Installing INTRAX Lowering Springs and KONI Adjustable Shocks - The Unofficial BMW M5 Messageboard (m5board.com)

KingM5 · 17th April 2006, 03:20

I purchased 4 INTRAX Lowering Springs and KONI Yellow Adjustable Shocks
which will be installed this week.

http://www.intraxsuspension.com/prod_springs.html
http://www.koni.com/

Fronts
KON8741-1372SP Sport Shock Absorbers
Rears
KON8240-1156SP Sport Shock Absorbers

KONI adjustment questions:

-When adjusting the Front Shocks I noticed it has 1 7/8 available turns from full soft (using knob) . So the recommended value of "3/4 from full soft" is 3/4 of 1 7/8 or simply 3/4 from the full soft reference?
The weird part is I tried to readjust them later and now I have no reference point the knob just keeps turning either direction without stop.
Any ideas? Do I have to compress the shocks?

-the Rears did not come with a knob(using a vice) and instructions say to compress the shock and turn it counterclockwise until it is locked. Then turn clockwise 180degrees(1/2turn). Once it is locked I noticed there is 2 3/4 turns available clockwise(not consistent)...again is it 1/2 turn from the full soft reference or 1/2 of 2 3/4?

I want to set the rears at 1/2 from full soft and 3/4 fronts as recommended.

Info from KONI;
Rears:
http://www.koni-na.com/comp.cfm
Front:
http://www.koni-na.com/knob.cfm

Thanks!

6spd · 17th April 2006, 04:04

KingM5, I know those springs are a good combo with Koni shocks, should work good for a all around setting. On the rear setting I'd suggest more towards the 3/4 turn from full soft. At first it will feel real stiff but it works it way to feeling looser.
If the front can twist with no stopping, I'd contact the seller or Koni before even wasting time on a install.

Lscman · 17th April 2006, 16:20

I think the rear shocks have a total of five "half turns" in them plus about 1/4 turn of slop. Maybe it makes more sense to convert this to degrees and be done with it (2T=720degrees, 3/4T=270degrees, so total 2-3/4Turns = 990 degrees)

Konis should be adjusted from the full firm setting to obtain the best balance between two different dampers. Greater error results if you're calibrating them from full soft. In addition, their internal mechanicals can not withstand being twisted hard towards the "full soft" stop. They should never be set 100% soft.

First, I generally figure out what the total range or span is by gently twisting in both directions while clamped in vise with plywood spacers to protect threads and shaft. (in this case 2-3/4T). Also be careful because the rod is thin enough that you could accidently bend it with accidental lateral force.

Example:

If the popular or desired setting is 1 full Turn (360 degrees) from full soft, that's actually 3 "half turns" plus 3/4 of a full turn from full firm ((180x3) for three half turns + 270 for 3/4 turn = 810 degrees from full firm). Always set the shock to full firm and rotate it the proper amount from there.

My wild guess would be 3/4T to 1T from full soft for Intrax. These are progressive lowering springs, so significant damping is needed. "Too soft" rear damper settings could cause underdamped bounce.

KingM5 · 18th April 2006, 07:33

Quote:

Originally Posted by Lscman

I think the rear shocks have a total of five "half turns" in them plus about 1/4 turn of slop. Maybe it makes more sense to convert this to degrees and be done with it (2T=720degrees, 3/4T=270degrees, so total 2-3/4Turns = 990 degrees)

Konis should be adjusted from the full firm setting to obtain the best balance between two different dampers. Greater error results if you're calibrating them from full soft. In addition, their internal mechanicals can not withstand being twisted hard towards the "full soft" stop. They should never be set 100% soft.

First, I generally figure out what the total range or span is by gently twisting in both directions while clamped in vise with plywood spacers to protect threads and shaft. (in this case 2-3/4T). Also be careful because the rod is thin enough that you could accidently bend it with accidental lateral force.

Example:

If the popular or desired setting is 1 full Turn (360 degrees) from full soft, that's actually 3 "half turns" plus 3/4 of a full turn from full firm ((180x3) for three half turns + 270 for 3/4 turn = 810 degrees from full firm). Always set the shock to full firm and rotate it the proper amount from there.

My wild guess would be 3/4T to 1T from full soft for Intrax. These are progressive lowering springs, so significant damping is needed. "Too soft" rear damper settings could cause underdamped bounce.

The front M5 KONI's have exactly 1 7/8 turn from full soft to full firm (675degrees) therefore I adjusted the fronts 506.25 degrees (1 7/16 turn) from full soft (3/4)

The rear M5 KONI's have exactly 2 5/8 turn from full soft to full firm (945degrees) therefore I adjusted the rears 472.5 degrees (1 5/16 turn) from full soft (1/2)

Please correct me if I'm wrong

Thanks

Lscman · 18th April 2006, 19:09

Quote:

Originally Posted by KingM5

The front M5 KONI's have exactly 1 7/8 turn from full soft to full firm (675degrees) therefore I adjusted the fronts 506.25 degrees (1 7/16 turn) from full soft (3/4)

The rear M5 KONI's have exactly 2 5/8 turn from full soft to full firm (945degrees) therefore I adjusted the rears 472.5 degrees (1 5/16 turn) from full soft (1/2)

Please correct me if I'm wrong

Thanks

You seem to have set the rear to 50% setting (halfway between full soft and full firm. From what I've seen, folks trying this setting invariably tear the shocks off a second time and soften them to somewhere between 1/2 to 1 turn from full soft. With the springs you have, anything over 1-1/4T from full soft will almost definitely be too stiff. If you could tell us the spring rate or coil specs, we'd know more. If you have a dial caliper, please tell me wire diameter, coil count and coil OD. We can compare them to H&R progressives for 540i and get a real good estimate for damper setting. The rear of the car is only 120# heavier than a 540i, about 1 skinny passenger or less than a tank of gas.

