[Lokki]

My Pilgrim's Progress is proceeding to the rear suspension. I have the swing arms off and the old shocks and springs out.

On my 71 spider somewhere in its ("recent") past the rear springs had been replaced with IAP's while the front springs remained stock. This explains the "speedboat" effect with the nose being so much higher than the tail.

Now it's time to replace the springs. I purchased a set of slightly used sport springs and discovered, interestingly enough that while the fronts are shorter than the originals, the rears that came with the set appear to be stock springs in that they're taller, less tightly wound, and lighter gauge than the (confirmed) IAP rear springs that were on the car.

So it's decision time as to how to mix and match the springs. I seem to recall reading (but can't find right now) that some people prefer the stock rear spring/IAP shorter front spring to the IAP rear/IAP front arrangement.

I'm definitely going to use the IAP fronts, but which are the best to use on the back?

I have four conflicting logic patterns going on in my head.

1. IAP Sport front and IAP Sport rear; matched set.
2. IAP Sport front and the rear springs that came with them when I bought them; matched set (but different match criteria).
3. Best handling: IAP fronts and ?
4. Best ride rake without the speedboat nose effect: IAP fronts and ?

Below is a picture of the springs. Note that the 'stock' rear springs are red because they were red when I received them, but I've since repainted them. the shorter IAP rears have the black vertical stripe on them (looks like a shadow in the picture). They're confirmed IAP's since one of them still had an IAP part label on it.


Oh, if it matters, the shocks are Koni Reds.

Advice? Opinions? Help? Thanks!

 

[howndog]

not that this will help u much but i put 4 centreline yellows in mine and the car was way to low. I should've gone IAP....live and learn. imo a nice even ride height is important, maybe moreso than achieving maximum handling

 

[alfaparticle]

I think that it depends upon how you like to drive. I have IAP sports all round and the car is pretty loose. It is lots of fun to kick out the rear on tight slow turns and to drift through faster ones IN DRY CONDITIONS. It can be a bit hairy when the roads are wet. I have just removed my rear sway bar to get rid of some of the looseness.

 

[Kilgore Trout]

I've had the IAP's (matched front/rear), but after a few months witched to the Centerline set. I find the handling with the Centerline's much more predictable, wet or dry, and while the ride height is slightly lower, the car never bottoms and tires never rub. Shocks are Bilsteins, and the Spider is a '74.

 

[alfasax]

IAP springs

I've got IAP red springs all the way around and Koni yellow shocks set to full hard up front and half way in back. Very stiff except on the road. Decent ride and great handling with Bridgestone RE11's. However, I feel the rear end is sitting too low and will be putting coil-overs in this summer.

 

[braino]

IAP/Centerline

I installed Centerline springs in my old spider. They're super stiff and the poster above is right in that you get this great, very predictable break in traction. It's very fun.

It also shakes the hell out of the car - there's virtually no give in them. They're really fun on smooth roads but if you live in California, those can be hard to find...

My current spider has stock springs with Koni reds. I have the front shocks maxxed out and the rears soft. The car sticks to the road amazingly well. It takes real work and high revs in low gear to break the tail. It's less predictable than the Centerline's were but for day to day driving it's also less stiff.

You're right in that the Centerline springs lower the car dramatically. It's a nice look for the car and I found that I had enough clearance for the most part. I never use sump guards. Drove my old Spider through Canyonlands off road and never had a clearance issue...

If you ever want to track the car - definitely go with the Centerlines.

B

 

[Lokki]

Thank you gentlemen -
My thinking has also been influenced by this thread

Road Spider suspension upgrades suggestions?

and the comment from 60'sRacer:
A common approach on the BB is to upgrade the springs - centerline or IAP are common. Then you usually need stiffer sway bar in front (much less often in rear). Some only replace front springs as the car handles well with the rear as soft as possible. Koni yellow set at mid range on the front and Koni red at rear on full soft. One limitation of lowering the car is that you get some "bump-steer" effect. Alfaholics and some others have a kit to counter this too. Be sure your route can take the already low oil pan being an inch lower yet! Or use spring spacers to restore normal ride height with the stiffer springs.


