[SoCal Racer]

Originally Posted by Swacer

Why did you not address the questions about the impact to mag-ride?

It is interesting that the MR part was cut out of my original question...maybe that was not accounted for in this project....?

In the multiple resources that I have researched and in speaking with several Chevrolet engineers @ SEMA there will be a point of lowering that the MR will not function as intended. They could not tell me what point that is, but I was advised jokingly by one of them that if I "slammed" an MR suspension it would be pretty much worthless in terms of function. I figure if anyone went low enough they are not really caring about the performance of their MR. For me personally, I am in the gray area, where I do track my cars and fully intend to track my new ZL1, but at the same time will be driving this to work and around town as well and am not really happy with the excessive wheel gap (personal preference, everyone is entitled to their own thoughts, of course)...so I am walking that line...carefully. Most cars that I have, I would just modify to a coilover suspension and not worry about it, but since I am paying for that MR technology and it is so good already, I really don't want to throw that away.

[zl1_tommy]

Originally Posted by SoCal Racer

It is interesting that the MR part was cut out of my original question...maybe that was not accounted for in this project....?

In the multiple resources that I have researched and in speaking with several Chevrolet engineers @ SEMA there will be a point of lowering that the MR will not function as intended. They could not tell me what point that is, but I was advised jokingly by one of them that if I "slammed" an MR suspension it would be pretty much worthless in terms of function. I figure if anyone went low enough they are not really caring about the performance of their MR. For me personally, I am in the gray area, where I do track my cars and fully intend to track my new ZL1, but at the same time will be driving this to work and around town as well and am not really happy with the excessive wheel gap (personal preference, everyone is entitled to their own thoughts, of course)...so I am walking that line...carefully. Most cars that I have, I would just modify to a coilover suspension and not worry about it, but since I am paying for that MR technology and it is so good already, I really don't want to throw that away.

Would really love to know what that threshold is :/

[Swacer]

Originally Posted by SoCal Racer

It is interesting that the MR part was cut out of my original question...maybe that was not accounted for in this project....?

In the multiple resources that I have researched and in speaking with several Chevrolet engineers @ SEMA there will be a point of lowering that the MR will not function as intended. They could not tell me what point that is, but I was advised jokingly by one of them that if I "slammed" an MR suspension it would be pretty much worthless in terms of function. I figure if anyone went low enough they are not really caring about the performance of their MR. For me personally, I am in the gray area, where I do track my cars and fully intend to track my new ZL1, but at the same time will be driving this to work and around town as well and am not really happy with the excessive wheel gap (personal preference, everyone is entitled to their own thoughts, of course)...so I am walking that line...carefully. Most cars that I have, I would just modify to a coilover suspension and not worry about it, but since I am paying for that MR technology and it is so good already, I really don't want to throw that away.

I think its a dead giveaway that the vendor knows the product takes away from the performance of the car, so you can have the "look". The look means #%(#&*$ if it takes away from the reason you bought the car.

But then again...wide body kits exist for a reason...

[17CamaroZL1]

Originally Posted by crankaholic

I'm with Mr. Wyndham regarding the suspension travel/height sensors... I was in an accident last spring and had to replace some front suspension components, including sensors, and MRC/Steering were completely out of whack (car was too soft and the steering felt like a 90's Deville. TC might have been impacted as well, but I didn't test) when everything was first put back together. The company that owns the body shop also owns one of the bigger Chevy dealers in the area and they had to recalibrate those sensors for everything to work properly again - this is just what I was told - they called GM engineers to find out what to do and had to load a custom calibration program for the Gen6 into their computer. After the sensors were recalibrated (unfortunately I didn't talk to the guys at the dealership and I'm not sure what that entails) the car started driving like it should.

