber and very slight toe in. I am now running Nitto NT01's (which have helped a lot) and I run them at around 36 psi HOT. Tires are wearing very good.

At this point and after talking with Pete @ JPSS I've decided to go with DSE solid sub frame bushings and adjustable toe rods with spherical bushings. Pete feels that the OEM bushings on the ZL1 are sufficient and unnecessary to change out.

Originally Posted by E. Bryant

The issue with high-power front-engine/rear-drive cars is that you typically can either tune the rear roll stiffness for neutral handling characteristics on corner entry and mid-turn, or you can tune it for good power application on corner exit, but it's extremely difficult to do both (especially with the constraints of a typical limited-slip diff).

I've eventually come around to accept some moderate understeer in exchange for better power application on exit. If that's not acceptable, the ultimate fix is either to move the engine closer to the rear axle or to put some torque to the front wheels. Those are difficult modifications to perform on a budget

I'm beginning to see that. I moved to a 305x19 square set up but I'm thinking about going to 325x19 out back.

[hammdo]

Almost everything is upgraded on mine. Will track it one of these days, when the body is ready ;o)..

Too much to list again... All on the first page of my build thread...

-Don

[BMR Sales]

Originally Posted by BaylorCamaro

Curious what everyone is doing with their suspension in terms of upgrades? I've currently only done sways on my ZL1 and I'm having issues putting the power down for corner exit. I'm going to do front radius arm inserts and solid sub frame bushings. However, there's a ton of other bushings and I'm wondering what else I should upgrade, especially when I have the rear end out?

When it comes to Polyurethane vs. Delrin I see a lot of debates across the web. Some swear that Polyurethane is too soft and will give over time and the firmness of Delrin reduces wear. But then on the flip side people say the hardness and lack of give in Delrin takes a toll on your suspension components.

1st - Polyurethane comes in all different hardness's. We use a Durameter to measure the deflection. The Higher the number the Harder (or stiffer) it is. I do see issues with Higher Durameter Poly Bushings in most cases. Most of those are on Drag Cars that put Super High Loads instantly.

Delrin is a Polymer that has to be CNC Machined to size. It is Solid. I like my Race Cars to be stiff, but as if you do that it adds stress to other components. Also if you run a car super stiff, there is less room for error in your driving!

Now it depends on which Bushings you are looking to change. Some (like the Cradle Bushings) you can go as hard as you want without issues. Diff Bushings if you go Hard, it will transmit a lot of NVH, same with Motor Mounts.