for those who have cut their H&R front springs
did you cut the top or the bottom? from looking at them I cannot tell which one is the dead coil.
04-02-2010, 01:12 AM
#5
Super Moderator
Trending Topics
04-02-2010, 10:46 PM
#12
Super Member
Join Date: Oct 2009
Posts: 720
Likes: 0
Received 0 Likes
on
0 Posts
Saab 900 SE
04-02-2010, 11:24 PM
#13
MBWorld Fanatic!
My H&R's look just like what Splinter posted. Yep, I don't see coils touching with my car at rest. While I do enjoy the handling with the H&R's on, the overall ride is kind of harsh. I'm pretty sure this is because the springs are not progressive (definitely don't feel progressive).
I've parked next to numerous '05 MYs and the H&R's are slightly lower than that setup (~1/2", or 1 finger, lower). I can't imagine lowering it anymore. Not only is the car lower, the overall travel is less than stock. On a few instances now when going around corners (or in parking lots) with rain gutters, the inside rear tire will actually lose contact with the road because it's hung up in the air. Yes - it's that stiff (Bilstein 'sport' struts/shocks on too). Freaked me out the first couple times it happenned, and I finally got out of the car to see what was going on.
I've parked next to numerous '05 MYs and the H&R's are slightly lower than that setup (~1/2", or 1 finger, lower). I can't imagine lowering it anymore. Not only is the car lower, the overall travel is less than stock. On a few instances now when going around corners (or in parking lots) with rain gutters, the inside rear tire will actually lose contact with the road because it's hung up in the air. Yes - it's that stiff (Bilstein 'sport' struts/shocks on too). Freaked me out the first couple times it happenned, and I finally got out of the car to see what was going on.
04-03-2010, 12:51 AM
#14
Super Member
Join Date: Jun 2005
Location: So. Cal.
Posts: 651
Likes: 0
Received 5 Likes
on
5 Posts
'02 C320 Wagon, '78 308 GTS, '06 Highlander Hybrid
I just spent a few weeks with different springs and struts/shocks on my '02 C320 wagon. I now have 3 sets of different springs and 2 sets of dampers.
First of all a dead coil has nothing to do with progressive rate springs. I believe that a dead coil is the last coil on the end of the spring that has been "shaved" mid-coil so that the end of the spring is flat (see Splinter's pic in post #5). This type of spring can be put on the ground and will stand up straight on its own. You can see in the picture of the other (H&R) springs that the end coils are not "shaved" and will not stand up. Progressive springs are just as mentioned before...they have different spring rates in different parts of the springs to try and give you the best of both worlds. I've not heard many good things about progressive springs because you can also end up with the worst of both worlds.
As for cutting springs, I don't think it is that big of an issue. Yes, the best way is to purchase different springs and/or coilovers. But, if done right, cut springs is a viable option. Beware that cutting springs will change their spring rate and make sure they are cut properly. If they are cut with a torch (or even a die grinder), they can be heated up enough to change their temper and/or hardness. I once had some springs cut and the guy submerged the spring in water to dissapate the heat, while he gut off the end that was sticking out.
Good luck.
First of all a dead coil has nothing to do with progressive rate springs. I believe that a dead coil is the last coil on the end of the spring that has been "shaved" mid-coil so that the end of the spring is flat (see Splinter's pic in post #5). This type of spring can be put on the ground and will stand up straight on its own. You can see in the picture of the other (H&R) springs that the end coils are not "shaved" and will not stand up. Progressive springs are just as mentioned before...they have different spring rates in different parts of the springs to try and give you the best of both worlds. I've not heard many good things about progressive springs because you can also end up with the worst of both worlds.
As for cutting springs, I don't think it is that big of an issue. Yes, the best way is to purchase different springs and/or coilovers. But, if done right, cut springs is a viable option. Beware that cutting springs will change their spring rate and make sure they are cut properly. If they are cut with a torch (or even a die grinder), they can be heated up enough to change their temper and/or hardness. I once had some springs cut and the guy submerged the spring in water to dissapate the heat, while he gut off the end that was sticking out.
Good luck.
04-04-2010, 12:28 AM
#16
Super Moderator
More worthless erratum to make of what you will.
