91 air ride tweaks ?

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donmega

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I was thinking of modifying the stock air ride and possibly interfacing to my alarm system.

BUT I have some questions, how low will the car drop with the stock air ride? How high up will it go?

I know with the current pump and selinoids you could never get it to raise or drop at a decent speed but I was thinking of interface my alarm system to deflat the air ride 100% when parked and armed, BUT throw in another relay so it wont do it while just armed, only when
Parked, NOT running, Armed
Then it will deflat 100% to hopefully set the car on the ground.

From there Ill interface the pump to kick back on when remote started, also add a timer to NOT deflat until
Car has been off/parked/armed for x amount of time, I can do that with a timer module.


I looked over the air bag assemblies and noted the control selenoids on top of the struts, I seen several wires and plan to pick up a haynes/chiltons to find out what wire needs to be grounded or supplied with 12v to let the selenoids release the air from the bags.

so what do u guys think? I know I can do cause ive done some pretty crazy shhtuff with alarms/relays/timers like forcing your blower motor to kick on max after remote started and temp has stabalized :)
But how low will it go?
 
it will drop to the bump stops... still clearance to drive, but won't ride worth a poop... as an indicator... at the top of the wheels, about 1/2 of the tire itself is up inside the wheel well. (at least in rear, mine was recently there!).

as far as venting the bags, they will drop FAST... raising them takes a while (compressor don't move much air). Grounding one of the leads on the solenoids will open them, and to vent air you need to open the vent solenoid in the compressor (not sure if it needs 12v applied or a ground circuit).

don't bother with chilton/haynes... get a Helm (factory manual). little more $, but often found on ebay cheap. will pay for itself the first time you need to use it. there is so many computers and electronic options on these cars, that changed from year to year, you really need the factory manual.

One thing you don't want to do, is fill the bags from totally empty any more than absolutely needed... the compressor has like a 5% duty cycle... it will greatly reduce its life expectancy
 
Well if I do this the first thing on my list will be a real air ride compressor and probably a pancake tank that will fit in the spare tire spot, maybe, i dunno yet where im going with this.

Any chance you can get me the wire on the selenoid to hit with a gnd and and the wire to hit on the compressor?

Thanks in advance
 
let me check in my manual, and will get back to you on the wiring... since the ride control computer is in the trunk, I will try to get the wire colors and position in the connector at the computer. I will also try to get the individual wiring info, incase my manual is different (its for a 92, but have found 99% of the stuff on the 91 is the same).

it might take a day or, so be patient unless someone else chimes in
 
So far I unplugged the hoses from the compressor, turned the key on and watch the front drop on its nose.

Not sure if the back dropped at all and if it did it was very little, this is probably because the solenoids for the rear didnt open with the key on at that time.

It wasnt too bad refilling them, shorter then I thought it was going to be without a tank anyway.

So heres where I think im going to go with this. I still need to have a good look at how everything comes together though.


/
T off the bags, one side goes to stock system, other side goes to fast action solenoids then to newly added tank.

Add tank + new compressor in trunk.

add five switches somewhere around dash, 3 position momentary switches for up down control of each bag + 1 switch to control all 4 at once.

Add another on/off switch to engage stock system or disengage to allow me to control the bags myself.

Ill also most likely add other goodies down the road like front/rear pressure gauges and possible eliminate the stock system and add features to my system like auto leveling, soft/firm & high low ride control switches, etc..

Lets keep this thread alive, I know im not the only one thats wanted to do this, I always wanted air ride but never wanted to buy/install the bags and comprimise a perfectly good spring/shock setup for something I think is usally too soft and cushy, but since its already there why not right?
 
I will get the wiring info posted as soon as I can.. again, this is comming from a 92 manual, altho the wiring is the same, some wire colors may be different.

The reason the front dropped and not the rear, is the rear was probably already high enough, but front low. the order of raising the car is rear first, then front.

Just an FYI,, there are 2 height sensors in front (one on each side), only one on rear (pass side).

even if you put in new solenoids someplace in the air lines other than using the ones on the air struts themselves. they need to be opened to raise or lower the corner.. also to lower the corner you need to open the vent valve in the air compressor.. when I post the wiring info, that will be there too.

if the compressor/dryer assy has an air fitting (for attaching an air chuck for shop filling of the system), that would be a good place to connect your additional air supply. otherwise, you can drill and tap a fitting into the dryer (near top). you want to make sure that you run ALL air comming and going in the system thru the dryer.. or your bags/solenoids/compressor will die early death from moisture.

Turning the onboard system off should be fairly easy... just wire in series with the switch in the trunk.

look for the wiring info a bit later (maybe tonite, but no promises)
 
well, here is some info.. hope it helps..


right front solenoid: O/R=comp pin 17
right rear solenoid: LB/BK=comp pin 38
left front solenoid: LG/O=comp pin 21
left rear solenoid: P/LG=comp pin 41

All wheel solenoids have GY wire grounded.

