Thread: Custom Shortened Konis - The general idea.

Are you talking about cutting the nub on the bottom? There are two schools of thought regarding the nub. One says to cut the nub. The disadvantage to cutting the nub is that it has threads for the bolt that holds the dampener into the housing. I prefer to keep all of my threads. The other way (which I am doing on my CSK's) is to use a hole saw and drill a hole in the bottom of the strut housing large enough for the nub to stick through, and then use washers to put "meat" around it so that you can bolt the dampener to the housing.

Regarding cutting the housing to a shorter length, even the Koni instructions tell you to cut part of the housing down. How else would the koni dampener sit any lower in the housing?

EDIT: based on your drawing, I would guess you have never actually held a koni insert in one hand, and an empty strut housing in another. The top of the koni housing requires you remove the top of the stock housing. it has a top-hat that .. .

Check out the pics and the animation. They show the nub being cut some, but not all the way. You still have plenty of good thread left. The pics also show the hole cut in the bottom of the strut that you're talking about so it can go even lower, while maintaining the threads. The images also show the washer you're talking about. It's all there in the image and animation. Look closer?
Do you still think I've made a mistake?

The Koni directions are useless for this mod. Koni knows nothing about this mod. The Koni directions are to be followed at your own peril. Overkill Engineering Motorsports being the most famous example.

Again, the Koni directions are meaningless.

How does the Koni damper sit any lower in the housing? Exactly as shown in the pictures and animation.

The diagrams and the animation are meant to show you the general idea of what is done to create a Custom Shortened Koni suspension in it's simplest form. The gland nut is not important in understanding the concept, so I've left it out.


(It's funny, if you follow the Koni directions to cut off the top of the strut housing, you won't have those threads left for the top gland nut.)

my point about the koni instructions is that they have you cut off and shorten the strut housing, with the intent of keeping the strut the same height. To lower the strut in the housing, you have to cut even more off.

there is no way you can fit the strut insert any lower without cutting away some of the top of the housing. for one reason, towards the top of the koni insert, it gets thicker, the second reason is that there is a tophat on the koni insert that keeps it from going any further than the original height.

You MUST shorten the strut housing.

B13 CSK - OE diameter springs - REAR Strut using B15 Spec-V Koni "yellow" inserts - SR20 Forum

http://www.sr20-forum.com/suspension/38187-b13-csk-research-thread-oe-diameter-springs.html


these two threads started out the same, but different input from the two sites took them in slightly different directions.

hey i just remembered why you must cut the nub on the FRONT struts..

if you don't, hit can hit the cv boots on crazy surfaces where you have a lot of wheel travel.

you don't have to cut the nub on the back..

but you ALWAYS have to shorten the strut housing.

Thanks for the clarification on that vqman. I don't know if I'll update my diagrams, but I'll add a link to your post so people know there's a bit more to it. I do believe the "breakthrough" with the CSK was that you can cut the nub and/or make a hole for it to pass through so you can get those dampers in deeper than Koni had originally intended. That's what the diagram and animation are there to show.

Those top hats that screw in have a specific name and I can't think of it for the life of me right now.

Edit: They are called gland nuts.

i would say that my threads aren't sticky ready yet.. I need to get unlazy and measure the exact lengths that need to be removed..

originally those threads were me trying to get a koni yellow in the rear strut housing and use a Hypercoil spring.. I have decided against that.. going with B13 koni reds in the rear.. but they are VERY hard to find now.

the "tophat" that Iwas referring to (may not be the right word) is that flange on the top of both the insert and the OEM strut that sticks out about 1/4" further than the rest of their respective housings.

This might have been stated elsewhere, but could you just briefly state why this isnt required for the rear?

There are two main reasons this is not required in the rear.

In the rear, there is more than 3" of stock travel between the bottom of the damper piston and the bottom of the damper housing. Lowering by an inch or even two in the rear can be done without worrying about bottoming out the strut if you have appropriately stiff springs.

Also, the rear fender opening on the B13s, B14s, etc. (pretty much any car in existence) are lower than the arches in the front. Because of this, when the car is level, the gap between the rear fender arch and the rear tire is smaller by about an inch than the gap up front. This means that most people don't even want to go lower than about 1.5" in the rear anyway even though you can without bottoming out the strut because you will run into interference issues with the tire and the rear fender. Performance wheel/tire packages make this even worse.

We actually have people who try to raise up the rear because of this lower arch issue.