Thread: B13 CSK Research Thread - OE diameter springs

to quote some other sources, here's Josh:





and another one I have read at some point by wes, this one for B14's
Project 200SX.... Overhauling the suspension. > MotoIQ > Magazine Articles

I'm starting to lean towards coilovers if Koni can't turn my B13 rear inserts into externally adjustable inserts like someone said they possibly could...

and another with some good pics towards the end:
http://www.sr20-forum.com/suspension/19514-csks.html

Hey I just got off the phone with Koni, the B13 Koni reds have half the rebound as the B15 koni yellows.

B13 red REAR insert:
min rebound: 500 newton meters @ 13" per second
max rebound: 1000 newton meters @ 13" per second
compression: 300 newton meters @ 13" per second

B15 yellow FRONT insert:
min rebound: 1050 newton meters @ 13" per second
max rebound 2100 newton meters @ 13" per second
compression: 450 newton meters @ 13" per second

he recommended that we try the B15 yellows in the rear at full soft and see if we like it before attempting a revalve job - which will cost approx $250 per strut.

Lies

Care to elaborate?

Or otherwise prove you're not just here to spam up this topic?

he's a buddy of mine and just messing with me..




DIE TROLL!!!!!

Kay ^_^

Good info from koni, but I would love to have the same info for the B13 and B14 front reds and the Maxima front inserts also. Did you get that info from tech support?

Here is my eval:

The B15 fronts are way over dampened on rebound when set 1/2 turn up ( around 1250 ) with 300 lbs springs. The car will go over dips and you can feel the rebound stop short. They are ok at min and up to about 1100 ( 1/4 turn ).

The rears springs are about 2/3 the stiffness of the front and the rear weight is about the same ratio. So lets assume that the rears would be proportional and ok up to about 2/3 * 1100 or about 740. I have the rear reds set up with 1 turn up which is in that range and they work well with 200 lb springs.

My guess is that the yellow is going to be overly stiff for the rear up until you are in the 300 lb + spring range. At that you would need a 450 lb + front rate to keep the car balanced and prevent the front and rear from reacting differently to bumps.

Remember that shocks are velocity sensitive so they will actually be harsher on bump with a softer spring as it lets the suspension move down faster and further. It is the opposite on rebound where the stiffer spring will make it rebound faster and thus make it harsher.

In some cases I would like even more bump than the yellow fronts have. But not a lot more rebound.

When Konis are over adjusted they will not let the suspension rise after a bump and a series of bumps will get the car down to the bump stops. Basically each bump reduces the available travel left for a short period of time. This is why they are never used for rallying.

my current plan is to install my B15 yellow front insertss in the rear of my B13, and send my blown B13 red rear inserts back to Koni to be revalved right in between the two and made "externally adjustable" at the same time...

B13 red REAR custom insert:
min rebound: 750 newton meters @ 13" per second
max rebound: 1250 newton meters @ 13" per second
compression: 450 newton meters @ 13" per second


They don't offer compression in anything but 150 increments, so 300 or 450 are the only options reasonable..

but remember I have Hypercoils Gen II's, max spring rate is 200 lbs in the rear (progressive) so maybe even my custom insert (above) is too aggressive, and maybe best suited for a RM spring?

I think the rear reds are perfect for the hypercoils as is. About 1/2 turn up on the adjustment and you are good to go. That puts them proportional to the fronts based on the weight and spring rate front to rear. That way the frequency should be pretty close front to rear which gives a good ride ( the front and back will respond to suspension movement pretty much the same).

Let us know how the yellows work in the rear. As soon as I can get my hands on a B15 front insert I will make and offer an installation kit for the rear.

Along that line... can you measure the B15 insert body length, basically the overall length of the yellow part?