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Ground Control coilover issues


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Had my struts sectioned (only have the rears installed at this point) such that a BZ3012 Tokico cartridge fits in the tube perfectly with no spacer. That's a 240 front strut cartridge. Put the suspension together and with 10" springs, and the collars turned up as far by hand as possible - I still have only about 1.5" of clearance between a 15" wheel (with a 225/50/15 tire) before it's going to hit the rear wheel well. The guy who sectioned my struts was given the measurements from John Mortensen's writeup - but he just fit the tube to the cartridge with NO internal spacer in the tube. Says he compared measurements after the fact and they worked out. Also stated that he only took out like 1.5" of the strut tube - which from what I've read - is correct.

 

Did I do something wrong? Even at full droop, the rear control arm is almost parallel to the ground. I had thought that by wrenching up the spring adjuster - that would buy me some more clearance, but in looking at GC's website about the coilover spanner - it says that some setups don't ship with it for a reason. My setup (that I bought off a member in this forum) did not come with the adjuster wrench, so I have to assume that either A) I tighten them by hand - and that's all that they want you to do, or B) it had the wrench and the original owner nabbed it.

 

I have a feeling when I set the weight of the car down on the wheel - it's going to dig straight in to the rear wheel wells........

 

Suggestions?

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The rear strut is cut too short. If the rear struts are cut to the correct length there should be a spacer underneath the shock 1 3/4" to 2" long (IIRC). If there is no spacer then your guy cut the strut tube too short.

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I'm sorry Jon - it was YOUR writeup that I gave him. Sorry to not give proper credit where it's due. OK - so i SHOULD have a spacer at the bottom of the strut housing when running the 3012's in the rear?

 

I didn't have this clearance issue until I installed the Ground Control camber plates. When I had the stock 280 rear strut top installed (the 3 bolt piece at the top) - the height was perfect. Now that I have the camber plates ( and can't go back because of all the cutting) I'm screwed. I will have to find out exactly how much he took out. He said it was less than 2". Just damn......

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OK - with that being said - what about my fronts? I used the BZ3099 MR2 struts. He cut them as well with no spacer in the equation. Should there be a spacer in the fronts as well? And if so, how long should the spacer be?

Dadgumit. - this is not my week.....and it's only Monday.......crap.

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OK - took some measurements last night. I measured from the top of the strut tube downward. I know the article states to measure from the inside of the strut tube - but I didn't have that luxury.

 

Taking the following statement from the article - "The most important measurement is the overall length of the strut tube (14.938" to 15"). " I am pretty dang close. Not sure how far in to the base the tube extends - but if he cut them too short - then I don't see it. I'm right at 15" - if not a little longer. If memory serves me correctly - the tube extends almost all the way down through the thick base of the housing seen below....again - I could be totally off.....that's why I'm posting.

 

LRMeasure.jpg

 

Spring perch measurement from the top of the strut as well.

 

LR_Perch.jpg

 

Yet - under full compression - this is what it looks like.

 

LRCompress.jpg

 

I'm going to be going with ZG flares eventually - but would like a little more 'adjustment' for some breathing room. I put the coilovers on to have the 'option' of going lower if I wanted to - but I don't want it slammed to the ground either. I prefer stock ride height minus about an inch to an inch and a half.

 

Again - when I had the original 280 strut top on - which is about 3" in height - I had all the clearance in the world. Now that I've put on the camber plates - I lost that 3" and need to figure a way to make up some of that distance.

 

The fronts turned out perfectly though - appears to have plenty of room with the 1" bump steer spacers.

LFwCaliper.jpg

 

The BZ3099 up front has no spacer in the tube - only the cartridge - and if anything, it appears to be a little long.

 

"The most important measurement is the overall length of the strut tube (12.875" to 12.938"). "

LF_Measure.jpg

 

So - what are my options for the rears? 2" spring spacer? I need something to gain back the lost distance from the camber plate install.....

Edited by 2eighTZ4me
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Is this installed on a 240Z or a 280Z? If its on a 280Z, then the rear strut tube lengths listed in the Strut Sectioning FAQ doesn't apply. The 280Z strut tubes are longer and the strut tower mounting point in the 280Z body is higher up in the chassis. For the 280Z rear struts you just cut out the same amount that's cut out of the front tubes.

 

Also, you lost 2" in ride height just by swapping out the 280Z insulator with the GC camber plate.

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Looks to me like you have a non-issue. Preload your springs some to raise your ride height. You haven't said what your spring rate is. They could be compressing quite a bit. I don't remember what all the write-up says but there is always room for deciding for yourself. You haven't mentioned where, in the stroke, you are at ride height. That is pretty important.

 

Easy fix is screw up the adjuster. Preload on the spring is fine. They come that way on all stock cars.

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Jon - this is a 78 280Z. I should have mentioned that. So - my options are find a pair of original strut tubes - DON'T section them - and make a spacer for the bottom of the tube for the cartridge to sit on?

 

My guy took less than 2" out of the strut in the first place - and he basically did the same thing for the fronts as the rears. I'll have to have him dig up the sections he took out - but he swears it was less than 2" on both front and rear. That being said - I'd be in the ballpark by not sectioning the strut tube at all - because I've already lost the 2" from the original 280 strut top - and going with the camber plates.

