US M030 or ROW M030 springs for slight lowering?
08-22-2006, 10:41 AM
#1
Weathergirl
Rennlist Member
Rennlist Member
Thread Starter
US M030 or ROW M030 springs for slight lowering?
Going to get Bilsteins and springs ASAP. I want to end up at a ride height right about at ROW non-sport, which is about where I am now, presumably from sagging stock springs. (See https://rennlist.com/forums/993-forum/293577-why-is-my-car-low-or-is-it.html )
The question is, am I better off with US M030 springs, adjusting the Bilsteins' lower spring perch down, or ROW M030 springs, adjusting the lower spring perch up?
Or to put it another way, how low can you go on US spec springs?
The question is, am I better off with US M030 springs, adjusting the Bilsteins' lower spring perch down, or ROW M030 springs, adjusting the lower spring perch up?
Or to put it another way, how low can you go on US spec springs?
08-22-2006, 11:04 AM
#2
Nordschleife Master
Join Date: Jun 2005
Location: Neither Here Nor There
Posts: 5,351
Likes: 0
Received 7 Likes
on
5 Posts
Originally Posted by RallyJon
Or to put it another way, how low can you go on US spec springs?
It depends on what Bilsteins you end up with. Let me explain that a bit more. Originally, the Bilstein HDs came with a shorted threaded portion. This threaded portion obviously permitted ride height adjustment by virtue of the ability to raise and lower the lower spring perch. However, when used with the MO30 springs (Euro), the original Bilstein HDs would permit lowering of the rear anywhere within the accepted ranges (i.e. RS to US SUV height). Unfortunately, the fronts didn't have enough thread to permit them to be lowered enough to maintain the proper profile with the rears. Therefore, the rears had to be raised. In other words, the fronts were the limiting factor in how low you could go.
Gert, from Carnewal, came up with the idea of simply extending the threaded portion on the front with 30mm more threads. Bilstein went ahead and modified HDs for Gert in Europe. For a long time, Gert was the only one who sold these HDs with the extra threads.
Well, jumping forward, Bilstein USA began modifying their own stock to have the extra 30mm of thread on the fronts and began selling them as the default arrangement in the US.
All that being said, and to finally answer your question, there still exists stock in the US that is the original non-extended-thread versions. Therefore, with these non-extended thread versions, even with using ROW MO30 springs, the lowest you can go in the fronts might be where you are currently at. However there is a chance that you might not be able to get back to your current height without the extended version. What I'm trying to say is that you are right on the edge of making the US MO30 work with the non-extended HDs. It might work, but I wouldn't guarantee it.
Hence, I would probably opt to get the ROW MO30 springs and the HDs (with the extended threads). This would enable you to adjust both the front and rears anywhere within the accepted range (RS to SUV).
08-22-2006, 11:33 AM
#3
Addict
Rennlist Member
Rennlist Member
Join Date: May 2004
Location: Los Angeles
Posts: 2,124
Likes: 0
Received 0 Likes
on
0 Posts
I agree with Jeff. If you hang around on RL long enough, you'll eventually want to lower your car to ROW or between ROW and RS height. It would be a shame to buy the non-threaded versions and eventually regret it. Now as to the question of whether you buy M030 springs or some softer version, well, that's a personal question.
08-22-2006, 11:36 AM
#4
Guru
Lifetime Rennlist
Member
Rennlist Small
Business Sponsor
Lifetime Rennlist
Member
Rennlist Small
Business Sponsor
I'm with Jeff. Go with the ROW M030 springs. The fronts are progressive whereas the US M030 are are more linear. This should enable a good ride quality while taking advantage of increased spring rate.
08-22-2006, 11:38 AM
#5
Weathergirl
Rennlist Member
Rennlist Member
Thread Starter
you'll eventually want to lower your car to ROW or between ROW and RS height
Seriously, I value ground clearance and suspension travel more than most.I'm guessing that the difference in spring height alone between ROW and US springs is about 1". If that's the case, there would be some overlap between the ride heights achievable with each, given the range of adjustment of the longer threaded Bilsteins.
08-22-2006, 12:10 PM
#7
Weathergirl
Rennlist Member
Rennlist Member
Thread Starter
For a general data point, I e-mailed the engineer who did my rally car (including custom suspension) and he had this to say about the topic in the abstract:
the longer spring (US) will experience less strain (therefore less stress) and will have less chance of sagging over time (assuming equal materials/construction)
the longer spring will have a longer stroke capability before coil bind (but both springs are designed to avoid coil bind for that specific application, one would hope)
in a nutshell, everything else being equal, go for the longer spring mounted on a low perch
the longer spring will have a longer stroke capability before coil bind (but both springs are designed to avoid coil bind for that specific application, one would hope)
in a nutshell, everything else being equal, go for the longer spring mounted on a low perch
Trending Topics
08-22-2006, 12:32 PM
#8
Rennlist Member
Originally Posted by InTheAir
Depends.
It depends on what Bilsteins you end up with. Let me explain that a bit more. Originally, the Bilstein HDs came with a shorted threaded portion. This threaded portion obviously permitted ride height adjustment by virtue of the ability to raise and lower the lower spring perch. However, when used with the MO30 springs (Euro), the original Bilstein HDs would permit lowering of the rear anywhere within the accepted ranges (i.e. RS to US SUV height). Unfortunately, the fronts didn't have enough thread to permit them to be lowered enough to maintain the proper profile with the rears. Therefore, the rears had to be raised. In other words, the fronts were the limiting factor in how low you could go.
