GTAm

[Takis]

Campagnolo magnesium 9X13 rear wheels...
Rear anti roll bar positioned under the body ...

[sono veL.O.ce]

Those pictures and captions are great! I didn't realize there were so many suspension and braking differences. It looks like the car is deviod of any undercoating as well!
Here are two questions:

Does anyone have more pic's of the "Guillotine" flat-slide throttle bodies/ linkages?

Is there a preferred method of fastening the flares?

[ossodiseppia]

Quote:

Originally Posted by sono veL.O.ce I didn't realize there were so many suspension and braking differences.

[italcarguy]

Quote:

Originally Posted by ossodiseppia Those look like Porsche 911 aluminum calipers.

[borrani]

Yeahhh, but we're not allowed to run'em in our historic class. Still, we could paint'em cast iron color!!

[Takis]

A replica GT Am as was raced in the past years here in Greece with much success ...

[Takis]

This GT Am uses the Spica fuel injection , I think the linkage from the pedal to the Spica is the same as the stock cars but from then on to the throttle bodies must be different because it operates on the right side instead of the centre between the bodies.
As for the attachement of the flares they used rivets and they still do as I have seen on some replicas.
Takis.

[Takis]

Lets get confused , another GT Am engine bay , in this case the guillotine is operated from the centre between the throttle bodies ...

[Alfaross69]

Takis,
What was purpose of steering knuckle extension,Could you explain?
Thanks for all the GTAm photos keep them coming.

[conedriver]

alfacross69,

The part is called a "Knuckle Riser", and was used on (early?) 105 series cars to improve suspension geometry. Does anyone know when this was incorporated into the stock suspension?. I'm particularly interested in when the change was made for square tail Spiders.

Quote:

Originally Posted by alfaross69 Takis, What was purpose of steering knuckle extension,Could you explain? Thanks for all the GTAm photos keep them coming.

[Jim K.]

Hello guys, I'm new here-nice place you got!
The knuckle risers were used to enhance geometry when cornering, giving the outside wheel negative camber as the car rolled. They are sold by a number of AR perts vendors at about 180Euros/pair. Another advantage in 105 cars, is the lighter steering effort required (although this can be the result of a small caster angle change after installation, most likely).
Jim K.

[papajam]

After searching around a bit, the only model I found that Alfa fitted what they called a 'joint attachment', part number 105.32.21.118.00, as standard equipment was the GTA. It was also offered as an option on the GTA 1300 Junior. Note the 105.32 p/n designation, the unofficial type number of the GTA (the official type # is 105.02/A).
The 11/71 and 2/77 issues of the Performance Options Catalog list an Autodelta 'knuckle riser extension', 105.51.21.118.99, for all 105 series cars which, because of the 105.51 p/n, leads me to believe that these extensions first appeared on the 105.51 GTAm. In addition, the steering knuckles listed in these catalogs have different part numbers than those knuckles listed in the parts books for the 'regular' production cars.
All this means though is that later production road cars didn't have knuckle risers. It does not rule out, however, the possibility that Alfa incorporated this suspension geometry for the later cars in the form of taller steering knuckles.

Quite the long winded response which boils down to I haven't got a clue.

[Jim K.]

If you look at the risers used in the GTAm, they're definitely a different part from the road GTA part. The lower plane is ground at an angle, presumably to make clearance for the wide rims, as they are about...2mm away from the inner edge! The same goes for a GTA Jr 1300 16v (droooool!!) I saw last week. For the record,1300, Spica,Trumpets, slide throttles, 195hp at 9500 rpm!! I was called over to help start the engine after assembly. Man,I'll never forget the sound of it as we revved it briskly from 1500 to about 5000!! What was more amazing was the fuel mist going in and out of the trumpets with rpm!! For the more technically minded, static advance needed was 25*BTDC and at 6000 it was 30*. There is no info available,but AD made about 3-4 such cars.They were the last to race in '72 or '73. In total no more than 5-6 such engines were made and this guy also has a...spare complete one!!
Jim K.

[conedriver]

Thanks Jim,

Maybe someone else knows about the Knuckle Riser. I may post a new question in the "Competition" area

Quote:

Originally Posted by papajam After searching around a bit, the only model I found that Alfa fitted what they called a 'joint attachment', part number 105.32.21.118.00, as standard equipment was the GTA. It was also offered as an option on the GTA 1300 Junior. Note the 105.32 p/n designation, the unofficial type number of the GTA (the official type # is 105.02/A). The 11/71 and 2/77 issues of the Performance Options Catalog list an Autodelta 'knuckle riser extension', 105.51.21.118.99, for all 105 series cars which, because of the 105.51 p/n, leads me to believe that these extensions first appeared on the 105.51 GTAm. In addition, the steering knuckles listed in these catalogs have different part numbers than those knuckles listed in the parts books for the 'regular' production cars. All this means though is that later production road cars didn't have knuckle risers. It does not rule out, however, the possibility that Alfa incorporated this suspension geometry for the later cars in the form of taller steering knuckles. Quite the long winded response which boils down to I haven't got a clue.

[genericwood]

I have been told that the later 105/115 spindles were changed to raise the height of the upper ball joint. This apparently eliminated the need for the knuckle risers, at least to some degree. I run the later spindles on my GTV. They have been further modified to lower the car by an inch (with no change in distance between the upper and lower ball joints). According to the suspension software I'm using, I should get 0.73 degrees of negative camber for the first inch of suspension travel (bump). I'm not yet convinced that is enough.

By the way, I see that "Jim K." has joined the group. You wouldn't happen to be Jim Kartalamakis would you? I would guess many of us have read your book "How to Power Tune....." several times.

Erik Wood