A/C doesn't fit on MKIV

[hrosenthal]

After following the instructions very carefully, and using http://www.kitcarmag.com/techarticles/142_0501_quality_roadsters_hvac_system_install/photo_01.html as a guide, I realized that the MKIV has a vertical pipe that interferes with the interior portion of the A/C unit. The only option I see is to cut the pipe, which I am afraid will compromise the integrity of the structure. Any suggestions???19429

[carlewms]

Several posts on this one on the other forum as I recall. I spoke to Whitby on Monday and they mentioned the need to relocate the support on the Mk 4. I am going to install but have not purchased the unit yet. I do think just removing the support would hurt the integrity of the dash support. I see a couple of options:

1. Move the support closer to the drivers side by:
a. Welding in a new square tube piece; or
b. Fabricating a new square tube with tabs that could be riveted to the dash frame at the top and the 2 by 2 frame at the bottom (this would not be as strong as the welding option but more doable if you do not have access to a welder);

2. Instead of going diagonally between the dash frame support to the 2 by 2 frame, go horizontally to the upper firewall support frame. This is clearly more of a compromise and while it does offer some support it is not the optimal method. You can go with the weld or rivet option.

I also plan on reinforcing the firewall where the unit attaches.

Carl

[hrosenthal]

S
1. Move the support closer to the drivers side by:
a. Welding in a new square tube piece; or
b. Fabricating a new square tube with tabs that could be riveted to the dash frame at the top and the 2 by 2 frame at the bottom (this would not be as strong as the welding option but more doable if you do not have access to a welder);

I don't know anything about welding, which is one of the selling poins of FFR. How would I fabricate a 2x2 square tube with tabs? I'm thinking of buying some square tubing at Home Depot, and cutting to size with an extra 3/4" on each end, then cutting 3 of the 4 sides to create tabs -- does that sound reasonable?

[CraigS]

The previous models didn't have that tube in that location so it is certainly possible to just cut it out and forget it. OTOH, I think your plan w/ the HD tubing will be fine, especially if you go w/ two tubes. BTW, that tube is either 3/4x3/4 or possibly 1x1, not 2x2. You would need to plan gauge location before figuring tube location. I would take your piece of overlength tubing and cut down at each corner maybe 3/4 inch. Bend 3 of the tabs down to approx. 90 degrees. The one left unbent could go up the back side of the dash hoop tube. The one opposite that could be cut off so the smooth dash side surface of the hoop isn't compromised. this will take a little bit of trial and error but the HD square tubing is usually 1/16 wall thickness so it's easy to work with.

[carlewms]

I think you got it!

Unless you want the larger 2 x 2 I would stick to the smaller size which is currently used in the kit.

Here is a photo of the setup in my Mk 4 BEFORE modification.

19443

To give you a better feel for it I ran out to the garage and using aluminum square tube I mocked up a a very rough solution to illustrate the idea. The final should butt up to the dash support without any gaps.

The first shows the part and the second shows it fitting on the car.

19444

19445

You could put a rivet in each tab mounting it to the 2x2 square frame on the front and the dash hoop on the bottom.

After fabricating the piece I would change the lower tab to be horizontal (in other words on the front of the new square tube) so it does not interfere with front of the aluminum above the transmission tunnel.

The position of the tabs may be dictated by room to get in a drill, rivet gun, or wrench (if you went with a rivnut) to drill the holes or mount the piece since you already have the firewall mounted.

Working with aluminum will be a lot easier but will not be as strong as using steel square tube.

Carl

[carlewms]

Another source on AC installation is Greg M's excellent photo log at

http://www.worldisround.com/articles/123897/photo63.html.

While not on a Mk 4, the ideas and craftsmanship are superb. In his case he added more support on the firewall as well as support from the dash hoop to the firewall.

Carl

[Mark Dougherty]

cut that tube out of there and don't look back. you will never miss it.
yes I have done this before and there are no ill effects from it.

[hrosenthal]

Thanks for the feedback

[GWL]

I cut mine out and as others have said, I will not look back.

The only problem I foresee will be getting the defrost hooked up. Don't really understand how or where to put the part they give you for the defrost.

George

[2FAST4U]

The tube simply supports the hoop from collapsing under weight. It can be removed. The original cars used round tubes that went from the hoop to the chassis.

http://oscaleguys.com/sites/Models/Cars/cobra.html

[carlewms]

Based on this feedback, it sounds the thing then is to cut it and forget it. I am going to focus on making sure the firewall is strong enough to support the unit.

While on that point what did you all do if anything to reinforce the firewall?

Thanks, Carl