Shortening the chassis

[LifeAsASuffix]

Getting ready to chop the pan, I've read everything I can find, searched every forum thread for advice and found most of the threads are old, and the pictures are long lost to antiquity.
I figured I would start my own thread on my process of shortening the chassis. I am still early in the process and have decided on a modified Z-Cut, and tried to lay it out in a manner that lines the pan and tunnel up as closely as possible.
I have layed out my cuts, but need to confirm measurements and make sure this is going to work.

I'm open to any advice anyone can share, or any links or pictures of their progress. I'm still a few weeks come actual cuts and welding due to a busy work schedule and weekend travel, so i have time for more research and learning.

[Dale M.]

This is way I do it and the way I see recommended the most... Lot simpler cuts... But if it gets you where you want to be its not wrong, just dont make it complicated..

As for measurement its what the body dictates... I would set body on chassis with front of body on "Nepolian Hat" and then see how much you have to remove to get rear of pan placed properly under rear of body... And average measurement is about 14.5 inches BUT it may vary according to your specific body design...

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
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All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[BL3Manx]

First step always, place the body on the chassis exactly how/where you want it to sit in front. Then make marks on the chassis rail right at the rear corners of the body. Measure from the mark to the rear corners of the chassis. That will be the exact dimension of the section you want to remove from the chassis. Don't use an approximate dimension, find out exactly the length so that the body will fit the shortened chassis perfectly. The length of body tubs varies quite a bit

The rear cross rail is 1.5" wide, so make another mark 1.5" forward of the first marks you made on the outer rails. That's where the forward cuts should be. The rear cuts should be right where the side rails meet the rear cross rails.

This system can be used with the angle cut Dale shows. An advantage is that the welded joint in the outer rail will be right at the corner, where the side rail meets already meets the rear cross rail. You can make a strong/smooth weld at the point just like the factory did. That way you will avoid having a butt welded joint in the channel under the body somewhere midway along the outer rails(which usually winds up a bit crooked). Also the bolt hole spacing along the edge of the chassis will be unchanged.

I actually cut the tunnel a bit long and then grind off the face of the cut until the two outer rails just kiss the rear cross rail, basically using the outer rails as a gauge. That helps keep the chassis straight(and the exact correct length for your body).

[Dale M.]

And just becasue posting in forum may be old does not mean they are not still valid.... Not much "changes" in buggy construction although each build is unique...

Might also consider viewing several videos before you cut to get idea whats involved...

https://www.youtube.com/results?search_query=shorten+vw+chassis

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[LifeAsASuffix]

Thanks for all the input. I've looked at a lot of the options on shortening the pan, and watched most of the videos online. Thanks for sharing them. One common thread I'm noticing on the chevron cut is the patchwork to make it fit at the end, especially at the corners. There doesn't seem to be a consensus on a best method, it looks like that angle cut technique is the good-enough and easy enough method. Most of the information I'm reading says to take special care with the guide tubes inside the tunnel, most of the people posting instructions seem to lob them off, and never mention it again.
I was researching the Z-Cut method mentioned here:
https://www.thesamba.com/vw/forum/viewtopic.php?t=...p;start=20
And there's a detailed instruction manual from 1969 hosted here:
http://www.tjkustoms.com/Dune-Buggy/Manuals/PanShortening.pdf
Though this looks more complicated than the chevron cut, I'm hopeful it will have a more sturdy outcome.
Thanks for the advice on placing the body on the napoleons hat and measuring from there. My measurement came out between 14.25-14.5" from the body to the back of the chassis. I'm planning on cutting 14.25" out of the chassis and error on the side of a little most space.
On my note about the old threads; I wasn't attempting to imply their age affected relevancy. My statement was more about the information in the thread is lost. Most of them reference websites and pictures that are long gone.
Keep the advice coming, I know there are plenty of people on here who have been at this longer than I've been alive.

[Dale M.]

About the tubes... Clutch and throttle need to be broken loose from frame but not cut off.... For e-brake, cut top off tunnel by doing cut from one side over the top to bottom of other side... Removing top piece but leaving bottom in tact... Note how e-brake tube are connected to bracket... You are going to duplicate this by cutting tubes about 6 inches from rear cut and and remove section between cut and e-brake bracket...When you bring the two half together you are going to cut to length and it the 6 inch stub into the existing e-brake bracket...

DO NO use reciprocation saw and just rip through pan, use 4.5 inch grinder with cutoff wheel and just cut deep enough to cut through pan material and not cut any internal tubes...

Clutch and throttle tube and fuel line will be just shoved out the back as you move rear section forward and cut to length later after pan is joined...

Also after initial weld on tunnel you may want to bridge the weld with stiffing strap maybe 2-3 inches wide cut from tunnel piece removed... Also same for tunnel bottom weld, bridge it with 3 inch wide stiffener... Note in my graphic of how welds were done, the stiffener over initial weld, its hard to see but its there... There is a lot of strain from some reason and tunnels tend to crack next to initial weld for some reason....Specially if car is in competition like auto cross...

Dale
_________________
“Fear The Government That Wants To Take Your Guns" - Thomas Jefferson.

"Kellison Sand Piper Roadster" For Street & Show.
"Joe Pody Sandrover" Buggy with 2180 for Autocross (Sold)
============================================================
All suggestions and advice are purely my own opinion. You are free to ignore them if you wish ...

[YDBD]

I agree with Dale, the buggy I have now is cut the same way and we've had it since '69....and passes inspection every year...
_________________
'56 pan Dune Buggy since '69
don't live in the past...but when I did:
'67 bug
'64 baja
'60 dune buggy
'73 Personenkraftwagen Type 182 "Thing"

[2bugtony]

im getting ready to cut my 73 chassy down too. Hope it runs straight down the road. my frame is not the same size where it will come back together. I guess that I will have to hammer it until it matches.

[Dale M.]

[mark tucker]

I wood do it like the mouse guy shows.with the exception of not but welding the tunnell. cut some off but leave enough for a 6" min over lap, then a few slices and bends, so it gos in and out side of it's self ,add some 3/8-1/2 " holes in the outer only portions neer the centers & ends of the inner flaps/pannels. add some holes for self taping screws so you can pull the panels up tight for welding AFTER you are sure it is all square and tacked. then full weld all the exposed edges and holes , remove screws and weld it togeather there too. BE SURE IT IS THE SIZE YOU WANT BEFORe WELDING!!!, then do the floors. my flors are slightly diferent than mickeys but any way to get it all fitting and blending togeather will work.( some people dont give a shit about weather any of it blends or not they just hammer the shit togeather and goober weld it. I have prints that came with my 356 for doing this nice and neetely when building your own chassis.
I dont know who built my chassie,some vw chassie builder up around wisconsin,mitchagain,indy, they guy I got the car from couldent remember. but it looks like factory. a very nice job .

if you just but weld it it's week, and....your gonna have to fill the gaps where it isant square.

[2bugtony]

Thanks for the x plan. I was thinking that would work but im glad that you say it works too. I'm getting ready to cut as soon as it cools down enough outside to do it. I'm going to do it just like Dale has said. butt weld then over lap with 2" OR 3" and let her roll. I've been worrying about getting it straight now going to pull the trigger