ALFAGTV6.COM

[Micke]

I did it and I'd do it again the "Mats'way".
It has several advantages.

1) you automatically get same angles left and right
2) the RC will drop a couple of cm's
3) you cannot get it wrong

The hard way you can ajust toe as well. Problem is you must be able to measure accurate while doing it. I used this method later to fix toe only. Then I didn't cut but just weld over the tube.

[ar4me]

Micke,
Where did you run the bead of weld for adjusting toe? How much toe-in did you add? I'm still planning to do it Mats' way, but I would like to add some toe-in. So, I'm hoping to do it in two stages:
1. do the cut, bend, and weld close to the Watts pick-up for -2.5 camber.
2. put a weld in the proper place of the dedion to gain 4 mm total rear toe-in (but where exactly, Micke?).
I have access to turn-plates and laser-guided measurement of toe, so I hope it is doable.
Thanks,
Jes

[Mats]

Make the camber change, refit everything and adjust ride height. Measure toe, in my case I didn't need to add additional toe.
Had I needed it I would have run a bead on the tube outboard of the forward running pipe and as you said, you really need a proper alignment equipment here or you will go mental.

[Micke]

Just like Mats said. Outside the tubes to the front.
I don't remember the values now. Problem is I had toe out at first and it was unstable like hell.
IMHO the DeDion doesn't need much toe in if any. How would you justify the need? As long as it's not toe out and same on both sides I wouldn't bother with it.

[ar4me]

Thanks for the pointers!

I can only think of increased high-speed stability. At some point it would be scrubbing off speed, I suppose Anyway, I know Ron recommends 4 mm rear toe in with his setup.

Jes

[junglejustice]

Just like Mats said. Outside the tubes to the front.

- But Mats was saying INSIDE of the tubes to the front...!? Now I'm confused - I am pretty sure Mats said inside - you're sayng outside...?

Thanks for not "nagging" Mats - yeah - I just want to understand this - by cutting to the inside of the hypotenuse (forward) bars, how the hell do you manage to move the camber? You have to now fight the other points that are still connected and "flex" those forward bars... I'm sure it's not much, but still.

Also, how do you do toe now with the other ponts still welded (without welding OUTSIDE of the triangle any way...) Seems that I would be better off then to just do all of it outside of the triangle to begin with!

Ron is convinced that these cars can use the toe in at the rear for the ultimate track/race setup... Describing some of the things experienced jumping from one car to the next ad talking with him for long hours about this, his comments all pointed to some toe at the rear as the solution/preferred setups in the cars that I seemed to favour...

Any way - I will be doing mine up on the alignment rack! Nicer that way - you can set up the alignment heads on the wheels, nut and bolt everything front to rear, do the basic alignment and then with it all set up - do the cutting and welding and make your adjustments "in real time" so to speak right from the computer screen...

[Mats]

JJ, are you sipping on that SA wine?

[junglejustice]

R U ? It's wine-time over there now - here on the West Coast it's not even beer-time yet...

I see now - Micke was talking about the welds for the toe-in...

Yeah - toe out on these cars would be a very bad thing - drove one with toe-out on the front - terrible![/i]

[kevin]

Hi JJ, Do you have any info from Ron what his ultimate set up in terms of kg's for front and rear springs with the v6 motor(with standard torsion bars still in) for 75 or GTV. Im thinking of less comprimise at the moment. Still got the 30mm anti roll upfront.

[junglejustice]

Well, as you know I have been fortunate enough over the past few years to be able to spend extensive time one-on-one with Ron on the subject. I have also driven about 20 different cars with various combinations of Ron's spring-rates. The short answer is that there is no silver bullet here. So many aspects such as wheels, tires, bushings, overall condition of the car, other modifications, total weight etc come in to play here.

The long answer is that it all depends on a number of other subjective (and some objective) parameters! Beyond the particular nuances from one car to the next and one setup to the next, it also depends on the individual preferences of the driver, the use/purpose for the car - even the road conditions where one uses the car...

Overall, the 125kg/70kg rates for a more aggressive setup will give you the best setup on a V6 Milano/75 with stock torsion bars. The lighter, shorter wheel-base GTV6 seems to favour the lighter rates at the rear - maybe 60kgs. Ron now also sells a 65kg rear for more fine-tuning. On a 4-banger I almost always start a guy out at 100 and 50kgs at the rear.

On a V6 street car, we typically set guys up with 115 fronts and 60 rears on either V6 car, (so that you have somewhere to go - up to 125 or down to 100 up front and up to 70 or down to 50 at the rear.) There are extreme setups for specific applications - we run 200s up front on the two 3.7s with NO torsion bars (but we still have 70s at the rear!)

For you, in your car for example - you want to keep more compliancy on the street from what I understand. For the next guy, he/she may want the best improvement and be willing to compromise some of the ride quality! I run 125/70 on my street/track 3.0 12 valve Milano WITH 27+mm torsion bars and it is great - even on roads that are borderline! (It's no fun on bad roads.)

It's been great while this car was used for dual purpose over the past few years, but now that the 3.7 is basically ready, I may drop the large torsion bars back to standard and MAYBE even go from 125/70 down to 115/60 and make this a street-only car...