Gert, from Carnewal, came up with the idea of simply extending the threaded portion on the front with 30mm more threads. Bilstein went ahead and modified HDs for Gert in Europe. For a long time, Gert was the only one who sold these HDs with the extra threads.
Well, jumping forward, Bilstein USA began modifying their own stock to have the extra 30mm of thread on the fronts and began selling them as the default arrangement in the US.
All that being said, and to finally answer your question, there still exists stock in the US that is the original non-extended-thread versions. Therefore, with these non-extended thread versions, even with using ROW MO30 springs, the lowest you can go in the fronts might be where you are currently at. However there is a chance that you might not be able to get back to your current height without the extended version. What I'm trying to say is that you are right on the edge of making the US MO30 work with the non-extended HDs. It might work, but I wouldn't guarantee it.
Hence, I would probably opt to get the ROW MO30 springs and the HDs (with the extended threads). This would enable you to adjust both the front and rears anywhere within the accepted range (RS to SUV).
It depends on what Bilsteins you end up with. Let me explain that a bit more. Originally, the Bilstein HDs came with a shorted threaded portion. This threaded portion obviously permitted ride height adjustment by virtue of the ability to raise and lower the lower spring perch. However, when used with the MO30 springs (Euro), the original Bilstein HDs would permit lowering of the rear anywhere within the accepted ranges (i.e. RS to US SUV height). Unfortunately, the fronts didn't have enough thread to permit them to be lowered enough to maintain the proper profile with the rears. Therefore, the rears had to be raised. In other words, the fronts were the limiting factor in how low you could go.
Gert, from Carnewal, came up with the idea of simply extending the threaded portion on the front with 30mm more threads. Bilstein went ahead and modified HDs for Gert in Europe. For a long time, Gert was the only one who sold these HDs with the extra threads.
Well, jumping forward, Bilstein USA began modifying their own stock to have the extra 30mm of thread on the fronts and began selling them as the default arrangement in the US.
All that being said, and to finally answer your question, there still exists stock in the US that is the original non-extended-thread versions. Therefore, with these non-extended thread versions, even with using ROW MO30 springs, the lowest you can go in the fronts might be where you are currently at. However there is a chance that you might not be able to get back to your current height without the extended version. What I'm trying to say is that you are right on the edge of making the US MO30 work with the non-extended HDs. It might work, but I wouldn't guarantee it.
Hence, I would probably opt to get the ROW MO30 springs and the HDs (with the extended threads). This would enable you to adjust both the front and rears anywhere within the accepted range (RS to SUV).
I can't believe there isn't a different P/N for the US Bilsteins with extra thread? Is it really a Hit an miss type of deal, and what happens if you end up with 1 strut with extra threads and 1 without. I can't imagine Bilstein would do something like that.
08-22-2006, 01:58 PM
#10
Addict
Rennlist Member
Rennlist Member
+1 on the benefit of the progressive RoW to the US spec spring - I swapped from US to RoW and found that the ride quality improved (with no other changes, RoW springs on US M030 car with 8k miles).
08-22-2006, 02:06 PM
#11
Nordschleife Master
Join Date: Jun 2005
Location: Neither Here Nor There
Posts: 5,351
Likes: 0
Received 7 Likes
on
5 Posts
Originally Posted by CAHRERA
I can't believe there isn't a different P/N for the US Bilsteins with extra thread? Is it really a Hit an miss type of deal, and what happens if you end up with 1 strut with extra threads and 1 without. I can't imagine Bilstein would do something like that.
Design changes are made is products without requiring a new part number. Chances are that any new HDs that are shipped from US distributors will be with the extra threads, but there is no guarantee of this because it is somewhat dependent on the older stock being used up.
If you buy them from a US authorized dealer, such as ViperBob, you will get the extra threads AND a full lifetime Bilstein warranty.
08-22-2006, 02:09 PM
#12
Nordschleife Master
Join Date: Jun 2005
Location: Neither Here Nor There
Posts: 5,351
Likes: 0
Received 7 Likes
on
5 Posts
Originally Posted by CAHRERA
I can't imagine Bilstein would doing something like that.
08-22-2006, 02:13 PM
#13
Nordschleife Master
Join Date: Jun 2005
Location: Neither Here Nor There
Posts: 5,351
Likes: 0
Received 7 Likes
on
5 Posts
the longer spring will have a longer stroke capability before coil bind (but both springs are designed to avoid coil bind for that specific application, one would hope)
in a nutshell, everything else being equal, go for the longer spring mounted on a low perch
in a nutshell, everything else being equal, go for the longer spring mounted on a low perch
08-22-2006, 02:53 PM
#14
Weathergirl
Rennlist Member
Rennlist Member
Thread Starter
You're not considering rallying this car, right?
08-22-2006, 03:27 PM
#15
Rennlist Member
Originally Posted by RallyJon
Definitely not. But fun driving on twisting, uneven, frost-heaved East Coast back roads with crests and dips does present the possibility of full-compression. I know 911s don't fly well, but you guys don't slow down to 20 for crests, do you? It's important to me to have good suspension travel.