Vent Valve (on compressor). GY= ground
PK= comp pin 42

compressor relay GY= ground
DB/Y= comp pin 35



Looks like on the diagram I have that you supply 12v
to the solenoids to open them (would double check it
first thou by measuring on un-altered circuit).

Gave the pins to turn on the compressor relay because
its fused at 40A already, no need to redo that stuff!

You may want to isolate anywork you do by putting diodes
in series with the ouputs from computer to protect it.


Looking closely at the wiring for the 92's.. there are
so many inputs to the ride control computer its not funny.
it moniters how much turn rate is on steering wheel, as well
as position of it, how hard brakes are applied, how fast the
ride height changes, how fast vehicle is going, and an input
from the engine computer.. uses this info to adjust ride
height as well as the firmness of the shocks.


I can't stress this enough, this info is from a 92 manual.. it may not be
exactly the same as the 91. I happen to have the complete car line for 92 on
CD, and since I have a 92 Cougar as well, it has served me well (for both cars). I will NOT be held responsible for any damage or other problems that result from this info
 
I agree with the diodes, now heres the only question I have.

Wheres the computer your reffering to located?
 
lemme remember....

I *think* it is located on left side of the trunk near the suspension shut off switch... but will verify that when I get home from work.

also, the stock amp for the stereo is located in that are too...(that I am sure of). The amp has heatsinks on it, the air suspension computer does not.
 
Cool I was wondering where I was gonna find that stock amp too.

Im gonna install an aftermarket 4 channel in its place, heres the cool thing though.

From my last car I still have all my audio equipment, and I remember thinking "damnit Im gonna have to run all new wires to the trunk for my highs again, not with this car though, just gotta run the rca's back and power wires.

For now I just ran my radio into the stock amp which sux cause its a sony and beeps everytime you change cd tracks, or radio stations and its amplified now.

I knew that was comming though since I helped a person back in '00 (he;s actually my best friend now) with wiring a radio on a cougar with a factory amp.

Think im gonna go ahead and throw my 15's in today and wire up those amps and my extra battery in the trunk and ill look for the computer while im back there, see if I can make something happen.
 
Well I got the system in today but didnt have time to play with the air ride, man it sounds like crap with the stock amp, the highs just give out way to soon, definetly need to put my amp in.
 
did you find the air ride computer???

did you replace the typically lame stock speakers??? unless you have JBL level sound, they are not much. At least on my 90, the JBL's in back are 3-way. but ya, the amp cant compete with most aftermarket amps.
 
Found the ride computer and the factory amp.

Havent done the high's yet. I have some decent 6x9's already from my neon which was my last car and some aftermarket 3.5" for the dash from my neon.

I didnt bother to take out the neon door speakers though because they where older panasonics I just had laying around.

I think this lincoln is 5.25 in the doors anyway and not 6.5".

So that will most likely be today with the bypassing of the factory amp.

I tested the 2 rear solenoids and just unplugged one of the lines from the pump and there went the rear so the colors appear to be right.
BUT word of caution, theres 2 purple/lt green wires, I got lucky and found the right one without checking the pin #, I also used a multimeter and tested to ground resistance and just used the one that matched closest to the right rear solenoid wire.

I want to buy a tank and another pump before I run any wires off those though because I dont want to abuse the stock pump to much, although like I said before it fills the bags pretty quickly for a stock pump and no tank.

Of course I might have to put all this on hold because of those wheel bearings or whatever it is I mentioned in my other thread.
 
I just thought of something that I don't think has been addressed yet...

the addon pump/tank.. you will need to isolate them somehow from the existing compressor/vent valve... what I mean is some way to keep the compressor vent valve from dumpin all the air in your reserve tank when the vent vavle opens. (probably a solenoid to close off the air line to the addon tank when it not used)

Also, I didn't mention (I don't think), but the air lines in the stock configuration do not hold any air pressure when the system is not 'active' (filling or venting). only when its doing something is there any air pressure in the lines. the sealing method isn't the best thing on the planet.. works for the application as designed tho. it is almost 'normal' to have some small amount of air leakage at the airline connections.
 
Ok I finally get a picture of how the system works, I see now the pump itself has no control over what bag gets or depletes any air, basically i just pumps into all 4 lines then opens the proper solenoid/s, then when venting is needed it opens the vent for all 4 lines and opens the proper solenoid/s.

So the best way is going to be to remove the factory pump all together.

Heres how it will have to go

Add a new tank and pump in trunk

Add 1 input + 4 outputs to tank, each output will need its own solenoids RIGHT AT THE TANK to prevent any line pressure when not in use.

