Questions about VW1302RSis ride

[VW1302RSi]

Phil,
When are they going to start drug testing at your work, they would need to before i fly with you guys.

Originally Posted by What-r-u-doing

Scott

Have you used that pile of bolts yet or do you just polish it like you uncle would?

When are you taking it to the track?, is the Intermargue series still going?

Now that you have finnished the Das-brokenwagen will you be starting the U2?

Its knock off time so i had better go and wake the monkies up, BTY Dude we don't let riff-raff fly with us.

Phil

Funny you should say that the 19 of May i'm going to the track and yes the intermarque is still going, you should buy the U2 off me or arn,t you man enought??

Scott

[Mikey]

Scott,

I noticed you're running coilovers in the rear. Have you thought about a Kafer cup brace? 5 bar would be best but at least a 3 would help stiffen the rear suspension. The stock towers were not desinged to carry the weight of the car. Since now the weight of the car is now on the shock tower you'll need something to help make the shock tower stronger. And by tieing the stock towers into the frame horns you'll tie the whole rear suspension together. It'll also help with 'wheel hop'.

Here are a few pictures of my 5 bar brace installed. I purchased this brace from Lanner (Flat) at VDubEngineering.

[zeroaxe]

Scott,

Love the number plate! Nice car you got there mate!

Mikey,

Ho-hum....now I wonder if I should change my 3 bar Kafer brace-build to 5 bar?

[Mikey]

Originally Posted by zeroaxe

Mikey,

Ho-hum....now I wonder if I should change my 3 bar Kafer brace-build to 5 bar?

Look at it this way, if you're going coil-overs. A 3 bar brace is better than nothing, but from what I've heard the best way to go with coil-overs is a 5 bar brace. I really don't need a 5 bar brace with the set up I'm using now, but then again some might say I don't need to go Subaru.

If you're going with the stock torsion suspension and just want to eleminate 'wheel hop' and stiffen the rear suspension, go with the 3 bar.

[VW1302RSi]

Hi all,

Zeroaxe,
Thanks for the comments about the car and the plate was a bonus, it’s the original plate that came with the car.

Mikey,
My rear coil springs are helpers only they and they have a very light spring rate, just to allow me to corner weight the car and adjust the handling.
The only time wheel hop occurs is when I do a burn out it starts to hop after I have hooked second gear and I’m not the in to doing burn outs, however a rear bracing system is on the drawing board, I can’t use a Kafer style bar due to other components in the way. I have a system in mind and when its done I’ll post some pictures and drawings.

Originally Posted by Mikey

Look at it this way, if you're going coil-overs. A 3 bar brace is better than nothing, but from what I've heard the best way to go with coil-overs is a 5 bar brace. I really don't need a 5 bar brace with the set up I'm using now, but then again some might say I don't need to go Subaru.
If you're going with the stock torsion suspension and just want to eleminate 'wheel hop' and stiffen the rear suspension, go with the 3 bar.

I have a question for you based on your above comment, if you fit a 3 bar “kafer cup type” set up to a std IRS rear end how does it work?
- Is the upper shock mount supporting the frame horns?
- Are the frame horns supporting the upper shock mounts?


Food for thought

Scott

[Mikey]

Originally Posted by VW1302RSi

Mikey,
I have a question for you based on your above comment, if you fit a 3 bar “kafer cup type” set up to a std IRS rear end how does it work?
- Is the upper shock mount supporting the frame horns?
- Are the frame horns supporting the upper shock mounts?


Food for thought

Scott

Hmm. that took me a second, but I believe I have an answer.

Both. The brace is there to help stiffin the rear suspension as a whole. The frame horns are not supported, and the shock towers are not strong enough to do what we're asking of them with coilovers. But, if you tie them together, and tie it back up to the torsion housing, it gives everthing the support it needs.

Similar to a roll cage. If it was separated right in the middle of the car, the front and back are strong by them selves, but since you tie them both together. They make the whole car stronger. One part isn't relying on the other for streingth, they more or less, compliment each other.

Does that make sence?

[VW1302RSi]

Originally Posted by Mikey

Hmm. that took me a second, but I believe I have an answer.

Both. The brace is there to help stiffin the rear suspension as a whole. The frame horns are not supported, and the shock towers are not strong enough to do what we're asking of them with coilovers. But, if you tie them together, and tie it back up to the torsion housing, it gives everthing the support it needs.

Similar to a roll cage. If it was separated right in the middle of the car, the front and back are strong by them selves, but since you tie them both together. They make the whole car stronger. One part isn't relying on the other for streingth, they more or less, compliment each other.

Does that make sence?

Hey Mikey


Your right in that the brace is there to stiffen the rear suspension and transmission mounting points. But I don’t understand your logic, and I was talking about a 3 bar not a 5 bar set up.

This is how I think a basic 3 bar set up works and why but it’s only my opinion and I have been wrong before, after all I am married.

The basis of my opinion,
I have never known a beetle to break a rear shock tower on the road, (if any knows better let me know) I have however seen bent and damaged frame horns, in fact if you jack your car up on the end of the frame horns you will see them bend quite a bit, try doing the same on the shock towers and you see no movement (well I haven’t), the only 2 times I have seen broken shock towers was once in a dune buggy that was airborne and came down hard on that rear wheel and it broke the shock tower and bent the shock, the other was in a car that spun out and hit a lamp post sideways.
If you look at the design of the shock tower it was designed to take all its force in an upward direction and not side ways. Under heavy acceleration, load, wheel spin or whatever the frame horn flexes, this causes the engine and trans to move, this movement can introduce shudder in the driveline and wheel hop.

How I think a 3 bar works,
So if you look at the rear of an IRS beetle with a 3 bar kafer cup brace you have the two bars going from the frame horns up and outwards to the shock towers, if there is any load that would have caused movement either up or down in the frame horn this load will transfer to the shock tower.
If the load is trying to push the frame horns up then the load will travel up in to the shock towers, as we know the shock towers are designed to take load in the upwards, the problem begins now the shock tower was not designed to take this sort of load in an upwards and out wards direction, in theory the distance between the two towers would increase with the load and allow the frame horns to move under load and the opposite would happen if the frame horns moved down the shock towers would get closer to each other and the frame horns would still move.
That is where the third bar comes in, this bar is the key to the system, it stops the shock towers from trying to clap hands or jump out from under the fenders.
I would ague that the shock towers would support the weight of the car with coilovers and modest spring rates, however if the shock was applying any side load (across the vehicle not fore and aft) to the shock tower then you would need to think about some sort of brace, If I was going to make a brace to do this I would go from (looking at the rear of the car) both top shock towers to the centre of the torsion bar housing seeing as this isn’t possible due to that pesky transmission. I would the top of the right hand shock tower across to the point where the left hand shock tower is attached to the torsion bar housing and of course the same for the other side, of course this would be used with the 3 bar set up as well.

That’s enough dribble from me, I’m just playing devils advocate or is that being a prick??

Scott

[zeroaxe]

Originally Posted by Mikey

If you're going with the stock torsion suspension and just want to eleminate 'wheel hop' and stiffen the rear suspension, go with the 3 bar.

Ok then. For now I am going stock IRS suspension in the rear. SO I will stick with my 3 bar set-up. However, I will make it in such a way that it can be 'converted' to 5 bar later if needed. :agree: