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3000gt Struts in Stance Housings Build

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  • 3000gt Struts in Stance Housings Build

    Turns out the 3000gt strut outer diameter is a perfect fit for the inner diameter of these blown stance coilovers.

    However the 3000gt strut is a little long and extends out the top of the housing (ie you can see about 1" of the yellow housing protruding. Is this a deal breaker? I know the top bearing for the strut is in that protruding part, is the yellow tube enough to support it?

    Edit picture here:
    Last edited by Russell423; 06-11-2018, 09:10 PM.

  • #2
    I think the yellow tube would support it with the small amount sticking out. You'll need to come up with a way to secure the dust seal. I put them in Buddy Club housings and to get the ride height where I wanted, the strut housing hit the sway bar link. I filed the bump off the back of the link and reduced the interference, but it still would occasionally rub.
    Don Johnson (really!)
    Just so you know.


    • #3
      Thanks for the response,

      I think i will lathe up some collars that slide over the top of the unthreaded top part of the tube and then weld them in place to extend the housing to fit the strut.

      Can you elaborate on what you mean? Do you mean with the bottom mount adjusted you had too much sticking out below, causing interference?

      I have been digging into older threads and saw you mention your Buddy Clubs. do you have any details on how you went about it? All of the photos have been purged.


      • #4
        I could also machine a snap ring groove into the collars to hold an appropriate 40mm seal.

        What about shortening the yellow housing? could i not push the bearing at the top further into the yellow housing and then part off the housing to shorten it? or would that also require me shortening the shaft?


        • #5
          The Buddy Clubs were inverted 36mm so they had the slide bearings in the housing already. I removed the 3kgt from the housing and mounted them inside the BC housings. The 3kgt exposed shaft is longer so I had to add an additional slide bearing. That worked but there was less "overlap" between the strut body and housing so it's not as stable. If you shorten the yellow housing to get it to fit, you'll have the same problem and the strut will likely pop out of the lower slide bearing in the housing.

          I did have to adjust the bottom mount to compensate for the longer strut and get the ride height where I wanted it. The modified stock strut housings that are used for the 3kgt struts have about 2" added to the bottom for this purpose. I don't have the car any more but I reviewed my pictures and the problem with the housing hitting the sway bar end-link was due to a different modification.
          Don Johnson (really!)
          Just so you know.


          • #6
            Hmm I wonder if I'm going to run out of threads at the top where the spring collars are if I have to bring the mounts up ~2"...

            Adjusting the lower mounts like you say just increases the usable travel doesn't it? Ride height set by the length of spring and the spring collars?


            • #7
              You'll be OK. I was able to run 8" springs and 2" tenders. The 3kgt strut is listed as 5.5" travel but it includes a 3" bump stop. I cut mine down to get more travel and you can do the same if needed. Use an Allen wrench and a 17mm box wrench to remove the strut from the yellow sleeve, trim the bump stop as needed and re-assemble before installing it into your Stance housing.
              Don Johnson (really!)
              Just so you know.


              • #8
                Last edited by djsilver; 01-04-2018, 11:43 AM.
                Don Johnson (really!)
                Just so you know.


                • #9
                  Guys looking for some advice on this build again.

                  Here is what i have worked out:

                  I think I want a 8k front spring. My car is mainly for street driving, I do not race it and this seems appropriately stiff but I am open to suggestions. QUESTION: Roughly how much sag is expected when the weight of the car is on the springs when using 8k fronts? my car is running a stock KA24DE and has minimal to no weight reduction.

                  Pictures with the Stance housings mocked up using the existing stance hardware (somehow it all just works with the existing threads on the strut - go figure)

                  Looks like with my setup i have about 9.75 from the top of the damper mount to the spring perch (when the perch is fully topped out).

                  ASSUMPTION: I can pick any spring length as long as i can find a helper spring that makes up the difference to a total of 9.75". Of course different combinations result in different damper travel

                  This would allow me to run an 8" spring with +2" helper (as you did DJ) or a 7" spring with a +2.75" helper, etc.

                  I have measured my travel (with the bump stops cut down) to approx 140mm or 5.5". This is how i received the damper from the previous owner.

                  the existing stance strut looks to be about 3.5" MAX before the bump stop becomes active (see pic)

                  The existing Stance hardware is for 65mm ID springs so i will go with 65mm ID Swift springs, they also have a nice selection of helper springs.

                  I have worked out the following formula for the travel after the helper has collapsed to its collapsed length:

                  Remaining travel = Total Travel - ( 9.75 - [Free spring length] - [Helper collapsed length] - [Spring perch spacer])

                  I see two options:

                  OPTION 1

                  Swift 8" spring (Z65-203-080 8k rate, 4.2" usable travel binds at 5") and 2.8" helper (H65-070-008 - .9" CL)

                  5.5 - (9.75 - 8 - .9) = 4.65 Remaining damper travel - Would exceed usable spring travel - QUESTION: how much would i need to limit the travel to? Could I set the upper spring perch to get max 4.2" travel? this would mean the spring is exceeding its "usable travel" as the damper begins to compress the bump stop.

