Tyre/Spring Perch Interference

PostPost by: Galwaylotus » Sat May 05, 2012 1:54 pm

I need to replace the tyres on my S3. It has 26R bodywork and the P.O. had 175R13s on Plus 2 (5.5-inch wide) rims on the rear and 155R13s on 4.5-inch rims on the front. There is a very shallow groove on the rear tyres where they just touch the spring perch. I want to go with Uniroyal Rain Experts front and rear but they aren't available in a 175R13 size. How much relief is possible by deforming the inside of the rear spring perch? I don't want to go 175/70 R13 as I'll lose too much on the effective final drive ratio but a 185/70 will be too wide without relieving the perch. With the 26R rear bodywork a narrow tyre would look a bit ridiculous too!
Any (cost effective) suggestions? Thanks. :)
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PostPost by: nebogipfel » Sat May 05, 2012 2:37 pm

Why not put 165R13 on the rear? That would give you clearance.
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PostPost by: garyeanderson » Sat May 05, 2012 2:45 pm

HEAT and HAMMER (I would remove the spring before applying any heat to the spring pan)

un-modified side
un-bashed.JPG and


This is not a matched pair but the above picture shows how much larger the spring pan is compared to the spring diameter.
bashed.JPG and


bashed1.JPG and


bashed2.JPG and


This is not my mod, I buy the adjustable spring perches and cut off the pans and get small diameter springs when I do it...

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PostPost by: Galwaylotus » Sat May 05, 2012 4:31 pm

nebogipfel wrote:Why not put 165R13 on the rear? That would give you clearance.

It would give the clearance but would be a bit lost in the 26R arches.
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P5050002.jpg and
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PostPost by: Galwaylotus » Sat May 05, 2012 4:33 pm

Gary,

You've come through once again! Thank you. Do you happen to have an approximate gain in clearance with the modification shown?
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PostPost by: garyeanderson » Sat May 05, 2012 5:23 pm

Galwaylotus wrote:Gary,

You've come through once again! Thank you. Do you happen to have an approximate gain in clearance with the modification shown?


Maybe as much as 3/8 of an inch or about the width of a coil

If you want more and don't care about future value then slash as much as this off, the original Ugly flair Coupe had these rear struts

elan-photos-f18/elan-flairs-the-good-the-bad-and-some-ugly-ones-t16400.html

and had 205/60 x 13 on 6 inch Front and 7 inch Rear Jap Magna wheels, I didn't drive it ever so I don't know how it drove but it did roll.
original ugly.jpg and


un-bashed and slashed.JPG and


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PostPost by: ceejay » Sat May 05, 2012 9:27 pm

Adjustable rear spring platforms, narrow wound springs, a bit of work (Well maybe a little more than a bit)
doing the conversion and the problem is solved.
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PostPost by: Galwaylotus » Sun May 06, 2012 7:56 am

Yes, but at what cost? Current budget mightn't stretch that far. :(
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PostPost by: ceejay » Sun May 06, 2012 8:16 am

Mmmm, if you want these things, sometimes you have to bite the bullet.
If you can machine and fabricate and do your own mechanical work the
cost is not all that great except for the springs.
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PostPost by: Bud English » Sun May 06, 2012 5:51 pm

Even with minimum fabrication resources the cost needn't be prohibitive. Here's what I did for my +2.

Spring Kit.jpg and

-I picked up the adjustable spring perches from eBay. Honda Civic/CRX struts are as close to the same diameter as your elan struts as you can get. The kit of four threaded sleeves, perches, springs and wrenches was $46.95 with free shipping in the US. The kit I bought isn't currently listed. The one in the picture is a little more money and looks a bit nicer than the one I used. You only use two sleeves, perches and the wrenches. Measure down from the top of the strut the length of the new threaded sleeves. Cut the original perches off at that point. On mine that left just the bottom ring portion of the perch with a bit of four diamond shaped indentations. I filled these with epoxy so they wouldn?t fill with water. Take care not to nick the strut tube. I used epoxy to fix the sleeves to the strut tube and to keep moisture from getting between the sleeves and the tubes.