Mtnman82 has it right. He and several others here have been through several spring/damper/anti-roll bar combinations in order to arrive at an acceptable handling/ride comfort/ground clearance compromise. There’s no free lunch. A pillow soft ride with razor sharp handling is not available to most with currently affordable technology. ‘Active’ suspension has thus far been rejected by most enthusiasts.
I dare say that our C’s sweet spot can show the quick way around to several ostensibly faster machines during closed course events. Sufficient jounce travel is imperative to be able to do so, even on modestly undulating circuits or terrain. The OP’s desire to obtain a lower ride height by shortening his springs creates a situation where jounce travel becomes so limited that roadability is adversely affected, as the wheel rate has not been concurrently increased enough to avoid bottoming. Appearing fast on the boulevard and actually being able to drive quickly through the twisty bits are not necessarily one and the same. To each his own.
To hanknum’s well-founded post, virtually all manufacturers do indeed vary the length of their vehicles’ springs to account for weight changes, intended use and desired ride height for the markets in which they’re sold. Shortening or lengthening springs – exclusive of their rate – is commonplace, thus the several (more than a dozen) OE springs available for our chassis. Wheel rate and damping is yet another variable available from their bag of tricks. I’ll spare the faithful my ramblings on those for another thread. A progressively increasing wheel rate with our antiquated MacPherson strut front suspension can only be achieved from judicious bump stop selection, excluding the springs fitted on aftermarket coilovers, of course. Note that H&R’s rear W203 springs provide progressively increasing stiffness through jounce travel owing to their bound coils. A rising wheel rate - with a linear spring - can be easily engineered via appropriate suspension link configuration, although not with our OE struts.
Respectfully disagree, however, with the assertion that bound or otherwise inactive coils do not alter a spring’s rate as it cycles through its typically available range of motion. A coil spring is simply a torsion bar in cylindrical form. The shorter they become, the stiffer their rate. A generally accepted formula for determining coil spring rate is:
where
K = Spring rate in pounds per inch
W = Diameter of the spring wire in inches
G = 12,000,000 for steel springs (a constant)
N = Number of active coils (number of coils that are free to move + 1/2 coil)
D = Diameter of the coils measured to the center of the wire, in inches
credit Paul Van Valkenburgh’s Race Car Engineering and Mechanics
It has proven to be surprisingly accurate, as verified by my local (Callas Rennsport in Torrance) shop’s digital rate checker.
Mtnman82 has it right. He and several others here have been through several spring/damper/anti-roll bar combinations in order to arrive at an acceptable handling/ride comfort/ground clearance compromise. There’s no free lunch. A pillow soft ride with razor sharp handling is not available to most with currently affordable technology. ‘Active’ suspension has thus far been rejected by most enthusiasts.
I dare say that our C’s sweet spot can show the quick way around to several ostensibly faster machines during closed course events. Sufficient jounce travel is imperative to be able to do so, even on modestly undulating circuits or terrain. The OP’s desire to obtain a lower ride height by shortening his springs creates a situation where jounce travel becomes so limited that roadability is adversely affected, as the wheel rate has not been concurrently increased enough to avoid bottoming. Appearing fast on the boulevard and actually being able to drive quickly through the twisty bits are not necessarily one and the same. To each his own.
To hanknum’s well-founded post, virtually all manufacturers do indeed vary the length of their vehicles’ springs to account for weight changes, intended use and desired ride height for the markets in which they’re sold. Shortening or lengthening springs – exclusive of their rate – is commonplace, thus the several (more than a dozen) OE springs available for our chassis. Wheel rate and damping is yet another variable available from their bag of tricks. I’ll spare the faithful my ramblings on those for another thread. A progressively increasing wheel rate with our antiquated MacPherson strut front suspension can only be achieved from judicious bump stop selection, excluding the springs fitted on aftermarket coilovers, of course. Note that H&R’s rear W203 springs provide progressively increasing stiffness through jounce travel owing to their bound coils. A rising wheel rate - with a linear spring - can be easily engineered via appropriate suspension link configuration, although not with our OE struts.
