Bilstein B8 -> Koni/GC

[MM89]

Currently selecting a new suspension setup, which consists of Bilstein B8 + (X) springs. I am quite keen on the Bilstein B8 unless anything else within a similar price range and quality can be recommended. I understand Koni Yellows can be had for similar pricing, but Bilstein seems to get most votes across the board.

The car is 95% daily driven and I've been quite used to a cheap height and damper adjustable coilover unit which probably required more damping for the spring it came with. The car now sits with stock EG suspension + front and rear strut tower bars. The front end sits lower due to the added mass of B18C, no air con. I would assume it still weighs more than the D15B.

What I'd like to know is what springs would be suitable to run with the B8 shocks. It would be good if somebody could clarify that these shocks can run up to 500lb/in (8.93kgf/mm) without sacrificing the longevity of the damper?

Only one set of springs will be used for street and track, so they need to be stiff enough to stay flat around the track but not too harsh for the streets; once again I've been riding around in entry level coilovers, so they probably came with 500lb/in springs front and rear anyway lol. I would like a more compliant ride but I'm able to tolerate a bit of bump.

Would
FRONT 460lb/in(8.21kgf/mm)
REAR 360lb/in(6.25kgf/mm)
be a good place to start?

According to an article on clubcivic.com, the H&R Race Spring runs the above rates for the DC2. Having looked at the amount of lowering the Race spring provides, I wonder if this will be too much? "Approx" 2.0" front and 1.75" rear.

On the stock EG suspension, the front sits lower than the rear with the added mass of the engine. I need the car to sit in between 1 and 2 "finger gaps" between the tyre and fender. Any lower and it will cause me issues. I will calculate how much lowering is needed from the current height to achieve that and maybe one of you suspension guru's out there may be able to help me out with an answer to spring rate and length.

I have been explained this concept once, yet still need some more clarification:

If two springs are different in height, the shorter spring has a thicker wire diameter and a higher spring rate. However both springs will give a similar ride height when placed on the same shock absorber. I have been told that even though the shorter spring of higher rate will make the car sit the same, it has a greater tendency to come loose when the car is jacked up or lifted off the ground. True?

So if I wanted to maintain the same spring rate with a properly seated spring, a longer spring is required? Also, I'm taking a guess that it would make the car sit higher?

Kindest regards
Michael

[MM89]

Also, I was considering the Mugen 5 way adjustables once upon a time, which I have found some spring rates for:

381F/252R

According to some, these are rather soft for track use. Which is why a combo like B8s and 460F/360R would probably be firmer all around?

After some research, some have also claimed that dampers such as Koni Yellows matched with 229F/156R springs are too stiff. Really? Apparently, it's due to the spring being too soft for the damper?

[vinnY]

just a word of warning about spring heights
i have the h&r cup kit(look it up on the h&r site)
their figure of 2" lowering is very conservative to say the least, when i have them in at the highest perch on the shock i still tuck the front tyre about 10mm

[MM89]

I see. Thanks for the reply.

I have since been convinced that Koni Yellow+GC+custom rates+top hats is the way I wanna go. Anybody have much experience with the use of this combo? 430lb/in seems to be the most that Ground Control offers for EG. However, If the application is for Integra, 545lb/in is available.

Similar to the B8, Koni Yellow will only take around 550lb/in springs anyway, unless re-valved. I was considering 430F/350R. I suppose ride height is less of an issue with this combination.

[mocchi]

I see. Thanks for the reply.

I have since been convinced that Koni Yellow+GC+custom rates+top hats is the way I wanna go. Anybody have much experience with the use of this combo? 430lb/in seems to be the most that Ground Control offers for EG. However, If the application is for Integra, 545lb/in is available.

Similar to the B8, Koni Yellow will only take around 550lb/in springs anyway, unless re-valved. I was considering 430F/350R. I suppose ride height is less of an issue with this combination.

what would happen if the konis were installed with say.. 850lb/in springs?
or say.. 50lb/in springs?

[MM89]

Btw, do you mean that a 2" drop is actually more after the spring has settled in?

I think the Koni+GC just makes things alot easier. I don't have to choose spring height diameter etc. My decision is simply based on the spring rates.

[vinnY]

the h&r site states about a 2" drop, straight away it was lower than that, then settled a further 5mm or so

i ran the gc sleeves before, they were pretty harsh on my koni yellows and i was only running 400/300lbs front and rear
then again i do have to drive on terrible sydney roads

they were much less comfortable than my cusco zero2's

[MM89]

Wow, I didn't expect that.

What stiffness was your Koni's set at? I thought the Zero2s had stiffer rates off the shelf compared to what you were running with the GCs. I would've thought that the Koni Yellow dampers would be more comfortable compared to an adjustable coilover damper.

[vinnY]

koni's were set pretty firm, probably somewhere around the 3/4 stiffness region(whatever that means on the adjustable knob), any less and it would just bounce more from the linear spring rates

[mocchi]

Michael, the B6 arent adjustable are they? Looked at Bilstein catalog and integra isnt listed in the B8.
Does that mean if you were to get the B8 shocks, the rear shocks will be fork type? not eyelet anymore?

[MM89]

MRK20CRX:
shit...18/16, surely not for road use right? The Koni Yellow SP3 seems to be another solution for extra travel on lowered cars. It's valved the same as OTS koni yellow, but the piston rod is 20mm shorter. Have you had much experience with the KY+GC on track? What spring rates were you using?

mocchi:
that i'm not sure, as i remember reading somewhere that the B12 is called B12 because it consists of B8 + 4 Bilstein springs or something like that, hence the name.
i think 713,000EUR sounds quite reasonable for a whole kit, before VAT and delivery and australian import tax. However i could be wrong...

[mocchi]

MRK20CRX:
shit...18/16, surely not for road use right? The Koni Yellow SP3 seems to be another solution for extra travel on lowered cars. It's valved the same as OTS koni yellow, but the piston rod is 20mm shorter. Have you had much experience with the KY+GC on track? What spring rates were you using?

mocchi:
that i'm not sure, as i remember reading somewhere that the B12 is called B12 because it consists of B8 + 4 Bilstein springs or something like that, hence the name.
i think 713 EUR sounds quite reasonable for a whole kit, before VAT and delivery and australian import tax. However i could be wrong...

fixed haha. no way it costs 713,000 euro.
cusco zero 2 (dc2 8/6kg) is good for me. bit bumpy on steep speed humps but overall very nice.

what are you running now michael? koni+gc?