Alfa Romeo ONLY please!
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Mats
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Post by Mats »

Z: You can also make a small collar on the threaded body that rests on the top of the shock body but naturally allowing the rod to pass through, plus adhesive. That way the shock is almost untouched (you need to strip the paint for the adhesive) which is good.

Fortis621: Ask the local fast guys at your track for frequencies (which is universal between cars) and work backwards from that, seems like european tracks are a lot different from your in terms of bumpiness and surface texture so any recommendation from me will probably be too stiff.

Dennis: You should try and read also, not just look at the pretty pictures... ;D
"The car was already built with coilover option in mind. My shock mounts, both front and back, have been heavily reinforced with the cage extending to the mount at the rear."

generally camber curve won't change dramatically when dropping the front down, what happens is that the roll center drops way low and causes the front end to be very roll-weak, which is why a lot of people lower the rear roll centre too to compensate, this is not as good as raising the front one because it will make the whole car roll-weak.
The better solution would be to raise the front roll center to make the car stiffer in roll, then you don't need the extra 10Kg with a bigger rollbar... ;)

And THAT is why I always nag about getting the front set up before doing major work at the rear. The rear is fine, the front is not.

BTW: Dennis, that price is a joke for custon control arms. You should shop around a bit and ask your local machine/welding shop, if you show up with a drawing with material specs it should cost a tenth of that.

I second that opinion about the cage work, looks top notch.
But you must be very short with that location of the main hoop, from memory mine is about 10cm behind the B-pillar...
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Post by MD »

Zamani,

You may or may not be able to help me out here. I have decided to configure an Alfetta sedan for my racer. The reasons are many none of which matters here.

I see you have some knowledge of torsion bars so I thought I would point this one your way.

One quirk of the sedan is that it has longer bars than the coupe due to it longer wheel base but I am keen to stay with the original suspension configuration. No coil overs for me at the moment.

My question is, do you know the source of these heavier bars but longer that could fit the Alfetta?
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Post by Zamani »

MD,

You could try the 33 t-bars from performatek.com. But don't you think PACE or Beninca have those? I'm sure they must have a source down there, because that's where some of us get our parts from!


Mats,

Where's alfapower.nu?

And where the heck is JimK these days.
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Post by Mats »

MD: You need to check which ones you have, the early cars have LONGER bars then the later (late GTV and 75), not sure if the Alfetta got the shorter bars too.

Alfapower is down because of some hardware problem, most likely a power outage, the router needs to be switched on manually and the guy with the server is in Greece until the 27th or something... dooh.

I believe JimK is in Greece too. ;)
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Post by Carel »

HI MD

Just a thought, did you measure the length of the Torsion bars? Here in South Africa we got the Guilietta and it too is longer than the Coupe, but all the parts are interchangeble. I am sure this is the same with the alfetta.

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Post by Maurizio »

MD, surely you can change to the later construction, have seen it on a giulietta. Where the 75 torsion bar brace was welded under the floor and 75 V6 torsion bars were used.
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Post by Dennis »

Mats, I was reading ;) Fortis doesn't mention a link between the cage and the front suspension, just reinforcing it. IMO you should reinforce but the link between the cage and front suspension is way more critical than the rear towers.
We all know how much our cars flex in the front end, especially on heavy cornering with slicks.

The price is huge, I know. However the guys that designed them have put a lot of hours into it and a couple of prototypes to end up with what they have now. All chrome-moly and beautiful handwork. They just try to get some of the labour investment back with the few sets they sell. I know that IF you can copy them and/or can fabricate your own you'll save a lot of money.

With the original lower A-arms you loose 0,5 to 1 degree of camber in cornering according to the guys here in Holland whom have made racing transaxles their business. With the A-arms they use they gain camber in cornering.....[/b]
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Post by Maurizio »

Hmmm,

Dennis what is different.

The camber parameters are the length difference between upper an lower arm and the angle between them (comes out of the upright length) and the angle towards the ground.
If by changing the lower A-arm active camber is gained it has to change one of the rotation points of the Lower A-arm.
So: In other words move rotation point chassis up or a upside down ball joint.