 

This sounds like the only possible solution to regain the ride height...yes?

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I'm running 365lb springs in the fronts - 285lb in the rears. They don't compress too much - maybe 1.5" to 2" - but that doesn't include fuel in the tank etc. - so I would suspect a little more when full of gas and interior. I'm going to 'try' a couple coilover spring spacers and see if that buys me anything. Really want to avoid the cost of going through this exercise again. I haven't set the car down on the ground yet to measure ride height - so I can't speak to that. Just got the fronts all zipped up last night and ran out of light (and willpower) before I could set it on the ground. I still need to get the motor and tranny in before I can draw any conclusions. I've got John Williams trying to source a pair of stock rear strut tubes just in case....

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Just a neophyte's view - in Post #5, you said the fronts look perfect but Picture 4 shows only about 1.5" of shock travel, with no load on the strut. logr had the key comment I think, about stroke. The whole point of sectioning is to allow the use of a shock absorber (aka insert) in a position where the stroke can be used effectively. You're almost on the bump stops already.

 

And in Post #1 you said that the BZ3012 was a 240Z front. It's a 280Z front for a stock setup, I believe. Maybe just a typo but could be important. Some of the Tokicos appear to be the same shock, just with different numbers, so it may not matter.

 

Good luck with it.

Edited by NewZed
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NewZed - what you DON'T see is the other 4+ inches of travel underneath the blue boot. The boot was just riding up on the shock shaft - there's plenty more room underneath there. The bottom of the boot is pulled tightly over the top 1" of the strut tube - everything above that is airspace - and shock shaft. BZ3012 and BZ3015 are identical struts. Only difference is the gland nut - everything else is the same. I'm getting rid of the 12" springs and going back to 10's on the front anyways - would seem to be good practice to have all 4 corners on 10" springs. I've got a pair of 385lb'ers in the shed.

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Sorry about that, I knew I shouldn't have posted. Good news for you.

 

By the way, since the gland nut fits on the back tube, then the amount your guy cut off would be the difference in length between the original strut insert with spacer and the one that's in there now. Just sayin', math-wise, since the strut tube length has to match the insert length plus spacer (if used), after cutting, to get the gland nut to do its job.

 

I'm done...

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No no no - I am very thankful for all your input - I'm glad you did post. You are exactly right about the spacer length. Now if I can just get him to dig up the sections that he cut - I can cut a spacer of the correct length when I get the stock strut tubes. Jon C hasn't chimed back in yet, so I'm assuming this is the route to go. You never know when a second set of eyes is going to reveal something you hadn't thought of! or overlooke.

Thanks again NewZed!

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I just got done redoing my rear struts after installing TTT camber plates. I lost about 1.5 inches of ride height after the install.

 

I had to add a section to the strut, lengthen the spacer under the strut, and raise the spring perch. It was quite a bit of work, but must be done if you want the right ride height with proper shock damping.

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Jon - these are 280Z strut tubes going on a 280. I have a pair of stock 280 tubes coming to do this exercise all over again. Looks like I'll just be cutting off the spring perch on those - not shortening them, and welding on a new perch. And then the powdercoating....and then the bearing and spindle pin removal....oh JOY!!

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If the fabricator shortened the 280Z rear strut tube to about the numbers listed for the 240Z strut tube in the Sectioning FAQ then he removed 3" of tube length. The inside length of the rear 280Z strut tube is 18". I suggest you remove 1" from the 280Z rear strut tube and add an appropriate length spacer under the shock.

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For 280Z tubes I remove an appropriate amount to get the BZ3099 strut to fit in the tube with no spacer (same length as a 240z front tube) and then remove an identical amount from the rear tube and make a spacer to take up the space under the rear strut.

 

I've used this method for all of my customers with 280Z tubes and never had an issue.

 

John's advice at 1" is solid, especially if you have gone with camber plates. If it doesn't put you where you want to be in your travel when you dial in the ride-height you can always take some more out of the tube and shorten the spacer. It isn't the funnest exercise in the world (especially if you're paying to have it done!), but it will eventually get you where you want to be.

 

Then again, dropping an inch from stock ride height doesn't really necessitate sectioning at all...

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The fact that I've lost nearly 3" alone from the original 280 strut top leads me to believe that I should just leave the stock tube intact and not take anything out of it. Ryan or Jon - how far up do you put your spring perch that the adjustable collar rests on? Measured from the top of the spindle base.

 

I guess I could go with a 1" splice. When I put a load on the car - the rear tire was resting on the rear tire well - and that was with the spring tension cranked up. 2" of clearance would be good - but since I have a 5" adjustable collar - I'm thinking that I could get as low as I'd ever want to go by just leaving the strut tube in stock form. You're right though - it's easier to take away than to add back!

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Assuming a 5" threaded collar I usually put the welded on ring 6" down from the top of the strut tube - that's for 10" springs in the 300 lb. in. range. You only lost about 2" from the removal of the 280Z insulator. The camber plate puts the upper spring perch about 1" down from the top of the strut tower.

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