Alfa Romeo Forums banner

Spring specifications for a fast road Super

35K views 78 replies 24 participants last post by  lpalmer 
#1 ·
There has been a backroom discussion going on amongst a couple of us regarding the best spring specifications for a "fast road" Super. The challenge is that various vendors offer sport suspension springs for the Giulia Super that are advertised vaguely in terms of specifications and results, with little quantitative information that could used to compare one set against another.

Specifically, there appears to be little or no available data on rates and free lengths of sport springs, and the resulting ride height and quality. Postings on the BB will mention that such-and-such springs were purchased, and then they had to be cut down or shimmed up to level the car to an acceptable height. It seems like a lot of trial and error for a car that was produced in relatively large numbers, and retains a strong following to this day.

So, my offer to the community is this: If you can provide the quantitative data and information listed below on front and rear springs that you've installed in your car, I'll compile the information and post a summary to save future Alfisti from having to figure it out on their own, and allow them to buy springs that give the desired results.

If you have data on stock springs, that would be useful too.

Year/Model:

Fronts:
- Source/Brand
- Rate
- Free length
- Change in height from stock
- Cutting or shimming needed to get desired height
- Comments

Rears:
- Source/Brand
- Rate
- Free length
- Change in height from stock
- Cutting or shimming needed to get desired height
- Comments

Thanks!
 
See less See more
#2 ·
Nice effort here Dean. The trouble with most will be discerning the type of springs on cars altered by PO's; I have one of those. Or if they were modified at some point. Alfa Tech Specification Bulletin books (I have several for Supers, as do others and the AROC Tech Library) show stock ride height (ground to jacking points) for the various cars. But this assumes a "stock" wheel/tire diameter. I have also found that the shocks (gas) can alter ride height. My front Bilstein B6 Sports raised Pinyo ~1/2". Also, Alfa offered shims in part to level cars which might have been a smidge off spec (L-to-R). I am tuned in here.
 
#3 ·
My premise is that the knowledge exists out there in the community, and I'm hoping that those who have it are willing to share it.

Also, a bit of adjustment is to be expected. Let's figure out the best starting point first.
 
#4 · (Edited)
Dean's thread is part of an on-going conversation we've been having re: performance suspensions for Supers. We've agreed that the stock Super/TI suspension places the ride height too high and ruins the looks of the car. Also, while the stock suspension, being Alfa designed, works well there is some obvious room for improvement.

Here's some received wisdom that I've picked up about the subject: 800lbs +/- front springs. While the usual recommendation is to use a 9.5in front spring and the shim for a rasied ride height, another way of doing this will give you a wider range of adjustment. If you use a 11in (typo corrected) spring instead and then place a shim between the spring pan and lower a-arm, this will give you quite a bit more ride height adjustment than with the 9.5in springs. Remember that there is a multiplication factor with front shim (3:1, I think) so 10mm will give you a lot of adjustment. This latter approach will be especially useful if you want to only lower your Super by just enough to close the gap between the front tire and front fender.

Rear springs: 185-200lb rear springs. Note that both front and rear springs are a bit heaver than published reports for the Harvey Bailey springs popular in Europe (the front springs especially apparently having much lower rates than US vendor preferences).

The problem: we don't know what the length of these rear springs should be.

So anybody got any suggestions/experiences/successes/failures?
 

Attachments

#5 ·
This is good idea to collect suspensions things on the one thread. Here are my short comments and some pics about the Eibach spring set I bought four years ago.

Front end;
– Brand, Eibach
– Rate, Unknown, just slightly stiffer than stock because they work with original spring pan set-up (shallow-deep)
– Free lenght, Unfortunately I never measured, they are clearly shorter than stock, look at the pic
– Change in height from stock, -40mm with 10mm spacers!
– Cutting or shimming needed to get desired height, 10mm spacers/shims.
– Comments, Front springs are definately too short without spacers. I haven't had bottoming problems, but higher front end clearly improve handling. And looks better too.

