egp320i

Ok, this has been beat on many times but has anybody figured out what the difference is between BE3-2669-M2 and BE3-2669-M3?

both are listed as sports yet the M3 at AJusa are $20 less then M2.

Bilstein's homepage lists both but is no help after that to exactly what the valving is, etc.

I know M2 is the safe bet for the CSQ but it makes me curious why the M3 is less in price unless it's actually rally valved then it would be pretty harsh yet should be more expensive.

Strange

dtompsett

Tried calling Bilstein to ask them? Thats all I can suggest.

Lago Blue

A couple of things that suggest to me that the difference is perhaps -just- the number of lower spring-perch mounting-ring grooves cut into the lower body O.D.

-The first thing is the Bilstein numbering system itself (see on page 32 of below link); and although it is of little direct help in this case, it does appear that code -after- the specific vehicle application's P/N (i.e. the "2669" in this case) would indicate the mounting designation. As we know, the upper mounting method does not vary amongst these cars; however, that leaves the lower mount, which although that is also all by the same method, some may be "height adjustable". This "height adjustable" feature is specifically mentioned as a "may be available" foot-note in the Bilstein catalog. The fact that there are different suffixes suggests to me that the amount of height adjustment variability is what is being designated in these different suffixes.

http://www.bilstein.com/305bilsteinapplicationguide.pdf

The second thing is that some have suggested as much (unfortunately, without any further "official" substantiation) here before:

https://www.audiworld.com/forums/sho...d.php?t=245583

This one below I think is particularly telling as Bilstein's own explanation is "The mechanic will know"

https://www.audiworld.com/forums/sho...php?p=18579074

But perhaps the best info I found is this one with photos:

https://www.audiworld.com/forums/sho....php?p=1864700

Which is where the photo shown here came from.

As I now have a new to me set of "Neuspeed" M3s, I'm also interested in your question.

As there are several other different P/Ns of rear dampers for our application, and the fact that these two are both called "2669"s, I'm inclined to believe that therefore; the damping is identical between them.

However, are these dampers called Heavy Duty/(HD)/"B6® Sport"; or are they perhaps Sport/(S)/"B8® Sprint" I have no idea! Except as I have seen the "M2" listed for both the "HD" and "SP" applications in a Bilstein catalog, which may confirm my suspicion that this ability to accomadate different spring lengths (I'm thinking OEM standard; & OEM sport), allows this one damper to carry both the "B8®" and "B6®" designations.

As disscussed elsewhere, since the corresponding front dampers rate between HD and Sport is small, and the difference is primarily in the ability of the sports to reliably contain a shorter spring, it does make sense that these rear dampers (lighter end of the car) cover both applications.

To conclude IMHO the M2/M3 suffixes simply indicate the number of lower spring perch height positions available as delivered. These grooves allow repositioning of the perch support ring when dis-assembled. One can also machine a like groove elsewhere to match ones want. As delivered, even the M3's make the 90 taller than it may have been originally!

egp320i

I notice a few things.
the BE3-2669's are listed under 96-98 100's, they have no listing for 90Q and the listing for A4's is BE5's.
If you go to AJusa or eshock's A4q is the BE3 from 96-98.
Somebody is off somewhere here or they changed the PN for the A4's.

They certainly like to make it confusing no doubt.

The sticker pic should do it. It would seem the M3's can be adjusted for more spring compression and a stiffer ride.
It makes the M3's sorta like Koni's except with Koni you can adjust them on the car whereas these to adjust M3's they have to be removed.

AJ has $30 off a set till 6/22, I might have to bite on that one. I've put off doing the rears for a long time but they are due.

I have the original Boge turbo gas shocks and amazingly the sticker is still there after 15 years.

Lago Blue

If I may, my opinion of the function of the adjustable lower perch is somewhat different.

In this case I think it does only one, and maybe possibly two things:

Primarily: Ride-height adjustment.

Given an OEM spring, mounted on it's applicable damper, the raising or lowering of the Lower Perch is only going to change the ride-height. One would have to both compress the spring beyond what that corner of the car weighs, and trap it within extended length of the shock, in order to "make it stiffer" as you have said. If one was able to accomplish this, the car would not sink, after the tire touches down, when the car is lowered; onto the ground.

This is not normally the case, and the weight of the car continues to compresses the spring until the weight and spring resistance are; in balance.

The adjustable perch does allow one to change the effective vehicle height at which this balance; takes place.

Secondary: Spring Length Accommodation.

Bilstein wants this shock, to correctly restrain both taller (and usually softer) OEM; and slightly shorter (OEM and aftermarket, usually stiffer) springs, when the damper is; fully extended (i.e. on the lift, airborne etc.). The adjustable perch -may- allow the spring installer to ensure there is sufficient pressure on a shorter than OEM spring, to ensure that it is -still- held securely captive, under some tension, between the perches. Otherwise, it would move out of position.

Finally this spring perch adjust-ability (apples) does not equate to the Koni damper feature (oranges) you describe, whether it be the traditional adjustment available for wear on some models or more recent compression and/or rebound adjustments. The equivalent Koni's lower perch is not adjustable. This Bilstein's "dampening" is not adjustable, unless you have it re-valved.

Lago Blue

Note the welded lower spring perch.

This is from the S4 project car write-up here:

https://www.audiworld.com/features/project_s45.shtml

95ninety

I have the M2s

egp320i

Thanks for all the good knowledge. Shocks are one of those things you install then forget or sometimes never replace unless you actually need to.
When I switched out the factory Boge's a few years ago I figured at 110K they were beat but to my surprise the Audi tech said they actually were in pretty good shape.
The rears though get more road flak by design and they are looking 15 years old. Not sure how thick the steel is but eventually the rust that coats them is going to break through, then they will be shot.
Mine are just plain due. I should have snagged them a few years ago as they have gone up a good 20-30 each since I looked at them.
$148 is about the best price I have seen on the M2's so far.

jnsluft

I hope I've just found the information I have been looking for.

I have a '95 90Q and have had a hard time finding rear shocks. Am I understanding this correctly that early (96-98)A4Q shocks will fit on my car? If this is the case, why don't the manufacturers list this? The only rear replacements listed for a 93-95 90Q are made by AC Delco.

If these Bilstein's will fit, are there any modification that need to be done? Should I be replacing any bushings or other parts at the same time? The suspension is stock and the front has already been redone w/KYB's and new mounts.

This is a great car and after this, only a couple minor issues to take care of.

I appreciate the help,
Shawn

Lago Blue

Maybe, there are a bunch of them. You may want to inspect them. Perhaps you can already hear one or two of them? The upper inboards are often the first to go. You can find more info with a search.