When installing my lowering springs I measured where the sensor arms sit, so I can do the same with new springs and make shorter connecting rods to keep the sensors in the same position as stock. I never got around to doing that second part so I don't know if it actually makes a difference or if a 1" drop affects anything to begin with. My recalibration experience doesn't make sense if those sensors are just for measuring rate of suspension compression/rebound

I can see how the sensors could be used to measure ride height so the system can stiffen the shocks the closer they get to full compression or extension, but they most definitely monitor movement and probably the rate of that movement in order to instantly adjust the shocks as needed. In your case with the new sensors that apparently weren't communicating with the computer, the MRC didn't know there was any movement occurring so it didn't stiffen the shocks any at all, resulting in that floaty feeling it sounds like you are describing.

I don't think I would change the rods on the sensors, especially if the system does stiffen the more the shocks are compressed, because if you shorten them on a lowered car, the computer will think the shocks are higher in the stroke than they actually are, and it could lead to a more harsh bottoming of the suspension if you hit a big bump. If ride height isn't monitored, and rate of movement is the only thing being used, the shorter rods aren't going to change anything except the geometry of the stroke, which actually could change how the sensor reads movement.

[crankaholic]

Originally Posted by 17CamaroZL1

I can see how the sensors could be used to measure ride height so the system can stiffen the shocks the closer they get to full compression or extension, but they most definitely monitor movement and probably the rate of that movement in order to instantly adjust the shocks as needed. In your case with the new sensors that apparently weren't communicating with the computer, the MRC didn't know there was any movement occurring so it didn't stiffen the shocks any at all, resulting in that floaty feeling it sounds like you are describing.

I don't think I would change the rods on the sensors, especially if the system does stiffen the more the shocks are compressed, because if you shorten them on a lowered car, the computer will think the shocks are higher in the stroke than they actually are, and it could lead to a more harsh bottoming of the suspension if you hit a big bump. If ride height isn't monitored, and rate of movement is the only thing being used, the shorter rods aren't going to change anything except the geometry of the stroke, which actually could change how the sensor reads movement.

I thought about that as well, but from what I was told pairing the sensors wasn't the issue... or maybe they were just trying to make the process seem more complicated than what it is, although they weren't charging for it so I don't see a reason for doing that.

I also agree that the sensors are definitely measuring the rate of change - that information is most useful for MRC. The slight bounciness I and others experience with lowering springs in track mode could stem from rebound being softened under more compression (from the lowered car) and compression being stiffened up... the point being that when the car is returning to it's natural height the rebound is instantly stiffened up and the whole motion is faster while retaining damping control, but the car never gets back to it's natural ride height. Again we don't know exactly how it works so we can just guess :(

As for messing up geometry of the sensor to suspension arm travel... lowering the car does that already - the sensor has to translate degrees of motion into vertical wheel travel - so more degrees off center equal less wheel travel. Keeping the original sensor position seems pretty important. Although again it's not like anyone did the calculations and determined how it all works exactly

[Mr. Wyndham]

Originally Posted by crankaholic

I'm with Mr. Wyndham regarding the suspension travel/height sensors... I was in an accident last spring and had to replace some front suspension components, including sensors, and MRC/Steering were completely out of whack (car was too soft and the steering felt like a 90's Deville. TC might have been impacted as well, but I didn't test) when everything was first put back together. The company that owns the body shop also owns one of the bigger Chevy dealers in the area and they had to recalibrate those sensors for everything to work properly again - this is just what I was told - they called GM engineers to find out what to do and had to load a custom calibration program for the Gen6 into their computer. After the sensors were recalibrated (unfortunately I didn't talk to the guys at the dealership and I'm not sure what that entails) the car started driving like it should.

When installing my lowering springs I measured where the sensor arms sit, so I can do the same with new springs and make shorter connecting rods to keep the sensors in the same position as stock. I never got around to doing that second part so I don't know if it actually makes a difference or if a 1" drop affects anything to begin with. My recalibration experience doesn't make sense if those sensors are just for measuring rate of suspension compression/rebound

This seems to support what I was thinking. If the sensors merely measured travel, and weren't indexed to any particular location...then you shouldn't have had a problem.

By requiring a recalibration...it sounds like, even if they are measuring travel rate and distance...they are indexed to a particular ride height.

