Narrowing IRS the easy way?
 

Hi, just need to bounce some ideas off people. I need to loose about an inch from the back of my bug so the tyres will not foul the arches.

I have IRS and have been looking about an easy(?) way of doing it. I see that if i remove the 1/2" spacer that sits between the bearing and the flange it would give me approx 1/2" inset however, the grooves/splines on the output shaft cease at the point of the spacer. If these were to be extended in 1/2" this would allow the hub to be moved in. Would this generate a weakness in the output shaft. Is it likely to cause any other issues?

On top of this i have thought about machining the back of the hub by 1/2" to give more room, this is giving less material on the hub and would it withstand 200+ bhp!?

The easier alternative is to switch the wheels, but i like the 7x16" Fuchs.

Thoughts would be appreciated

you could always buy a set of narrowed trailing arms from aircooled.net.

they sell custom arms that are 1.5" narrower then stock for $400 a pair.

If you go that route, then just go though blind chicken racing. They're the supplier for ac.net. Also they're a little cheaper. They might take a little longer than ac.net because ac.net has them in stock, but to save a few bucks it might be worth it.

blind chicken racing

I just checked, BCR is $350 a pair compared to ac.net's $400.

Wow 1.5" may be a bit too much and i could run into issues or the tyre rubbing on the inside. I shall certainly give it a thought though as it looks like an easy bolt up option although I would have to source correct length drive shafts.
I have to admit though the arms look damn ugly!

EASY - Will I wouldn't say that about it.

The Spring plates on the NTA's that Blind Chicken Racing makes have been relocated to the inside of the torsion spring plate for added tire clearance. As to having to much clearance..., there is no such thing in my book.

If you have to much clearance (Tire under the fender to far), you can always put spacers under the lug nuts to center the tire between the body and spring plate. If it's outset to far (Tire sticking out from under the fender), your screwed. I drew a few pictures to keep my mind uncluttered and to stay somewhat focused.
Here's da'link http://community.webshots.com/album/526070220fpJhrZ
This info was posted with and to the thread: IRS Wide 5 Disc Brake options here on the forum.

As John at AC net says, don't forget the narrowed axles that you'll need in addition to the NTA's. Get these after you have everything together. As to locating axles for your needs: http://www.swayaway.com.
Two axles made to length, $181.00, this was two years ago. Again Call them.


Trivia bonus answer:
If you know the trick of finding out axle length, this well just bore you. For those who don't, cut 3" out of your axle, bridge the axle with a piece of angle iron a few inches longer on ea. side of your axle cut. Hose clamp this on the axle, rock your suspension though its full motion range with the tire not binding and you have the length. The axle should free float an 1/8" to a 3/16" when the wheel is at mind travel C/L to C/L of trans flange and stub axle. CARRRREEEfully remove the axle and measure it, get your credit card out and make that call.

I was thinking the same thing, if the narrowed trailing arms move your wheel in too much, just use spacers.

As for the axles. The type 3 automatics have an offset transmission, 1 short and 1 long axle. I thought that the short axle would work for the 1.5" narrow trailing arms. I doubt they'd be "custom" cut axles. When you go to put a Bus tranny in a bug you use the short axle out of a T-3 Auto. So I bet Sway-A-way makes the axle.

Another thought, since the trailing arm is 1.5" narrow-er. Couldn't you subtract 1.5" off the length of a stock axle? That would give you the lenght you need. (I'm not saying cut 1.5" off a stock axle.)

That's exactly how you figure out the length you need.


To install 7x16" Fuchs, you can do it with stock TAs and stock drums. A 205 tire will fit. I know a guy with a 75 IRS Beetle and 7x16s on it with stock TAs. I believe he uses 205/55s.

Flush=best

If you need to go an inch, im sure you can roll the lip on your fender flat. Also you can do the bearing case mod thats on the tech section on this forum. Also, depending on your rim size etc, u can always get a different tire.

for the fuchs, a 195/50 or 55 pulled would be nice.