Comments on: 2nd gen Illumina to 1st gen conversion (and other things) HOW-TO - Page 4

**spoolz** · 12-28-07, 20:43

It's funny this thread is back because I'm installing coilovers w/koni inserts right now. I used a hack saw to cut the perches off above the weld, intending to leave a flat surface for the coilover sleeve to rest on. Since I have the stock struts, there are only 3 welds.
Assembling the sleeve to them, for the most part I would have only 1 or 2 welds contacting the sleeve, regardless of how much I filed them down. I think if you're cutting the perches (unless you have illuminas with continous bead) it would be a good idea to remove the weld completely and have a steel collar fabbed up and welded for you...it gives you a nice even landing area for the sleeve.

Also, has anybody had problems with the clearance between the sleeve and the strut housing? The housing outer diameter is ~50mm, the sleeve inner diameter is ~52mm...not really a snug fit. Some people wrap the housing with duct tape as a spacer, then slide the sleeve on. Is this worth it?

**gavin** · 12-28-07, 23:41

Project_2501.... Id say call up ground control. I bought my set way before they had their online ordering setup so Im not sure why they have 2 listings for the coilovers. There is a difference in the strut bearings, perhaps they have 2 different upper spring perches?

As for the dimensional differences of the 1st and 2nd gen struts, the width isnt an issue as the sleeves are wide enough to accept a variety of aftermarket struts, which brings us to....

spoolz....the width is pretty standard for reasons listed above. They have to fit all the OEM replacements available for the car, KYB, Monroe, tokico, etc. I generally make up the difference in width with a bicycle inner tube, tape...whatever is apprporiate.

Ive used stock shocks with coilovers as well and used the 3 weld with no issue. I havent seen the issue you mention, but I can imagine it happening.

Gavin

**spoolz** · 3-1-08, 14:45

Quote:

Originally Posted by AMD IS THE BEST

I had to cut the bottom part of the strut mount. I placed the cap on the eibach spring and tried to put the strut shaft through the mount, but the strut mount was too deep and the threads would not reach the top of the mount to thread the nut on. I'll see if I can get some pics when I take it apart to figure it out. Nick

going back to an old reply, but I took some pictures to show what he meant by this. There's no way the threads are coming through, because the shaft can't travel any more- it's limited by the GC spring perch. I'm wondering if there's a difference between later model strut mounts, because I know the ground control parts are correct.

These 4 raised bumps from the stock strut mount make it a sloppy fit, there's no flat surface for the spring perch to rest on:

The only way to make this work nicely is to grind down the 4 bumps from the strut mount, and machine the through hole in the ground control spring perch so that the strut shaft can move through it and make it to the top of the strut mount. Anybody do something similar?

**Dutch** · 3-2-08, 11:33

i had the same problem u show us there.
ive had a spacer made up to fit the strut top and the hat.

**gavin** · 3-2-08, 15:45

The second picture makes it look like the strut shaft cannot pass through the hole in the GC upper spring perch. Is this the case, because it should. The shaft is 22mm(?) thick and should pass through the hole in the included upper spring perch. The shaft then gets bolted to the stock upper spring perch/mount.

Gavin

**spoolz** · 3-2-08, 19:27

yep, the GC perch's through hole measures 20mm, the shaft measures 22mm. Did GC change this maybe?
Like Dutch, I'll be making a spacer- with a larger opening so the step down on the shaft (from 22mm to 20mm) will be resting on the mount. It will also provide a nice surface for the spring perch to rest on. It's not the cleanest solution...I might just get rid of the gc perch altogether and merge it with the spacer, one piece aluminum.

Crude drawing (upside down, just the spacer):

**gavin** · 3-2-08, 22:12

Forget all of that spacer business. Thats not the issue here.

You need to punch out the hole in the spring perch(or return them for the correct ones), thats the fix for your issues. The hole in the GC upper spring perch should be 22mm and be able to slide over the strut shaft. Somehow you got the wrong upper perches.