Remember...travel through a suspension from full extension to full compression is not at the same rate, since the geometry is not exactly linear, nor is the spring rate.

Originally Posted by Ricardo@Phastek

Mr. Wyndam and the others are making good points as far as the mag ride is concerned. So I didnt see any reason to jump in on it.

To get the look there are going to be some compromises.

As there is with anything!

That car does look sooooo nice.

Originally Posted by Ricardo@Phastek

Our customer, and us as well, had the same concerns. After driving the car about 20 miles on Houston roads, Hwy 290 and 1960 area to be more specific, we found that the ride was not that bad at all. We were surprised that the ride was not effected all that much. With a 5th Gen I will agree with you, the ride did change dramatically and was very rough for some reason. Not sure why this car is so different but we liked the way the car handled after the springs.

Good to know!

Originally Posted by SoCal Racer

In the multiple resources that I have researched and in speaking with several Chevrolet engineers @ SEMA there will be a point of lowering that the MR will not function as intended. They could not tell me what point that is, but I was advised jokingly by one of them that if I "slammed" an MR suspension it would be pretty much worthless in terms of function. I figure if anyone went low enough they are not really caring about the performance of their MR. For me personally, I am in the gray area, where I do track my cars and fully intend to track my new ZL1, but at the same time will be driving this to work and around town as well and am not really happy with the excessive wheel gap (personal preference, everyone is entitled to their own thoughts, of course)...so I am walking that line...carefully. Most cars that I have, I would just modify to a coilover suspension and not worry about it, but since I am paying for that MR technology and it is so good already, I really don't want to throw that away.

This, too, seems to support my theory that the sensors are calibrated to a specific ride height. If you lower the car too much, the hardware in the suspension (arms, links, strut) lives in a state of compression, according to OE design...the sensors must be aware of that, and the MR damper, or calibration, or both - must not function the way you intend it to.

Originally Posted by 17CamaroZL1

I don't think I would change the rods on the sensors, especially if the system does stiffen the more the shocks are compressed, because if you shorten them on a lowered car, the computer will think the shocks are higher in the stroke than they actually are, and it could lead to a more harsh bottoming of the suspension if you hit a big bump. If ride height isn't monitored, and rate of movement is the only thing being used, the shorter rods aren't going to change anything except the geometry of the stroke, which actually could change how the sensor reads movement.

I agree. Which brings us full circle again to the original concern: if the calibration is not set up to deal with a lowered car, and adjusting the sensors to "fool" the system could cause harm as well...then there is really nothing we can do to compensate for the fact that the car is lowered...aside from recalibrating MR, itself.

A slight drop....Say .5-.75 inches, would merely simulate a load in the car...the system can no doubt handle that. But our question is....the safety threshold...

And I imagine we're tickling the reason that GM did not develop (yet *fingers crossed*) a lowering kit for the MR-equipped SSs rolling around...

But the suspension system is popular, relatively affordable, and extremely effective. It's making its way into much, much less expensive cars than in years past...I predict we will see companies begin to branch out and calibrate MR for suspension modifications, in a similar manner, that some exhaust companies are beginning to adopt the NPP system into their aftermarket designs.

[17CamaroZL1]

It would be really nice if someone in the know could explain exactly how it works, and if the ride height makes a difference in how it works or if it's just the springs and new static position of the suspension that is changing the ride.

[17CamaroZL1]

Originally Posted by Mr. Wyndham

A slight drop....Say .5-.75 inches, would merely simulate a load in the car...the system can no doubt handle that. But our question is....the safety threshold...

I agree. I don't see a slight lowering causing any concerns. I would even venture to say a full inch would still be ok. I just wish someone would divulge the reason the front of the cars were raised in the first place and confirm everything will be fine to sit it down to equal out the fender gaps.

[XWoodyX]

Anyone ever consider that you can lower a C7 vette on stock bolts ~1" with no issues? And if I am not mistaken both cars are on FE4...

