RCR 40 Spider Position on Chassis - Guidance Appreciated

[Jason Ferraro]

I fear that my whole body is too far back on the chassis. I have pushed the rockers to the rear (as recommended) to get front wheel clearance etc. but I think I have gone too far. The lower edge of my window seems further back compared to other photos on the forum.

Can another RCR owner tell me how far back the leading face on the spider B pillar (Marked A!) is from the front edge of the tank (Marked B)?

My dimension is 1,093mm or 43". Is this too far?

As a side note, do all RCR owners find they need to weld a bracket to the chassis to stabilise the bulkhead on the tank? There are holes in the firewall but no bracket (cannot bolt the bracket to the chassis or it will pierce the tank!).<!-- google_ad_section_end -->

 

[Randy V]

Jason - you may want to see this thread;

http://www.gt40s.com/forum/rcr-forum-rcr40-rcr70-p4-mkiv/24993-rcr-body-fitting-hints.html

And also look over Eglitom's build thread. Lots of good information...

 

[EGLITOM]

Jason

one way to find the correct position of your windscreen spider frame ist via the front clip rear edge.
Althoug i found my position as described in my built log, one of the results of a perfect positioning seem to be also the final location of the fuel caps. If i put them center in the front clip cut out with a equal gap all around and the cap opening without touching the clip, the precut hole in the chassis is also dead center within the fuel cap. Than try to achieve a gap fo app 4 mm between the clip and your windscreen base.

I will give you the requested dimension on from my car tomorrow.

please forward your email adress to me and i also send you a picture on the firewall bracket.

TOM

 

[Jason Ferraro]

Thanks for the help guys. Would appreciate the dimension Tom. my email is [email protected]

Thanks for the thread link Bigfoot, missed that one. Looks like a few adding that "reaching" bracket for the firewall stabilisation. I will need to weld one as for Australian ADR side impact will require the firewall to be very rigid (supoports the striker).

Gather you guys also have your front lower suspension arm full forward or at most with one washer fitted at the front?

Also has anyone heard of anyone "shaving" the vertical sides of the front window down about 3-4mm to fit within the spider better? Mine is tight on the sides. I was told by another GT40 manufacturer that this can be done sometimes by a windscreen fitter.

 

[Randy V]

Thanks for the help guys. Would appreciate the dimension Tom. my email is [email protected]

Thanks for the thread link Bigfoot, missed that one. Looks like a few adding that "reaching" bracket for the firewall stabilisation. I will need to weld one as for Australian ADR side impact will require the firewall to be very rigid (supoports the striker).

Gather you guys also have your front lower suspension arm full forward or at most with one washer fitted at the front?

Also has anyone heard of anyone "shaving" the vertical sides of the front window down about 3-4mm to fit within the spider better? Mine is tight on the sides. I was told by another GT40 manufacturer that this can be done sometimes by a windscreen fitter.

My front lower control arms are pushed as far forward as they can go. The uppers as far back as they can go.

Shaving the windshield - I need to make a couple of adjustments on mine.
As you are seated in the car - the lower right side needs to be shaved a bit.
Once that is done - the rest of the windshield fits but a bit tight.. Clearance? I would say about 1/16" of an inch with the windshield spaced out from the spider about 1/8"..

How to shave it?

Good question.. I have heard of some people using a belt sander. Me - I'm not that adventuresome.
Unless someone has a better way - I will most probably use wet/dry sand paper starting with 240 grit and finish up with 400 grit.

 

[Jack]

Just a silly question guy's, but wouldn't it be easier to add reinforcement to the fiberglass pillars and spyder if necessary and grind the 'glass back to obtain
your best fit? I would attempt that before having to purchase a windscreen because I screwed it up or broke it.

 

[Craig White]

Jason, on the Aussie delivered RCR-40 kits we use a frame and nylon straps to support the rear clip during the alignment process. Do you have any handy roof beams etc above the GT. Makes it a lot easier as you can hold the rear clip in exactly the position you want and then tighten the rear mounts. We actually hold it a touch higher than ideal as when it is bolted it settles a little as the weight is applied to the mounts.

We mount the body alignment pins first.

Then we start with rocker position(lower sill) and move them back so they both sit 52mm measured from the rear of the chassis. One will require a little trimming on the front/inside to move back that far. We don't restrict the in and out movement of the rockers or the forward and backward movement until further in the alignment process.

We then mount the rear clip in the position we think it should be.

We then mount the front clip in the position we think it should be.

We then fit the spider, then juggle the spider, rear clip, front clip and rocker covers until we get very good alignment. It's during this process where we tape down the rocker covers. We keep an eye on chassis location of the body.

We also keep fitting the windscreen to the spider during the process. We haven't had to shave any windscreens for fitment. But it does make a big difference to windscreen fitment to the actual position of the spider. You can tweak the spider into the correct shape if required. It's also easy to twist the spider by accident and that can cause a lot of problems.

We also use a support under the front of the spider as it tends to droop a little until the windscreen is fitted.

Also make sure the bulkhead isn't interfering with the spider fitment. Also make sure the bulkhead is straight. Sometimes it can twist forward at the sides where it presses against the fuel tanks.

With the bulkhead we just Sikaflex it to the fuel tanks. You can use something like an angle braket and Sikalex for extra strength. For ADR compliance you will need to tie those door strikers back to the roll cage mounting points. Same goes for your upper seat belt mounts, attach the retractor off the mount plate for the main hoop and the pivot off the upper roll cage.

There are a few different approaches you can use for body fitment. There are some really good posts linked above for fitment, but use the process that works best for you.

 

[Jason Ferraro]

Thanks guys for the comments, some very helpful info. Craig my right rocker is 52mm and left more like 60. Shifting the left forward will rotate the front clip which will help. Thanks for that dimension, VERY helpful.

Any pictures of the door latch and belt anchors to the chassis would be great as I will need to do similar for compliance.

Molleur, considered what you say but it could lead to the A-pillar having a varied width that would look strange. I was told they trim the glass with a grinder and special wheel!

With the Easter break I hope to get some time to try all the good advise given, thanks to all.

 

[Johan]

What does the car look like overall ? I have never seen one. Sounds cool.

 

[Craig White]

What does the car look like overall ? I have never seen one. Sounds cool.

Johan, I assume you think we are talking about a Spyder version(chop top). We are actually just talking about the spider, the roof/cockpit body section of the RCR-40. Hope that helps.

 

[Johan]

Oh, I see. Thanks !

 

[Craig White]

No problem. I can see that it would be easy to make your assumption.

Hopefully Jason is progressing well over the long weekend.