Rear end;
– Brand, Eibach
– Rate, Unknown, slightly stiffer than stock
– Free lenght, Look at the pic.
– Change in height from stock, -35mm with cutted two rounds off!
– Cutting and shimming needed to get desired height, Cutted two rounds off
– Comments, These are probably bit too stiff for the best handling, but you can take passangers on back seat without bottoming problems. You can easily cut couple of rounds off and still get enough preload.

Pictures; Eibach springs beside stock springs, My Super with unmodified Eibach set(with steel wheels), My Super with modified Eibach's as detailed above.

Summary; To me Eibach set wasn't ”ready to road” straight from package, but with some mods it clearly is better comparing stock springs.
 

Attachments

#7 ·
This is exactly the thread I was waiting for, although I'm pickier than most and won't even have a Super until 2016.

Gentlemen, please list the condition of your local roads as well as their technicality- are they smooth, sweeping, on-camber 60mph corners or 35mph blind crests into off-camber bumpy stuff? How's the front to rear balance, taking into account damping rates? How well does your chosen spring rate work with your chosen damper? Are you running larger sway bars? What profile are your tires?

I know I'm adding variables, but the variables change the effect of the spring and make narrowing down spring choices a little easier.
 
#8 · (Edited)
Pictures; Eibach springs beside stock springs, My Super with unmodified Eibach set(with steel wheels), My Super with modified Eibach's as detailed above.
Thanks Jorma. The before/after photos are especially helpful. Am I correct that your GTA style wheels are 14in?

Interesting too, that you can still use the back seat after the springs install and modifications. Until you said this I believed that transporting people in the back seat would create bottoming problems. I wonder if this is a function of the Eibach's rear springs being progressively wound? Progressively wound springs increase their rate under load.

ALso: please note the the photo my Super shows a rear ride height influenced by a third "Granny" overload spring which is mounted on the top of the differential and supposedly comes into play when carying a heavy load. As installed it adds a bit to the ride height.
 
#10 ·
Jim, Yes Gta wheels are 14” further 14x6” ET33.

To be a honest, I can’t imagine long trips with two adults on back seat, it’s not so fun to drive in fully loaded, but no scraping or bottoming problems. Indeed rear springs are progressive, I think the linearic ones would be better for handling, but can’t carry enough weight for “sedan purpose”

I think I’ve never seen that kind of third spring set, interesting. So it’s mounted as a progressive unit and comes in play when load increase, but it’s free in normal usage?
 
#9 ·
Jorma --

Just the level of detail and documentation that I was hoping to compile. It looks like you could estimate free length of the front springs by scaling from the spring cushions (doughnuts).

Who else can contribute to the discussion?
 
#11 ·
Dean, I did rough estimate by measuring stock springs and here's what I get;

Fronts; Stock, free lenght 32.5cm
Eibach, " 27cm

Rears; Stock, free lenght 47cm
Eibach, " 38,5cm

I also measured ride height of my Super and get 34.5cm at front end and 22.5cm at rear end (distances between wheel center hub and wheel arch lip.

Hope this helps,
Jorma
 
#12 ·
Perfect.

Converting to inches, it looks like the front Eibachs are 10.6", and you had to add a 10mm (0.4") spacer. So, an 11" (28cm) spring would seem just about right.

For the rears, you mention cutting off two "rounds" or coils. I assume thaose were at the bottom. Any idea how much that reduced free length?

Thanks.
 
#13 · (Edited)
Yes, I cutted two coils from the bottom end. Started by cutting half coil at a time and test ride it after each cutting, two full coils are where I ended up. Free lenght (again just a rough estimate) about 33,5cm. At least in my case that was also the shortist possible set up for rear springs without shortening rebound straps.

edit; added track test pic
 

Attachments

#14 ·
Poking around the BB this morning, I came across the following thread from a few years ago: http://www.alfabb.com/bb/forums/sus...camber-front-suspensionj.html?referrerid=8941

Based on alfajan's rate information and Gasolina’s length data for Eibach’s (and rounding a bit):

Fronts: Length = 11.0” (shimmed length) and Rate = 600#

Rears: Length = 13.0” (cut length) and Rate = 100#

Now, alfajan's rates are for a spring set that drops the car 40mm, but it seems like we're getting a more complete picture of at least one successful option.

Can anyone comment on this from their experience?
 
