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Discussion Starter #1
Hello All,

1991 Spider Veloce with about 94K miles.

As an early Christmas gift to Rosa, I ordered new springs from Classic Alfa. Front and Rears.

My intent is to go stock with the springs.

While I am working on the rears, I noticed that the spring height from Classic is noticeably shorter.

The original springs (I have no reason not to believe the aren't original) are 18 7/8" tall and the new Classic springs are 17 5/8".

New on the left, original on the right.

I have contacted Classic, but its Sunday and I thought I would reach out to the group.

IMG_4674.jpg


As always, thanks in advance.

Vin
 

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You can't really go by height. As the new ones are coiled tighter and probably use a stronger steel.
 

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Discussion Starter #3
You can't really go by height. As the new ones are coiled tighter and probably use a stronger steel.
Ok, thanks

I'm not looking to lower my ride.

Vin
 

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The spring formula is somewhat complicated, but involves the number of coils, diameter, etc. I'm sure they will be fine.

What was wrong with your old springs?

Sent from my ONEPLUS A3000 using Tapatalk
 

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The big decision you have is whether you want to leave or remove the shim cups.
 

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Discussion Starter #6
The spring formula is somewhat complicated, but involves the number of coils, diameter, etc. I'm sure they will be fine.

What was wrong with your old springs?

Sent from my ONEPLUS A3000 using Tapatalk
I found the spreadsheet Alfaparticle posted. Did all the measurements and the spreadsheet shows the new springs are a bit stiffer. Interesting enough unsprung height had no effect on spring rate.

We will see in the Spring when I can take her out for a ride.

Like I said, it was an early Christmas gift and I figured 30 years was enough for the original springs.

Vin
 

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Discussion Starter #7
The big decision you have is whether you want to leave or remove the shim cups.
Is that for ride height?

I will be able to see the ride height when I put them in, hopefully in a week or so.

I will also see how they feel in the Spring.

Thanks,

Vin
 

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Yes the shims are there to get the height for federal regs.

Removeing the shims and keeping the stock springs will get you the height that the early 70's spiders had.
 

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Rear shims are a aluminum cup above the rear spring.

Front shims are a aluminum ring in the bottom of the spring pan. Also different height springs pans were used in combo with the shims.
 

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Where the shims put is for the USA head light height requirement?
I am not so sure.
the spares catalogue (S4) shows same shims, same PNs, whether you look at the USA or the Euro catalogue.

Now, something I have not noticed before is (both USA and Euro catalogues) lists only 1 shim for the rear (doesn't say which side, diagram seems to be the lh/driver's side though) and one each side for the front.

no choices of shim thickness either, be it front or rear.

But what is with the 1x shim only in the rear? is that to compensate the different depth front spring pans?
(you'd have to swop it all around I suppose if it were a rhd car!:))

So Vin,
did your car have a shim each side in the rear, or just the one side (or none!)? does it have two different depth front spring pans? (I know a lot of S4 owners say theirs never had different spring pans in spite of what the catalogue says)


item #4 here:
 

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Discussion Starter #12
So Vin,
did your car have a shim each side in the rear, or just the one side (or none!)? does it have two different depth front spring pans? (I know a lot of S4 owners say theirs never had different spring pans in spite of what the catalogue says)


item #4 here:
Well, for now, I can tell you that I have 2 shims in the front and both my front Spring pans are the same depth. Been through that before. I even bought a passenger side spring pan that is 10mm deeper, but haven't installed it yet.

I will have to wait till tonight to see about the rear Spring shims.

Vin
 

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I will have to wait till tonight to see about the rear Spring shims.
Vin
Ok, it'll be interesting to see what you have.
Maybe with both same depth front pans, your car got 2 shims at the back!?

(keep the anti-rubbing rubber coil things from the the rear springs, as seen in your 1st photo, as new springs won't have them, and they are another 10-15 bucks a shot, when you find them)
 

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installed spring length = free length - wt on corner of car/spring rate.
You can use a stock number for wt of car and front/rear wt distribution - my guess 60/40.
 

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Discussion Starter #15 (Edited)
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Discussion Starter #16
installed spring length = free length - wt on corner of car/spring rate.
You can use a stock number for wt of car and front/rear wt distribution - my guess 60/40.
So since I have not changed the weight of the vehicle, it means that the installed spring length will be shorter on the new spring.

New spring is 1.25" shorter, so I can assume the ride height will also decrease by that amount?

Thank you for your help and education.

Vin
 

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New spring is 1.25" shorter, so I can assume the ride height will also decrease by that amount?
Yes if the spring rate is the same. Wire diameter has the greatest effect on spring rate followed by coil diameter.
 

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Discussion Starter #18
Confirmed NO shims at the top of the springs. Just the cup and rubber parts.

Vin
 

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The aluminum cups at the top are the shims. Look at the first page of parts on the rear suspension.

 

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Discussion Starter #20 (Edited)
Yes if the spring rate is the same. Wire diameter has the greatest effect on spring rate followed by coil diameter.
Hi Ed,

I used your excel spreadsheet for Spring Rate and looks like someone was doing their homework.

While the wire diameter, coil width and unsprung height are different (slight differences), number of coils the same, they both have a calculated spring rate of 87.

Looks like I will have a lower rear end if I don't put in sizeable, 1 1/4" spacers up there.

Not really happy as all I wanted to do was replace old springs with new and stick to stock.

Thanks,

Vin
 
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