New Spring in Old Spring.jpg and

-The springs, 14?, 100lb rate coilovers, were from Speedway Motors (via eBay again). $76.62 including shipping for the pair. The springs are good ones and come with the test reports for each spring. I chose 14? to give me some height adjustment to go back to the original ride height. You could also use twelves.

-The bump stops are VW Passat , front strut, items, again from eBay. Used and in nice shape, $23.46 for the pair including shipping. They are the right length, as firm as the originals, and fit the small diameter springs.

Spring Plate.jpg and

-I made the top spring plates from my original parts and some scrap prop shaft tubing I got from my local machine shop for free. The tubing pieces are 5/8? long. I centered up the tubing and welded it before cutting off the excess.

New Spring & Adj Perch 2.jpg and

I haven?t compressed the springs yet but I think you get the idea. These were US sources and I didn?t go on line to see what was available in the UK. I?m sure there are inexpensive parts available there as well.
Last edited by Bud English on Sun May 06, 2012 6:23 pm, edited 1 time in total.
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PostPost by: gjz30075 » Sun May 06, 2012 6:00 pm

Great solution; I'm working on something similar. How did you figure out the VW Passat front strut parts are what is needed? What years? Are they 'close enough' or right on?

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PostPost by: Bud English » Sun May 06, 2012 6:21 pm

This is a case of blind luck triumphing over science and technology. I really am located in the middle of nowhere like my location states. The auto supply places don't stock any struts to sort through to see what you might need. Being somewhat familiar with VW's, I knew the rod diameter what was right for what I needed. Looking at eBay pictures, I looked for something that had the right shape and size relative to the rod hole size.

The auction title was, "VW B3 B4 VR6 Passat Front Strut Rubber Bump Stop 1993-1997 Suspension 1H0412303". I was buying used in case it wasn't going to work, but these are in great shape and I'll use them.

The length is about 1/2" longer than the originals and will engage a little sooner. Not a bad thing. When you compress this one, that first half inch gives a little easier than the original, but only for that half inch. The two are pretty equal after that. That's not a scientific test, just compressing them by hand. One of my originals is so dry rotted that it crumbled when I compressed it. The other is still sound.
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PostPost by: Galwaylotus » Sat Sep 08, 2012 9:47 pm

Ok. I had a good look today now that the car is on jackstands and the wheels are off. There is virtually no gap between the spring O.D. and the perch I.D. on my S3 so I've decided to go with 165/80 R13 Uniroyal Rain Experts on the rear and 155/80 R13 at the front. I spoke with my tyre supplier today and the factory won't be making them until Friday, 14 Sept. so I can ring him on Monday morning to change the rear spec from 185/70 to 165/80. I'll save a bit on cost too!! :lol:

On a related issue, my front damper mount upper bushings are perished and I've bought poly bushes to replace them. My normal spring compressor won't fit so does anyone have a cheap and easy solution to compressing the spring to fit the new bushings? I've spent a lot on the car this month so I don't want to get into special tool purchase if possible. Thanks.
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PostPost by: garyeanderson » Sat Sep 08, 2012 10:27 pm

Galwaylotus wrote:On a related issue, my front damper mount upper bushings are perished and I've bought poly bushes to replace them. My normal spring compressor won't fit so does anyone have a cheap and easy solution to compressing the spring to fit the new bushings? I've spent a lot on the car this month so I don't want to get into special tool purchase if possible. Thanks.


what do you need a spring compressor for?

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PostPost by: Galwaylotus » Sun Sep 09, 2012 9:20 am

Thanks, Gary. It's clear now! :oops: I just need to remove the roll bar attachment, the outer wishbone bolts and then the spring/damper unit. I wasn't sure before and didn't want to take anything apart and find I couldn't get it back together! :D
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