#15 ·
I have quit measuring springs as the rate interacts with their final length. so a few observations.

100# in the rear for a Super is nowhere near enough. Never mind that you cannot take passengers or load anything in the trunk .... The closest thing I ever ran to that was Euro 2000 GTV springs - the fronts were OK but the rears - they are softer than stock Super which is about in the #150-160 range but more than #100 - were not. I later changed the rears to cut down stock Giulia rear springs and this was a nice set-up but not stunning from a performance point of view.

I have driven quite a few suspensions on my Super and my TI and have driven a few more on friend's cars.

Eibach 40mm drop - didn't like. Quite low and not stiff enough.
Shankle Super Sports w/ F&R bars. Extremely fast for Autocross. Too low and stiff for the road.
Shankle Sports w/ F&R bars. OK. Too much bar.
Ward & Deane. Too stiff for the chassis.
Stock springs cut front and rear. Too soft on the front end.
Harvey Bailey set up #600 fronts with larger front bar. Good. Could have more roll resistance on the front.

Shocks: specially valved Bilstein - GTA Nurburgring set-up - do not even try the regular Bilsteins. Standard Bilstein fronts with Koni red rears will work but are inferior. SPAX are great but they do not last as long as Bilsteins or Konis. Stock rear shocks have never lasted for me. I personally prefer the specially valved Bilsteins to the high end double adjustable Alfaholics ones unless you really know how to dial them in.

I do not recommend coil-overs if you travel bad roads unless you seriously!!! reinforce shock towers - they now need to hold both spring and shock load which is otherwise distributed in two different areas. Reinforced shock mounts are of benefit but not essential w/ Bilsteins, unless you drive extremely hard on bad roads, as they put larger load on the mounts.

Anyway, my vote goes for #800 fronts with #185 rears with an Alfaholics 29mm sway bar - do not use a blade end bar (e.g. shankle style) unless you the car is very track focussed. No rear bar. Alfaholics suppies this set-up and it is first rate. Even though I have the 2.25" FIA spring kit, I'd give it a miss for a street car.

With this set-up I also run knuckle risers (2.25") w/ the tall 10" spindles and short steering arms. The car needs to be bumpsteered if you run the knuckle risers - otherwise it is almost undrivable. BTW, Vin Sharp in Australia makes a modern adaptation of the old knuckle riser - an ingenious design.

Dial in Max caster, 0 toe and about 1.25* neg. camber. For track use you need more camber.

This set-up allows a blistering pace. It is great for tarmac rally and it is great for road use on all but the very roughest Northern California backroads - broken pavement and potholes - where I needed to back off a bit and a friend in a late 3-series BMW was able to go faster and catch up as it was softer sprung and dampened.

If you don't do the knuckle risers or other roll center modifications, eg Alfaholics geo-kit, you might want to go stiffer in the front but this will likely result in a rougher ride on bad roads. Certainly didn't like #1200 pound W&D springs in the Super - way too harsh for what is a relatively soft chassis.

Do not make the mistake of running a very heavy bar w/ soft springs ....
 
#16 ·
Oops!

If you use a 14in spring instead and then place a shim between the spring pan and lower a-arm, this will give you quite a bit more ride height adjustment than with the 9.5in springs.
I just realized I made a big typo mistake which I must correct. Using a 14in spring on the front is MUCH to long for a front spring! What I meant to say was tp use an 11in front spring and then shim between the lower arm and the spring pan if you want to have a longer range of adjustment.

Sorry . . .
 
#17 ·
Thanks for the info, Ulrich. I was hoping you'd join in. :)

I have driven quite a few suspensions on my Super and my TI and have driven a few more on friend's cars.
Well, you're being a bit modest. I think you've tried more combinations than just about anybody else I know of. And, of course, the practice did get you a suspension setup that brought you a class win in the '08 Carrera. . .

Maybe you can help settle a mystery I'm puzzling over. Are all the suspension kits you tried generic to the full 105 series of cars, or do Supers and TI's require different (i.e., taller) springs to achieve a similar drop when compared to the GTV's and Spiders?