All of Ron's setups this side of 125kg fronts and 70 rears are pretty mild though. Keep the 30mm anti-roll bar up front - just make sure that the adjustable reaction-ams are not pre-loaded at rest on the ground.

[la_strega_nera]

Ok, Ron's spring rate numbers have always bugged me. What units are they? Kg/mm? Kg/cm? Kg/inch?
Lets look at the rear rates all of their own.
*normal* live rear axle wheel rates (cars of various spec, weighs between 1500 and 800kg) are somewhere between 120lb/in at the ford escort end of the range, up to 220ish lb/in on a bigger leaf sprung car.
So,
60kg/mm would be incredibly stiff (3352.8lb/inch)
60kg/cm would be fearsomely stiff (335.2lb/in)
60kg/inch would be kinda soft (132lb/in), but the right ball park given the low unsprung weight.
So i guess thats kg/inch, which is a little goofy?
Wish I could remember my old GTV's rear rate.

[kevin]

Two years ago i loaded all of Rons springs and as far as I remember they were kg/10mm(9.8mm) and were nearly 100% accurate. The rear on my stan dard GTV were only 17kg/10mm.
I picked up on one of your post about good turn in and then understeer mid way through the bends, this is what is happening at the moment but its totally controllable as its gradual and you just tap off a bit. Looking at fast sweeps and semi banked oval sections between 120km and 170km. So i was thinking stiffen up front more to bring it inline with a more of a race set up approach and then start my cycle again. What your thoughts?

[kevin]

Two years ago i loaded all of Rons springs and as far as I remember they were kg/10mm(9.8mm) and were nearly 100% accurate. The rear on my stan dard GTV were only 17kg/10mm.
I picked up on one of your post about good turn in and then understeer mid way through the bends, this is what is happening at the moment but its totally controllable as its gradual and you just tap off a bit. Looking at fast sweeps and semi banked oval sections between 120km and 170km. So i was thinking stiffen up front more to bring it inline with a more of a race set up approach and then start my cycle again. What your thoughts?

[la_strega_nera]

How stiff is the front end at the moment? Is this your racer that you don't have a lsd in yet?
There comes a point with going stiffer on the front end starts to make it understeer again on most of these things, so I'd be leery of going too stiff in the front. With my old GTV i cured that trait with more rear rate, but that was always fairly softly setup.

These days I'd approach it all a bit differently, for example my Falcon the setup is soft as I'm comfortable with in the rear because i'll be chasing traction out of the corners, and the front is a little softer than common practice in my class because of the geometry fixes.

With a GTV6 I'd be stiffening the rear a bit to make it looser in the turns and work at carrying corner speed a bit more because traction on corner exit shouldn't be as bad as trying to feed nearly 6 litres of motor through 245 bias plies... basically the less powerfull you are, the less you try to tune corner exit oversteer out. More rear bar will give you the shift in balance while letting you keep traction out of the slow corners/in a straight line.

At the moment I'm plotting ways of curing the heavy trailing throttle oversteer that my 105 has... its currently stock except for the knuckle risers, no rubber or poly in the front end and poly in the rear. On spirited road runs it's that little bit oversteery when you have to back off or even brake in a corner, and the front end is no-where near the limits. Feels a little like its going to swap ends under heavy braking too, its just a combination of the high rear rc and its jacking effects, and the soft stock springing letting it almost pull the the rears off the deck (i wonder if it went full travel on the axle limit straps?). A bit more front spring rate should help, but even better would be a lower rear RC.

Interesting that Ron's stuff is that stiff... what's it ride like? I vaguely recall the black car's springs were 30% stiffer than stock, and it had the early 19mm rear sway. Can't for the life of me remember the front sway setup. Is the motion ratio of the front end when running coil overs with no torsions really that crook that you need 1120lb/in of rate to get a decent wheel rate? or is it compensating for a sub-terranian rc caused by low ride heights and no geometry correction?

I'm currently investigating selling the Falcon to build a GTV6 for Classic Tarmac rallying, the cut off date is 1st Jan '82, but GTV6s made FIA homologation in April '81, so I'm kinda keen to re-learn all the 116 platform stuff I forgot...
My current line of thinking is fairly basic, something like Ron's kit with upside down lower BJ at the front, and a lowered rear watts pivot (or even a completely "corrected" rear watts). Be nice to piss those cast lower arms off for something lighter though.

Anyone ever chopped the A frame section off of a dedion and replaced it with a 4link? 4 lighter links would have to drop a bit out of the unsprung weight.

[Mats]

Since the parts are made in Europe and prolly have the stiffnes in plain writing on the spring I bet the figures are in N/mm, all the other ways to measure springrate are wrong. (And you know this Ben, right? )

The insane front bar and such is to compensate the RC drop as you indicated, I have a front bar that is nowhere near that on my racecar (flipped joint).

I won't pretend I know something about the 105 chassis but the problem usually is that the front spring rate is impossible to get high enough, with the biggest springs the LCA even flexes...
What does it feel like when it's not trailing throttle? exit under power, steady state etc. Different at speed/slow?
Do you have an LSD? That would make it tighter at turn-in.