A1 rear wheel alignment

[Sandro]

I have just finished making some, and they are IT legal. I will be testing them out hopefully on Nov 14

[Joe Camilleri]

Tom, look on page two of my build photo album.

[Tom A]

Thanks for the replies, and Joe, nice car.

Joe, what are you running for sway bars, if you don't mind my asking? It looks like yous is similar to the Neuspeed I have, but I notice some bolt heads on top of the beam, is there another bar under it?

Thanks,

Tom

[Joe Camilleri]

Thanks Tom,

Yes, I have a Neuspeed type bar and a homemade Shine type bar bolted under the beam. I don't have enough track time yet to tell you which combination of bars and springs works best.

[Flyinglizard]

Does that panhard bar bolt to the center of the axle??The pivot point is the same as the axle itself? It will bind quite a bit otherwise, and result in a rapid spring rate rise.
Is this to keep toe in or toe out , with travel? I think that it will add some dynamic camber, with load, but very little.
It may work best, tied to the other wheel bottom.
I have loaded these axles up, on my front end machine, and found very little flex @ 1000# of load.
I started developing the rear steer about three years ago, with my Son's solo car. It worked so well, that I have used it on our 3/8mile, circle burner, and IT car( and customer setups). The dynamics, when the rear tire tracks well outside the front tire, are outstanding. Think of a three legged stool. Try to tip it over, pushing against the widest three points, and than along the narrow direction. The change in effort is substantial. The VW is the same as a three legged stool!!. The more that the rear tire is outside of the front tire, the more effort it takes to tip it over.
The dynamics result in more inside front tire load, less outside front load, lower inside rear tire, more load on outside rear tire. More rear tire load means that I can use less rear spring, to get the same turn it feel, along with more grip.
I am trying to envision a "panhard " bar to add to this rear steer, for the road race cars. I can only come up with a "traction" bar, to the rear of the car. This would pull the axle back, upon deflection,but not side load.
Has anyone come up with a side load sensitive system??
The ultra soft bushings are where I am at right now. It works well,but I would like more control of the axle and more high tech stuff back there...
BTW, the circle track car set fast lap, and all of a sudden, all the front wheel drive cars had 1 in of rear toe out. It makes a huge difference with our rules, stock springs, 9in Goodyear slicks. The rear tracking about 10 in outside of the front , unloads the outside tire and adds drive to the inside front tire. Worth about 2tenths,on 17 sec.
MM

[Flyinglizard]

I came up with a "Dynamic Toe Control" rear steer setup. It consist of a triangular lower link to the lower shock mounts. The pivot is in the center of the car, right about the rear of the floor, near the pan cross brace. 40 in panhard bars are available, with rod ends. That seems to be a workable lenght.
The axle bushing size is the only limit to actual toe out under load. I messed with one of the cars ( with soft bushings) and I think that I can get about 3/8 in travel, maybe .5 in. (each side).
The optimal angle of the control arms will take a few tries, as it makes a large difference in travel, as you multiply the side load, into for/aft load.
Anyone interested in this setup, email me direct and I'll foreward the part numbers, and status.
Mke Ogren, Protech, [email protected]

[Tom A]

So if I understand your post, you install super soft bushings, then stayrods that are designed to bind under bump, deforming the bushings and force the whole beam to shift and induce some toe out on the loaded rear wheel?

Interesting.

Tom

[Flyinglizard]

Side load sensitive. The angle between the trailing arms VS the axle pivot, mulitply the side load into rearward force. This can be increased by allowing the axle to move laterally. MM

[Bildon]

Guys keep in mind that the wording of the rules have changed WRT the toe links. No longer a "gray area" nor legal.

For toe, use the camber shims and rotate them and drill new holes.

[JamesB]

pretty much. Then again, I have bent my beam with enough spins that camber was no longer the issue, I had to use the plate nearly sideways to fix the toe.

