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Discussion Starter #1
I have some coilover questions that I wasn’t able to answer from reading various posts on this board. These are basic as my knowledge is limited. ouich

I recently installed GC coilovers. Right now the coilovers are set at OEM settings. Basically, the dampers are turned all the way to the right (i.e., soft setting) -- and I am not sure about the current camber settings.

As my car is pretty low in front, I am getting more “bottoming” in the front than I would like (just the front right for some reason). Therefore, it looks like I will need to raise the front.

Does anyone have instructions on how to raise the car? I am looking for specific tools needed and any other guidance (e.g., do I need to remove the wheels). Anything is appreciated, as I couldn’t find anything / illustrations on the board or web related to the GC coilovers. I know it is easy, but not sure about the specifics.

Also, can you please let me know how many turns from soft you are running on your set up. It looks like from what I have read on the board that 1 and ¼ turns from soft would be about right (even though I will need to play with it).

For those that have adjusted the camber on this set up, it appears from what I have been told I just need to loosen the three strut bolts and move the damper. Is there anything out there that illustrates the best way to move the damper and how much it should be moved? For example, if the damper is moved half of the permitted way, is this around 1.6 of negative camper (or there about). Is it moved by just pushing on it.

Also, I take it the wheels should be removed to facilitate this process. Finally, does it matter if both sides are not even?

Thanks guys. :cheers:
 

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Discussion Starter #4
If I firm up the front will this reduce the bottoming?

Thanks for the help.

ray540inyc said:
maybe you should just firm up the front a little?

ray
 

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im pretty sure it will , if what you mean by "bottoming" is the control arms hitting the bump stops on the frame causing the car to jutter. i think if you firm them up even a 1/4 turn you wont really notice anything driving wise.
im sure some one with a little more knowledge will chime in here.

ray
 

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Discussion Starter #6
I know it has to do with the bump stops hitting something. I thought the dampers, but don't really know.
ray540inyc said:
im pretty sure it will , if what you mean by "bottoming" is the control arms hitting the bump stops on the frame causing the car to jutter. i think if you firm them up even a 1/4 turn you wont really notice anything driving wise.
im sure some one with a little more knowledge will chime in here.

ray
 

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Assuming you are after handling performance and not just looks, the only way to properly setup coilovers is with a set of scales so you can corner balance the car. When you do this, one side of the car will actually be lower than the other (assuming you corner balance with your weight in the driver seat and nothing in the passenger seat), but the car will handle better. Here's a discussion and some alignment specs:

http://www.m5board.com/vbulletin/archive/index.php/t-39108

That being said, id be really interested in checking out your GC setup as Im considering the same for me. Can you post some pics??
 

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Discussion Starter #8
I cannot seem to post the same picture twice in different threads . . . Those guys are "trixy" they are . . .

However, my signiture has a link to DA where some pictures are located. I am also trying to get Bill to post a response once he is free and tired of me calling him . . . it might take some time ;)

Some pictures are also here

http://www.m5board.com/vbulletin/showthread.php?t=51405

It is a nice set up, but I am not too familar with the mechanics and would like to limit the bottoming that is now occuring.

03E39M5 said:
Assuming you are after handling performance and not just looks, the only way to properly setup coilovers is with a set of scales so you can corner balance the car. When you do this, one side of the car will actually be lower than the other (assuming you corner balance with your weight in the driver seat and nothing in the passenger seat), but the car will handle better. Here's a discussion and some alignment specs:

http://www.m5board.com/vbulletin/archive/index.php/t-39108

That being said, id be really interested in checking out your GC setup as Im considering the same for me. Can you post some pics??
 

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2003 M5!!! said:
I have some coilover questions that I wasn’t able to answer from reading various posts on this board. These are basic as my knowledge is limited. ouich

I recently installed GC coilovers. Right now the coilovers are set at OEM settings. Basically, the dampers are turned all the way to the right (i.e., soft setting) -- and I am not sure about the current camber settings.

As my car is pretty low in front, I am getting more “bottoming” in the front than I would like (just the front right for some reason). Therefore, it looks like I will need to raise the front.

Does anyone have instructions on how to raise the car? I am looking for specific tools needed and any other guidance (e.g., do I need to remove the wheels). Anything is appreciated, as I couldn’t find anything / illustrations on the board or web related to the GC coilovers. I know it is easy, but not sure about the specifics.

Also, can you please let me know how many turns from soft you are running on your set up. It looks like from what I have read on the board that 1 and ¼ turns from soft would be about right (even though I will need to play with it).

