Swing Axle vs IRS Technical Topic

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chunkynichols
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Re: Swing Axle vs IRS Technical Topic

Post by chunkynichols »

Can you IRS or Sa to a stock gear box?

bobley
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Re: Swing Axle vs IRS Technical Topic

Post by bobley »

You cant use a stock box as is. You need to pull it apart and flip the differential over otherwise you'd have 4 reverse gears.

A stock box with a flipped diff would then be usable in an SA setup. To use it in an IRS setup would require changing the side plates and diff components. It would be much easier to use a stock beetle IRS box and switch the nose of the stock box onto it.

chunkynichols
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Re: Swing Axle vs IRS Technical Topic

Post by chunkynichols »

To do the IRS conversion with a beetle box does the nose of the stock box fit straight onto the beetle box or does it require adaptors? Is there an age of beetle that has the right gearbox ie anything before 1970?

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Re: Swing Axle vs IRS Technical Topic

Post by moler »

chunkynichols wrote:To do the IRS conversion with a beetle box does the nose of the stock box fit straight onto the beetle box or does it require adaptors? Is there an age of beetle that has the right gearbox ie anything before 1970?
The stock Split nose cone fits straight on to a Bug box.

It's not an age of Beetle, but the type, you need to be looking at boxes from 1302's, 1303's, and late type3's.

:)

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Surfbus
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Re: Swing Axle vs IRS Technical Topic

Post by Surfbus »

Can anyone tell me the difference in accelleration and top speed for rpm with the different gearboxes?

ie 4.375, 4.125, 3.875 ?

I have no idea what these mean. I currently run a 1641cc bus but at some point will go bigger.

Think I currently have a 1500 SA box but its started jumping out of 4th gear cruising at 3000 revs so its time for a used replacement but didnt know what changes a different box would make.

Cheers.

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raiz
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Re: Swing Axle vs IRS Technical Topic

Post by raiz »

Surfbus wrote:Can anyone tell me the difference in accelleration and top speed for rpm with the different gearboxes?

ie 4.375, 4.125, 3.875 ?

I have no idea what these mean. I currently run a 1641cc bus but at some point will go bigger.

Think I currently have a 1500 SA box but its started jumping out of 4th gear cruising at 3000 revs so its time for a used replacement but didnt know what changes a different box would make.

Cheers.
Whats your rim and tyre size too :wink:
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Surfbus
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Re: Swing Axle vs IRS Technical Topic

Post by Surfbus »

Tyres are currently 175x65x15inch
Was thinking of putting some 185x60x15inch on as I have 2 new yokahamas in that size.

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Re: Swing Axle vs IRS Technical Topic

Post by j0hn »

Thought I'd post up here rather than start a new thread in the main Tech forum.....

I'm after a bit of advice needed regarding gearbox choice for the bus.

I've managed to gather up most bits for a stright axle conversion now - need bearing caps, and most importantly a gearbox! :?

I'm running a 2007cc Berg motor so got plenty of grunt for pushing along. Tyres are 175x65x15.

I want a box that'll cruise away nicely on the motorway at 65/70 without screaming the engine.

1500 boxes seem to be recommended (or the nice rancho that's on VZi ;) ) but obviously cost more, and they all seem to be miles away from the North East :roll:

I've seen a cheapish 1300 box out of a mexican '82 bug with 40k on it - but it is local and under a ton. Would this be too low geared for my needs?

Or one final option - could I Frankenstein it a bit and put the diff out the the old gearbox into the 1300 'box for a better ratio ('67 large nut RGBs)? If so how easy is this?

Anyone got experience with running one or the other?

Cheers,

j0hn

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Re: Swing Axle vs IRS Technical Topic

Post by Splittist »

Well I've just managed to buy a 1500SA gearbox and axles etc only to come across a '64 type 3 gearbox and axles a week later ... so I've now got a spare gearbox - all polished up like a tart! Anyone interested, I want £150 for it.

But that's not the reason I'm posting. I'm looking at the prices of the SA lowering kits and they seem disproportionately expensive, you usually pay the same price in pounds as they are in dollars and you get accustomed to that, but US price for the bus boys kit is $350-ish, so why the **** do we have to pay £460 odd for them in Blighty?

How easy is it to modify the axle sleeves yourself? What are the mods that the likes of Bus boys are doing to their axle sleeves? The spring plate rework look easy enough, that could be done in a machine shop. And then what do you need, a few gaskets etc?

Maybe I'm just being tight fisted, but if one of you bright sparks could point me in the right direction, it would be appreciated. :D
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j0hn
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Re: Swing Axle vs IRS Technical Topic

Post by j0hn »

Could be interested in your gearbox. :)

I believe the BusBoys kits use the "correct" length tubes - i.e no bodged offset spring plates.

You need the end castings from a set of short tubes, and a set of modified length tubes - you need two sets of tubes to make these. Overall length should be 21 7/8" for the tubes.

I was planning on doing this myself and have collected a set of short tubes and also some long end casting tubes - but in a similar twist of fate as your gearbox - shortly after I managed to get hold of a ready done set :wink:

Perhaps we could come to some sort of arrangement?

PM me so we don't clutter up a tech thread :)

Cheers,

John

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raiz
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Re: Swing Axle vs IRS Technical Topic

Post by raiz »

So i'm going Porsche IRS ive got bug irs box and will be narrowing torsion on Porsche arms...

Its the drive shafts im unsure on?

i have Porsche 944 shafts can i use these?
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Splittist
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Re: Swing Axle vs IRS Technical Topic

Post by Splittist »

So it's all kinda falling into place ... one thing that I'm still wondrin about is spring plates. Being the skinflint that I am, I'm not paying for a bus boys kit when all of this stuff can be sourced.

So can someone tell me what spring plates are suitable, are we just talking late standard type 1 swingaxle? ie without the sticky out bit.

thanx :wink:

OK - I've been advised that I can use my bus spring plates modified to match the corresponding bolt pattern on the short end castings.
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Chief_Wiggum
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Re: Swing Axle vs IRS Technical Topic

Post by Chief_Wiggum »

I have a straight axle setup on my bus, with a 1500 beetle gearbox. The axles are perfectly horizontal (2 splines down I think) at the moment, so can't really go higher or lower without messing up the camber (or affecting oil levels at the bearings)

I've gone a bit lower than I intended though, as I'm always scraping by exhaust and can't easily get the wheels on or off. Considering switching to a Boxwagen IRS setup because presumably this means I can run a couple of inches higher without messing up camber? Or am I just kidding myself? I could just get bigger tyres!

BTW- definitely not going back to RGB's - driving on motorways is so much nicer now.

Thanks

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Re: Swing Axle vs IRS Technical Topic

Post by jambo »

Evening

lookin to IRS my 67 bus, which would be the best kit to go for ? also what final drive would be good ? would like the usual be able to cruse at 70 i am running a 1776 at the mo but may go bigger next year, running 15 wide 5's 185 55's well that what the wheels came with.

any ideas ?

many thanks Jambo
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Re: Swing Axle vs IRS Technical Topic

Post by jambo »

vwJim wrote:Yes, seen that on a few buses, and will be using that system soon on another.

Like it as there is camber adjustment that you can dial in once its all fitted.
VW Jim did you fit one of the those kits in the end ? if so would you mine me askin if it was any good ?

Cheers Jambo

Oh i take it you were refiring to the box wagon kit ?
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