Modifying Bilstein Shocks

[xwd]

You could also look at the stuff Stout racing used which is JRi. The JR in JRi used to be a lead engineer for Penske. They sell very modular and user revalvable/rebuildable shocks as well.

They have a set for the GR STi which is almost identical to the BRZ/FR-S.

http://www.jrishocks.com/shop/street...stable-shocks/

[AyJay]

I can't believe the price increase for a Bilstein revalve. I have a set of Bilstein PSS coilovers revalved for custom rate Swift springs on my S2000. When I had Bilstein SoCal revalve the shocks it was only like $68 / shock. This was around 2010-ish.

I thought it was a great deal at the time ... now, not so much.

[Kostamojen]

So does anyone actually sell spring perches for converting B14's to linear springs?

[Ro_Ja]

Originally Posted by Kostamojen

So does anyone actually sell spring perches for converting B14's to linear springs?

I'd guess Raceseng or HVT. You also might be able to get RCE to sell you a set.

[Kostamojen]

Originally Posted by Ro_Ja

I'd guess Raceseng or HVT. You also might be able to get RCE to sell you a set.

Are there just the two kinds of spring perches out there for camber plates: OEM spring size and coilover (60mm correct)?

[Ro_Ja]

Originally Posted by Kostamojen

Are there just the two kinds of spring perches out there for camber plates: OEM spring size and coilover (60mm correct)?

For our cars, yes.

[Kostamojen]

Is the bottom spring perch 60mm with the B14?

[Ro_Ja]

Originally Posted by Kostamojen

Is the bottom spring perch 60mm with the B14?

It should be. The only other item you might need aside from the upper spring perch is a divider if you intend to use helper springs.

[Kostamojen]

What would be the correct length for linear springs to replace the progressive springs on the B14's?

[burdickjp]

A question:
What about Eibach's coilovers?

and a comment:
If I have been informed correctly, there's an OEM Subaru part which allows standard sized coilover springs to mate to the stock hats. N2 washers, or something like that. Anyone care to comment to that?

and another comment:
I'm currently considering starting with B6s and then throwing on GC sleeves. It's an inexpensive progression.

[JoeHK]

Hey guys, i'm going to bump it up here!
So i have 18x9,5 et44 wheels in a squared setup, tires are 255/35. Also the car is lowered on Bilstein B14's extremely happy with them, BUT if i lower the car too much, the wheels will hit the springs up front... I could use a 3mm spacer for now, but over time i might like to switch out the springs to some linear springs, like swift springs (from what i've read in this entire thread they have a smaller diameter than the bilstein springs so they should fit just fine with the wheels). Which ones should i need, or what specs should they have? Also, do they sell the spring perches for the lower diameter springs, or do i have to get them custom made?
The car is a daily with some very spirited driving, if that should matter
Anyone any ideas on what parts to get?
Thanks


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[strat61caster]

In the process of investigating this myself, was kind of going to sit on it until I had done it but ah fuckit, maybe someone will come up with a good idea and I can save myself a few bucks.

60mm springs will fit the bottoms and then you need to choose length and figure out a way to fit them to the top hats. On the OEM front and rear top hats iirc I think you could get some custom cups to fit into the OEM hats and center the narrower springs. Given that the height is adjustable on the B14's and in my experience there is plenty of thread left on the damper bodies to switch to a shorter spring without impacting ride height or travel. Bilstein's springs are ~8.6" front, ~8.9" rear which puts you in kind of a no man's land for buying springs of a similar length off the shelf, but again I believe you can go to a shorter length spring with no ill effects, especially if you're going stiffer you could potentially raise the ride height of the car if I'm understanding everything correctly. I believe that 60mm diameter and 8" length springs are the right way to go for hassle free replacement.

However, 60mm springs seem to only come in 1kg/mm stiffness increments which translates to ~56lbs/in, not a huge deal for the casual enthusiast, but I'm used to playing with spring rates as a primary tuning tool and want that in my back pocket, 2.5" diameter springs are common and seem to come in 25lb/in increments in 8" lengths. You'd need adapters for the bottom on the shock body but those are not uncommon, eibach sells some but they seem pricey at $20 a pop. Some people say you're fine at 60mm vs 63.5 there's about a 1//8" difference (and that's diameter so on average just 1/16" away from what's 'supposed' to be there) just slapping them on but I'm not too comfortable about that, I don't want the edge of the spring hanging off the perch or shifting around, just doesn't seem right to me.

http://eibach.com/m-america/en/motor.../perch-adapter

Circling back around, I've got raceseng cascam camber plates, swapping out the top perch is cake and they sell replacements for $60, I could also turn down the 90mm perch I initially purchased or have something fabbed up locally. I'm tempted to stay with the OEM rear mounts, but limited travel may be a no-go there in which case I end up paying raceseng more money for their 1" or 2" rear top hats, which claims to accept standard spring sizes off the shelf and can use an adapter to fit OEM 90mm springs.

http://www.raceseng.com/shock-top-re...ubaru-brz-2013

http://www.raceseng.com/shock-top-re...u-brz-2013-719

[JoeHK]

Damn... You seem like you've done quite the research, sir!

I'm very new to suspension mods so i do my best to understand everything, although i must say... It seems like quite the job & investment to switch the springs to thinner ones than the ones provided.. It definitely seems do-able, but not as easy as putting swift springs on bc coilovers for example, i get the impression our bilsteins need more supporting mods since else the thinner springs wouldn't be supported correctly...
I think i'm going to have to do quite a bit more research to see if it'll be worth the hassle in the long run
Thanks for the explanation! Helps me a lot though!


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[strat61caster]

Originally Posted by JoeHK

I think i'm going to have to do quite a bit more research to see if it'll be worth the hassle in the long run
Thanks for the explanation! Helps me a lot though!

If you're leaving the damping untouched then switching springs is going to be a gamble if it gives you anything useful other than being pretty. Without any knowledge you might get some benefit going to springs rates within the progressive rates provided by Bilstein but if you step outside of those the dampers may not keep up.