Gavin

**spoolz** · 3-3-08, 10:38

It's only part of my issues. One is the perch hole not being large enough, the other is the perch to strut mount fit is not nice. I'm going to replace the perch with this one piece spacer/spring perch:

The top of it will seat in the recess of the strut mount (see the 3rd picture I posted), bottom of it is the spring perch, and there's a 23mm hole for the strut shaft. We'll have to see how that thin area at the top will do after some driving.

p.s. I've measured 2 sets of rear spring perches from GC, both are 20mm holes.

**gavin** · 3-3-08, 11:55

Thats pretty fancy, but again, really unnecessary. The issues you described really arent so much.

GC has sent out a batch of incorrectly sized upper spring perches. If the ones you have measured are 20mm, thats simply wrong as the hole for the shaft is too small. Ive had a set of these for years and I can assure you the spring perch does in fact slide over the shaft freely and others who have gotten these over the years(1st and 2nd genners) can attest to this. The "fix"? Alert GC to this error and have them send you the correct items..or punch the shaft holes out to the correct size.

As for the fitment with the stock mount...theres no magic there. They simply rest on the mount as seen and provide location for the new springs. Thats it, nothing more. You may be creating a solution(albeit a nifty one) for a problem that doesnt exist.

PS: Dutchs issue was actually different from yours. He wanted an interface between the upper spring perch and the spherical ball of the camber plate he was using for misalignment correction.

Gavin

**spoolz** · 3-4-08, 21:14

I'm going to tell GC about this, but I will be making the spacer/spring perch just because I can do it cheap and fast, not because it's absolutely necessary. I just don't like the fit, that's all.
I'll post pics when I have it machined.

**spoolz** · 3-9-08, 16:49

GC spring perch on the left, my spacer on the right:

Assembled to the strut mount:

I lose a little bit of adjustability, but I prefer this setup to the standard setup, where only half the perch contacts the strut mount. Not absolutely necessary though.

**SABBAi** · 3-12-08, 7:56

very nice machine work spoolz. solves the problem nicely.

What are the GC spring rates for the 1gen?

**spoolz** · 3-17-08, 22:06

Thanks, I wish I could take credit for the actual machining, but it was a friend who made them.
Spring rates are 375lbs/in front, 250lbs/in rear.

3-12-08, 7:56	#57 (permalink)
SABBAi Join Date: Apr 2004 Location: Melbourne, Australia iTrader: (1)	very nice machine work spoolz. solves the problem nicely. What are the GC spring rates for the 1gen?
	Teh Telstar can NEVAH lose!

12-28-07, 20:43	#46 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	It's funny this thread is back because I'm installing coilovers w/koni inserts right now. I used a hack saw to cut the perches off above the weld, intending to leave a flat surface for the coilover sleeve to rest on. Since I have the stock struts, there are only 3 welds. Assembling the sleeve to them, for the most part I would have only 1 or 2 welds contacting the sleeve, regardless of how much I filed them down. I think if you're cutting the perches (unless you have illuminas with continous bead) it would be a good idea to remove the weld completely and have a steel collar fabbed up and welded for you...it gives you a nice even landing area for the sleeve. Also, has anybody had problems with the clearance between the sleeve and the strut housing? The housing outer diameter is ~50mm, the sleeve inner diameter is ~52mm...not really a snug fit. Some people wrap the housing with duct tape as a spacer, then slide the sleeve on. Is this worth it?

