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winstontj

School me on front (rabbit insert) coilovers please?

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It's been a while but I'm starting to get back into things...

I found a sealed box in my storage unit; called the shipper and found out that I am the proud owner of (6-years old) brand new, in box, Bilstein Sport Rabbit inserts.

I also have tii strut tubes that I've ground off the spring perches but that's it.

Again, it's been a while... Should I just ship out the tubes to someone who knows what they are doing? If so, who??

I just want to cut them down, weld them up and I guess get some sleeves and springs.

So who is the go-to shop to send these things out to? Do I need to send these shocks out with the tubes or will they (i hope) know the measurements?

Thx.

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You'll need to send the shocks along because they are so short they need a spacer made no matter what. Usually just a hollow pipe of the right diameter cut to the right length, though I believe I have seen some made from solid Delrin cylinders.

Since I have a MIG I do my own cut and weld. Many remove 2", though next time I might remove 2.5" for track-only application. I have a piece of heavy-gauge 90° angle iron that I use to hold the pieces parallel when I do the initial placement spot weld. I check for straightness after each initial weld and adjust as necessary. Once three welds in place (120° apart) the shape is stable and I weld up. Then I fab a collar to weld to the struts for the threaded spring perch tube to rest on. Looks like IE might have a nice piece for this you could buy as part of their coilover kit.

http://www.iemotorsport.com/bmw/2002-suspension-steering/02frtcoil.html

Make sure spring tube does not come down too far and interfere with the tire. Same thing with the spring perch itself, you can only go so low until there is interference.

I have a pair of 400 lb Eibach springs I ran on the street in good shape if you are interested. I think they are 10" , I went to 8" 425 lb for track use.

Best, Fred '74tii & '69GT3

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I used a 4"chunk of pipe cut in half as a spacer, 2" for each side.

For welding it up, a trick i adapted from Colin on here is to get a bit of copper pipe that is near the internal strut diameter. I then slotted it and put a hole in near one side so that it can be taken out. After some bending, the copper tube keeps the two pieces you're welding together tight. It is also possible to use a old shock for this.

I think I took out about 2.25" of strut on each side, maybe a bit more.

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if u r still in CT and close to SCR....Matt and the fellas can do it.....not that hard. or any race/weld shop can do it.

Patrick at Midnight can do it...but he is in PNW

fyi...a 10 inch spring sounds a bit too long tho....most run 7 or 8 w/ that set up....

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I owe Matt a visit. It's been so long he probably doesn't even remember who I am...

Sadly, this is turning into a borderline "checkbook" restoration.

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a 10 inch spring sounds a bit too long tho...

Good catch JR. My old 400# springs are in fact 8". I checked my build sheet and the ones on my track car now are 6" long. --Fred

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I used old Bilstein shock tubes for the spacers in my race car. They have held up for 25 years. G

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The IE kit comes with pretty specific instructions if you want to DIY.

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when it comes down to it i'll probably just send them out so I really don't care. I want to be able to lower the car for track events, etc. but 99% of the time it'll be at or close to stock height (or maybe 1-2" lower) and used on the road.

hopefully whoever does the work will know how much I need to chop them.

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Well if you cut the struts 2" you will be 2" lower in front. Then shorter springs can drop you below that. Unless you did coilovers (or an adjustable height platform with stock diameter springs) in the rear, you will not be able to raise/lower the rear of the car for stance reasons. I assume you will be using shorter springs in the rear, like the IE 350 lb "IT" springs, correct?

Truth be told, after I did the coilover fronts and IT rear springs on my Fjord blue '73tii street/track car, I never did raise the height for street use. Drove that combo for about 7 years on the street before building a dedicated track car (the Colorado '74tii). Unless you need ground clearance for some reason (maybe some offroading.....?), leaving it at track height is fine. At least it worked for me.

Fred

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Well if you cut the struts 2" you will be 2" lower in front. Then shorter springs can drop you below that. Unless you did coilovers (or an adjustable height platform with stock diameter springs) in the rear, you will not be able to raise/lower the rear of the car for stance reasons. I assume you will be using shorter springs in the rear, like the IE 350 lb "IT" springs, correct?

Truth be told, after I did the coilover fronts and IT rear springs on my Fjord blue '73tii street/track car, I never did raise the height for street use. Drove that combo for about 7 years on the street before building a dedicated track car (the Colorado '74tii). Unless you need ground clearance for some reason (maybe some offroading.....?), leaving it at track height is fine. At least it worked for me.

Fred

I'm not sure what I'll do for rear trailing arms but I know I'll do coilovers on all four corners.

A few years back I built/modified a set of e30 rear trailing arms to fit in a 2002 chassis so I might use those because they are also converted over to a 5-lug setup.

I've also got a set of boxed '02 arms so I may just use those and try to figure out a 5-lug swap on '02 arms.

I have no idea other than it'll have adjustable coilovers on all 4 corners.

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Truth be told, after I did the coilover fronts and IT rear springs on my Fjord blue '73tii street/track car, I never did raise the height for street use. Drove that combo for about 7 years on the street before building a dedicated track car (the Colorado '74tii). Unless you need ground clearance for some reason (maybe some offroading.....?), leaving it at track height is fine. At least it worked for me.

Fred

+1

i would guess that 99% of the people who get adjustable height spring perches so they can change it......never change it after the first setting. the 1% who do are the track nuts who change it for corner weighting. :-)

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+1

i would guess that 99% of the people who get adjustable height spring perches so they can change it......never change it after the first setting. the 1% who do are the track nuts who change it for corner weighting. :-)

I'll probably be guilty of that as well but I like to tell myself I'll change it :)

I'll probably do two settings and mark them (counting by # of turns). One for street/DD and one for track events. If I lower the car for a track event it will be corner weighted, etc. and done properly - but then I'd just use that as a base setting and just count/add turns from that up to a "normal" street height that I like.

So is taking 2" off enough? I somewhat disagree with the comment that taking 2" off the strut tube lowers the car 2". It all depends on your perch position and the height of your springs. Generally the goal is to lower your car but if you put the perches too high and run long springs you could chop the tubes, run rabbit shocks and maybe get back to stock ride height (and blow up your shocks).

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Your goal should be to put the shocks at the middle of their travel at the rest height of the springs in order to maximize possible travel in either direction, because hitting travel extremes can damage shocks. With adjustable spring seat height, this is not always possible, but getting it close enough is usually sufficient, as there is minimal performance difference at various shock height. 2" spacers and 2" off the tubes worked for me... my IE sleeves are mounted about half an inch above the brake line mount on the strut tube, and i have about 3" of damper shaft exposed at rest height. (Will get more accurate numbers today)

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