Then link each solenoid on the tank to the existing solenoids on the car, so the computer will open 2 solenoids at once instead of just one.

basically the pump will maintain itself and wont need to be wired to kick on when needed cause it will just keep the tank @ whatever pressure.

This will work for filling the bags
Now for venting.

I want my bags to vent as fast as possible so I will need 4 more solenoids and I will need to T off the stock lines, I also want them to vent outside of the car for that cool "swissshhhhhhhh" noise.

So I will basically T off with about 5" of line then mount another solenoid goin into freeair.

From there run the stock pump vent trigger wire to ALL 4 solenoids outside the car so they all will open then let the computer or my additional controls decide which bag/s to vent from the solenoids on the bags.

OK now your thinking, well if you do that your tank will also open to the same bag and try to fill as your venting.
EASY add a relay to each solenoid so the ones on the tank WONT open IF the vent wire is hot.

What do you think?

BTW the venting could be done easier, ALOT easier without T's and all the extra wiring if I wanted to vent at the tank but I figure if im gonna do it then its gonna be the way i want.

So now the computer and myself can control the air ride and not only that but response time will be greatly reduced when the computer is controlling the system.

Got a few very important q's though.

1- Whats the max pressure on the bags? Will need to know this to know what psi to set the tank to.

2- Does the stock computer monitor pressure at all to know when their full or does it just pump until a certain height is reached?

3- What size lines are these anyway?

4- Are the lines being reduced anywhere? As in are there bigger fitting to possible accept a larger line at the bags?

Thanks for helping me with this btw.
 
#1... rears need about 85 or 90 psi I have heard to lift em.. fronts 100-115..
#2... does not monitor air pressure.. just pumps till the computer reads the right height.
#3... dont know the actual dimension, but they do not have any splices or anything... I belieive they are are one piece from the dryer to the solenoid at the wheel.
#4... dunno.

one thing you may need to address is moisture.... the system as designed by ford dries the air on the way into the lines, and uses exhaust air to 'dry' the dryer.. (thats why vent valves fail so often, they rust). the bags want and need good dry air. you will probaby want to somehow make sure the air going into the bags is dry.
 
1- was wondering what the max pressure I could put to them is, not whats needed to lift them. Sorry for the misunderstanding.

I just dont want to blow them out if I fill the bags to 175psi.


For the drying I plan to use a moisture trap between the pump and the tank then another for the front lines and another for the rear lines. That should be plenty.
 
the drying solution would seem to be a good one.

as for the max air pressure, I am not sure... since the bags need in the neighborhood of 100 lbs (give or take depending on end) to raise the car to ride height, I would *guess* 150 would be safe. I am guessing that because of the increase in pressure when the suspension compresses. but that is just a guess.. based on no facts at all!
 
I think what im gonna do is hook up the stock pump to a small tank with a gauge and see what it can do max and take my que from that.

Probably gonna start buying parts now since the solenoids are so damn expensive that way I'll have everything when it gets warm.

Im gonna go out on a limb and say these are 1/4" lines and just buy that and make it work :)

Maybe Ill have to stop by and show it off when its all done, Im near Detroit.
 
I doubt they are 1/4 inch... they are plastic lines inside rubber protective hoses.. the rubber does not carry any air. I would guess 1/8th, if I had to make a guess.. but then EVERYTHING on this car is metric, so it wouldnt surprise me if they are some metric size
 
Oh I didnt know if they measure by the OD or ID, if its ID then yeah 1/8" but if its OD then its 1/4"

Also by any chance do you have the wire colors for the stock speakers @ the factory amp? I have the colors for the wires from the radio to the amp but not from the amp to the speakers.

Also wanted to let you know I picked up a manual and now I have a real good visual as to how everything is for the air ride, The solenoids are connected directly to the bags with a push and turn connector, so upping the line size is NOT an option, neither is replace the stock solenoids with better/bigger/faster ones.
 
will post what I have for the 92's speaker wires.

your right on the solenoids... quite an ingeneous design, actually. but it does limit you to modifications. I would offer to send ya a stock solenoid, but I need to keep my spares, I am replacing mine as I change my struts out (my parts car has 44000 miles on it, and less than 2 years on the struts!).

you could up the line size, just have to drop it down close to the solenoid... it won't be as good as large line all the way thru, but will help some.

If you need splices for the lines, one of the aftermarket strut people (either strutmasters, or arnott) sells a splice kit for the stock lines...
 
So far I havent had any luck finding reducers to 1/8" lines, I did find some place that sells 1/8" but no reducers.

I can change any line size from 1/4" - 3/8" - 1/2" those 3 sizes but theres really nuthing out there for 1/8"

Ill check strutmasters and the other site like you mentioned and see what they have.

Maybe I should post a new thread asking if anyone converting or replacing their bags/solenoids would sell me one for shipping or something just so I can disect it and see it in person.
 
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