How To: Coilovers and strut tube modification (with pictures!)

[blueapplesoda]

I generally use a table spoon or two of ATF in the bottom of each strut tube. The master tech who told me to do so never told me why though to my knowledge.

What I read somewhere is that it increases surface area contact with the outer tube allowing the shock to use the outer tube as a heat sink.

By all means it makes sense as a shock absorber converts motion energy into heat energy by means of liquid/gas/mechanical friction. But do they really get that hot?

And yes, two metals in contact for long period of time without some sort of corrosion inhibiting substance could become chemically welded.

[Moto-Mucci]

i read a post by Peerless on e30tech he said to do the same thing. its gotta do something with rust prevention or some kinda of damning of the shock flexing in the housing maybe?

Yup, it's for rust prevention when you've got snuggly fit (correct diameter) shocks in the shock housings.

Their usually supposed to fit pretty snug - maybe a mm or 2 of clearance. Metal against metal in a confined area can cause rust, then you cant get the shocks out, so a bit of oil prevents that.

The G60 / Shorter konis are a bit smaller in diameter then stock e30 shocks though, so more oil would be required.

[ewejin9394]

ahaha...the answer is no.

Now i understand how it works ~ All these while i was thinking that you cut the shocks and re-weld it... After some research then i came to an understanding that you actually cut the housing and then insert the new shock into the housing..

So one question, any suggestions what kind of shocks works best? How much lowering will i get (inches)... I'm looking getting a comfort ride if possible...

Cheers

[!kid]

ahaha...the answer is no.

I generally use a table spoon or two of ATF in the bottom of each strut tube. The master tech who told me to do so never told me why though to my knowledge.

i read a post by Peerless on e30tech he said to do the same thing. its gotta do something with rust prevention or some kinda of damning of the shock flexing in the housing maybe?

[!kid]

cool thanks for your input. i just picked up a pair of 8 inch coil springs for 30$ used. they came off a Honda(skunk 2 springs),need to find out the spring rate is though.

edit: called skunk 2 they are 6K springs=336 lbs/in

[ak-]

My experience:

Cut my housings ~2.25'' in use with my 6'' 440lbs spring and I was slightly tucking the rim(yes the damn rim) of my 16x8's with a 205/45 tire with my adjusters spun all the way UP. Problem was my spring was too soft and 6'' was too short without a doubt.

Luckily, my friend had 7'' 550lbs front springs for me. Slapping those in resulted in tucking 1 finger-width of tire with the adjuster set exactly in the middle.

This is with my GC kit and IE Race camber plates.

[!kid]

Is an 8 inch long coil spring to long for the front? What size springs are you all running?

[tonywonder]

"do you have to weld and cut the stock spring perch???"

no, what i did was cut off the perch, cut out that section from the tube (so i could use the threaded part still) and then welded the two halves of the shock housing together and welded the supplied d-shaped perch from ground-control

your answer is a bit contradictory.i think he was asking if modification is necessary for coils. in regards to that i think it actually depends on what coils are purchased. the advantage to cutting the stock perch and shortening the housing is more suspension travel for lowering. some setups may not require it and you can still run it without modification but you will not have as much travel as if you were to shorten the housing.

[Oolop]

I was wondering if you need to fill the tube with gas/oil or something before inserting the shock into the tube? hmm..

no, i think thats for when u use a smaller diameter shock for some reason. the koni's fit like a glove so u wont need to.

"do you have to weld and cut the stock spring perch???"

no, what i did was cut off the perch, cut out that section from the tube (so i could use the threaded part still) and then welded the two halves of the shock housing together and welded the supplied d-shaped perch from ground-control

[immajackuup]

do you have to weld and cut the stock spring perch???

[bimmerteck]

I generally use a table spoon or two of ATF in the bottom of each strut tube. The master tech who told me to do so never told me why though to my knowledge.

[mr.vang]

I was wondering if you need to fill the tube with gas/oil or something before inserting the shock into the tube? hmm..

ahaha...the answer is no.

[ewejin9394]

I was wondering if you need to fill the tube with gas/oil or something before inserting the shock into the tube? hmm..

[mr.vang]

i also found an issue when cutting off 4". the adjuster is going to rub against the wheel..

[AlarmedBread]

It's called droop travel.