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Chassis mods for de-dion bar
Avoneer - 18/12/04 at 10:47 PM

Hi guys,
As I now have my standard book chassis and will be buying a GTS de-dion in the new year and have to modify the rear end of the chassis.
Can I just weld the new lower bars almost next to the ones that are there at the mment and them cut the old ones out - that way making the whole job a lot easier.
If so, shall I weld the new bars on the inside or the outside of the ones currently there?
Hope that makes sense - will try and get a better explanation pic...
Pat...


Avoneer - 18/12/04 at 11:01 PM

Pic courtesy of uncle ron. Rescued attachment 1.jpg
Rescued attachment 1.jpg


undecided - 19/12/04 at 08:27 AM

Best way is to tack tubes to hold the chassis in place then cut original tubes out and weld new ones in....DON'T just cut a rail out hoping all will be well........it will and does move!.......sure new lower rail is set 100mm in from each end to allow clearance for De-Dion end casing but you had better ask GTS to be on safe side.


Avoneer - 19/12/04 at 09:46 AM

I wasn't gong to cut the old one out without the new one being in place.
Might be better to tack the new bars on the inside of the ones already there. Just trying to save myself having to jig the whole end.
Cheers,
Pat...


Mr G - 19/12/04 at 12:58 PM

I can't see why you need to cut the chassis around?

You need to rose joint one end of the panhard rod so it misses a part of the chassis but thats about it on the de-dion we have (not gts)

Unless the GTS de-dion ends are massive brutes then I cant see why it won't clear a book chassis.

Cheers


G

EDIT:

The part you mention cutting out.

Best to draw a piccy

De-dion Mod
De-dion Mod



[Edited on 19/12/04 by Mr G]


Toolbox_USA - 20/12/04 at 04:20 AM

GTS ends are pretty healthy in size.

I think Darren has the plans readily available. You may want to check to see if he can email it to you.

I took a few quick shots for you. (large)

My photo archive


Mr G - 20/12/04 at 11:12 AM

Nice Avatar......


Avoneer - 20/12/04 at 12:06 PM

Cheers.
I'm guessing that it won't be detremental for me to weld the new "lower" bars on the inside of the two already there and then cut the old ones out.
Cheers,
Pat...


Toolbox_USA - 20/12/04 at 12:15 PM

My friend Larry did that avatar for me...

I think he has Locost-envy!

Had to keep it.



Avoneer - if you need a specific picture or something, let me know. My chassis is a GTS one, though.


dozracing - 20/12/04 at 03:39 PM

The chassis mods are basically confined to what is required for droop clearance on the dedion axle.

Thats why you end up with a flat section, where in the book it is angled.

There is a drawing for download on the website. Go to the DeDion section and click the first PDF link for a drawing.


Avoneer - 20/12/04 at 04:34 PM

Thanks Darren - I have the diagram and trying to determine how critical the two horizontal bars (one on each side) are if they end up 1 inch further in towards the diff as a pose to where they should be mounted?
I can't see it being a problem.
Thanks,
Pat...


dozracing - 20/12/04 at 05:41 PM

I can't see it being a problem.

Great thing with the DeDion, is all the loads save for the panhard rod go into the seat back and side rails of the chassis, so the back part of the chassis is sort of along for the ride in many ways.

Kind regards,

Darren


Avoneer - 20/12/04 at 06:25 PM

Thanks Daz,
Will do it with those bars ever so slightly closer now.
Thinking about it, IRS chassis' bottom bars are even narrower and like you say with the de-dion - the back is just along for the ride and the 4 other diagonal uprights at the back should hold it all together.
This will save me loads of work as I can weld the new mods in and then cut the old bars out - no jigging (unless it's cold).
Cheers,
Pat...


ned - 20/12/04 at 07:14 PM

check my photo archive for pics of how i did mine..

Ned.


Avoneer - 20/12/04 at 08:20 PM

Hi Ned,
Yep, have looked at your pics many times!
I know how the bar is meant to go and where and at what angle etc, but as I have a book chassis and need to modify the bottom bars, I want to weld the ones in like yours on the inside of the bars that are already there and then cut the bars that are already there out if you see what I mean - just trying to determine if it won't effect anything else if the two bars that I will weld in (like yours) are a bit close rtogether than they should be.
Cheers everyone so far...
Pat...


ned - 21/12/04 at 09:43 AM

I know i may be criticised for saying this, but i did it wrong, i cut out one side, then welded the new one in place, then cut out the other side and did the same. As Daaren rightly says with the dedion the rear of the car ceases to do much structurely as the loads are taken but the dif at the rear of the tranny tunnel so i wasn't bothered is one tube had moved a couple of mm's, it's only purpose is to hold the fuel tank in and have the rear panel knocked round it....

Ned.

[Edited on 21/12/04 by ned]


Avoneer - 21/12/04 at 01:11 PM

Sorted then.
My bars will be slightly close than yours - so there!
Thanks everyone for your help and advice.
Pat...