I'm thinking that I will try the IAP sports fronts and stock rears...My chassis stiffener is in the mail. If the rear is too soft or two tall, I now have the experience to change the rear to the IAP's without too much trouble (particularly noting that everything is nice and clean and all the bolts are freshly torqued (and not crudded on by 40 years of stasis.

I'm also influenced by the fact that my rear suspension rebuild kit from Centerline came with poly bushings for the rear swing arms.

I have a feeling that I'm going to be looking for some softer seat cushions to protect my butt from the stiff ride I'm going to have


Am I crazy wrong or stupid here?

IAP fronts with the spacers that were under the springs; Koni reds set at 2 clicks front. Chassis stiffener. Stock rear springs with poly bushings on swing arms and sway bar. Koni reds set on soft.

Somehow this sounds right but feels wrong... should I be using the IAP rear springs too?

Do I understand correctly that the Koni's should be set two clicks in the front and full soft in the rear?

 

[rogerspeed]

December '97 I took my CA 1971 spider and moved back to PA and the joys of dodging potholes. Rebuilt all the suspension bushings stock, used the IAP red springs, chassis stiffner and KYB's. Quite satisfied the with ride, handling and feel (had an Super TI clone with the ''gold" racing springs, ex-Rivkin GTA, too stiff for either). These days I prefer stock height. I like ground clearence. As for a softer seat cushion, resilience is the quality your looking for.

 

[Gubi]

Lokki, I've pretty much got what you're proposing: sport springs in front, stock in rear, Koni reds all around, chassis stiffener. With this setup my '91 sits level and seems to ride and handle decently. No need for additional butt padding.

Sport springs in the back were just too low which is why I've got the mix. Konis are (I think) half stiff on the front, full soft on rears. Note that the Spider reds don't "click", they're continuously adjustable so you need to count turns.

What *will* require butt padding is if you crank up the tire pressures too much in the misguided search for sportiness. I've tried this on both the steel 14s and the alloy 15s and the handling and ride really seem happiest at or near stock.

 

[60sRacer]

Separate ride height from spring choice. You can use spacers and occasionally different front spring pans to adjust the height. Choose springs based on the handling you want, then adjust the height F & R to suit your road.

If the front lower A-arms are tilted (higher at the wheel then at the body), you will get some bump-steer. That's when the steering wheel twists as you go over bumps. This is pretty unstable, and makes driving at the limits downright scary. There are a few ways to fix this. Alfaholics makes a kit, a few folks bend the steering arms. One of the best is modified spindles - I think RJR made some - that keeps the lower arms level.

The GTV's really drive better with the tail seemingly too low. The Spider tends to be too tail high with so little weight in the back. Before custom wound springs were made, we'd just cut one turn off the F & R springs (makes them stiffer and lower at the same time), then adjust ride height with spacers. All the modern custom springs are very close to this!

Generally soft at the rear helps keep the driving tires on the ground; there's a lot of roll at the front outside tire that tries top pick up the inside rear tire.

I'd choose the softest rear springs (the skinny wire rear springs?), and shorten them to get a good ride height (but only if they are too high - shortening will make them a bit stiffer), and use the softest shocks on the softest setting [it's all about keeping the tires on the road as the front twists and dives]. I'd also stiffen the front with the heavier (IAP?) springs, using spacers as needed. I have an old Shankle front sway bar that is much stiffer than the stock one, and use Koni Yellows about mid range for the street. Yellows on full stiff along with stiff springs will rattle your teeth and stress a lot of welds too!

For street use, first get a height that keeps the oil pan intact. Then set up the rear as soft as you can. Now try some combinations of front springs and sway bar that gets you the basic driving feel you want. Finally adjust the rear sway bar to balance over/under steer. [Oversteer is more fun in the dry and more scary in the wet].

Being a tinkerer, I'd try ALL the combinations you have, and take very good notes and performance measurements. Data is amazing in how it wipes out mis-preceptions.

Robert

 

[Lokki]

Thanks guys!