There may be a simple answer that I've over looked but this is how I brought the car I didn't do these modifications myself so is there any way adding disc breaks to the rear will decrease the rear track measurement? I always believed it would make it slightly wider... heres what I've measured,

Standard rear track 1378mm from vehicle standards, Standard wheels are et 40 I think? which makes mounting face to mounting face 1458mm
My rear track at the moment is 1450mm the wheels are et-15 that makes mounting face to face measurement 1420mm

1458 standard vs 1420mm disc brakes. So even if I'm out a few mm on measurements there is still a big difference
Any suggestions I can post some pics if it will help

Hi

My 1972 1302 owners book says that the rear track is 1362.

My 1303 had Type 3 rear drums, it measured 1405 drum face to drum face, I think you need to take the 40 ETx2 away from you rear track.

While you have your tape measure out, can you measure your wheelbase for me?

Steve

Interesting Steve... I just found a web site that says rear track is 1350mm so who knows what to go by... I might carry a tape measure around for awhile check all car parkings lots for 71 supers

I'm pretty sure you would add et 40 x2 when the offset is positive because positive offset wheels put more wheel inside.

Wheel base is 2430mm

Hi

The 1971 had 4 inch wheels, the 1972 had 4.5 inch wheels. I think the 1971 wheels were ET 40 and the 1972 were ET 41. That would make the rear track 10 mm wider on a 1972 model.

The Beetle wheels have more rim on the inside. They are positive offset, see photo

Very confusing.

I have an issue with my 1303 at the moment having too long a wheelbase, its 2450 mm, the book says it should be 2420 mm. I measured a stock bug on the weekend, it was 2440 mm

Steve

Track is the taken at the center of the tyre, so changes in rim width doesn't affect the track.

So Steve... with your 1971 ET40 and 1972 ET41 example, the track would have only changed by 2mm.

Heard about your wheelbase drama's - not good. The 2420 would only be at bog stock weight, caster, wheel align etc. - could it just be that you have extra caster on, effectively pushing the stubs forward ???

Also sitting lower on rear suspension would push rear axles backwards... increasing wheelbase by at least a few mm.

Hi Sides

Your right, now that I think about it.

I've fitted a stock front bar and reversed "offset caster bushes" and I still can only get it back to 2440, the only thing that I can do now is make plate to bolt to the chassis to push the lower control arms back more.

This the car that I measured at 2440 mm wheelbase on, I checked both sides.

Steve

Sides thats what i thought with offset because i just bought some wide wheels at et40 to keep my track the same, glad I did that right...

Steve going by your pic for positive offset you can see that you do need to add et40 each side to the track measurement to get out to the mounting face, but this still doesn't explain why my disc brakes are sitting inside what a standard drum brake super would be going by track measurements and offsets that I've been given.

If anyone has a complete stock standard 71 super it would be greatly appreciated if they could measure wheel track and offset for a comparison I mean confusion! cos thats what it most likely will do seems everyone has a different measurements, sure makes engineering hard when they want it precise.

The 5 original factory rims all dated 10/70 from my 71 super under the house are 15x4 et38.

The later 15x4.5 seem to be a mix, my Lbug ones are all et41, I have a couple of type 3 15x4.5 et46 there and might even be a few 15x4 et40 there as well.

Alot of people don't check and just assume all vw 4 lugs are the same.


Steve, we threw the tape on mine this morning, no surprises, 2440mm

Funny I was measuring mine the other day for somebody that is going to buy it now

'71 Super Chopped Convertible I have doesnt have stock rims, has Sunraisers and Sits a little higher then stock 1440mm

Where as the Stock standard 1971 Super I have with original rims and ride height in the rear is 1360mm

Big difference I thought

According to this website
http://www.1302super.com/page5.html 

it is supposed to be

Dimensions and weights
Wheelbase - 7' 11.75" | 2420mm
Front track - 4' 6.25" | 1379mm
Rear track - 4' 5.25" | 1350mm
Length - 13' 4.5" | 4080mm
Width - 5' 2.5" | 1585mm
Height - 4' 11.75" | 1500mm
Unladen weight - 1918lbs | 870kg
Convertible - 2028lbs | 920kg

The 4 lug wheel I have I get et 37 so thats close enough to yours Joel maybe to much paint on mine..

jeremyluke if your stock super is 1360 thats close enough to steves owners manual of 1362mm.

But that still makes 1362+ 76 et= 1438 mounting face to face. Mine is still 1420mm disc face to face which is less with a disc brake conversion

Is it possible the trailing arms have been moved or spaced in at the torsion bar? I'll post a pic someone might know if it looks modified

Just found out 1378mm from vehicle standards is actually the max track thats 1352mm (53.2 inches) same as the web site above plus the 26mm (1inch) that you are allowed to go over so thats 2 confirmations at 1352mm and 2 confirmations (1 car 1 Owners manual) that say 1362mm

Hi

I have seen people narrow rear trailing arms, maybe they have been narrowed on your car.

Thanks Joel, I don't know what's going on with this wheel base thing. Maybe VW took a guess, I have a 1303 manual from a 74 bug, it says that the wheelbase is 2400.

The 1974 1303 owners manual has theis track information.

Front track 1394 with 41 et wheels or 1407 with 5.5 inch 26 et wheels
Rear track 1349 with 41 et wheels or 1363 with 5.5 inch 26 et wheels, make no sense when compared to the track for a 1302 which uses the same rear suspension

Steve

Sorry about the thread hijack Dub_life

Hi

The wheelbase measurement is actually part of the blue slip process in NSW, you have your car engineered, then blue slipped which is like a more detailed rego check, part of the blue slip is the wheelbase measurement, then you pay your rego.

As soon as I went to the RTA with my car they whipped out a tape measure and told me I was 50 mm over, I then questioned them what it should be, they said 2400, I told them that they were using data from a standard bug, but I was still over 30 mm.

They told me an increase in wheelbase would make the car an ICV, an individually constructed vehicle, which is a whole new can of worms.

The 1302 & 1303 are supposed to have the same wheelbase of 2420 mm.

I have one German looker on the road, my sons bug which I spend a lot of money on, I use it as my daily.

Steve