And yes I understand the springs are different between the two cars but are the dampers the same?

Scroll down to fasttoys response and watch the video.
http://www.corvetteforum.com/forums/...post1585075142

This may cause more questions than answers.

Another reference, scroll down to post #39 where he describes that the sensors are for relative position and #41 for more explanation on ride height affects:
http://www.ssforums.com/forum/wheels...springs-4.html

If nothing else, I will let you know as this is my car.

[laynlo15]

The proper way is to measure from the bottom of the wheel to the bottom of the fender well opening. A tire could be 1-2 lbs off and cause the measurement to be different or the floor might not be perfect. I've tried both ways and the most accurate is from bottom of the wheel. Try both ways you see the difference. I like it a little lower myself. I've got the springs from Phastech and mine is lower, this might be a different version then the SS.

[OminouSS]

We're talking about a pretty minor drop here. I do not think the mag ride will be rendered useless at 3/4". Perhaps there will be some compromise, but I really doubt it will be much. Watch this car squat at the front end when braking hard. Body roll at .3 G. My wife's fat friend sitting in passenger seat, etc.. The suspension is still functioning effectively. At a couple hundred bucks, I am willing to give this a shakedown if for only an A for effort. I may not change the back, but DANG, something needs to be done with this front. I get the heebeejeebies being up so high. Altitude sickness even.

[17CamaroZL1]

Here is Woody's post #39 reference that really helps explain how MRC works and supports my thoughts and understanding of it.

"I may be able to help clear up this topic a bit. I have been a damper and chassis systems engineer for more than 25 years. I worked for Delphi for nearly 20 years and spent several years of that time in their Chassis Advanced Development group helping to develop MagneRide (MR) dampers. I left the company several years ago, but at the time of my departure I was considered an expert in the technology.

The short answer to the OP's question: Lowering the vehicle will not affect the basic operation of the system. The system works by using the position sensor output to calculate how each wheel is moving relative to the other wheels and the vehicle body. From that information, the system calculates the ideal setting for each damper for any given road input. The key term here is RELATIVE; lowering the vehicle does not really affect how the wheels move relative to each other. However, please note that there are some specialized tuning features available in the MR system that can be affected by the vehicle ride height, but these features may or may not be in use in the SS. Even if they are enabled, they would only affect the system response at the limits of suspension travel, which is a pretty infrequent occurrence.

DISCLAIMER: My direct involvement with the system ended 8 years ago when I switched jobs. It is highly likely that additional features and improvements have been implemented in the control algorithm and electronics since then that may be affected by lowering the vehicle, but the basic system functions have not changed. "

[17CamaroZL1]

And here is post #41 Woody references. This is stated by the same damper and chassis engineer in post 39.

"One additional comment on spring changes: As stated above, lowering the vehicle won't affect the system. However, I forgot to mention that changes in spring rate, stab bars, etc, will cause some shift in the response. The system will still work to calculate the "ideal" damping force for any condition, but the system tuning is optimized for stock components, so there may be cases where the ideal isn't obtainable, especially for huge changes from stock. For reasonable changes in spring rate (say 20-25% or so) and ride height (say a 1" drop), you most likely won't be able to tell any difference from stock. In any event, you don't have to worry about damaging the dampers, even with large ride height drops, as long as you do not change the suspension stops or adjust the position sensors."

[17CamaroZL1]

Originally Posted by XWoodyX

Anyone ever consider that you can lower a C7 vette on stock bolts ~1" with no issues? And if I am not mistaken both cars are on FE4...

And yes I understand the springs are different between the two cars but are the dampers the same?

Scroll down to fasttoys response and watch the video.
http://www.corvetteforum.com/forums/...post1585075142

This may cause more questions than answers.

Another reference, scroll down to post #39 where he describes that the sensors are for relative position and #41 for more explanation on ride height affects:
http://www.ssforums.com/forum/wheels...springs-4.html

If nothing else, I will let you know as this is my car.

Thanks Woody!! Very good information! Please do let us know how your lowered ZL1 performs.