Well, I purchased a used set of GC coilovers, and then purchased a used set of GC camber plates from another person.

On the coilovers, I received the following:
150.64.66 = 6*2.5*370 <--- If my conversion is correct
200.64.44 = 8*2.5*250 <--- If my conversion is correct

I plan on DD this car, and attend 3 or 4 auto X events per year. Are this spring rates ok for what I need?

When I installed the front coilovers, there was a huge gap (about 3 inches) between the GC spring perch and the OEM Shock Upper Mount. Is that how is supposed to be? Or do I need longer springs?

Now a question on the GC camber plates and the KYB AGX struts, the ID of the spherical bearing on the GC camber plate is much smaller(.625) than the OD of the strut shaft. Is there any way around this, beside machining the strut shaft?

 

Man, maybe I asked too many question at once

Let me start by asking one question at a time

With the current 6 inch tall spring, I am seeing a 2.0 to 2.5 inch gap between the spring perch and the strut mount. Is this correct?

I was told by GC: The reason the three inch gap is there is because the car is lifted in the air. When you set the car on the ground, the gap will go away.

I can see that, but wouldn't that shorten the strut travel?

 

Those are the "stiff" spring rates that GC recommends for the FC.
Normally, they offer the 7" spring for the fronts, so I guess the previous owner wanted the car LOW.

GC recommends to machine the shock shaft to fit their camber plates.
I dunno how else you can do this properly?
They just chuck the shock on a lathe and machine away...

Yeah, you need to stuff everything on the car.
The gap you see will go away.
Yes, there is a chance you will bottom out the shock and kill it.
What kinda shocks are you running?
(Holy gawd, big (@#%^*$( pics!)
Red paint...KYB AGX's? GABs?


-Ted

 

hey ted, if you look, he said agx

peace

 

bahahhah, bad vision rearing it's ugly head again... :P

The KYB AGX's are just about maxed out to handle those spring rates.
The KYB AGX's can handle some pretty low set-up's, but I'd keep those front springs jacked all the way up if possible.


-Ted

 

Thanks for the help!

I don't want to "machine" the struts; sounds like a whole lot of work, for a DD car.

 

Noticed how I didn't attached the picture to the post?

 

I don't mine replacing the 6 inch springs in favor of a 7 inch ones.

 

Ground Control did the same thing to me. They threw 6" springs on the fronts, and there was a bunch of gap. I assume this could be ok for some shocks, but mine seem to have a very short stroke. When I attempted to install this on my car, the tire would crash into the fender well. In fact, I had to dial in max negative camber on my plates just so I could fit the tire into the fenders. It was absolutely ridiculous, and my front end was so low that I probably couldn't even drive over a dime.

I took the parts back to GC and had them switch out the 6" springs for either 7 or 8" ones. These work much better, and keep the shocks at the top of their travel when unloaded. Even so, the front end is still too low.

I'd fit these on and see how well they work first. If you run into clearance/ride height issues, get different springs. GC doesn't always take every application into account, preferring to throw parts that usually work at you.

This is what their springs looked like on my front ohlins:



This is how low the front end is, with the shock at the very top of its travel:



Keep in mind, this is with no real suspension loading either. The tire actually rubs the fender lining on hard cornering. Make sure you don't get these issues with your parts. It's probably my fault for having such a short stroke, especially since the PO ran 600lb springs on the front.

 

Yes, you will have to grind the shock shafts down to get them to fit into the camber/caster plates. I did it with a bench grinder. I guess it took about 2 hours. If you do it yourself, just do it carefully, measure often and don't let them get too hot.

You'll want that camber and every bit of those springs for autocross or track!

I have AWR camber/caster plates with AGX and 6" 450 lb. springs. My front ride-height is 12.5" (wheel center to fender brim), and could get it a little higher. I guess the upper spring perch is a little lower on the AWR.