For those that have adjusted the camber on this set up, it appears from what I have been told I just need to loosen the three strut bolts and move the damper. Is there anything out there that illustrates the best way to move the damper and how much it should be moved? For example, if the damper is moved half of the permitted way, is this around 1.6 of negative camper (or there about). Is it moved by just pushing on it.

Also, I take it the wheels should be removed to facilitate this process. Finally, does it matter if both sides are not even?

Thanks guys. :cheers:
I would try calling Jay at Ground Control he developed these coilovers for the M5 ,he should be able to help answer your questions.
If you try a search using the words "jack stand" you will find some detailed information on how to safely raise your car.
 

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Are you sure all 4 dampers are set to full soft?? If the rear dampers were set full soft when installed, you will most likely need to tear them out, readjust and start over.

Damper settings:

A too-low damper setting will cause bottoming in the front and/or rear. I heard that Ground Control was shipping kits with damper preset with an "optimal setting" according to the springs chosen. I am perplexed when you say the dampers are set full soft...did you or your mechanic fiddle with the damper settings??

The front damper setting is easy to increase...get the knob & twist it. I would think a reasonable front damper setting would be 50% (1-1/4T from full soft). Be advised that the koni front damper specs are a bit are less ggressive than the rears, so they need a bit higher setting than the rear.

The rear setting is very, very difficult to increase. The shock must be removed and you need to basically "start over" with the install (remove the rear seat etc). The full soft setting on the rear Koni E39 shock is better suited to a stock 525i with stock springs. In fact, the same part# is used on 6 cyl cars. For this reason, a full soft setting is not adequate for an M5 and it is a worse match for the higher rate GC springs & lower ride heights. A setting of 3/4 turn to 1 turn from full soft (270 to 360 degrees) is a better match. You are not going to "play" with this setting too many times (lol). Sane street drivers looking for some comfort without compromising handling will prefer 3/4T from full soft. Folks who don't care much about ride quality and want to do lots of road racing events may want 1T or perhaps even 1-1/4T from full soft. Beyond that, the rear gets too loose in transient maneuvers or on damp or variable road surfaces and handling actually suffers. A racer will be hard pressed to turn better lap times with a setting of 1-1/4T compared to 3/4T, so keep this in mind. Folks who want a catchable, forgiving setup (BMW-like) should lean towards the softer setting. This will keep you off the guiderails after a few beers. In addition, lower settings reduce throttle-induced wheelspin exiting corners.

Spring preload & Ride heights:

Set the right and left side GC spring collars to the exact same thread count/position. Screwing the collars upward raises the car by the exact same amount. If you screw the collar upward by 3/4", this will increase the ride height by 3/4". The best ride heights for street are probably in the neighborhood of 13-1/2" to 14" from fender lip to center of wheel roundel. If you are experiencing lots of bottoming & you don't even know what ride height you have, better get out your tape measure. The rear is typically set slightly lower than the front...this is your call. A ride height of 14" or more will minimize bottoming in the front. Most E39 cars with coil-overs are set too low and jounce travel is inadequate. If you want good handling, the car should not be near the bumpstops at rest.

Do not be concerned about corner weights. Assuming your car is not bent from a horrific accident, the corner weights will be very good with balanced collar settings (same thread count right and left side).

I hope you know how to adjust the threaded collars. They are nuts on threads....just turn them. It's not rocket science. Jacking the car up with a hydraulic floor jack centered under the frame pocket under the motor will allow the suspension to droop. Under this condition, the springs relax and the collars can probably be turned with your fingers (or tool), after removing the wheels.

Hope this helps.
 

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2003 M5!!! said:
For those that have adjusted the camber on this set up, it appears from what I have been told I just need to loosen the three strut bolts and move the damper. Is there anything out there that illustrates the best way to move the damper and how much it should be moved? For example, if the damper is moved half of the permitted way, is this around 1.6 of negative camper (or there about). Is it moved by just pushing on it.

Also, I take it the wheels should be removed to facilitate this process. Finally, does it matter if both sides are not even?

Thanks guys. :cheers:
After reading your post, I realize that coil-overs and adjustable camber plates are a "real challenge" for non-gearheads. You need to study sites about coil-overs & camber/caster plates to get a handle on your new setup. It is wonderful, assuming you understand it.

The strategy used for adjusting camber plates varies widely. For your application, I would first get my ride heights set right before trying to fuss with the camber and caster settings. Any alignment efforts would be a waste of time at this point. I am not clear if you had the camber plate bolts cinched to 0/0 or some non-std setting.

