1LE suspension kit

[LCPLPunk]

Hellllz ya man!

[cdb95z28]

I went with the full Z/28 suspension (springs/DSSV dampers/anti-roll bars and control arms/bushings) on my 1LE. I ran a couple of years with it street and track. Yes,it is stiff, but on the track you can be super aggressive in transitions and it sticks. It's more planted and stable than the 1LE setup. If your track is smooth, even better. The stiff setup is not good on rough surfaces. To exploit the Z suspension you'll need more tire than the OE Goodyear 1LE tires. I've run RE-71s, Goodyear 3R and PSC2. The 3R is an awesome tire and it matches the Z suspension very well. I did think I needed more anti-roll bar with the 3R tire though.


Last year I installed the Detroit Speed kit 1 lowering springs and anti-roll bars with the DSSV dampers. I gave up a tiny bit of transitional stability but the car still corners flat. The ride is a little bit better. The DSSVs are stiff. it's not all about spring rate. It's lowered now too. One misconception is that the Z/28 suspension lowers the Camaro. This is (partially) wrong. Chevrolet's Z/28 literature did not claim the car was lowered, only the center of gravity was lowered. The car did lose some overall height with the Z springs vs the 1LE springs due to the shorter 305/30-19 tire. On my 1LE with the Z springs, only the rear dropped in ride height.

Also, I have the GM service manual. Nowhere does it does it state to replace the suspension bolts. They specifically state to replace some lock nuts after use but do not think that because GM has a torque plus angle fastening method that they are automatically TTY bolts that need replaced after 1 use. They do however call out replacing caliper mounting bolts, so they do recommend some bolts being replaced, but not suspension bolts. I have tracked my 1LE for 5 years and have reused suspension bolts. Just torque to spec, paint stick 'em and keep an eye on them if you run your car hard.

The Z arms and bushings will offer some increased alignment control with reduced deflection. So if you are tracking they are worthy upgraded. Just be aware that the 1LE and Z share some of those components. And going poly is not always the better way. Some of the 1LE/ZL1/Z/28 joints are excellent and offer zero deflection. Rear solid subframe bushings are a great upgrade.

There is one suspension fastener that has a history of loosening, the rear upper control arm vertical bolt. It will loosen over time. And it sucks to get a torque wrench on it to get it back to spec.

It was mentioned above about the ZL1 rear anti-roll bar. It is the same as the rear 1LE. There is no difference between the two. If you already have the rear 1LE bar, you are good to go. And a wider rear tire moves the balance towards understeer. Wider rear tire=more rear grip.

[KJZ28]

That is a great write up cdb95z28!

[15AGM_SS]

cdb95z28 Thank you for the inputs. Your build is one of the ones on here i have followed and looked to for ideas and I know you know your stuff when it comes to suspension.

[SS 310H55A]

Originally Posted by cdb95z28

Also, I have the GM service manual. Nowhere does it does it state to replace the suspension bolts. They specifically state to replace some lock nuts after use but do not think that because GM has a torque plus angle fastening method that they are automatically TTY bolts that need replaced after 1 use. They do however call out replacing caliper mounting bolts, so they do recommend some bolts being replaced, but not suspension bolts. I have tracked my 1LE for 5 years and have reused suspension bolts. Just torque to spec, paint stick 'em and keep an eye on them if you run your car hard.

Angular torque is torque to yield. The suspension bolts you refer to are TTY. Re-use as you wish but they technically should be replaced.


https://wbtools.com.au/blog/how-to-u...orque-to-yield

For the record, I have a Camaro shop manual that does state to replace the suspension bolts. It specifically states to discard and replace.

[cdb95z28]

Originally Posted by SS 310H55A

Angular torque is torque to yield. The suspension bolts you refer to are TTY. Re-use as you wish but they technically should be replaced.


https://wbtools.com.au/blog/how-to-u...orque-to-yield

For the record, I have a Camaro shop manual that does state to replace the suspension bolts. It specifically states to discard and replace.

Where does it specifically state to replace the suspension bolts?

[Rons1le]

Originally Posted by cdb95z28

Where does it specifically state to replace the suspension bolts?

Any where it says torque to yield means replace them when you remove them.

Sent from my SM-G960U using Tapatalk

[cdb95z28]

So in other words, it's assumed. Not "specifically stated". That's a big difference. Nowhere do they specifically state that the bolts in question are torque-to-yield (TTY).

If GM wanted the bolts replaced, they would actually state it, like they do for the caliper bolts and other specific bolts (cylinder heads). Why would they NOT say to replace if they are truly torque-to-yield??

I think people are confusing torque to angle with torque to yield. GM specifically states do not reuse a bolt like cylinder head bolts.

The fact is, the suspension bolts are not specifically stated to replace. They do specifically state to replace certain nuts though.

Torque-To-Angle without being TTY a real thing
https://www.tomorrowstechnician.com/...-tty-fastener/

http://www.engineprofessional.com/TB/TB071916-1.pdf

[SS 310H55A]

Originally Posted by cdb95z28

So in other words, it's assumed. Not "specifically stated". That's a big difference. Nowhere do they specifically state that the bolts in question are torque-to-yield (TTY).

If GM wanted the bolts replaced, they would actually state it, like they do for the caliper bolts and other specific bolts (cylinder heads). Why would they NOT say to replace if they are truly torque-to-yield??

I think people are confusing torque to angle with torque to yield. GM specifically states do not reuse a bolt like cylinder head bolts.

The fact is, the suspension bolts are not specifically stated to replace. They do specifically state to replace certain nuts though.

Torque-To-Angle without being TTY a real thing
https://www.tomorrowstechnician.com/...-tty-fastener/

http://www.engineprofessional.com/TB/TB071916-1.pdf

Thank you for calling this out. I was wrong. My manual says to replace many of the nuts, but not the actual bolts. I read the links you posted and researched this a little more.



It does appear the suspension is simply a torque-angle specification and not torque-angle torque to yield, or else the manual would specifically call out the replacement of those bolts. I looked up the brake caliper procedure and that does call for replacement of the caliper bolts, but not for the actual suspension components.