Respectfully disagree, however, with the assertion that bound or otherwise inactive coils do not alter a spring’s rate as it cycles through its typically available range of motion. A coil spring is simply a torsion bar in cylindrical form. The shorter they become, the stiffer their rate. A generally accepted formula for determining coil spring rate is:
where
K = Spring rate in pounds per inch
W = Diameter of the spring wire in inches
G = 12,000,000 for steel springs (a constant)
N = Number of active coils (number of coils that are free to move + 1/2 coil)
D = Diameter of the coils measured to the center of the wire, in inches
credit Paul Van Valkenburgh’s Race Car Engineering and Mechanics
It has proven to be surprisingly accurate, as verified by my local (Callas Rennsport in Torrance) shop’s digital rate checker.
04-05-2010, 12:33 AM
#17
Super Member
Join Date: Jun 2005
Location: So. Cal.
Posts: 651
Likes: 0
Received 5 Likes
on
5 Posts
'02 C320 Wagon, '78 308 GTS, '06 Highlander Hybrid
Very informative post Splinter, thanks.
BTW, you were talking about bump stops. I just installed a H&R Cup Kit on my '02 C320 wagon (includes springs and struts/shocks). The front was lowered about 1-1/2". I reinstalled the OEM bump stops. Would you think that thinner ones should be installed due to the lower ride height and shorter travel? I bought the kit used, but I don't think it originally came with any other bump stops.
Sorry for the hijack.
BTW, you were talking about bump stops. I just installed a H&R Cup Kit on my '02 C320 wagon (includes springs and struts/shocks). The front was lowered about 1-1/2". I reinstalled the OEM bump stops. Would you think that thinner ones should be installed due to the lower ride height and shorter travel? I bought the kit used, but I don't think it originally came with any other bump stops.
Sorry for the hijack.
04-05-2010, 01:04 AM
#18
Super Member
Cut from the top that way the imperfect sharp cut edge can wedge it's way into the spring pad...at least that's the route I took. Even coil overs won't go as low as I needed to go without cutting at least one coil.
04-06-2010, 01:58 AM
#19
Super Moderator
hanknum,
Can’t speak knowledgeably regarding H&R coilovers, as I’ve not tried them.
Any bottoming, ground clearance or massive understeer issues with yours?
It’s likely your OE wagon bump stops are close to ideal. MB currently offers three W203 bump stops from which to choose: 203 320 08 44 (standard fitment, medium height & soft), 203 320 07 44 (“sport” chassis, shorter & higher rate), and 203 320 09 44 (“springs for higher ground clearance” [wagon], taller and higher rate).
Some OE pieces - save for a pair - that have since been relegated to the spares bin…
photo credit AMGDave
tangentially related bump stop information
Had to ditch the aforementioned H&R front springs when their travel and ground clearance proved too low to clear our driveway, or even provide sufficient rate or jounce travel when getting after it with the other ne’er-do-wells.
Have since fit OE C55/CLK AMG front springs, revalved Koni struts and modified jounce stops originally intended for another MB chassis. Aft has revalved Bilsteins and custom specification H&R springs.
Always willing to share its specific setup details and other subtle tweaks upon request.
*even more off topic*
Is it reasonable to surmise that the Ferrari and Suzuki are your weekend machines? Nice! The C32 is her daily driver.
Still miss our former W124. Been looking for a clean E500 ever since – a link to yours FS, please?
Can’t speak knowledgeably regarding H&R coilovers, as I’ve not tried them.
Any bottoming, ground clearance or massive understeer issues with yours?
It’s likely your OE wagon bump stops are close to ideal. MB currently offers three W203 bump stops from which to choose: 203 320 08 44 (standard fitment, medium height & soft), 203 320 07 44 (“sport” chassis, shorter & higher rate), and 203 320 09 44 (“springs for higher ground clearance” [wagon], taller and higher rate).
Some OE pieces - save for a pair - that have since been relegated to the spares bin…
photo credit AMGDave
tangentially related bump stop information
Had to ditch the aforementioned H&R front springs when their travel and ground clearance proved too low to clear our driveway, or even provide sufficient rate or jounce travel when getting after it with the other ne’er-do-wells.
Have since fit OE C55/CLK AMG front springs, revalved Koni struts and modified jounce stops originally intended for another MB chassis. Aft has revalved Bilsteins and custom specification H&R springs.
Always willing to share its specific setup details and other subtle tweaks upon request.
*even more off topic*
Is it reasonable to surmise that the Ferrari and Suzuki are your weekend machines? Nice! The C32 is her daily driver.
Still miss our former W124. Been looking for a clean E500 ever since – a link to yours FS, please?