You are not equipped to deal with multiple variables. Go to sites specializing in M3 and similar track cars and search for posts about this topic.
 

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Just a little note:

Koni's do NOT like to be at Full Soft. If they are single adj. then you are only adjusting rebound, not compression.

Jordan
 

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Discussion Starter #13
Thanks Lscman,

I am not sure how GC sent the shocks out and am in the process of getting the installation details from Bill. I think Noe of DA installed them, and think the settings were changed during install to "OEM" -- but it sounds like full soft is less than OEM?

I was a little suprised to find the fronts at full soft but these are very easy to adjust. The rears are a pain and would hope they are at the GC settings or somewhere closer to a half turn. Worse case, I will just have someone help with the rears at a local shop in a bit.

Thanks again as this information is very helpful -- as usual.




Lscman said:
Are you sure all 4 dampers are set to full soft?? If the rear dampers were set full soft when installed, you will most likely need to tear them out, readjust and start over.

Damper settings:

A too-low damper setting will cause bottoming in the front and/or rear. I heard that Ground Control was shipping kits with damper preset with an "optimal setting" according to the springs chosen. I am perplexed when you say the dampers are set full soft...did you or your mechanic fiddle with the damper settings??

The front damper setting is easy to increase...get the knob & twist it. I would think a reasonable front damper setting would be 50% (1-1/4T from full soft). Be advised that the koni front damper specs are a bit are less ggressive than the rears, so they need a bit higher setting than the rear.

The rear setting is very, very difficult to increase. The shock must be removed and you need to basically "start over" with the install (remove the rear seat etc). The full soft setting on the rear Koni E39 shock is better suited to a stock 525i with stock springs. In fact, the same part# is used on 6 cyl cars. For this reason, a full soft setting is not adequate for an M5 and it is a worse match for the higher rate GC springs & lower ride heights. A setting of 3/4 turn to 1 turn from full soft (270 to 360 degrees) is a better match. You are not going to "play" with this setting too many times (lol). Sane street drivers looking for some comfort without compromising handling will prefer 3/4T from full soft. Folks who don't care much about ride quality and want to do lots of road racing events may want 1T or perhaps even 1-1/4T from full soft. Beyond that, the rear gets too loose in transient maneuvers or on damp or variable road surfaces and handling actually suffers. A racer will be hard pressed to turn better lap times with a setting of 1-1/4T compared to 3/4T, so keep this in mind. Folks who want a catchable, forgiving setup (BMW-like) should lean towards the softer setting. This will keep you off the guiderails after a few beers. In addition, lower settings reduce throttle-induced wheelspin exiting corners.

Spring preload & Ride heights:

Set the right and left side GC spring collars to the exact same thread count/position. Screwing the collars upward raises the car by the exact same amount. If you screw the collar upward by 3/4", this will increase the ride height by 3/4". The best ride heights for street are probably in the neighborhood of 13-1/2" to 14" from fender lip to center of wheel roundel. If you are experiencing lots of bottoming & you don't even know what ride height you have, better get out your tape measure. The rear is typically set slightly lower than the front...this is your call. A ride height of 14" or more will minimize bottoming in the front. Most E39 cars with coil-overs are set too low and jounce travel is inadequate. If you want good handling, the car should not be near the bumpstops at rest.

Do not be concerned about corner weights. Assuming your car is not bent from a horrific accident, the corner weights will be very good with balanced collar settings (same thread count right and left side).

I hope you know how to adjust the threaded collars. They are nuts on threads....just turn them. It's not rocket science. Jacking the car up with a hydraulic floor jack centered under the frame pocket under the motor will allow the suspension to droop. Under this condition, the springs relax and the collars can probably be turned with your fingers (or tool), after removing the wheels.

Hope this helps.
 

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Discussion Starter #14
Lscman,

Can you suggest a site that will have a good discussion? I have done a bunch of web searches and just get this and that . . .

Thanks again.

Lscman said:
After reading your post, I realize that coil-overs and adjustable camber plates are a "real challenge" for non-gearheads. You need to study sites about coil-overs & camber/caster plates to get a handle on your new setup. It is wonderful, assuming you understand it.

The strategy used for adjusting camber plates varies widely. For your application, I would first get my ride heights set right before trying to fuss with the camber and caster settings. Any alignment efforts would be a waste of time at this point. I am not clear if you had the camber plate bolts cinched to 0/0 or some non-std setting.

You are not equipped to deal with multiple variables. Go to sites specializing in M3 and similar track cars and search for posts about this topic.
 

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Discussion Starter #15
Thanks.

