Quote:
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 
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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.
Quote:
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.
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As there is with anything!
That car does look sooooo nice.
Quote:
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.
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Good to know!
Quote:
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.
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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.
Quote:
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.
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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.