                  OPTION 2

                  7" spring (Z65-178-080 usable travel 3.7", ), Swift 2.8" helper (H65-135-0008 - 0.9" CL) and a .25" machined spacer to give some pre-load to the helper (QUESTION: is this needed? how much helper Preload should there be at full droop?)

                  5.5 - (9.75 - 7 - .9 - .25) = 3.9" Remaining damper travel. would need to adjust spring perch down (or spacer) to get to 3.7" travel)

                  Personally, it looks like option 1 would be the best choice as it would give me the most leftover travel and travel can be adjusted independently of height anyway using the stance housings... so why not max it out.

                  Thanks if you got this far. Please let me know what you guys think. This seems to check out to me.

                  Some additional notes:

                  I am having a collar machined that i will weld to the top of the threaded stance housing to support the yellow strut housing as well as retain a dirt/dust wiper with a snap ring.

                  I estimate i will have to raise the stance bottom mount approx 1-2" to maintain my existing ride height - seems like there is ample room between the lower control arm and the bottom of the coil-over housing.

                  I am assuming my tire will clear the lower spring perch - QUESTION: what tends to be the limit of rim width/offset before this is an issue? I am running a 17" rim, 8.5" wide 17 offset tire has some stretch. approx 1.5 degrees of camber.

                  If anyone is wondering these are from defunct stance "Street" Coil overs that i cant find any information on these days. They have a 52mm thread on them and are exactly 46mm ID when gutted. The same Coilovers use an M14 1.5 thread at the top and as far as i can tell, all of the Tophat/spring perch hardware is compatible with the 3000GT bilstein.

                  Swift springs part list:

                  Swift helper springs part list (click through to the helper section):
                  Last edited by Russell423; 06-11-2018, 09:03 PM.


                  • #10
                    Big photo dump incoming

                    So i ordered the 8" 8k springs and helpers from swift. They should be here next week. While i wait i'm continuing on with the build.

                    I drilled and tapped the housing for an M10x1 thread. Here it is set up in the lathe:

                    I'm using brass shim stock here to prevent damage to the threads.

                    To extend the housings i had a machininst friend make up these steel collars. They hold hold a wiper seal that is retained by a snap ring.

                    The snap rings were far to heavy for this application and were difficult to install so I cut them in half to make single turn snap rings. These are easier to deal with. I may also increase their ID somewhat to make them easier to install/remove.

                    The collars fit on top of the housing and extend the housing to fully support the upper bearing in the strut. Here is everything mocked up. I also cut ~.200" off the top of the housing.

                    To fix the extension collar on the housing I set up for two small fillet welds. Just enough to keep it in place and resist the drag of the seal on the shaft. These will mainly be supporting side load so the weld will not be under much load.

                    As the collars are machined to be a close fit to the strut body it is important that the ID of the collar stayed aligned with the ID of the housing after welding or the strut body might bind as it is slid into the housing. To ensure proper alignment and also reduce distortion by acting as a bit of a heat sink I machined this aluminum plug from some scrap. It is match fit to the ID of the housing/collar (i simply took half mm cuts until it just barely slid into the housing.

                    Fully assembled and ready for welding:

                    I machined in the groove in the aluminum piece in case it didn't want to come out after welding.

                    Ghetto welding setup. I'm using a bar clamp to keep the stack of parts tight together and an old machinist's vice to keep it in place. Ground is attached to the vice.

                    I really like using these heavy vices for fixturing because unlike a bench vice you can move them around but they are still heavy enough to keep everything in place.

                    Unfortunately that's where my phone ended up running out of battery. In the end I did two .25" long 1/8" fillets per collar.

                    Next steps are to paint the upper portion of the housing as it is just steel and then its assembly time!


                    • #11
                      Cool! Nice fab work.
                      ~1992 240SX, SR20/Koni track day car
                      ~2016 M3, daily driver


                      • #12
                        Cool stuff - seems like quite a bit of work tho'!

                        On the spring rate, I probably would have toned it down for pure street usage unless you want it to have an "aggressive" ride. I think a 7k or even 6k spring up front would be a little more liveable on a daily basis. Keep in mind stock springs are ~2 k, which is very soft, but at the same time, we're debating 3x or 4x stiffer than stock, quite a jump!
                        '18 Chevrolet Volt - Electric fun hatch for DD duty!

                        DefSport Koni Sleeve and Spring Perch Buy!!!


                        • #13
                          The original stance spring is 7k so I can always go back to that if I don't like the 8k.


                          • #14

                            Got the housings re-plated because **** corrosion.

                            Final assembly in a couple days.