I did send Jay an email. I know he is very busy so we will see.

M5HP said:
I would try calling Jay at Ground Control he developed these coilovers for the M5 ,he should be able to help answer your questions.
If you try a search using the words "jack stand" you will find some detailed information on how to safely raise your car.
 

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2003 M5!!! said:
Thanks Lscman,

I am not sure how GC sent the shocks out and am in the process of getting the installation details from Bill. I think Noe of DA installed them, and think the settings were changed during install to "OEM" -- but it sounds like full soft is less than OEM?
The Koni rear yellow sport shock can not easily be compared to OEM. At full soft, they will feel a bit stiffer than stock...but this would be a poor match to the GC rear spring. Dampers must be matched to springs.....stiffer spring requires a stiffer damper. Underdampening is never desired unless you're on a pogo stick.

The full soft setting is not advised on the Koni adjustables because it can cause issues. I think it has to do with the threaded adjustment inside being stressed under some conditions. With healthy bumpstops it may or may not be an issue....don't know. You should generally turn it at least 1/4 turn off the stop.

A full soft setting does not provide good jounce/rebound balance, so this is another shortcoming.
 

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2003 M5!!! said:
Lscman,

Can you suggest a site that will have a good discussion? I have done a bunch of web searches and just get this and that . . .

Thanks again.
Try Corner-Carversdotcom and other sites that attract amateur Road Racing track junkies who own rear wheel drive cars with mcpherson strut front suspension. This will include M3 & Mustang. Search on camber plates, corner weights, coil overs and such. Such information will not exactly fall in your plate though...it'll take work to collect & sift thru baloney.

When you get your ride heights set properly, I can advise you how to use the camber plates to your advantage. This strategy will allow you to temporarily alter settings for track or special duty & then precisely return them to street settings with a wrench in about 15 minutes. This is the beauty of adjustable suspension...you can improve handling and reduce tire wear.
 

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Discussion Starter #18
Thanks Lscman!

Lscman said:
Try Corner-Carversdotcom and other sites that attract amateur Road Racing track junkies who own rear wheel drive cars with mcpherson strut front suspension. This will include M3 & Mustang. Search on camber plates, corner weights, coil overs and such. Such information will not exactly fall in your plate though...it'll take work to collect & sift thru baloney.

When you get your ride heights set properly, I can advise you how to use the camber plates to your advantage. This strategy will allow you to temporarily alter settings for track or special duty & then precisely return them to street settings with a wrench in about 15 minutes. This is the beauty of adjustable suspension...you can improve handling and reduce tire wear.
 

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Discussion Starter #19
When DA installed them Bill indicated that he would put them at near stock settings . . . . and as I don't know what that means (and just figured out about what people like for the Konis post installation ouich . . . I am still learning) I kind of left it in his and Noe' hands to get it to the correct starting point for me to play with, etc.

It is possible that the rears are not at full soft (as I was suprised, based on what I have read, that the fronts were at full soft) but I am tracking down this information. I am trying to give Bill a breather as I was taking up a bunch of his time via phone and emails while my car was there. The "issues" with the full soft setting is what concerns me and makes me wonder if I need to adjust the rears ASAP. I read about some of these issues on line too.

Thanks again for your help. It is greatly appreciated. Once I get through these issues, I will send you a note on the cambers.



Lscman said:
Try Corner-Carversdotcom and other sites that attract amateur Road Racing track junkies who own rear wheel drive cars with mcpherson strut front suspension. This will include M3 & Mustang. Search on camber plates, corner weights, coil overs and such. Such information will not exactly fall in your plate though...it'll take work to collect & sift thru baloney.

When you get your ride heights set properly, I can advise you how to use the camber plates to your advantage. This strategy will allow you to temporarily alter settings for track or special duty & then precisely return them to street settings with a wrench in about 15 minutes. This is the beauty of adjustable suspension...you can improve handling and reduce tire wear.
 

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Discussion Starter #20
As usual Lscman was on it . . .

I called GC to figure out if the dampers in the rears were pre adjusted and to what setting. I talked with the guy (who says he did mine . . . who knows . . . maybe he did Mark's) and he indicated that the rears come pre set at 3/4 turn from full soft (or 1 and 1/4 turn back from full stiff).

They also indicated that the fronts do not get pre adjusted so they come at full soft (man I feel like I am conducting a sex ed class . . . hiha ).

I did adjust the fronts to 1/2 from soft (and need to add some more probably given the new info) and the bottoming issue has gone away. If it stays away then I might leave the ride height as is . . . .

Thanks everyone!
 
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