Awhile ago I checked the IAP site and they specifically don't list a performance spring kit for Berlinas (and nothing of course for Supers) while Alfaholics states that installing one of their GTV/Spider kits will introduce a corresponding greater drop in Supers. To me this says you should use relatively longer springs when setting up a Super's suspension.
 
#20 ·
I'm in need of stronger (stiffer) rear springs. I often carry passengers and luggage and the rear sinks lower then I would like. I like the current ride hight when empty so I would think I just need stiffer rear springs then the stock ones. Any advice?
 
#21 ·
Alfa's data, from the Technical Characteristics publications for these models; TI is Pub. No. 955 from 10/63, Super is Pub. No. 1133 from 12/65.

Giulia Super
Front springs
Free length 12.31"
Length under 2100-2650 lbs load: 7.8"

Rear springs
Free length 17.7"
Length under 710-740 lbs load: 10"


Giulia TI
Front springs
Free length 12.2"
Length under 1976-2100 lbs load: 7.8"

Rear springs
Free length 18.15"
Length under 753-799 lbs load: 9.9"

Andrew
 
#22 ·
I'm really encouraged by the level of technical detail that this thread is attracting.

I'm also starting to think that knowing stock length under load, desired drop in vehicle height, desired new rate, and weights provides enough information to estimate the free lengths of stiffer springs to match the desired rates.

Andrew: I wonder if the later cars had different suspension settings. Do you have any stock specs for later Supers (e.g., Nuovas)?
 
#23 ·
These are the only tech characteristics pubs I have for TIs and Supers. I have others, Duetto, GTV, 101, etc., but no later sedans.

My guess is, and I had planned to say so up front, that they would differ model by model, and even by market (cars to Africa and Australian Outback probably need longer springs and a higher ride height than cars to Los Angeles, just as a guess). But I don't have any other specs. A diesel Nuova probably has heavier front springs than a 1300 TI due to the weight, for instance.

Andrew
 
#24 ·
Very interesting thread.
I'm currently restoring my '65 Giulia Ti so have a vested interest here.
Most of my experience to date has been with the coupes - I favour the usual stiff front/ soft rear set-up: My daily driver ('67 Sprint GT Veloce with T/S) has Harvey Bailey springs, 29mm bar, Koni Sports 3/4 stiff at the front, while at the rear stock (trimmed to lower but hence slightly stiffer) springs, Koni red on softest set (no rear bar). Great street/ track compromise - comfortable enough to drive 2000 miles to Italy & back, & good enough for track days at Goodwood but shows up shortcomings as an out-&-out track car... (the Alfaholics LSD gives it great rear-end grip though!). I too found Eibach springs lowered too much without stiffening (easily bottomed out). Bilsteins at the rear are too 'bouncy' on a road car (think original Mini?) while I found the bounce/ rebound rates of Spax completely wrong for 105 series cars (though on my first Super, an ex-Chris Whelan racer, the front coil-overs turned out to be Spax from an AC Cobra! As Alleggerita says, the turrets needed extra welding!).
 
#25 ·
For those that are stateside, a very high quality option that gets very little play on this site are the springs by Dave Rugh in Oregon. Something around 600 lbs up front, and mildly stiffer than stock in the rear. Coupled with Koni Reds all around (mid-ish rebound up front, dead soft in the rear) gives a very nice, lower than stock stance, and fast touring type ride that won't knock your fillings loose. I also added a Shankle front sway bar (no rear bar at all), and dropped spindles, and my Super turns in and corners like it's on rails, even with mediocre tires.
 
#29 ·
I had Rugh springs on my GTV, thanks to a recommendation from Peter, above.
I know I talked to Dave on the phone, but could find only this contact info. Maybe that can lead you to a phone number? He's not a fulltime business, does this on the side, has springs made in batches to his specs, as I recall the conversation with him.

Rugh Engineering
14190 NW McNamee Rd
Portland, OR 97231

Andrew
 
#31 · (Edited)
Lowered suspension and T-bar "timing"

As many of us have probably noted after lowering rear suspension Trunion bar timing marks are not lined up anymore. Side bushes are quite much twisted all the time because of more sag. Not a good thing at all, at least in theory. So how much this really matters, if any? Hope someone got my point.
Comments please :)
Thanks, Jorma
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top