[Sandro]

Guys keep in mind that the wording of the rules have changed WRT the toe links. No longer a "gray area" nor legal.

For toe, use the camber shims and rotate them and drill new holes.

Little confused, your saying this is not legal ?

http://www.bildon.com/pub/A3_panhard_rod.jpg

[Flyinglizard]

I have it under traction bars and watts link. Traction bars run up under the rear axle. There are no definitions nor mention of any required angle of said arms. Nor does the rule say anyhting about FWD or RWD axle control, as far as I can tell. I have the rules here, but maybe they are old?? They were loaded last week.
Is there an update that I have missed?
By your response, Bildon, I assume that you are passing on the opportunity to market this.
The way I read the rules The device that I have engineered is legal. Also goes faster. Testing went well Sat.
Mike Ogren

[shwah]

Traction Bar - A longitudinal link to an axle housing or hub carrier which resists torque reaction from the driven wheel(s) by acting in compression or tension.

This is the current GCR defenition. I don't think what you are proposing meets this definition. I am pretty sure this was recently updated specifically to close the loophole that you found.

[Flyinglizard]

Thanks Chris. I have it very linear, with the control arms. I can go back to just controlling the axle with the bushings. It works pretty well, but I cant get the sideload multiplied. I can just vector the side load, inside the bushing. This works about as well,but doesnt look as cool under the car, nor cost as much.
BTW What is the GCR def of a panhard bar???
Peace, MM

[shwah]

Every time I read about your bushing solution it intriques me. I just worry about what else that might effect. How durable do you think it would be in a side impact to a tire wall, or with another car?

[lateapex911]

I came up with a "Dynamic Toe Control" rear steer setup. It consist of a triangular lower link to the lower shock mounts. The pivot is in the center of the car, right about the rear of the floor, near the pan cross brace. 40 in panhard bars are available, with rod ends. That seems to be a workable lenght.

The optimal angle of the control arms will take a few tries, as it makes a large difference in travel, as you multiply the side load, into for/aft load.
Anyone interested in this setup, email me direct and I'll foreward the part numbers, and status.
Mke Ogren, Protech, [email protected]

Mike, I'm no expert on VWs, but the traction bar definition stipulates longitudinal members, and driven wheels, and it sounds as though this is anything but longitudinal, and the driven wheels are certainly not involved. Further, the rule calls for any traction bar to be of a one tube/bar design. So I'd say legality-wise, you're on thin ice, if not on unfrozen water!

Further, the rule allows the addition of A panhard bar, not multiple, so again, I think you will run into difficulties in the tech shed.

JMHO, and I may not be understanding your situation properly.

(But, it also sounds as though you haven't been through the GCR with a fine tooth comb, and that's a key elelment to the build process. Again, I might be reading things wrong, my apoligies if I am.........)

[Flyinglizard]

Jake, You are right.thanks for looking it up. "Driven wheels" is new. I can connect the trailing arms and call it a sway bar. Or I can try for a more controlled soft bushing.
I have been running static toeout for 16 yrs. It works because it removes dynamic weight from the outside front tire. There are a lot more small reasons and longer explainations if anyone cares.
Chris, FWIW, I have at least 1000 laps, and 10 hits on the ministock Jett. The axle bushings are fine, the rest of the car is tired. It is the fastest by 1.5 tenth. I have soft/ modified bushings in all of my race cars(3) and maybe some customer cars...
MM

[Grumpa]

Bill Suloff,
Refer to the picture in reply 14 of this thread. I am working with an A1 axle and have the following question. Where would/did you locate the opposite end of the toe link?

[Sandro]

I have mine dead center(left to right, and up and down) on the center flat vertical section of the beam. Before welding I triple checked dimensions to make sure they were in the center. I can swap my left and right toe link bars, without adjusting them.

[Flyinglizard]

I am pretty sure that you need to connect them, to be legal. It has to act a bit like a sway bar to fit the rules. IMHO. MM