Installation Results, Take 2: JDM Bilstein Spec-B Struts & STi Pinks

EDIT: Due to server limitations some pictures may no longer be availible, for an Adobe Acrobat Document of this post including most of the original pictures; Right Click, Save As: Bilstein.pdf

I have completed the install!

Before I begin with new info, let's review what I previously "found":

This morning I set out to install the JDM Bilstein Spec-B Struts and appropriate STi Pink Springs into my Legacy GT Sedan, here is what I learned...

 

Front Struts:

 

The front JDM Bilsteins WILL require a new upper strut mount to be installed in the USDM cars, the USDM front upper strut mount WILL NOT WORK with the Bilstein struts. I would assume the best bet would be to source the actual upper strut mount the JDM Spec-B uses. Without it...you won't be installing these struts... Basically there is a spacer built on to the top to accomodate the bearing size in the upper strut mount, USDM uses a different size than the JDM, See below:

 

http://www.thel7.com/Wills/2.5GT/SpecB.JPG

 

The parts you WILL be able to use off the USDM front struts are: the dust boot, the upper spring cushion, the upper perch and the nut to hold it all together. You WILL NOT be able to use the USDM bump stop...but that's OK, inverted struts (like the Bilstein's) don't use one.

 

Rear Shocks:

 

Good news! The rear JDM Bilstein shocks are identical to the USDM versions, the dust boot, rubber cushion and top mount can all be used without any issues.

 

STi Pink Springs:

 

As Racecomp has already told us, these springs fit perfectly with the USDM setup, since I had the suspension apart anyway, I went ahead and installed the springs on the OEM-USDM struts.

 

The STi springs claim to lower the JDM 2.0GT about 15mm front & rear, that equals about 1/2" inch. The USDM 2.5GT gets right around the same at slightly more than 1/2" inch front and rear. It sits very level.

 

The ride and handling:

I installed these at Mastro Subaru so I got to take a 30 mile ride home on several different types of roads on the way home to give them a pretty good evaluation.

 

The car still rides exceptionalbly well. The struts are ever so slightly underdamped for the springs but it is very, very minor. Most drivers would never notice. The car is still quiet and very well mannered on city streets and at speed on the interstate. Acceleration from a stop feels much, much better as the rear end does not have the "sagging" feeling anymore on hard acceleration it pretty much stays flat.

 

That being said, on spirited romps through curves the car feels much more nimble, turn-in has improved and there is a bit less lean on sweepers. The car feels much more planted and stable than it was before and has lost the "floaty" feel at highway speeds all while maintaining it's comfort. The car feels much closer to what I thought it should feel like from the factory. It's actually quite good now and will probably be very close to perfect when the Bilstein struts get installed.

I had received the JDM Spec-B Upper front strut mounts from Paul at AVO last week, here are some pics of the differences between the two (USDM on Left, Spec B on right):

Top side:

http://www.subaruchallenge.com/Wills/05/Comp1.JPG

Bottom Side:

http://www.subaruchallenge.com/Wills/05/Comp2.JPG

Side view of USDM Mount:

http://www.subaruchallenge.com/Wills/05/USDM%20Side.JPG

Side View of Spec B Mount:

http://www.subaruchallenge.com/Wills/05/SpecB%20Side.JPG

I started the install as any other by removing the front strut and disassembling it:

http://www.subaruchallenge.com/Wills/05/USDM%20Apart.JPG

Out of all those parts you will only need a few things off the USDM front struts to use on the new front Spec B struts. Parts needed are the dust boot, the spring, the top perch and the nut:

http://www.subaruchallenge.com/Wills/05/Parts%20Needed.JPG

Start by snapping the USDM dust boot down into position on the Spec B strut:

http://www.subaruchallenge.com/Wills/05/Dust.JPG

Then put the spring in place (you will need to use a spring compressor at this point), place the USDM upper spring perch in place (position it properly), place the Spec B strut mount in place and secure it all together with the 17mm nut and your all set! Position it in the car and secure all the bolts to the specified torque.

http://www.subaruchallenge.com/Wills/05/SpecB.JPG

Heres a look at differences between the USDM and Spec B struts mounts installed in the car:

USDM Mount:

http://www.subaruchallenge.com/Wills/05/USDM%20Mount.JPG

Spec B Mount:

http://www.subaruchallenge.com/Wills/05/SpecB%20Mount.JPG

The only "issue" I had was that the little USDM rubber dust caps for the upper strut mount (to cover the strut nut and bearing top) didn't fit with the Spec B mounts, no biggie for now, I'll see if the guys at AVO can get those for me too!

As I said before, the rear Spec-B shocks work perfectly with the USDM hardware, they went into without any issue.

I started the project at 5:30pm tonight and finished about 9:00pm, not bad for working alone in my 1 car garage! It was a little cold (about 50 degrees!) but it went pretty smoothly.

