Swapping front hubs for more caster?

[andy10v]

Did you machine the groove for the pinch bolt 360* like the original balljoint?

Could you not machine it so it will only locate in the proper orientation, like a B5 A4 outer track rod end?

Like this



Instead of this

[90quattrocoupe]

Yes I am alive. The extenders worked fine, but the driver's side turned in its mountings under heavy braking. .

Glad you are alive. Just because we want the extenders.

Did it turn in the hub carrier or on the ball joint? The bolts in the slots didn't hold it in place? Interesting.

Greg W.

[Mr.Crossfire]

Yes I am alive. The extenders worked fine, but the driver's side turned in its mountings under heavy braking. I have to make the bits to prevent that from happening. Other than that, the car was really fun to drive. I didn't dare to push it into extremes as this was first "summer" trackday and first time with the extenders etc, but according to the performancebox data, I managed to get something like 1-1.1g lateral (peaking at 1,2g) with practically no understeer at all. Of course it's not only due the extenders but the other modifications as well.

According to the quotes I have received from machine shops, the pricing would be something like 250-260e/pair. So a set of four ~500e or so. That would include bolts, nuts & the possible turning prevention pieces. Quite expensive due the tough material.

[vwmannen]

I would be interested i a set of 4 as well

[90quattrocoupe]

I'll give them a spin around the track on sunday, and if I come out alive .............

So it is now Monday, are you still alive?

Greg W.

[my2000apb]

estimated price?

[90quattrocoupe]

I will take 6. That makes 10, half your order.

Greg W.

[Audi_CQ]

I'll take 4 (they fit both front and rear I assume?)

[Mr.Crossfire]

I'll give them a spin around the track on sunday, and if I come out alive then I think I will be arranging the serial manufacturing. I have to contact the machining shop again, to see if they have time to make these. And they also said that 20pcs is the minimum quantity, so I need to see if there are some other people interested as well. Few people I know already here in Finland.

[Ryss]

I think I will be interested in a set too, if the price is right.

[Audi_CQ]

Ready to accept orders?

[90quattrocoupe]

I am surprised at that load, that the ball joint did not come apart.

Greg W.

[Mr.Crossfire]

Okay, yesterday it was time for some more serious testing. Here's the setup:

http://mrcrossfire.kuvat.fi/kuvat/90q/osia/Alusta/20130410_172535.jpg

I had two prototypes to test, the one in the picture is machined from aluminium, and the other one was machined from steel. Unfortunately I don't know the alloys, but I'm pretty sure that the steel one was regular S355.

Anyway, the results were such that the aluminium one bent with 1300kg load. That was really more than I would expect. The steel one bent with 2000kg, but I was somewhat surprised that the strut stayed intact! So all in all, the results were very favorable. I estimated that with the 816kg front axle mass in my 90q, with 1g lateral and roughly 80% of the load being at the outer tire the statical load would be something around 650kg. So it seems that I have a generous safety margin, considering that the real extenders machined from 42crmo4 have something like 2-3 times the yield strength compared to the regular S355. And it also seems that the original struts are also up to the task. The strut in the test was the 1-piece design, but I don't think the 2-piece design is much weaker. I will test with 2-piece strut also, but I need to aquire the parts first.

[Avantus]

After reading on weight distribution on the last pages.

I had my RS2 cornerweighted last year, and with 1/2 tank fuel that was 58/42.
I'm convinced that with some mods like aircon delete and some other stuff it should
be able to reach 55/45, which isn't that bad for a 4wd car.

[Mr.Crossfire]

Yeah, I've been thinking that too. Well, to be exact I was thinking about making an U-shaped plate to cover both sides. Have been driving around a little now with the extenders installed. Gut feeling is that the body roll is now less, but I have not been pushing the car very hard, studded tires still on etc. At least the extenders have not twisted around or anything yet.

I even conducted a preliminary structure stiffness test:

http://mrcrossfire.kuvat.fi/kuvat/90q/osia/Alusta/20130330_011155.jpg

The strut was going into the bin, so I decided to sacrifice it to the science. Also in the picture is the first, aluminium(!) prototype. Jacked the weight of the car up with no problem whatsoever. Next week I'm going to test the structure with a heavy duty force sensor (up to 2,5t) and a hydraulic press. It will be tested until destruction. Btw. the shock absorber in the pic was wasted already, not bent by that experiment.