Having Z51 and Also E60 Does Not Result In Total Height Adjustability Loss

[John]

UPDATE: THIS THREAD BASED ON LATER, UPDATED INFORMATION, IS NOT CORRECT.

Clearly a most recent hot button topic, so I wrote to Harlan seeking clarification as this was a significant question as to whether having Z51 and E60 resulted in the loss of adjusting spring perches height adjustability. Pictures thanks to “2slow2speed.”

Please read through to the very last sentence!




[Quote=John]Your help again please!


SUBJ: If Z51 & E60 combined, retains ride height adjustability?

Harlan,

This has been a hot topic in both forums this past weekend, but I did not want to bother you during the weekend.

We all so appreciated your response back a week ago, then confirming that as we thought, that the Z51 has adjustable spring perches to adjust ride height.

However, if one were to get a Z51 and add in additionally E60 lift option, does one lose the ability to adjust a C8’s height?

It’s two different things so one does not effect the other.

Now - if someone lowers there car with Z51 spring seats, obviously the front lift will not go as high as it is all relative.

[/B]

[Meldoon]

My interpretation is that it will raise the nearly 2 inches from the un raised level, whatever that may be.

[whl3]

John, as I see it, the adjustable spring perches on the individual shocks are more for 4-corner balancing the car than they are for lowering it. This was not available on previous generations of Corvettes. 4-corner balancing is something done with all professional race cars fitted with four coil over shocks and 4-wheel independent suspensions. It will be interesting to see what the balance is on Z51 equipped cars when they come from BGA. Typically the car receives a 4-corner balance with the driver in place suited with all racing gear. For even the average Z51 driver who might even track the car, how it comes from BGA will mean very little to them, especially if the factory setting very closely balances the car without a driver. I would see no practical reason to further lower the car unless it was used exclusively for racing or track use. Very shortly after taking delivery of my C8, I will take it to a very well known suspension and alignment specialist here in Cincinnati to have the car balanced.

Bill

[John]

Glad you have your post-delivery plans all set. Good for you. Happy racing success.

As a non-racer, the height adjustment will have a “functional,” (LOL) usage for me, creating the exact visual stance I want on all four corners, and still having front end lift capability when I need it.

Interesting how an option has so very different many uses.

[Teamzr1]

If I was to buy a C8 it would have to have the Z51 as to the added cooling better rear-end, etc
Z51 purpose if for better performance, IE, racing

No 2 race events are the same as to how the car has to be setup and the purpose of coil-overs is to corner weight/height each which also then needs to be re-aligned for those changes

Not sure there was a total answer on this as the lift system was about max travel of just under 2 inches
The claimed specs of adjustment for coil-overs is about 1 1/2 inches

So how does this work ?
All corners are not equal, assume right front has less weight then left front, when balanced adjusts that means the travel on one is going to be less
who can the lift system do much if via coil-over adjustment also lowering the car 1 /2" but not the lift system has no travel less and
being the height of both fronts are different how can the lift system handle that imbalance to travel ?

Being cars weight ratio is about 40/60 F/R and depending how engineering designed to prevent high push/under-steer, means to get better center of gravity
lots of cornet height changes will be needed and hence baying for a lift system may be washed out with cornet weight balanced

Also no coil-over springs are the same, normally need different spring rates for each corner and how stiff/soft the springs are
This then can effect cornet height and does that wash out the lift system from being used ?

Example of corner changes to center of balance back to my 1994 ZR-1 for road course racing.

[John]

Thank you teamZR1 for your adding great technical content! As to your question/thought...

This then can effect cornet height and does that wash out the lift system from being used ?

Responding not from your technical area expertise but from those of us who want the lift option to a) reduce or eliminate potential front splitter damage, b) get into and out of places we could not without it, and c) use the height adjusting system mostly for visual wheel gap adjusting...,

Harlan’s answer today was that if you used your adjustable spring perches to lower the front of your car, to the degree you used it (paraphrasing here), you were going to lose some of the maximum 1.57” lift system capability.

To me, if that means I am loving (visually perfecting) my front’s stance by lowering it via the spring perches by say, .57” from what height it arrived at the dealership, and I therefore only have 1” axle lift capability left , that would still be a grand slam, World Series bottom of the 9th in the 7th game, win for me. We have travelled to 22 states and still have no damage to our OEM carbon fiber splitter (though a couple of minute underside scratches); my Tech had lowered it during the PDI to about 4 3/4” front clearance (which I later fine tuned as the suspension settled a small amount), and so I am used to and very capable of traversing 98% of what I encounter.

A net 1” lift capability would get us into close to but all of the remaining places we would want to go. Still all in on the E60 option.

Thanks again teamZR1 for all the great technical info you are adding into the forum!

[Teamzr1]

Hi John

Thanks for your techie response and I understand it.

What my question is
IF in let's say lifting the right front corner via the coil-over adjustment 1/2"
or lowering just the left front (less travel)
If the lift is a hydraulically function and it lift both sides the same height, how does that effect the right front that now only has 1 inch lift
where the left front could be 1 1/2" ?

Does the lift system have one limit travel switch or one for each front ?

In any case it sounds like if people have the car lowered all four corners the lift system then have less travel movement and if so then lift
function or not much of real use or if there is now lift motion will it trigger some type of DTC (errror code) ?

It should be clear is if most want to lower the C8, and lift then is limited travel then may be a reason not to pay if that is a optional cost.

Would be interested in knowing that and still wondering why they will not publish what each forward gear's ratio is ?

[Meldoon]

Is it hydraulic? Do we know how it operates?

[Bikerjulio]

Thank you teamZR1 for your adding great technical content! As to your question/thought...
Harlan’s answer today was that if you used your adjustable spring perches to lower the front of your car, to the degree you used it (paraphrasing here), you were going to lose some of the maximum 1.57” lift system capability.

I don't think that is what he said. He said the 2 things are independent. You will still have 1.57" lift but starting from a lower place if you have lowered the car.

[Meldoon]

If it works like this KW system, I believe the hydraulic device sits on the spring perch. Therefore, it will provide the same amount of lift, regardless of height adjustment, provided you don’t run out of travel.

[Teamzr1]

Is it hydraulic? Do we know how it operates?

Watch the GM video on the lift function and it says it is hydraulic

https://youtu.be/f0FBZ7x5jng

We do not know what the mechanical makeup is and how attached to understand travel movement

[John]

I don't think that is what he said. He said the 2 things are independent. You will still have 1.57" lift but starting from a lower place if you have lowered the car.

Now - if someone lowers there car with Z51 spring seats, obviously the front lift will not go as high as it is all relative.

I take that one way. However, let us assume the following and might this give us a second way to interpret it.

The Z51 is on perfectly level ground. The height to a specific part of the car is 20.0”, but 21.57” when the front lift is employed.

The. Z51 owners lowers it exactly .57”. Does it mean that the height to this same point on the car when the lift is employed remains at 21.57” or would it instead only be 21.00?”

Anyone

[Bikerjulio]

The. Z51 owners lowers it exactly .57”. Does it mean that the height to this same point on the car when the lift is employed remains at 21.57” or would it instead only be 21.00?”

Anyone

I was picking up on what you said

you were going to lose some of the maximum 1.57” lift system capability.

OK let me try again. You still have the same amount of lift as before but obviously if you lowered the car the final clearance would be less. You have not lost any lift capability. Meaning the amount the car rises when you hit that button.

[Meldoon]

21”..................

[John]

Thank you very much; I know understand.

I am a happy camper, are are hundreds of millions, that we do not lose adjustability with the inclusion of the Z51.