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Maurizio · Post by **Maurizio** » Wed May 23, 2007 5:45 am

Mats wrote:Maurizio: Better RC?
up or down?

Up off course, for the gross of lowered transaxles (referring to my V6) But I keep it like it is, is enough time needed to do one semi-racer. And it looks ok so low

For my track car (TS) the rc is ok, but I want to move the CG down

castor bar ball joints

It the common used 105 joint. I didn't like the idea off cutting the already flimsy sheet metal. So I did the spacer design which now is sold in several places. (Performatek sells them in aluminum, rs has derivative in steel).
Harshness is not much different from stock setup feel is much better.

ps castor rubber: go to an align shop and get the car aligned. Then lean a moment on the front of the car after that control the alignment. From then on you only want a ball joint in there.

Mats · Post by **Mats** » Wed May 23, 2007 6:48 am

Well, the ball joint caster arm is the first modification you should do! Zero drawbacks and huge improvement in feel and stability. I felt the change when rolling the car by hand in the garage after the switch, that's how good it is.

My front setup is totally custom, tubular control arms upper and lower, custom built coilover Bilsteins, modified spindle to have a spherical bearing on the bottom instead of above and corrected for bump steer, modifier AR-bar droplink and mounting points. Stiff springs and flimsy AR-bar

2.0 carb as you might know.

On the other hand I strongly think you should consider not to touch the front setup and just add a lot of spring, 30mm T-bars to start with and go from there. There are a lot of very fast cars out there with no drop-spindles or any "hard" front end geometry changes.
The T-bars is the second thing after the tie-rod/caster rod I would change because it has such a huge impact on the handling, control the wheel movement and the RC has a smaller impact. Simple.

BTW, if you have Bilsteins and a V6, 30mm T-bars are definetly not "too harch" for street use. The guys claiming this is always the same guys that will tell you that the Red Konis or maaaaybe the yellow ones are the best damper around for the 116 chassis.

grant · Post by **grant** » Wed May 23, 2007 7:03 am

Echo,

The RSR doesn't have anysprings that are softer than 27.3 mm torsion bars (for a Milano's long bars atleast). What I'm saying is that you use stock torsion bars until the helper springs have been compressed ... so the ride is quite nice on small bumps. The rear springs are linear however, with rates of more than 6kg I think. Pretty heavy stuff.

Also, I think Mats was saying that you wouldn't need a bar softer than stock on a V6 car, so you don't have to worry about throwing it away later.

So, it really depends how serious you want to go with the car. Mats I see is suggesting the use of 30mm T-bars, but I don't think you can get them in the US. And if you go that route, importing thick t-bars and springs from Sweden or OZ, you might as well use RSR. Even the softest RSR spring rates are goign to be way stiffer than any street torsion bars sold in the US. Performatek sells a 33mm bar, but I think that would be for a car that was strictly race.

Mats, how much are 30mm bars in your area?

And it's interesting that Maurizio feels that just a thick front sway bar would make the car balanced? Is this because you're stiffening the front up, the resulting good camber control makes up for a front end that is too stiff? If you have that much roll stiffness in the front only, how does that leave you with a neutral setup?

With my 27mm T-bars and 154lb/in springs, using just a 28mm front AR bar and stock rear bar, I had a car that understeered heavily wherever I went. Maybe the speed was faster than with just stock sway bars (?) but it definitely handled worse.

grant · Post by **grant** » Wed May 23, 2007 7:04 am

One more thing: If alfettas and 75's have different length torsion bars, a 30mm on an Alfetta is going to be stiffer than a 30mm t-bar on a 75/Milano, correct?

What is the spring rate of a 30mm bar?

Echo Leader · Post by **Echo Leader** » Wed May 23, 2007 8:25 am

Wow, seems like I should order those castor bar ball joints....

It's a beautiful thing when a budget modification makes such a huge impact with so few (or zero!) drawbacks.

Mats, so you recommend bigger Tbars while leaving the front AR-bar stock? These very fast cars all run a configuration that forgoes a big front AR-bar? As well as ignoring hard geometry changes?? I guess if the goal is to simply control wheel movement, I could achieve this with the AR-bar and have less harshness? Is the main reason you don't recommend going in that direction the future compatability of that decision with other modifications?

Slipped into confussion...

Grant, I worry a bit about doing the t-bar-until-tender-spring-compressed thing. You basically have made a dual rate spring, with a pretty drastic differential. This would be impossible to properly damp. If I had the super-neato Kopp & Bianchi torsion bar traverse and was able to use this method to only get to and from the track, maybe....

Speaking of that piece, has anyone played with it? This is thier suspension page, but I can't really read much on there. Looks like they also have some slick control arm upgrades...

The longer the T-bar the less spring rate it has for a given thickness. Good questions on the 30mm, I'm curious myself.

At least we all seem to be in agreement that the castor bar ball joint upgrade is sweet!

Mats · Post by **Mats** » Wed May 23, 2007 9:35 am

The 30mm bars are NLA.

Stock torsion bars until helper spring is compressed sounds like trouble, imagine going down the straight doing 200Km/h and having the same spring rate as the stock torsion bar. Did I hear wobbly? I have gone down Fuchsröhre and Flugplatz with a bone stock 75 TS at those speeds and it wasn't exactly what I would call "a solid ride" (or straight).

FCUK small bump pleasentness, this car isn't going to be a little sunday driver car anymore with these mods, you need to understand that. To have a car thet you are going to develop some real driver skill in it will have to be borderline uncomfortable on the streets. Everything is a compromise. BUT! on the other hand if you're into active driving all that will seem like a small sacrifice because the reward is so much bigger!

