Ground Control rear coilover issue

Suspension, including wheel, tire and brake.
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mroverkill
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Joined: 15 May 2015 17:13
Location: Atlanta

Ground Control rear coilover issue

Post by mroverkill »

Howdy fellas,

I'm working on putting together the rear coilover set I purchased from Ground Control and I am having a few issues.

I can't reason why I'm encountering this issue and GC, while helpful and communicative, seem stumped as well. I figure that bouncing it off of you guys can't hurt.

The lower spring cup of the coilover impacts the inside of the spindle just above the lower shock mount and the spring and upper spring seat impact the fender well and shock tower towards the inside of the car. This is only happening on the passenger's side. The Driver's side has about 1/16" clearance between the cup and spindle at full droop and 1/4" between the spring and fender well/shock tower at full droop.

It is hard to capture with the camera, but here are some pictures:

Image
Image


I can't figure out why this is happening or why it should be different from side to side on the same car (a 71 two door for reference). All parts other than the coilover kit appear to be oem.

Thanks in advance, fellas.
dislexicdime
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Joined: 09 Aug 2004 18:26
Location: tigard oregon

Re: Ground Control rear coilover issue

Post by dislexicdime »

You have them up side dowm
L series only have one header!

i need another garage mine is full of part's
mroverkill
Posts: 98
Joined: 15 May 2015 17:13
Location: Atlanta

Re: Ground Control rear coilover issue

Post by mroverkill »

No, I don't. Ground Control mounts them that way to decrease unsprung weight. It's also impossible to put this set in upside down without some weapons-grade idiocy.
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Byron510
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Re: Ground Control rear coilover issue

Post by Byron510 »

From Ground Control’s web site;

Bolt-on rear coilover kit for Datsun 510 (68-73, not wagon)
IN-HOUSE SALES ONLY, Fabrication and technical advice associated with this kit is beyond the scope of dealer sales.

We have been building and selling these kits for several years now, but we have never put them on the website. We start with a Ground Control designed rear upper shock mount. Machined from high carbon steel, and using a grade 8 bolt, this rear upper mount is designed to carry the weight of the car after springs are added to the shock. We utilize a Koni monotube rear shock, adjustable for rebound damping. This shock is available in our standard default damping for standard width cars, or heavier damping for wider cars with higher spring rates. The Koni shock is mounted inverted for less unsprung weight, and features the exclusive GC coilover hardware with single-locking sleeve and and your choice of Eibach race spring. If you are considering over 500 pound rear springs, we recommend fabricating a double shear rear lower mount to supplement our lower mount.
Any spring is available, enter your choice in the ordering menu or select "email me"

Also – see Sleepys-14 posts about half way down this page that actually concerned my camber brackets on PMK’s car.

viewtopic.php?f=10&t=6946&p=219678&hili ... ol#p219678

viewtopic.php?f=3&t=22786&p=208717&hili ... ol#p208717

You should get PMK and Sleeps-14 to comment on what they did to make these coil overs work.

Byron
Love people and use things,
because the opposite never works.
mroverkill
Posts: 98
Joined: 15 May 2015 17:13
Location: Atlanta

Re: Ground Control rear coilover issue

Post by mroverkill »

Thanks for the links, Byron. I should have clarified that to put them in upside down unintentionally would require some serious stupid.

Maybe one of them will chime in, but I didn't see anything pertaining to clearance issues in their posts. I'm starting to think that perhaps the suspension bushings are so worn that they have allowed the spindle to move more onboard than it would normally be by 5-10mm.
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PoorMtnKid
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Re: Ground Control rear coilover issue

Post by PoorMtnKid »

Hey Mr Overkill. I actually had the same issue you are having with them rubbing on one side. Then I did what Sleepy did by putting them in "upside" down by doing a little customization. Before I did the mods to get them to mount the opposite way they did not rub anymore and I was never completely satisfied with them for track use. They were good for street driving, but when I was on the track it never felt like I had enough travel.

I know my post did not help solve the issue, but if there is anyway of getting your money back and going with another brand I would do so. It seems like Ground Control just threw something together to satisfy a small demand. Other brands are : Techno Toy Tuning , Troy Ermish Racing, Chasing J's.

I went with the Troy Ermish rear coils which are a little pricey but so far they have been really good for the street. First track day will be in a month.
looking for pass. side arm rest
mroverkill
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Joined: 15 May 2015 17:13
Location: Atlanta

Re: Ground Control rear coilover issue

Post by mroverkill »

Thanks for the information, PMK. I was actually thinking about trying to get my money back and buying some Ermish coilovers. Will have to see how things settle after I get back to Atlanta.
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PoorMtnKid
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Re: Ground Control rear coilover issue

Post by PoorMtnKid »

mroverkill wrote:Thanks for the information, PMK. I was actually thinking about trying to get my money back and buying some Ermish coilovers. Will have to see how things settle after I get back to Atlanta.
No problem. From what I can say about the differences is the followng:

- Ground Control uses a Koni Shock that when I went to get replacements it came up as a dirt circle track shock on Jegs/Summit
- Ermish uses a QA1 shock.
- Ground Control, or Koni should I say has 3 levels of adjustment on their shock which is a huge PIA to adjust, you have to remove the whole coil over and get pop the dust cover off the strut tube to adjust. There are some generic youtube videos showing you how.
-Ermish/QA1's have the adjustment knob on the bottom of the shock with I think 12 or 16 adjustments of which Troy told me over the phone to only use 2-6 .
- Ground Control does not offer much adjustment up and down where the ermish has a huge amount of adjustment.

I feel the build is overall better , and when I was talking to a buddy of mine he just mentioned its coming from a guy who is into Datsun's and especially the 510 so why not trust his judgement over a company who deals with multiple cars......
looking for pass. side arm rest
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Byron510
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Re: Ground Control rear coilover issue

Post by Byron510 »

Interesting feedback PMK, thanks for sharing this.
The rear coil over is a mod I have been wanting to do for years. In my car were there are no rubber parts anymore, the rear springs and the height adjusters (weight jackers as they were originally termed) make a lot of noise from the springs banging around on top of the seats. And the shocks that were matched to my springs are way too stiff. I have been eyeing Troy's set up and I think it'll be the on me for me whenever I get around to it...

Byron
Love people and use things,
because the opposite never works.
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