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AUSDM SpecB Bilsteins - Which Rev?

PostPosted: Fri Apr 25, 2014 11:08 am
by SubMeister
In reference to the excerpt below from the legacygt.com forum in the States, can anyone here confirm which Revision our post FL SpecB GT and 3RBs have?

And where are the part nos on the billies located, can one eyeball them without removing the wheel?

url]http://legacygt.com/forums/showthread.php/faq-jdm-oem-suspension-61108.html[/url]

Revision is actually a misnomer. The lettered "revisions" refer to model years in JDM. A is MY2004, B is MY2005, C is MY2006 and so on. Indeed, the suspension actually was revised several times that resulted in differences in dampening and springs. Generally each subsequent revision got softer due to the complaints that these cars ride too stiff.

Note, there was no "original revision" or "revisionless" Bilsteins. Some posts, including the "Part numbers" thread in turbo section contain incorrect information.

JDM GT Rev.A

Original GT setup. Great balance of performance and ride comfort. I currently use this setup as my winter suspension. It is firmer, but not too firm. Closer to JDM SpecB Rev.B than to JDM GT Rev.C (had both setups earleir). Everyone who has this setup seems to praise it, especially with Pinks.

Part numbers: 20310AG060 (front right), 20310AG070 (front left), 20365AG040 (rear)

JDM GT Rev.B

This one is bit of a mystery. Does not really feel softer than JDM GT Rev.A. Interestingly rear shocks are the same as on JDM SpecB Rev.B, front struts are different. I just drove a car with these on Pinks and indeed the setup seemed more complaint than JDM SpecB Rev.B, but the difference is not big. Note, there is an old post quoting someone from Bilstein Japan saying this setup is for SpecB and tuned for 18 inch wheels - that is incorrect, I verified this against JDM parts database.

Part numbers: 20310AG140 (front right), 20310AG150 (front left), 20365AG120 (rear)

JDM GT Rev.C

This is the current JDM GT and JDM 3.0R setup, present on Rev.D cars as well. Also used on 2006-2007 USDM SpecB (not sure about 2008 yet). These are noticeably softer than any other revisions. Give nice and controlled and oscillation free ride, but they are more on the comfort than performance side. There were complaints that these do not handle stiffer springs (Pinks) very well and feel bit underdampened. I can believe this as in certain high speed situations these did not feel as secure as other revisions.

Part numbers: 20310AG400 (front right), 20310AG410 (front left), 20365AG260 (rear)

JDM SpecB Rev.A

The original SpecB setup, stiffest of the bunch. I rode in a car with supposedly this revision (not 100% sure, not confirmed by part numbers) - it felt marginally stiffer than SpecB Rev.B. Opinions about this setup range from "great ride" to "too stiff for daily driver". I guess this is very subjective plus it depends on the road conditions, wheel size, tires, etc.

Part numbers: 20310AG100 (front right), 20310AG110 (front left), 20365AG050 (rear)

JDM SpecB Rev.B

Supposedly softer than Rev.A. I had it on my car with Pinks for few months and liked it very much. Excellent performance, yet still great ride. However, can be too harsh on really bad roads if paired with stiff tires like RE070.

Part numbers: 20310AG180 (front right), 20310AG190 (front left), 20365AG120 (rear)

JDM SpecB Rev.C

This is the current JDM 2.0 SpecB and JDM 3.0R SpecB, present on Rev.D cars. Bit less aggressive than Rev.B, yet still excellent handling and great ride. This is my favorite Bilstein setup so far for a street car - I think they really got this one "perfect".

Part numbers: 20310AG420 (front right), 20310AG430 (front left), 20365AG270 (rear)

Re: AUSDM SpecB Bilsteins - Which Rev?

PostPosted: Fri Apr 25, 2014 12:39 pm
by alexeiwoody
Why do you ask? Not sure which rev they are, you won't find them being significantly different to any of the revisions. If this bloke can feel the difference just by changing the tyre compound...

Get a set of billies custom reprogrammed and match new springs for a real difference. They're capable of much more than what the factory ever released them with, on any revision.

Source: Driving on Spec B billies with stock springs and tbSti billies with pink springs. Car sways like a boat around corners (as most factory shocks do), and yet if you hit just the right bump in the road, you'll hear metal on metal. We deserve better :D

Re: AUSDM SpecB Bilsteins - Which Rev?

PostPosted: Mon Apr 28, 2014 5:14 pm
by SubMeister
I ask because I'm in touch with a SpecB owner in the States and we were comparing notes on USDM vs AUSDM. It's not my intention to debate or speculate on how good the author of that excerpt is, I just posted it as a reference point.

Your comment on stock Spec B billies caught my attention - could you elaborate on this a bit more?

They're capable of much more than what the factory ever released them with, on any revision.


I want to set up my 3RB wagon for street comfort that's more BMW touring wagon that Audi RS6. Am thinking revalved Billies with STI pinks or Swifts. Eibachs would have been ideal but they are discontinued.

Re: AUSDM SpecB Bilsteins - Which Rev?

PostPosted: Tue Apr 29, 2014 12:43 am
by alexeiwoody
I've written about this a fair bit, if you search my posts, and Coyote is the one who developed these, and I basically copied him. In summary -

coyote wrote:"Front springs need to be progressive, but no more than 300lb. I think it may have been less than that. Front shocks need LOTS more rebound and also more slow compression. Fast bump is fine, the compression damping curve is too linear. (Alexei: very important)

Rear springs 400-450lb linear and the shocks just need the rebound tweaked, but are pretty good."


Follow that setup to the letter and you'll have yourself a better setup than the BC BRs or Racecomps etc, basically you'd need $3000+ coilovers to top this setup. And these won't need to be replaced or rebuilt every 50-100k, like coilovers.

Coyote had Kings springs, I have custom ones (+50% stiffer and a bit lower than stock) made to Eibach spec, but I have linear at the front and not progressive, and I would love to see if that makes a difference to comfort. I was a noob and didn't insist on more slow compression (stock bilsteins have terrible slow comp at the front, it's amazing how they missed that) and ended up with a very uncomfortable and annoying car for about 2 months until I got the fronts revalved again. Handling is still great, just so much more peaceful to drive.

50% stiffer springs are a must in my and coyote's and the guys' at Trutrack opinion. Don't bother with sti pinks. They are simply pink coloured, lowered stock springs. I had them on my tbSti and it was like driving a corolla, albeit lowered. Same comfort as the stiffer springs, just that the car would sway like a boat around corners, dip at acceleration and braking etc.

Hopefully that answers some questions. The revalve is around $150 a corner, springs shouldn't be too much, all in all you should walk away with something around the price of BC BRs, but much more longevity, stockness and insurance friendly.

Let us know how you go :)