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Post by Mats »

Dennis: ok, ok, I assumed that the "heavy reinforcement" was linked to the cage. My bad. ;)

But I think those guys have either some extreme BS going there or they are not aware of the fact that they are incorrect...
The camber curve is dictated by the gometry in the control arms i.e. lenghts and mounting points (like Maurizio said in the post above), the standard control arm will definetly give camber gain and the fact that the lower control arm is pointing upwards doesn't have anything to do with the camber curve really. It does mean that the roll centre is totally off but that is not the same thing.
Maybe they are calculating a total camber number that includes body roll in a turn? That could actually be accurate but would vary with the degree of body roll and in that case you could get "camber gain" by raising the roll centre. :)
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Post by Zamani »

Actually why not mount the upper balljoint underneath the upper a-arm and put a 1/2-1" thick spacer between it and the upper a-arm. Cheaper than the drop spindle.
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Post by MD »

Thanks Guys for your feedback.
Found the performatek site quite interesting. Will check out Benica too.
So what is the verdict, 27 or 33 mm bars? Would this be a difference in application say like the terrain the vehicles would have to go over such as rally versus track. So a rally car may use 27mm to be more compliant for unknown surfaces and a track car would use 33mm where the surfaces are (supposed to be) more predictable or is this nothing to do with it? I must say the use of 33mm bars sounds absolutely huge !! I can see some bridge girder construction mods coming up in the front end to stop the chassis twisting instead of the bars !!
In response to other points. Yes my Alfetta bars are 19mm and longer than the ones on my coupe. Matter of fact I have spare bars from a coupe but can't use them 'cause they are too short unless I modify the rear mount and bring it closer to the front. I see Performatek list two different model bars and I suspect it is to cover this issue. Anyhow, appreciate the leads as always.
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Post by Zamani »

About the spring rate. I had 125 lb/in and it was just enough to stiffen the front a bit (when I had AVO coilovers).

So I would say, start at 300 lbs/in. Springs are relatively cheap so I wouldn't be surprised if you end up going through 2-3 sets.

I found an interesting article here:

http://www.944s2.com/suspension/suspension.htm

And of course, the best site (IMHO) is:

http://www.e30m3performance.com/tech_ar ... /index.htm

(eventhough we all here "love" BMWs.... especially Mats :) )
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Post by Mats »

MD, I don't know what the tracks are like down under but if they are smooth (i.e. not bumpy) I would definetly go for the 33mm bars, a 30mm bars is not uncommon on street cars here...
You will need a matching spring though.

Bar lengths are not body specific but rather age, early cars = long, late = short, breaking point is around 82-83 somwhere, body series change dependant probably (GTV).

Z: Those numbers are spring rate right? any wheel rate numbers? Frequency?

/Mats (Who is expecting a delivery of a BMW after the weekeend ;) )
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Post by MD »

Hey Zamani, I think you are onto something there, Mats does love BMW's here the most- so I am led to believe. I hear he wanted to sleep in one but couldn't get a heater big enough to warm his big feet stickin' out the window in the Swedish winter !! Could be just a furphy I dunnow? :D

Hi big guy. Thought I would prod you a little under the ribbs just to see if you are asleep behind that wheel? The place is gettin' too quiet and orderly like...

On the sane side, thanks for the tip on the bars. When you make reference to needing springs, I presume you mean rears to balance up the front and not springs in say the coil overs?
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Post by Mats »

wtf? I'll let you know that the BM has both RWD and LSD, not many Alfas after the 75 has that option. :P ;)
I'll post a pic in a while and I'll show you who's the top dog. :D

And yes, I did mean the rear springs. I'n my opinion you either stick with the bars or switch to coil overs, not a mix for serious track cars, it weighs too much and is definetly difficult to dampen right because of the resulting progressive spring.
Shocks is the next "black art" we need to discuss about the setup, I guess the above statement is pretty much out the window if we don't use adjustable shocks (but not those crappy yellow koni, they are always sucky ;) )
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GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
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