12-28-07, 23:41	#47 (permalink)
gavin Join Date: Jan 2001 Location: santa cruz.ca iTrader: (1)	Project_2501.... Id say call up ground control. I bought my set way before they had their online ordering setup so Im not sure why they have 2 listings for the coilovers. There is a difference in the strut bearings, perhaps they have 2 different upper spring perches? As for the dimensional differences of the 1st and 2nd gen struts, the width isnt an issue as the sleeves are wide enough to accept a variety of aftermarket struts, which brings us to.... spoolz....the width is pretty standard for reasons listed above. They have to fit all the OEM replacements available for the car, KYB, Monroe, tokico, etc. I generally make up the difference in width with a bicycle inner tube, tape...whatever is apprporiate. Ive used stock shocks with coilovers as well and used the 3 weld with no issue. I havent seen the issue you mention, but I can imagine it happening. Gavin

3-2-08, 15:45	#50 (permalink)
gavin Join Date: Jan 2001 Location: santa cruz.ca iTrader: (1)	The second picture makes it look like the strut shaft cannot pass through the hole in the GC upper spring perch. Is this the case, because it should. The shaft is 22mm(?) thick and should pass through the hole in the included upper spring perch. The shaft then gets bolted to the stock upper spring perch/mount. Gavin

3-2-08, 19:27	#51 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	yep, the GC perch's through hole measures 20mm, the shaft measures 22mm. Did GC change this maybe? Like Dutch, I'll be making a spacer- with a larger opening so the step down on the shaft (from 22mm to 20mm) will be resting on the mount. It will also provide a nice surface for the spring perch to rest on. It's not the cleanest solution...I might just get rid of the gc perch altogether and merge it with the spacer, one piece aluminum. Crude drawing (upside down, just the spacer):

3-2-08, 22:12	#52 (permalink)
gavin Join Date: Jan 2001 Location: santa cruz.ca iTrader: (1)	Forget all of that spacer business. Thats not the issue here. You need to punch out the hole in the spring perch(or return them for the correct ones), thats the fix for your issues. The hole in the GC upper spring perch should be 22mm and be able to slide over the strut shaft. Somehow you got the wrong upper perches. Gavin

3-3-08, 10:38	#53 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	It's only part of my issues. One is the perch hole not being large enough, the other is the perch to strut mount fit is not nice. I'm going to replace the perch with this one piece spacer/spring perch: The top of it will seat in the recess of the strut mount (see the 3rd picture I posted), bottom of it is the spring perch, and there's a 23mm hole for the strut shaft. We'll have to see how that thin area at the top will do after some driving. p.s. I've measured 2 sets of rear spring perches from GC, both are 20mm holes.

3-3-08, 11:55	#54 (permalink)
gavin Join Date: Jan 2001 Location: santa cruz.ca iTrader: (1)	Thats pretty fancy, but again, really unnecessary. The issues you described really arent so much. GC has sent out a batch of incorrectly sized upper spring perches. If the ones you have measured are 20mm, thats simply wrong as the hole for the shaft is too small. Ive had a set of these for years and I can assure you the spring perch does in fact slide over the shaft freely and others who have gotten these over the years(1st and 2nd genners) can attest to this. The "fix"? Alert GC to this error and have them send you the correct items..or punch the shaft holes out to the correct size. As for the fitment with the stock mount...theres no magic there. They simply rest on the mount as seen and provide location for the new springs. Thats it, nothing more. You may be creating a solution(albeit a nifty one) for a problem that doesnt exist. PS: Dutchs issue was actually different from yours. He wanted an interface between the upper spring perch and the spherical ball of the camber plate he was using for misalignment correction. Gavin

3-4-08, 21:14	#55 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	I'm going to tell GC about this, but I will be making the spacer/spring perch just because I can do it cheap and fast, not because it's absolutely necessary. I just don't like the fit, that's all. I'll post pics when I have it machined.

3-9-08, 16:49	#56 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	GC spring perch on the left, my spacer on the right: Assembled to the strut mount: I lose a little bit of adjustability, but I prefer this setup to the standard setup, where only half the perch contacts the strut mount. Not absolutely necessary though.

3-17-08, 22:06	#58 (permalink)
spoolz Join Date: Dec 2001 Location: fort lauderdale, FL, USA Age: 28 iTrader: (0)	Thanks, I wish I could take credit for the actual machining, but it was a friend who made them. Spring rates are 375lbs/in front, 250lbs/in rear.