al 96 Ram Air T/A

I'm still in the research phase, but after speaking with Bilstein yesterday, I'm even more confused.


The Bilstein HD for the 4th gen cars used to be part number B46-1913 for the front and B46-1914 for the rear. The 1913's were rated at bump/rebound 159 lbs./279 lbs., while the 1914's were rated at 86 lbs./174 lbs.

Now, for the confusing part(s). SLP Bilsteins, part number B46-2071 is a revalved front HD, rated at 130 lbs./397 lbs., and is designed to work with the stiffer, shorter springs designed by Eibach for SLP. These are NOT relabeled Eibach Pro Kit springs...that much I know for sure.

After doing a bit of reading, I discovered that Bilstein has replaced the B46-1913 & 1914 with the new HD's, are there part numbers are BE5-2406 M1 for the front, and BE5-2407 M1 for the rear. According to Bilstein, the 1913/1914 are no longer being produced. These new parts are not rated the same as the old...but I haven't proven that yet.

I discovered on another message board that someone was told by Bilstein that the "new" 2406 is the same as the SLP revalved Bilsteins, and were chosen because this combination proved to be very successful (???).

He states in Dec. 2005: "Bilstein have replaced the front shock for the F-body this week. The originals were B46-1914 HD rear & B46-1913 HD front.

The B46-1914 rear is unchanged but is now numbered F4-B46-1914-M0.

The new front shock is F4-BE5-2406-M1. This an SLP Performance spec road racing shock built for SLP by Bilstein. I spoke to Bilstein today to make sure that it is fully compatible with the B46-1914 and they assured me it is. It performed significantly better than the old B46-1913, so they have adopted it as the F-body standard.

SLP on their website have an SLP spec rear shock as well so I have e-mailed them to confirm they have no issues with the B46-1914 paired up with their front units."


When I asked Bilstein about this, of course the woman had no idea what I was talking about, and said that the only HD's listed for the 4th gen F-bods were part number 2406 and 2407. I asked her for the ratings, and now I'm really confused.

The 2406 is rated at 1440 and 2815 (bump/rebound). The 2407 is rated at 1420 and 1085 (bump/rebound). (That's right, bump is HIGHER than rebound...I double checked with her.) First off, she did not know what these numbers were, but I'm certain it was in Newtons. When I convert to pounds (1 Newton = .2248 pounds) I arrive at ridiculous numbers.

The 2406 is rated at 323 and 633 lbs (bump/rebond), and the 2407, which is the rear shock, is rated at 319 and 244 lbs (bump/rebound). How can this be??? 319 lbs. on the rear bump???


Has anyone else noticed this yet? All of the recommendations I've read on the Bilstein vs. Koni debate are referring to the old HD ratings.

atljar

I have NO idea on your question, but I do have a brand new set of HD bilsteins about 2 years old sitting in my room.

If you decide you want to go the route of the old ones, let me know and we can work something out as I will never use them.

al 96 Ram Air T/A

Holy cow...what a mess!!

I just spent 20 minutes on the phone with a Bilstein rep. pleading with him to help me. He's what I've learned.

According to him, the 1913 and 1914 have been replaced by the 2406 and the 2407. After telling me over and over agin that "Bilstein engineers did extensive testing to make sure these shocks were compatible with our cars" (give me a break...) he told me that the valving was identical on the old and new part numbers. Also, the 1913 and 1914 will no longer be sold.

However, when I told him that the numbers I was given by another rep. were different (funny note...he said these numbers were proprietary and the rep. who told me this should be fired/shot), he confirmed the 1440/2815 for the 2406 and the 1420/1085 for the 2407. I asked him again...you're telling me that the compression is higher than the rebound on the rear, 2407 shock? He said yes!

However when I told him on the old 1914 the compression was half the rebound, and 1/4 the rating of the 2407, he clammed up

I asked to speak to an engineer and was given a voice mail. How annoying!!!


So, the question remains, are the new HD's the same as the old HD's??? All of the comments I read are based on the old numbers. Does anyone know what Sam's revalves are rated at? Do they compare with the "new" HD numbers?

Sam Strano

you'd think for a second you'd just ask Sam........ You won't get a straight answer from them. Sorry.

And my Revalves vary depending on use. But did you ever stop to think that you'd just chasing your tail? Maybe you have some situation in which you'd be better off with Koni's anyway....

al 96 Ram Air T/A

HaHa...Yes, asking Sam would make sense, wouldn't it?

But seriously, Sam, has Bilstein given you any details on what the new HD's are rated at? I find it odd how they replaced the 1913 and 1914 with shocks that are suppossed to be valved the same, yet their numbers are vastly diferent.

If, in fact, the new HD (2406 and 2407) ratings I was given are correct, how would they complement 1LE/WS6 springs with your front and rear antisway bars?

Is it possible that the numbers are so different than the 1913 and 1914 "published" numbers?

Don't get me wrong, I haven't eliminated the possibility of auctioning off one of my kids to pay for 4 Koni SA ( ), but the more I dig, the more curious I get as to how the new HD would be on my ride. Heck, they are 1/3 the cost of Koni's...

Sam Strano

Sam's not going to get into this online. Sorry......

94CamaroZ28

[QUOTE=al 96 Ram Air T/A]Now, for the confusing part(s). SLP Bilsteins, part number B46-2071 is a revalved front HD, rated at 130 lbs./397 lbs., and is designed to work with the stiffer, shorter springs designed by Eibach for SLP. These are NOT relabeled Eibach Pro Kit springs...that much I know for sure.

