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Discussion Starter #1
Hello, i have to change the springs of my GTV, the previous owner made a mess, the rear springs are different and wrong, the car has bilstein suspension the yellow one not the adjustable, ill send them to make them softer, i have also a torn upper housing to fix.
I would like also to lower a bit the car, i was looking at the eibach that classicalfa and alfa service have, but i am worried that 40mm lower is to much and ia friend of mine said to me tha eibach are hard springs for track days.

Can you advice me about other springs?

Regards
J.
 

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The free length of the spring, the spring rate and the weight on the spring determine the compressed length and hence the ride height. Stiffer springs have to be shorter or they would jack up the car.
The common red springs from IAP & Vick are about 180 lb/in and the stock springs are about 80 so there is a massive difference. Centerline sell springs for Duetto's that are about 150 lb. I recently put them on the rear of my 79 Spider to replace the red springs and the ride height was lowered by about 1/8". I like them so far but I need to get softer springs on the front to get the car balanced.
 

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The torn housing is likely attributable to a too stiff Bilstein shock. Consider revalving at least the rear shocks or run something different on the rear axle.

Hello, i have to change the springs of my GTV, the previous owner made a mess, the rear springs are different and wrong, the car has bilstein suspension the yellow one not the adjustable, ill send them to make them softer, i have also a torn upper housing to fix.
I would like also to lower a bit the car, i was looking at the eibach that classicalfa and alfa service have, but i am worried that 40mm lower is to much and ia friend of mine said to me tha eibach are hard springs for track days.

Can you advice me about other springs?

Regards
J.
 

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The IAP red springs(per Frank) have a free/unweighted height of 9.5" and weighted to 6.8" for the front while the rear are 13.75" free and 9.3 weighted. I asked if he had any lb/in data and he did not. I have a set for my GTV that I never installed if anyone is interested.
 

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the rear are 13.75" free and 9.3 weighted.
I don't believe those numbers. IAP rear springs (I have a spare pair) are about 180 lb/in. A spring with a free length of 13.75" needs a load of 800 lb to compress to 9.3". The load on a rear wheel of an Alfa Spider or GTV is 500 - 600 lb which results in a compressed length of about 10.5"
 

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Ed,

Since the spring perch is mounted on the trailing arm and not directly above the wheel, would that make IAP numbers more believable? My Alfa's are in storage for the winter, so I can't measure the distance from the center of the axle to the center of the spring, but I think it would make a difference.

Dick Stachowiak
71 GTV
71 Spider
 

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Dick,
The spring perch is pretty close to the axle so the spring ratio is close to 1. It has little effect on wheel rate calculations. I have calculated changes in ride height using this ratio and they have been very close to what I measured.
 

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For the original poster.....
Please talk to Classic Alfa or Alfaholics for the best set-up for your car. They have been working on these for decades and understand how to give you the setting that will work best for you.
 

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I would like also to lower a bit the car, i was looking at the eibach that classicalfa and alfa service have, but i am worried that 40mm lower is to much and ia friend of mine said to me tha eibach are hard springs for track days.

There's actually quite a lot of discussion over the years on the bb about springs. Spend a little time searching and you'll find hours of interesting reading. Vendors are understandably a bit circumspect about specifics but, for a 105 GTV or Spider, a front spring length of about 9.5in appears to be a standard. It's worth noting that aftermarket springs are seldom "bolt-on" so you should expect to do some adjusting with shims/cutting or both.

For front springs, if your initial install is too tall, you can effectively lower the front by putting shims (washers) between the spring pan and A-arm. There's about a 2.5/3.0 to one ratio of thickness to lowering.


Here's some interesting data from around '07. Thanks to George Willet:

As tested on a spring checker in 1999. Some of the suppliers may have changed the product as of this date (2007)

Front: in inch/pounds
• Stock ’69 GTV : 370
• IAP red: 450 (they had a .685 in wire dia.)
• Centerline yellow: 975 (wire dia .790 in)
• Dave Rough: 630 (wire dia .685 in)
• Alan Ward has told me he uses and supplies spring rates in the 1200 (mostly) and 1300 range.

Rears:
• Centerline #PS411 : 150
• Centerline #PS412 : 185
• In a phone call to Alfa Recombi at that time , Julius said their blues were 185 (.500 inch dia wire)
• Shankle red Super Sport pn 4732B tested: 150
• Dave Rough: 175
• Rear springs, from 65/69 gtv, .433 in wire, with one and one & a half coils cut from open end: 180

Antiroll bars:
• Stock @ 222 in/lbs;
• Shankle bar @ 1 1/16” dia: 382
• 26mm ft bar: 306

FYI:
• From my experience, the addition or removal of rubbers/spacers under the front springs is a 3:1 ratio of ride height change, (1/4 inch makes a ride height change of ¾ inch). In the rear it is a one to one ratio.
• To reduce understeer in a corner; Carroll Smith told me to “keep adding front spring rate 10% at a time until the front end starting to “skate”, then reduce spring rate 10%”. (Works if the car is fairly well balanced front to rear to begin with.)
• An antiroll bar transfers weight to the opposite end of the car. Adding a rear bar on a 105/115 car “kills” the rear to help the front. C Smith “Work on the end of the car where the problem is”.
• Springs alone will not make a good handling car. Springs, shocks, antiroll bar, tires (size and compound), and a good driver (practice, practice, practice) can.  .

