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Air Suspension Question

CTX-SLPR
December 30th, 2004, 09:37 AM
Howdy,

Does anyone know the operating pressure of the Air Suspension system and what kind of inputs the chassis control computer that controls the system takes? I'm considering attempting to retrofit the control module from a Mk VIII to control an Air Ride shockwave system on a 65 Riviera and I'd like to see how simular the system is to the Air Ride and if I can fabricate the needed inputs for the computer.

Thanks,

CTX-SLPR
January 7th, 2005, 09:30 AM
Oh come on!! I know ya'll know the operating pressure if not the inputs to the computer that controls all of this. Throw me a bone here.

1wykdmk8
January 7th, 2005, 09:43 AM
Oh come on!! I know ya'll know the operating pressure if not the inputs to the computer that controls all of this. Throw me a bone here.

If you are using Air Ride Technologies parts, why not use the auto leveling Ride Pro module they have, or their new LevelPro?

djKale
January 7th, 2005, 10:02 AM
Howdy,

Does anyone know the operating pressure of the Air Suspension system and what kind of inputs the chassis control computer that controls the system takes? I'm considering attempting to retrofit the control module from a Mk VIII to control an Air Ride shockwave system on a 65 Riviera and I'd like to see how simular the system is to the Air Ride and if I can fabricate the needed inputs for the computer.

Thanks,

It takes 100psi to raise the front of a Mark VIII and about 60 to raise the rear. The system does not work off of pressure, it works off voltage from the height sensors. It also has an input for the speed sensor so it can raise/lower at speed. The module that controls the suspension also controls the power assist.

The module sends out a 5v reference and depending on what it gets back, it tells the computer that the car is at A) trim height, B) too low, or C) too high.

It is also finicky and will error if it gets an out of range signal, thus shutting the system down. The module controls the four air bag solenoids, a vent solenoid and the compressor via a solid state relay.

I think it is possible to retrofit the module to control shockwaves, but then the system will work the same way as a stock Mark VIII. That being the case, you would be wasting your time IMHO since it was not designed to function the way most aftermarket air suspensions operate. I have a 93 Mark VIII that has been through many different air suspension set-ups. I used the computer to control my fast bags, but ran into many quirks. I could write a long list a drawbacks (for my application - a fast bag system), but I'll spare you the details. There's lots of other things to know about how the system works and what all it ties into. Email me if you have any questions.

Kale

CTX-SLPR
January 7th, 2005, 12:05 PM
Thank you,
I didn't look at Air Rides site very well and my research from a few months back about the possible purchase of a MkVIII led me to remembering the air suspention.
What I am really interested is the feature of the MkVIII system that lowers the car at speed and I thought the system had a vehicle stability control built in so that it would help counteract body roll and improve handleing. Please shoot me an email on how you think would be the best way, if any, to accomplish what I thought the MkVIII controller would do.

Thanks,

Jamler3
January 7th, 2005, 12:40 PM
It takes 100psi to raise the front of a Mark VIII and about 60 to raise the rear. The system does not work off of pressure, it works off voltage from the height sensors. It also has an input for the speed sensor so it can raise/lower at speed. The module that controls the suspension also controls the power assist.

The module sends out a 5v reference and depending on what it gets back, it tells the computer that the car is at A) trim height, B) too low, or C) too high.

It is also finicky and will error if it gets an out of range signal, thus shutting the system down. The module controls the four air bag solenoids, a vent solenoid and the compressor via a solid state relay.

Kale


Kale, I've got a bit of a rub situation only in the REAR on my '98 MKVIII.
Sounds like you have experienced enough stuff on these air systems to let me know what my options are... The Air Springs are working fine... However I don't think the rear is getting enough air... This is only based on the fact that I'm getting some tire rub when I hit s stiff dip in the road. I'm not sure anything has changed on regarding sensor hight. I know I did not touch anything, however perhaps the guys who put my wheels/tires on did...

djKale
January 7th, 2005, 09:49 PM
Kale, I've got a bit of a rub situation only in the REAR on my '98 MKVIII.
Sounds like you have experienced enough stuff on these air systems to let me know what my options are... The Air Springs are working fine... However I don't think the rear is getting enough air... This is only based on the fact that I'm getting some tire rub when I hit s stiff dip in the road. I'm not sure anything has changed on regarding sensor hight. I know I did not touch anything, however perhaps the guys who put my wheels/tires on did...

You can try raising the rear slightly by moving the rear sensor bracket. You would need to move the rear sensor top mount down so the rear sensor compresses more when attached.

Read the last part of this page where it talks about the rear suspension.

http://www.lincolnmarkviii.org/suspension/sensorlowering.htm

Kale

djKale
January 7th, 2005, 10:04 PM
Thank you,
I didn't look at Air Rides site very well and my research from a few months back about the possible purchase of a MkVIII led me to remembering the air suspention.
What I am really interested is the feature of the MkVIII system that lowers the car at speed and I thought the system had a vehicle stability control built in so that it would help counteract body roll and improve handleing. Please shoot me an email on how you think would be the best way, if any, to accomplish what I thought the MkVIII controller would do.

Thanks,

I'm not sure exactly what all is involved with adapting this feature to different car, but I know the stock system lowers 20mm at 105km (~65mph) and starts to raise back up when you hit ~45mph.

When you start a Mark VIII and sit in the seat, it raises 20mm from it's parked position. So when it lowers 20mm at speed, it actually sits at the "parked" height. Conversely, when you stop the car and close the last door, the car drops 20mm to rest at it's parked height.

Within one hour of shutting off, if the car senses it is too high, it will lower until the sensors are within spec. On the other hand if it senses it is too low, it will not raise until the hour has passed, then it will attempt to raise the car for 45 seconds (to conserve battery life).

The only reason I mention all these features is to give you an idea of how extensive this system is and how it is integrated into the many different vehicle systems. It might be easier to tap into the speed sensor and create your own circuit just for lowering/raising if that is what your objective is.

You might want to read this article:

http://www.lincolnmarkviii.org/suspension/asexplained.htm

Kale


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