Jasko

I'm in the process of having a weld in cage installed in by 964. The plan is to model the cage after the Cup Car cage, using 1.75 DOM. I'm picking up most of the info from the carreracupUSA site.

While I have the interior stripped out, I'm going to have some seam welding done. This is being done using the RS seam welding section in the factory manual. I've also looked a bit at Geoffrey's project, and tried to gain some information from his pictures.

Most of the factory manual is self explanatory. The only step that has confused me is Step 10 in the Body, Rear section -"Weld in bearing cup stiffener". To me, this is addressing the inner pickup point for the spring plate bearing. Can anyone shed some light on whether this means to weld in a reinforcing plate such as in the sway bar support, or to simply seam weld around the existing plate?

Any insight is appreciated. I'm off to the fabrication shop next week.

Here is a pic of the location from the carreracupusa:


Thanks
Dave

Geoffrey

You may want to consider your options on the roll cage because depending on your weight, you can run different bar diameter. I'd consult your race series rules. PCA is 1.5x.095 under 2500 in mild steel and 1.75x.095 or 1.5x.120 for over 2500lbs. If you are over 2500 and choose alloy steel it is 1.5x.095. You might consider "weighing your options"

I cannot remember what I did with step 10 and will have to look later. I also have the Porsche VIP car driven by Mika Hakkenin in for restoration back to the Tag Heur livey, so I can check that too.

Jasko

Geoffrey

Thanks. I looked up your old posts. You had a picture of the underside of the transmission tunnel in the process of seam welding. I could not make out what you had done at the inner pickup point as the image was cut at that area. Do you have anymore pics of your seam welding work that you could share? And any info (and pics) on the Tag Huer car would be appreciated!!!

I am looking at the cage options, and unfortunately, its going to be tough to get below 2500# this year as the budget only allows for a fiberglass hood and tail, and poly windows. I think that with glass doors, I could get close, but thats next year. That puts my in the 2500+ category. I guess I'll need to look at the cost for chromoly 1.5 x .095.

Just checked the NASA rules and they do not differentiate between mild and alloy steel. NASA allowable for 2100-3000# is 1.75 x .095 or 1.5 x .120 both mild and chrome.

Thanks
Dave

Cupcar#12

i would go for ChroMo if possible - stronger = better.

The seam welding was around the entire pick up point and it is not "plated" if i remember correctly

my car is at 2585 in street trim - less than 2500 should be possible without uber $
you are removing all sound deadening and undercoating right? or are you jsut grining away where you have to to install the cage and seam weld?

Jasko

Rob

Thanks - If I understand correctly, you mean to weld here (thanks for the pic Geoffrey):


Current plan is just clear the areas where seam welding will take place. I know this is a compromise, but I just don't have budget to strip entire car this year. May be project for next year.
Other than that, everything else is thinned out - glass, wire harness, window mechanism, heat/ AC.

The other weight factor is that this is a C4. I plan to run it with the 4wheel until to breaks, then convert to a C2.
With the C4 in, I hope to get down to 2600-2650#. It should be a fun car at that weight, and I'm interested in seeing how it fares against the RSAs and cups at that weight. UNfortunately, GT2 rearely runs with the cups!!

Thanks,
Dave

Geoffrey

I actually went with mild steel because I wanted a cage that would deform and absorb some of the energy rather than being so stiff. I think there are going to be many opinions on what to do with the cage. I also went with .120" wall thickness to accomodate different race series.