Help with Saturn Chassis Back End

[andysredmini]

Im struggling to work out the rear end of my saturn MX5 based chassis.
I have uploaded a drawing on my blog http://2.bp.blogspot.com/-_mpP1kf8gv.../s1600/BE2.PNG of the back end and will hopefully try and explain what i mean.
I cut d11, d12 & 13 to the new sizes and tried to fit them in place as show in the guide but it doesn't work out. It appears that d11 should be cut as original and fitted in the original location but the guide has d12 labeled as d11. Looking at d12 and 13 cut from the guide they don't fit where the existing d12 & 13 fit. the angles shown are the wrong way and according to the drawing i have done are the wrong angle on 1 end.

On the drawing it also shows that d11 (12 on the drawing) doesn't follow the line of plate cp7 on the shock / roll bar mount assembly. should it follow the angle? it still doesn't follow it if i sit it on the corner of the tube and not the diff plates as show.

I also couldn't find a drawing of rp1 & rp2 but i think they are listed as grp1 & grp2 in the cutting list at the back.

Sorry if this doesn't make sense. i have confused myself trying to work it out and more so trying to writing it down.

If anyone could take a look at the dimensions on the drawing on my blog and offer any advice it would be gratefully received.

Many thanks

Andy

[skov]

I think it depends on whether you're planning to use the Saturn (or is it NTS now?) GRP rear tub, or an ali rear tub.

RP1 and RP2 are only fitted if you are going for an ali tub.
Whereas GRP1 and GRP2 are used if you're going for a GRP tub.

I made my the top diagonals follow CP7 (but it might be better to trim CP7 to make it follow the diagonals?)
You can just about see the way I've done here:

https://lh4.googleusercontent.com/-E...0/S5033022.JPG

[andysredmini]

Good point on the grp1/2 referring to the rear end used
I'm going to be using a grp so ill use the grp tubes.

does your d12 sit on top of the dif plate or on the corner?

Andy

[vmax1974]

D12 does indeed sit on top

[andysredmini]

that makes more sense thinking about it. Ill have another look at the pieces later.
Trouble is when drawing it is that the easiest way is to use a frame generator, only a sketch is drawn and tube assigned to the sketch lines ( see second pic down) http://bamaroadster.blogspot.com/201...r-chassis.html.
These are then trimmed and mitered to suit. this leads to problems when overall dimensions are not easy to work out or just tube lengths are given.
but it does make things easy to change just by inputting a new dimension to change the position of the line.

[skov]

Like vmax says - it sits on top of the diff plate.

Little tip - it's easier to drill the holes in the diff plates before you weld in D12.