Hope this helps.
 

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There's actually quite a lot of discussion over the years on the bb about springs. Spend a little time searching and you'll find hours of interesting reading. Vendors are understandably a bit circumspect about specifics but, for a 105 GTV or Spider, a front spring length of about 9.5in appears to be a standard. It's worth noting that aftermarket springs are seldom "bolt-on" so you should expect to do some adjusting with shims/cutting or both.

For front springs, if your initial install is too tall, you can effectively lower the front by putting shims (washers) between the spring pan and A-arm. There's about a 2.5/3.0 to one ratio of thickness to lowering.


Here's some interesting data from around '07. Thanks to George Willet:

As tested on a spring checker in 1999. Some of the suppliers may have changed the product as of this date (2007)

Front: in inch/pounds
• Stock ’69 GTV : 370
• IAP red: 450 (they had a .685 in wire dia.)
• Centerline yellow: 975 (wire dia .790 in)
• Dave Rough: 630 (wire dia .685 in)
• Alan Ward has told me he uses and supplies spring rates in the 1200 (mostly) and 1300 range.

Rears:
• Centerline #PS411 : 150
• Centerline #PS412 : 185
• In a phone call to Alfa Recombi at that time , Julius said their blues were 185 (.500 inch dia wire)
• Shankle red Super Sport pn 4732B tested: 150
• Dave Rough: 175
• Rear springs, from 65/69 gtv, .433 in wire, with one and one & a half coils cut from open end: 180

Antiroll bars:
• Stock @ 222 in/lbs;
• Shankle bar @ 1 1/16” dia: 382
• 26mm ft bar: 306

FYI:
• From my experience, the addition or removal of rubbers/spacers under the front springs is a 3:1 ratio of ride height change, (1/4 inch makes a ride height change of ¾ inch). In the rear it is a one to one ratio.
• To reduce understeer in a corner; Carroll Smith told me to “keep adding front spring rate 10% at a time until the front end starting to “skate”, then reduce spring rate 10%”. (Works if the car is fairly well balanced front to rear to begin with.)
• An antiroll bar transfers weight to the opposite end of the car. Adding a rear bar on a 105/115 car “kills” the rear to help the front. C Smith “Work on the end of the car where the problem is”.
• Springs alone will not make a good handling car. Springs, shocks, antiroll bar, tires (size and compound), and a good driver (practice, practice, practice) can.  .

Hope this helps.
180OUT you bring up an interesting point. My 72 GTV was higher in the front to meet the US standards for headlight height. With that said, I had two aluminum spacers on each side that I removed. For my US model how much would the front end drop please?
 

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[ I had two aluminum spacers on each side that I removed. For my US model how much would the front end drop please?
[/QUOTE]

I don't know. The best I can tell you is to be prepared to do a bit of on and offing until you get the height where you want it. Working with some all-thread and gear-wrenches makes the job bearable. After you've done it a couple of times, it starts to feel easy . . . Another alternative that I'm interested in trying is to use one of the through sockets that allow you to work on long bolts with a ratchet wrench. The first time I saw one of those sets I immediately thought of changing front springs using all-thread!
 

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For my US model how much would the front end drop please?
The drop will be twice the thickness of the spacers.

I just won a set of Shankle springs on ebay. They are stiffer than stock but softer than the currently available "sport" springs. It will be interesting to see how the Spider handles with them.
 

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Discussion Starter #14
From classicalfa replied that stock front are 400 lb and rear 85lb
Does anybody know the eibach kit specs?
 

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From classicalfa replied that stock front are 400 lb and rear 85lb
Those are close to the numbers from measuring original springs - 310 and 78
 

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If it is like the Eibach springs that I have, the rate will be very close to stock, Only the length is a bit shorter to give about 1" drop.
My '67 GTV is on old Ward & Dean street springs with a similar spec.
Most US "performance" springs are too stiff for real world road driving.
 

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Did you talk to them about how you would be using your car ?
Road use does not need 800 # front springs.
 

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Discussion Starter #19
They have an classicalfa kit rated 650 front and 180 rear, and they said tha this kit is harder than the eibach one,
A friend of mine said that eibach are alot harder than stock... Thats why i am confused now
I want a little bit harder adn lower kit for performance road use
 

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400 lb and 40mm lower in the front without other suspension changes handles like a barge and is a potential sump killer ... just my opinion.

800 lb while it may be more than needed for most with good shocks will work even on quite rough roads.

600 lb and less than 40mm drop is likely ideal for most people.
 
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