Lets start with a little history: I've owned my S13 for about 2 years now and loved every aspect of it. However the shocks came blown, and Last year I had plans to swap over to Konis. For those of you that knew, the 2812/2817s that whats his name used on his S13 for SCCA racing would probably be best, but at $800 a shock it was a little steep. Some of you might ask why not simply go with the yellows, and the response is simple - 1) i want full preload and ride height adjustability and 2) the fact that you have to have the shock out of the car to adjust the rear is rubbish.

So I looked into the 8610/8611 series: They have more or less digressive valving, comes in 240sx friendly sizes, and retails for ~$200-300 a shock. The only problem was they came as strut inserts ONLY, and one had to make housing for these. veilside180 had the right idea, but he didn't have offerings for the rear and I didn't feel like paying that much when I had access to a full machine shop myself.

K sport came out with their kontrol pro series last summer and I got on the special for $699 a set. The reason being that I was told the piston was 44.5mm, which would allow the koni to fit into the threaded housing. The plan was to gut the ksport shocks and fit the Konis in. Long and behold, the k sports showed up and they were too short. I drove around on the ksports for awhile and man they were crap (topic for a different discussion). Since the k sport housings were too short, I sourced 4 pieces of 4310 piping at 2" OD, 1.75" ID, 1' long and turned 2mm threads onto the outside (which would allow the k sport pieces to fit on.) The bottom cap was a flat piece for the 8610s, and chamfered (is that the right word?) for the 8611s. The top of the tube had 24tpi threads turned on the inside, and corresponding plugs were made out of the same material. In the end I had 4 housings that are completely serviceable, and compatible with the k sport system. The result? Amazing! With 350lb springs all around, the car is completely streetable. It no longer freaks out over expansion joints and bumps like the k sport. The ride is still stiff, but it is perfectly composed and confidence inspiring. The rebound is only turned up 3/4 of a turn, and I have another turn and a half to go! All I got to say is Koni rock!

This thread would be pointless withot pictures, I wish I took more during the actual construction phase:

Top hats modified for the 5/8 threaded portion of the 8611 to fit through

Threaded top locknut

The underside of the top locknut, notice built-in spacer to properly center the 8611/8610 within the tube

One of the 8611 fitted into the front housing. There is barely any clearence!

The bottom plug for the rear before finishing and TIG welding. The front has the machined spacer like the top plugs.

Mass assembly stage. The ksport springs were not used because they were too short, and I didn't like the staggered spring rate.

The completed set back in the box for the garage. They look completely innocent!

South Bend Heavy 10s, there are 2 more on the opposite wall. I burned the motor out on one of these turning the 2mm thread. The other side of the room had 3 south bend mills, where I drilled the holes on the top plugs for the pin wrench.

interesting read! Thanks for the pics...

awesome info... adrian linked this in another thread and really piqued my interest.

Can you give anymore details on the machining required on your custom sleeve/strut housing?

Sanjuro wrote:

Sweet dude!

I got 8610 fronts and housings from veilside coming soon, im just doing yellow rears for now though.

Any reason for not staggering spring rates?

wow i didn't know people would actually read this, I totally forgot about this topic. lemme try to answer some questions

hannibal wrote:awesome info... adrian linked this in another thread and really piqued my interest.

Can you give anymore details on the machining required on your custom sleeve/strut housing?

I did it on a bridgeport 10 (actually more like 4, I swapped around). The main threaded portion is something like a 2mm/turn pitch, so you either had to get a metric leadscrew or use a transposing gear set. I bought mine off ebay for $150, worked well. The only bad part is that the gears didn't work on a heavy 10 without mods, which I should've done. Threading DOM tubing even with a carbide bit is something that should only be handled by a heavy 10 or larger.

The "gland nut" is custom, and has standard threads on it for ease of machining. this is again done on the bridgeport, with the corresponding thread cut on the inside of the main threaded tube. The pin wrench holes were made on a bridgeport end mill, but you could easily do it on a drill press. the bottom caps were made quickly on the bridgeport lathe, and TIG welded to the whole assembly.

slappy wrote:Sweet dude!

I got 8610 fronts and housings from veilside coming soon, im just doing yellow rears for now though.

Any reason for not staggering spring rates?

I looked into it, and turns out that the 240 has a motion ratio of something like 0.97/0.7, so it made no sense to stagger the rates. so far highway bombing has proven this to be a good combo, and I've not had the chance to take it autocrossing. it handled great for drifting though