Here is a list of tools I used:

Floor Jack

Jack Stands (2)

Air Impact

Air Rachet

19mm, 17mm & 14mm standard sockets

12mm deep socket

19mm combination wrench

14mm racheting combination wrench

1/2" Drive Breaker Bar

1/2" Drive Torque Wrench

1/2" Drive 6" extension

3/4" Torque Wrench

I went for a quick drive after I finished to make sure everything was good. Car felt firmer than before and very well matched to the STi Pink springs. I can't wait to give it a good shakedown on my 30 mile jaunt to work in the morning! I'll give some measurements of the lowering effect after the car has time to settle (It actually looks about 1/2" higher than it did with the STi pink/USDM Strut combo right now) and I'll also give a review of the handling and ride. I'll be getting an alignment on Wednesday or Thursday of this week once it's settled.

Opie, congrats on the install! I'll be following this thread closely for your review.

Ditto SC GT's comment. Thanks for the pics and keying the writeup to the particular items.

SBT

Keep it comin' Opie! The Sti springs on stock USDM are pretty good but not a perfect match. I might need to go the Bilstein route as well.

Tom

Well I performed my initial road test this morning, 30 miles to work that consisted of several different types of road surfaces including; smooth new pavement, rough under-construction sections and city streets.

The Spec-B struts are much, much better matched to the STi springs than the stock struts were. The ride is firm and controlled, no bounciness and not jarring. There is a slight increase in NVH, but it's not bad. As a comparison, the LegGT is still quieter than my wife's '03 Legacy. All in all, the car feels and rides wonderful, much more like a performance sedan than an everyday family sedan while still being very liveable and easy to get along with. Believe it or not, the bumps where new pavement starts in the construction zone that were jarring with the stock struts / STi springs are now very un-eventful, no bottoming out, no hard clunk.

Body roll is almost non-exsistant now and the car feels much more tossable and stable, more-so than the STi pinks on the stock struts.

If I were to rate the suspension setups:

OEM Struts / Springs: 6 out of 10

OEM Struts / STi Springs: 7 out of 10

Bilstein Spec-B Struts / STi Springs: 9 out of 10

The car is sitting about 1/2" higher than it was with the OEM Struts & STi Springs, it will be interesting to see if it settles and ends up with the same stance or not. I'll take pics on Wednesday to give it a chance to settle.

The car is sitting about 1/2" higher than it was with the OEM Struts & STi Springs

For me, this is a good thing.

Tom

For me, this is a good thing.

 

Tom

This will be true for many people, Tom. Opie, what's the ride quality difference between this setup and stock? 90% of the time, the STi/stock strut combo wasn't any different as regards ride quality from the stock spring/strut combo.

Does this setup ride more like the SPT kit for the WRX, or is it softer than that? Percentage-wise, what's the NVH gain over stock?

Kevin

[Voice in Kevin's head] "Buy the struts, buy the struts!"

What did I say? View those pass-through sockets as talismen.

Kevin

This will be true for many people, Tom. Opie, what's the ride quality difference between this setup and stock? 90% of the time, the STi/stock strut combo wasn't any different as regards ride quality from the stock spring/strut combo.

 

Does this setup ride more like the SPT kit for the WRX, or is it softer than that? Percentage-wise, what's the NVH gain over stock?

 

Kevin

Comparing this setup (Spec B/STi pink) to stock it is definity firmer than stock, but by no means jarring or bouncy (unlike the stock struts with the STi pinks that was both a little bouncy and a little jarring). Ride quality is still comfortable and very controlled.

I've never ridden in a WRX with the SPT kit so I can't really give a good comparison. But compared to my previous cars setup; (Impreza 2.5RS w/STi Ver.5/SPT Springs) the Legacy setup is much more forgiving and comfortable, but is still firm enough to make for a sporty feel when pressed.

As far as NVH gain, I'd say it was very minimal, maybe 2% at most.

My 30 mile ride home tonight only re-enforced my liking of this setup...I'm sure that even the wife will like it!

...and the car is still about 1/2" higher than it was with the stock struts...

BTW: For reference, I'm 34 and regularly use my cars for family duties and occasionally motorsport activities . I auto-xed the 2.5RS for 4 years and now attend events in a dealer prepped/sponsored 1993 Impreza L for some auto-x and mostly rally-x events.

...and the car is still about 1/2" higher than it was with the stock struts...

Opie - Are you saying it is now 1/2" higher than is was stock/stock or stock/pinks?

Thanks!

1/2" higher than is was stock/stock or stock/pinks?

Tom

Opie. is the ride height increase over the stock struts / pinks due to the difference in the distance between the spring land surface and the surface that mates to the car (base of the studs) see (Side View of Spec B Mount picture right where your index finger is pointing..sort of.

It looks to me as if the mount sits lower in the car, or am i missing somthing. I wonder if the Swifts would maintain the drop? I Recall reading that Swift's ride lower although i never figured out why. Some say they are the same spring.

Stupid question -- USDM and JDM What does the DM stand for?

