RedlineMan

Hey Dave;

As odd luck would have it, a guy I know stopped in my shop with an '02 360 yesterday. What a sweet car. I actually fit! I'm sure not used to anything near that kind of HP. I gotta admit the sound is intoxicating.

Anyway, the beam that is used to mount the belts on the Competizione cars is indeed entirely structural. Further it is strengthened by having the tie in points for the engine subframe on the backside of it.

Given proper mounting, I would not hesitate to use it as the shoulder belt mount point. That is exactly what I am going to do!

dwe8922

Hey john,
It is a very fun car to drive, and the sound is special. I've started work on the project with the help of another 993 owner/Rennlister. We're making an adaptor to mount the sliders and side mounts, and were planning on building a harness bar. I went down to the FCA track event at sebring, and saw how others mounted their. Some were downright scary, but some seemed ok. Probably the best one a guy mounted large aluminum backing plates on the engine side of that truss, and then used steel washers/eyebolts. One of the Ferrari experts I talked to scared me about galvanic corrosion w/ going this route. He went as far as to say that I would need to use a certain kind of drill bit that had never touched steel to even drill out the holes, let alone the hardware that touches aluminum.
BTW, the factory fix for the challenge stradale is to use certs that insert into the truss, and then you just bolt to them. I wouldn't feel comfortable with that.

David

RedlineMan

What a lot of Hooey;

That's how he justifies $100-something an hour, probably. And you have to wear a clean suit and hypo-alergenic non-latex gloves when you do it. If "you're" afraid of corrosion, slob everything with grease before you put it together, for chrissakes.

The idea of the plates behind the bulkhead beam is a good one. That's where I was going. Like you, I also do not trust the aluminum to actively hold a fastener. I want the BEAM to do that, and passively to boot. Steel is what I trust for such things.

I will also be fabricating attaching plates that weld to the Momo sliders for the lap belts. Since this is only a DE car, I am not worried about exclusion because of using non-segregated mounting.

Can you tell me if Ferrari included inserts in the front seat floor beam for the flat Momo sliders? The Competizione schematics show a bolt going straight down, which does not match the angled front bolt hole for the stock slider. I wondered if they had both sets of threaded inserts already there?

Also, how do the rear interior panels come out? I know the panel at the base of the rear window has push pins, but I am not sure about the upper window opening, the quarter window surrounds, and the inner b-pillar panels. I'd like some knowledge going in to hopefully avoid damaging fasteners.

dwe8922

Hi John,
The challenge cars actually have another beam welded to that truss. My first post has a picture and a pdf of the challenge setup. There is no plate existing in the front to allow you to flat mount a slider. The CH uses an angle adaptor block that the flat adaptor/rail mounts to. The rear mounts flat. There are steel threaded plates under the rear floor truss, and front angle portion. Both have play for adjustment. The CH setup also has another plate under that rear truss for the lap belt eyebolts that you can't add in retroactively. Also, the challenge adaptor kit costs $900 just for the plate and hardware!
If your customer is tall beware; there's not a lot of room. The stock seat actually sits very low, probably lower than a normal sidemount with slider and one piece seat. I had to sit the seat on top of the rear bolt head of the sidemount, and drill new lower holes on the side to give enough room for the slider. And, the stock rear bolt head will have to be machined 1/32" (diameter) to allow it to work w/ the recaro slider.
To get to that rear beam on the firewall, take off that panel below the window, the boxes covering the ecu's, and the map pocket. I think from there you can tease out the rear carpet panel. I don't know about the other leather pieces.
Please take some pictures. I'd like to see how your project goes!

David

RedlineMan

Hey;

I'm not sure when I will be getting into it. He has to find a seat that fits him first. He is about 6'2", but I'm not worried. My seat will be lower than the stock one because I will make my own side plates and weld them directly to the Momo/Sparco slider. I will also likely adapt the flat front of the slider to match the existing angled holes in the frame beam. In looking at things, I think I can set the seat at a perfect height to use the rear upper crossmember beam to directly mount the shoulder belts. I will go through it and tie into a plate on the engine side of this beam.

Stay tuned...

chrisp

galvanic corrosion is a definite issue. On the galvanic table (a listing of common metals) as you move up the table, the one below is corroded by the one above. Steel is near the top of the list and aluminum closer to the bottom. So, steel does corrode aluminum. That said, if the parent material (in your case aluminum) is accepting a higher ranked metal the amount of corrosion is lessened as the amount of parent material increases. Meaning, if you screw a steel bolt into a 1" square of aluminum you will get much more corrosion than if you screwed that same bolt into a brick of aluminum. So in your case, i don't think screwing a steel bolt into an aluminum chassis member is a big deal. Plus, corrosion is increased where water is present. If you won't be getting the parts wet the risk is even further minimized. If you want to go one step further, coat the steel parts with Tef-Gel. It's designed to insulate dissimilar metals from each other. I'm not a materials engineer but I researched this stuff on two occasions. Once for my aluminum trailer and once for a plumbing catastrophe I had at home where a steel nut screwed onto copper tubing failed.

dwe8922

Thinking of all of this made me wonder for my featherlite enclosed trailer. I talked to the distributor, and they didn't think much of the corrosion issue, saying that they just used stainless hardware, and that since the interior wouldn't be exposed to moisture, that corrosion wouldn't be much of an issue. Also, I was told that FL insulates any steel from aluminum when they bolt on things. How did you handle fitting things to your trailer?

chrisp

I haven't gotten to that point yet. I was researching what was involved in bolting a steel tire rack to my aluminum featherlite (mine is the open model). From what I researched, steel bolts in aluminum is much less corrosive than aluminum bolts in steel for the reasons I mentioned above. I don't see any insulation of any type on the hardware holding the trailer together. There is insulation however where large pieces of steel contact the aluminum. The three places are the ball mount plate up at the tongue and where the two axles are bolted to the aluminum frame. For te axles there's a steel plate that spans several aluminum support beams under the deck, one on each side of the trailer. All three of these spots have a thin plastic (may be felt paper) sheet between the steel and aluminum parts.

I think the TEF-GEL is the right thing for hardware but I'm still not sure if it's required.