Fill all the voids in the pillars, sills, frame rails, crossmembers, etc, with two part structural eurathane foam.

This is a very labor intensive and messy job, it took me many hours on the phone and online to find what I wanted to use then get it sourced and ordered, cost is around $350 with an application gun and shipping.

There are some places we cannot fill with foam for various reasons so we are prepping them ringht now for seam welding, the trick is to weld every other inch for best results, some I have seen weld every other half inch.

In those areas and others we are removing all the factory caulking so we can weld or just remove the weight.

Obsessive? Of course, if you plan on building the fastest(all around, not some dyno queen) tC with a world class audio system on board you have to go to extreme measures


This is just one of several ways to acheive the desired results, full cages work well also and can be combined with seam welding but I have never seen a car done with those and structural foam. (there are several types of foams considered structural, by some standards the foam is so dense and rigid it only expands 30%, that would end up weighing far more than a cage and costing thousands in materials, not a good option to do a whole car with)

Rick

 

are you taking pics of the progess? i remember seeing the matrix on matrix owners, so i am interested in the progress of the tC. i don't think people realize how serious you are about this stuff

 

Pics are being taken, not going to post alot of them though as they are mainly for a build log for future plans we have;)

I will post a few of course

Right now we are busting our butts scrapping all the factory caulking inside the car to reduce weight is just part of the reason, the rest is to get things ready to seam weld.

Even though we are filling all the primary structural members with strutural foam we are welding all the readily available seams we can get to inside the car, quite a bit more than we planned when I made the first post on this thread.

Not sure if we are going to make out scheduled show 400 miles south of here on Saturday, not looking to promising now, keep adding more to the work load, lol!

Rick

 

damn, your going to have the nicest tC out there. Cant wait till you guys cut off the glass roof.

 

Thanks, we are trying but not a showboat at all, this is a performance car first and formost, it probably will never set foot on a trailer

The roof can be unbolted and removed in one piece!!

Rick

 

good man. remember to post the pics

are you doing any chassis bracing?

 

Luckily in stock form the chassis has alot of small braces and a couple of real beafy ones like under the rear seat. The reason we are lucky is by SCCA autocross rules in Street Mod class where we will race against highly moded M3's and WRX's we can only add braces running for and aft, not across or cross braces We will add a couple of the ones we can but only a few places have any need for them.

Seam welding and filling the cavities is the a great way to work around the rules and legal

In time we will deffinately do a legal roll bar but now considering as full a Chromolly cage as we can live with, which is legal and the four differnent mods together would result in an insanely stiff chassis

As a minimum we have to do a proper roll bar just to be able to run track days as it is a given the car will be far faster than is allowed without one.

Rick

 

wow i can't wait to see how this looks

 

i know this is probably a dumb question... but would the warranty on the car be voided if you replaced the glass tops with a solid metal roof and one sunroof

 

No, as long as the parts did not cause any warranty related problems, which would be about impossible other than a gasket leak, no worries

We are finding the seam welding far more difficult than in other cars we have done, so much so I took a break from it.

The factory undercoating under the car, we are just doing the interior seams for now, and seam caulk catches on fire easy and the gases mess up the welding gas, or something similar. I have to constantly adjust my welder, get a great bead then a crappy one, very frustrating to say the least.

We finally recieved out "pillar foam" today, $300 and I think I need to double the order I will do some of the areas then decide but this is going to be rather costly.

Rick

 

Rick, I'm interested in learning more about the two part structural urethane foam in this application. Do you know of any online resources that you could point me to?

I am a budding obsessionist

 

Very little real help, have used it a few years ago for audio reasons, reminded me in the current issue of SSC but they one they mention I could not find even from the manf.

I did not bookmark any specific sites but SEM is the only one I found to have what appeared to be the best product(actaully listed as rigid and strutural instead of just acoustical value.

SEM 39997 http://www.sem.ws/msds_tech_sheet.php

You have to really dig around the site to find it.

I did not find much of real value and I searched for many hours, just try to find structural foam, pillar foam, etc.

Wish I could help more.

Rick