GC had originally sent me 7" 400s to go with Tein mount and AGX. That didn't work at all. The Tein had to use the stock spring plate (bottom part of top mount), so even the 6" 450s were too tall. I never told GC though. They should know what works with their mounts and AGX.

You can measure to make sure the shocks won't bottom out. Once you grind it, assemble one side without the spring or bumpstop. Jack up the wheel and see when and what hits. My tire hit the fender liner at ~10". Then see (or feel) how much the shock rod has to go, and also see how much bumpstop you need (when crushed).

On the 3" spring gap, without helper springs, you will still have a gap with stiff springs like that. With a sway bar, you will have to get the whole front airborne to get the springs loose, which may never happen. Even so, it will be fine.

 

I received a 8 inch spring for the rears; I might try them up front, just to see if I have any gap or clearance issues.



Thos pics are with the 8 inch spring?

Thanks for the info!!

 

Now that I think about it, I didn't explain the problem clearly. The GC spherical bearing does not clear the threaded portion of the strut shaft. If I were to machine the shaft; I would have to start from the very top, which means that I would have to do a new thread on the strut shaft.

I found a couple of places on line, that sell spherical bearings on different sizes; I'm going to try that.

Do you DD your car? It seems that the AGX can't handle anything springs over 400lbs.
I guess GC did improved on their customer service\support; but I am not impressed with their "improved" support.

Putting the strut to that stress, just because I decide to use a shorter spring on purpose; does not makes any sense to me. I will try to measure everything this weekend, and take it from there.

Thanks for the help!!

 

No, I don't DD my '89 na.
For a few months and 3 autocrosses I've had 450/325 with RB tubular/stock sport 14mm.
If I put the AGXs on 2/5 it's fairly bouncy, but not jarring. If I turn them up from there - and it's mainly the rear that I feel the most - it feels like the shocks are harsh and stiff on small bumps, but if it's a larger bump that gets the rear moving up and down, it feels uncontrolled. I haven't tried 4/8, but on 4/7 it is very harsh and is still a little uncontrolled. It's better with no weight in the car.
It feels fine on the autocross course though. I'd like to get a film of it so I can see how much it's rolling and bouncing.

I will get some other shocks when I decide what springs I'm going to stick with. I wasn't planning on doing this to the car when I got the AGXs. I've thought of having 2 sets of struts/springs and swap them for the street or racing/track.


Here's how I see the springs...
Your springs are 370 lb/in.
Let's say you car weighs 2700, 1300 on the front, 750 lbs on each front wheel.
So, your 370 lb/in springs each will be compressed ~2" when your car sits on them, regardless of the length of the spring.
You should probably put one corner together, lower seat at it's highest, and see about where it sits. Then you can estimate the spring length. Have enough that you can set it as high or as low as you want it. Any more spring than that is extra weight.
I think the 6" 375 lb. spring is about 2.5" long when fully compressed. So, you have about 3.5" of travel. Hmm... Sounds like we both need a longer springs!

Ok, so 375 lb compress 2" with the weight of the car, say you want a ride height range of 12.5 - 13"... so you need to compress another 3"...
From the Eibach catalog:
0800.250.0375 (8" 375 lb): length compressed: 3.24, total travel (free to bind): 4.76.
1000.250.0375 (10" 375lb): Lc: 4.32, Sc: 5.68.
Looks like highest ride height for 8" 375 is ~12.76" (wheel center to fender brim).
Highest ride height for 10" 375 is ~13.68".

This is with short hard bumpstops that just keep you from hitting your fenderliner or whatever - which is best for racing if your springs are stiff enough. Otherwise softer microcellular bumpstops like GC sells are good. Their "spring rate" is progressive and they don't have much rebound, which is good if your shocks are set for the lower rate springs.


Oh, and I don't have a problem with GC. I had a nice long informative conversation with them when I got the coilovers. They just guessed wrong with the front spring length. It's really that the Tein camber plates have the spring mount very low. With the AWR mounts, it now looks to me like I need at least 8" at 450 lbs.