[Me]
According to Sam, if I read him correctly, NO Bilstein is designed for any kind of lowering spring, much less a stiffer spring with less travel.

al 96 Ram Air T/A

Believe me when I say, I'm not doubting Sam's knowledge or experience. I do value his opinion...but the scientist in me is curious.

This started out as a simple internal debate in my head to justify spending the extra $500 on Koni. However, the more I researched, the more I discovered I may not be comparing apples to apples if in fact Bilstein has redisgned the HD shocks like I think they have.

All of the comments I have read over the past month on dozens of message boards /websites seem to share a common thread - Bilstein 1913/1914 shocks, while better than the DeCarbons, are underdamped for stiff springs.(i.e. 1LE, SLP Level 1/2, Eibach Pro Kit, etc.) With that said, the numbers Bilstein provided me for the "new" HD seem very high, almost to the point of making me wonder if they are right. If in fact the numbers are true, then everyone's opinion on the Decarbon vs. Bilstein HD vs. SLP Bilstein vs. Koni SA debate do not apply to the redesigned HD shocks.

One thing is for sure. There's more to this then simply a change of part numbers...

I'm going to continue to try an get Bilstein to tell me what the 1913/1914 shocks were rated at, before they stopped producing them.

al 96 Ram Air T/A

Finally getting somewhere...


I spoke to another Bilstein Rep. this mornig, and she was willing to give me shock ratings.

The B46-1913 are rated at 1597/2791 (compression/rebound), while the B46-1914 are rated at 865/1745 (compression/rebound). I am assuming these numbers are in Newtons, but not positive. I 've seen many posts describing the ratings on these shocks, but it was always posted in lbs.

However, here's the catch: According to old posts, the 1913 are rated at 159/279 lbs. (compression/rebound) and the 1914 are rated at 86/174 lbs.
These numbers are smaller than what Bilstein just told me, by a factor of ten. Be it as it may, the assumtion of the lbs. rating is either wrong (i.e. the person simply thought the number was in pounds when it was in Newtons all along), or the number Bilstein provided me is in pounds, but adjusted by a factor of ten...I'm not sure.

But, now for the real eye opener. The Rep. confirmed the "new" BE5-2406/2407 are not the same as the "old" 1913/1914. As I've posted earlier, they are rated at: BE5-2406 1440/2815, BE5-2407 1420/1085. While the front 2406 is similar to the 1913, albeit a slight bit less compression, the rear 2407 have TWICE the compression and nearly HALF the rebound of the 1914.

SO the jury is still out: are the Bilstein numbers in fact Newtons (1 Newton=.2248 lbs), pounds (but off by a factor of ten) or something else. All I can say for sure is the "old" and the "new" HD are not the same.


The quest continues...

Sam Strano

And at what piston speed are these values given? What does the curve look like in general? And did you notice the change is basically nothing in the front? And in the rear, for some stupid reason they moved back *TOWARD* the ****ty (excuse the language, but there is no other word for it) DeCarbon's.

There is a reason I spend my time Revalving and selling Koni's. Again, I'm not going to divulge info I worked hard, for online. But I'm not some pencil-pushing moron who made up numbers just for fun.

HD's can't damp lowering springs, and not with the "new" change they do it even more poorly in the back of the car. MHO

TobyZ28

I think shocks are a measure of force per distance ie. Newtons/meter usually or Newtons/cm, not just newtons. Just like pounds is pounds/inch or foot or something like that. So you need to convert torque from one unit to another, not just force.

1 000 newton centimeter = 88.507 457 674 pound inch
or
1 000 newton centimeter = 237.303 604 71 poundal foot

So it sounds like the messup is just your typical non-metric-> metric conversion problem.

http://edition.cnn.com/TECH/space/99...ars.metric.02/

If you can figure out what the correct units they used are things should start to make a whole lot more sense

When are you guys gona switch to metric

al 96 Ram Air T/A

Sam...I hope I haven't offended you...that was not my intention. If I did...I appologize. I was not directing any of my frustrations at you, simply trying to learn how suspension react to different off-the-shelf shock settings.


With that said, I'm amazed how Bilstein wants the public to "trust them" without providing any real-world data we can use to compare. It's taken me weeks to get to where I'm at, and every conclusion seems to be the same.

When I was told that "our engineer tested these very shocks on his own V6 car" I knew something was not right. Bilstein wants me to trust them, "we know what we're doing", and yet they are telling people the new HD's are the same as the old HD's, but have different ratings. How's that???

Anyway, just trying to shed some light on helping others uncover the truth about Bilstein HD shocks. Perhaps they can be spared some of the confusion I had to go through to get to this point.

BTW...I'm going to pick up a set ouf your antisway bars, front and rear, and wait till' I can afford a set of Koni's. Seems to be the best bet...


Again, no disrespect meant...sorry for the misunderstanding.

Sam Strano

You haven't offened me.... not at all. But by your own admission you've gotten a lot of conflicting reports, which happens with most companies, and is something I'm not big on. Sadly, this kind of thing is also what they did with the BTS kits for these cars. Not good. The old HD's were suitable in a number of situations, lowering not being one.

al 96 Ram Air T/A

Great thanks

I'll be ordering your bars this weekend...what is the preferred ordering method?

Sam Strano

phone is best, by far.