Andy

domestic market

OEM Struts / Springs: 6 out of 10

OEM Struts / STi Springs: 7 out of 10

Bilstein Spec-B Struts / STi Springs: 9 out of 10

hmmmm

that dosn't leave alot fo room for a setup like the zeal..

Could you snap a jpeg of the stock strut just the same as the first pic in this thread?

-- Thanks so much for sharing this info.

Andy

...and the car is still about 1/2" higher than it was with the stock struts...

 

Opie - Are you saying it is now 1/2" higher than is was stock/stock or stock/pinks?

 

Thanks!

To clarify, when I originally installed the STi pink springs on the stock struts it lowered the car about 1 inch, now with the Bilsteins Spec-B's & STI Springs is approx. 1/2" higher than it was with the stock struts and the STi pink springs, but still 1/2" lower than it was stock.

Opie. is the ride height increase over the stock struts / pinks due to the difference in the distance between the spring land surface and the surface that mates to the car (base of the studs) see (Side View of Spec B Mount picture right where your index finger is pointing..sort of.

It looks to me as if the mount sits lower in the car, or am i missing somthing. I wonder if the Swifts would maintain the drop? I Recall reading that Swift's ride lower although i never figured out why. Some say they are the same spring.

 

Stupid question -- USDM and JDM What does the DM stand for?

 

Andy

I believe it is actually a result of two things;

1) The Stock Struts with the STi pinks had about 2,000 miles of settling in on them, the Spec-b's with the springs have only had about 70 miles. I think it will settle a bit more once it gets some more miles on it.

2) The design of the Spec-B upper mount, the Spec-B mount has most of its rubber dampening material at the bottom of the mount and the USDM version has it all at the top, this results in the actual upper mounting location to be a few mm lower with the Spec-B mounts.

Side by side the struts were exactly the same length when fully extended, and the same set of springs were used on both.

On a flat, level concrete surface the car is currently at:

25.75" Front

25.25" Rear

Measuring from the ground, across the center cap to the top of the fender arch using a metal yardstick.

I measured the Stock/STi spring setup the same way and sent the results to Kevin (gtguy) but I didn't save them for myself....if he still has them, maybe he could post them...

hmmmm

 

that dosn't leave alot fo room for a setup like the zeal..

But that's because I don't consider coil-overs as a practical "street" setup. IMHO, Coil-overs are only practical for motorsports usage (auto-x, track days, etc), used just as a means for lowering all their true benefits are wasted.

My car, being for street duty only has no need for coil-overs.

Could you snap a jpeg of the stock strut just the same as the first pic in this thread?

 

-- Thanks so much for sharing this info.

 

Andy

Sure can! And no prob!

http://www.subaruchallenge.com/Wills/05/USDM.JPG

EDIT: Oops, did you mean a pic with the strut alone? Hmmm, might be a day or so before I can do that, they are already up in the attic...they are almost identical to the pic, main differences are:

1) The little spacer shaft at the top of the strut, just below the threads is more than double the height of the one on the Spec-B struts.

2) The piston shaft on the stock struts is only 7/8" wide compared to the Bilsteins that are almost 2" wide.

3) The stock strut bodies are black.

Thanks Opie, actually I was looking to see the strut off the car to see the difference in the area of the spacers. You have text defining a spacer difference of 8 to 20 mm.

Can the struts really push the car up a 1/2 inch?

Thanks Opie, actually I was looking to see the strut off the car to see the difference in the area of the spacers. You have text defining a spacer difference of 8 to 20 mm.

Can the struts really push the car up a 1/2 inch?

I'll work on getting that pic tomorrow evening...

Like I said above, I don't think the strut has anything to do with the height difference, I think it has more to do with the fact the new install hasn't had a chance to "settle" and the different design of the upper mount.

Opie, if they are in the attic don't worry about it. I fired off a reply before your EDIT posted. I tend to agree with you that the springs will settle a bit and the upper mount is different.

Thanks, Andy

OK, finally got around to taking a pic of the stock strut (literally in the attic ), here it is:

http://www.subaruchallenge.com/Wills/05/Stock.JPG

Compared to the Spec B:

http://www.subaruchallenge.com/Wills/SpecB.JPG

One other odd thing I noted while looking at the stock strut...the actual strut "cartridge" on the stock strut is shorter than the one on the Spec-B. Not the length between the strut upper & lower mounts but the actuall cartridge itself...look:

In this pic (I know it's an odd angle) the lower strut mounts extend below the strut cartridge, to the point that you cannot stand the strut up on it's bottom and balance it.

http://www.subaruchallenge.com/Wills/05/USDM%20Apart.JPG

But on the Spec B struts, the bottom of the strut cartridge is even with the bottom of the mount, so the strut will stand up on it's own...

http://www.subaruchallenge.com/Wills/05/Dust.JPG

I noticed this when trying to stand the stock strut up to take a picture....kinda odd.

Just keep in mind that they are still the same length from lower strut mout to the top of the shaft, just the Bilstein cartridge is larger....