If the dampers are set too high with moderate rate progressive springs, you will discover that the car goes into an instantaneous oversteer condition under hard transient maneuvers. This makes the highly predictable E39 chassis feel more like like a solid axle Mustang in evasive meneuvers and rain conditions.....not good. The car will be unforgiving try to swap ends under racey conditions. It can get you in trouble if you have a couple beers or conditions are not optimal.

The setting you chose is higher than Ground Control or Dinan recommends & I found it to be way too stiff also. In this case, higher is NOT better for handling. I might try 1-3/8 Turn from full soft if I had 425lb/in GC-Eibach race setup...generally most other springs are lower rate and require less damping.

If you set the rears to 50%, your first test drive impression will be yikes. It will ride harder than a Z06 or M3. The extra damper rate will most definitely degrade handling, even on a dry track. I think you would need 500#/in rate springs to make those shocks move in a properly-controlled fashion, so tires follow the road surface and allow suspension movement instead of overpowering the springs & skipping along like a solid axle...

There are a few threads here and elsewhere about koni settings that have been posted by folks who learned the hard way. You might review them. The optimal shock settings for GC are lower than what you chose.

JMO.....

KingM5 · 19th April 2006, 02:40

Quote:

Originally Posted by Lscman

You seem to have set the rear to 50% setting (halfway between full soft and full firm. From what I've seen, folks trying this setting invariably tear the shocks off a second time and soften them to somewhere between 1/2 to 1 turn from full soft. With the springs you have, anything over 1-1/4T from full soft will almost definitely be too stiff. If you could tell us the spring rate or coil specs, we'd know more. If you have a dial caliper, please tell me wire diameter, coil count and coil OD. We can compare them to H&R progressives for 540i and get a real good estimate for damper setting. The rear of the car is only 120# heavier than a 540i, about 1 skinny passenger or less than a tank of gas.

If the dampers are set too high with moderate rate progressive springs, you will discover that the car goes into an instantaneous oversteer condition under hard transient maneuvers. This makes the highly predictable E39 chassis feel more like like a solid axle Mustang in evasive meneuvers and rain conditions.....not good. The car will be unforgiving try to swap ends under racey conditions. It can get you in trouble if you have a couple beers or conditions are not optimal.

The setting you chose is higher than Ground Control or Dinan recommends & I found it to be way too stiff also. In this case, higher is NOT better for handling. I might try 1-3/8 Turn from full soft if I had 425lb/in GC-Eibach race setup...generally most other springs are lower rate and require less damping.

If you set the rears to 50%, your first test drive impression will be yikes. It will ride harder than a Z06 or M3. The extra damper rate will most definitely degrade handling, even on a dry track. I think you would need 500#/in rate springs to make those shocks move in a properly-controlled fashion, so tires follow the road surface and allow suspension movement instead of overpowering the springs & skipping along like a solid axle...

There are a few threads here and elsewhere about koni settings that have been posted by folks who learned the hard way. You might review them. The optimal shock settings for GC are lower than what you chose.

JMO.....

My bad. I contacted Intrax and KONI and they both agree that a 180 degree(1/2 turn) from full soft is the best setting for the car in the rear (as you mentioned)
The fronts I don't have to worry about so much so 3/4 will be set for now.

On another note I talked to one installer with KONI experience and he told me he has had countless issues with the KONI shocks leaking etc. Some cars needed replacements in 2 months. Have you heard such things? Other vendors report no problems..

Lscman · 19th April 2006, 03:16

Quote:

Originally Posted by KingM5

My bad. I contacted Intrax and KONI and they both agree that a 180 degree(1/2 turn) from full soft is the best setting for the car in the rear (as you mentioned)
The fronts I don't have to worry about so much so 3/4 will be set for now.

On another note I talked to one installer with KONI experience and he told me he has had countless issues with the KONI shocks leaking etc. Some cars needed replacements in 2 months. Have you heard such things? Other vendors report no problems..

I never heard of Koni's leak out-of-the-box like that unless they were NOS (old stock). I've seen situations where vendors hold onto Konis for many years and these can have hard seals that puke hydraulic oil. One area of concern is ebay & you may get hassles from Koni if you ever try to get them rebuilt under warranty without a retail sales reciept. Koni tries to prevent warranty work on shocks that are not original owner. One important thing to consider when buying Konis is to buy from a vendor with high stock turnover rate or get confirmation on the date code stamped into the body of the shock. I bought stale 4 year old Konis for my Lincoln and they needed rebuilt after 130K mi, but I consider this lucky. The konis can actually puke out their fluid if they're stored for extended periods laying flat. Ideally they should be stored in the position they sit on the car & pushing the rod in once a year will keep the seals damp and effective.

If the rods get nicked upon installation, they will leak for sure. The tiniest mark will do it. An installer will generally never admit causing rod damage. The rear shoocks are a real pain to install without gouging or scratching something.