The wheel rate difference between the long and short bars probably has less impact on handling then the wheelbase difference between a 75 and a GTV. I have no idea about the wheel rate but if you really want to know it's probably pretty easy to calculate or measure.

Echo: Bigger T-bars first and matching rear springs, then you play with AR-bars. I believe the fast cars have stock or possibly the 3.0 or optional (28mm) AR-bar. Probably 26mm, haven't actually measured but by eye it's nothing fancy.
Springs and AR-bars are not the same (this is what me and Maurizio were discussing), maybe if you had a perfectly smooth track you could run softish springs and sick AR-bars but the tracks I race all have bumps and such. Also when you brake the weight transfer will make your nose dive with softer springs and this will give you more camber = less braking traction. Imagine what would hapen in a fast corner if the outside front suddenly went into a small dimple on the track, all the load would suddenly be on the inside front and outside rear and there would be some pitching to further upset things (and no springs to counter the pitching).
I'd get some nice firm springs and balance roll/grip with the AR-bars, but that's just my opinion.

If you cant get a 30mm, go for the 33.

Maurizio · Post by **Maurizio** » Wed May 23, 2007 10:58 am

@grant, yes you got it right. The huge ar bar makes it a lot better due to the better geometry. In theory the bar pulls the inside wheel up during cornering which is not good.

My statement was. If you want low budget go for huge ar-bar. If you go full stiffness upgrade, etc. Doesn't matter what T-bars or coil-over. You don't need the huge ar-bar. I would go coil-over, is less budget and a lot easier to adjust change and play with.
But not forget spring stiffness needs matching shocks! I had bilstein, who made a nice damper for my 75 and the ring.

I had already the 32mm ar-bar and it staid on the car even after the coil-over upgrade. Car still goes good.
Maybe could do with a smaller one, I haven't tried it.
I run 105kg/cm on top of the standard 22mm t-bars and 70 kg/cm in the back. On public roads this thing isn't a lot of fun, or you have to drive it in anger.

On the nurburgring the car is only understeering in one corner (Eiscurve) . In which I always carry to much speed going in. There are 2 corners (one is Brunchen 2) in which when I get them right the cars backside makes a small step. So for my driving style this is nice balance

grant · Post by **grant** » Wed May 23, 2007 11:28 am

That does sound balanced. Was it this way when you just had the thick front sway bar and stock springs and t-bars? Like I said, I got gobs of understeer with just a bigger front sway bar and the 27mm T-bars and matching springs.

Mats · Post by **Mats** » Wed May 23, 2007 12:05 pm

Vee six under the hood, am I right?

grant · Post by **grant** » Wed May 23, 2007 2:06 pm

It's quite possible (cause of the understeer that is, I'm pretty sure I have 6 cylinders down under).

So....would it be as simple as mounting the battery in the trunk and ditching the AC or something to get rid of the understeer? The differnece between the two engines is 75-100lbs right? I guess the v6 block is longer..

But regardless, I know people have said otherwise on these 116 cars, but if you do that same move on just about any other car in the world and it will upset the balance of the car..even if cornering speeds increase.

Echo Leader · Post by **Echo Leader** » Wed May 23, 2007 2:21 pm

Mats wrote:FCUK small bump pleasentness, this car isn't going to be a little sunday driver car anymore with these mods, you need to understand that. To have a car thet you are going to develop some real driver skill in it will have to be borderline uncomfortable on the streets. Everything is a compromise. BUT! on the other hand if you're into active driving all that will seem like a small sacrifice because the reward is so much bigger!

Yeah, 'borderline uncomfortable' is fine, and I certainly would love the additional responsiveness. My only real concern is that somehow the European set seem able to run higher spring rates.

I'm not sure if the roads are nicer there, or if the men are just more manly...but I think going with a set of 27mm Tbars as a first step would be completely streetable.

I like your compare/contrast of the Tbar upgrades vs the AR-bar. I personally never liked the concept of creating a non-independent front suspension via an AR-bar.

Mats wrote: I'd get some nice firm springs and balance roll/grip with the AR-bars, but that's just my opinion.

I like this philosophy. I much prefer using the AR-bars to strike the right balance vs. making them the dominant feature of the suspension.

Mats wrote:If you cant get a 30mm, go for the 33.

So you have the 30mm bars and the custom Bilstein coils?? Dang....I guess my plan to go with 27mm bars is kid's stuff.

Maybe with my lack of spring rate, a bigger AR-bar would be beneficial?

GarthW · Post by **GarthW** » Wed May 23, 2007 3:49 pm

You guys in the USA, couldnt you all put in a group order for Vince@Pace and get him to send up afew bars seeing that the american dollar is way stronger than ours..?

Mats what the difference between yellow Koni's and coil-over Bilsteins?
I mean are they alot better than the Koni's? My Koni's are great, but would like to hear about the Bilsteins!!

Echo Leader · Post by **Echo Leader** » Wed May 23, 2007 4:44 pm

GarthW wrote:You guys in the USA, couldnt you all put in a group order for Vince@Pace and get him to send up afew bars seeing that the american dollar is way stronger than ours..?

What kind of products does he offer? I honestly hadn't heard about Pace until just a few days ago. He have a website, catalog or anything?

grant · Post by **grant** » Wed May 23, 2007 4:51 pm

Hmm, James, maybe we should give Vince at Pace a call. Beninca I think is expensive even before the shipping, maybe Pace's prices will be better.

Echo Leader · Post by **Echo Leader** » Wed May 23, 2007 5:00 pm

Yeah, I'm curious to hear what he's got to offer...