Roll Cage is IN

#1

Just had a car towed-in from the cage builder’s (TC Design for you in Bay Area). I am very happy with the work. Engine, tranny, susp., etc still needs a lot of work, but at least I get to check something off my list. Here are links to few pics of the cage

Igor

http://show.imagehosting.us/show/908255/0/nouser_908/T0_-1_908255.JPG

http://show.imagehosting.us/show/908269/0/nouser_908/T0_-1_908269.JPG

http://show.imagehosting.us/show/908273/0/nouser_908/T0_-1_908273.JPG

http://show.imagehosting.us/show/908276/0/nouser_908/T0_-1_908276.JPG

http://show.imagehosting.us/show/908279/0/nouser_908/T0_-1_908279.JPG

http://show.imagehosting.us/show/908283/0/nouser_908/T0_-1_908283.JPG
http://show.imagehosting.us/show/908286/0/nouser_908/T0_-1_908286.JPG

Update: Based on the comments from other posts I contacted my regional Spec E30 dir (who in turn also contacted NASA tech for the region) and I got a ruling regarding my cage legality:

There is nothing wrong with the downtubes on my cage, however the welded in bar from one shock tower to the other was deemed illegal.

I have to cut it out and can use bolt-in tower brace if I want to.

So if you are designing building a new cage keep this in mind.

Regards,
Igor

#2

Thanks for sharing. Looks good!

#3

Igor wrote:

[quote]Just had a car towed-in from the cage builder’s (TC Design for you in Bay Area). I am very happy with the work. Engine, tranny, susp., etc still needs a lot of work, but at least I get to check something off my list. Here are links to few pics of the cage

Igor

http://show.imagehosting.us/show/908255/0/nouser_908/T0_-1_908255.JPG

http://show.imagehosting.us/show/908269/0/nouser_908/T0_-1_908269.JPG

http://show.imagehosting.us/show/908273/0/nouser_908/T0_-1_908273.JPG

http://show.imagehosting.us/show/908276/0/nouser_908/T0_-1_908276.JPG

http://show.imagehosting.us/show/908279/0/nouser_908/T0_-1_908279.JPG

http://show.imagehosting.us/show/908283/0/nouser_908/T0_-1_908283.JPG
http://show.imagehosting.us/show/908286/0/nouser_908/T0_-1_908286.JPG[/quote]

Pretty nice looking! On the rear supports…why did you go to the shock towers instead of the spring perches? Just curious.

#4

Yeah, I was wondering about that too. When I talked to Tony, he strongly discouraged me from tying into the rear towers, yet many of his cages do so. Was this your decision or his?

#5

As I prepare to gut my car, I’m wondering how long that process took you. Did you do anything special to remove adhesive residue or have you not tackled that project yet?

Sasha

#6

I told Tony (cage builder) what class(es) I intend to run, and we discussed cage design a bit, but I went along with his recommendations (guy knows more about the subject than I do, plus has more experience building cages on E30s then I). He feels that rear shock towers on E30 are ‘weak’ (relatively speaking) point, and wanted to insure structural integrity by tying them to the cage ( I am being careful how to ward this as I don’t want to make it sound as if it is a performance enhancement – from my research cage is legal in SpecE30 ).
It took me few weekends of on-and-off work to get the interior out, and to clean up adhesive. It’s PITA job, and I ended up using ‘goo-be-gone’ and plastic scraper to get it off.

Igor

#7

Ex36 wrote:

[quote]As I prepare to gut my car, I’m wondering how long that process took you. Did you do anything special to remove adhesive residue or have you not tackled that project yet?

Sasha[/quote]

If you’re talking about the tar-like sound deadening on the floor, set some dry ice on it for 5 minutes, remove, and whack with a rubber mallot. Makes it a 20 minute job.

#8

sdais wrote:

Just be careful, though, as you might remove too much weight by getting rid of the sound deadening. If I pull mine, I’ll be 30-40lbs underweight – and I’m a large guy.

#9

Is that underweight even with some ballast? I’m figuring I’ll remove the entire interior including the trunk felt (except for the insulation on the floor of the trunk), the A/C compressor, the power steering pump, the cruise control, and the e-brake. Would that make me underweight or did you remove more? I’ll weigh about 205 with all my gear on.

Sasha

#10

are you going to cut out the sunroof sliding mechanism since you’ve riveted the sunroof shut?
cheers,
bruce

#11

[quote]are you going to cut out the sunroof sliding mechanism since you’ve riveted the sunroof shut?
cheers,
bruce [/quote]

I already removed all parts of the sunroof mechanism prior to riveting. Everything was out and just the “top roof plate� (for the lack of better term) was riveted in.
Regards,
Igor

#12

it looks like you still have the part that extends over the back seat (that the panel slide into) - I’ve heard of people cutting on the side of that, leaving a stub on the roof but getting rid of all that metal in the middle. I’m curious how much that weighs.
cheers,
bruce

Igor wrote:

[quote][quote]are you going to cut out the sunroof sliding mechanism since you’ve riveted the sunroof shut?
cheers,
bruce [/quote]

I already removed all parts of the sunroof mechanism prior to riveting. Everything was out and just the “top roof plate� (for the lack of better term) was riveted in.
Regards,
Igor[/quote]

#13

I’m a big guy. 250 with gear on. I can get the car to be very close or even a bit underweight if I ran it low of gas. Still has sound deadening on floor panels, but not in trunk. No A/C, P/S, Sunroof.

I’d focus on removing weight forward FIRST, weigh on scales, then up high SECOND, THEN start on sound deadening and stuff like that…but only at the heavy end of the car!!!

You can’t move stuff around to cornerweight the car (you can judiciously choose where you mount your fire bottle, coolsuit cooler, etc) Ballast can only go in the passenger footwell.

But you can choose what you remove. Knowing what I know now I’d have left everything I could in the trunk and tried to get car down to weight.

Ric

#14

[quote]it looks like you still have the part that extends over the back seat (that the panel slide into) - I’ve heard of people cutting on the side of that, leaving a stub on the roof but getting rid of all that metal in the middle. I’m curious how much that weighs.
cheers,
bruce [/quote]

I understand what do you mean now. I am planning to leave that in.

Ric, thanks for the info ( I am ~240 lb 6’4� ).
What is consensus with spare tire – do most of people have it in the car or not? Obviously I am thinking about weight, but I also heard someplace that it is part of BMW’s crash protection. Thoughts?
Regards,
Igor

#15

Igor wrote:

[quote]Ric, thanks for the info ( I am ~240 lb 6’4� ).
What is consensus with spare tire – do most of people have it in the car or not? Obviously I am thinking about weight, but I also heard someplace that it is part of BMW’s crash protection. Thoughts?
Regards,
Igor[/quote]

IIRC, most pull the spare since it hangs past the rear axle.

As for weight, just keep in mind that you’re limited to 100lbs of ballast and it’s probably best to keep it to less than 40-50lbs of ballast, so that you have wiggle room. IIRC, the weights are:

[li]30lbs - A/C[/li]
[li]24lbs - Sunroof[/li]
[li]~35lbs - trunk sound proofing[/li]
[li]34lbs - P/S[/li]

I believe that www.e30tech.com/forums has a weight reduction thread in the stickies section with figures.

#16

leggwork wrote:

[quote]it looks like you still have the part that extends over the back seat (that the panel slide into) - I’ve heard of people cutting on the side of that, leaving a stub on the roof but getting rid of all that metal in the middle. I’m curious how much that weighs.
cheers,
bruce

[/quote]

Removing that panel is where most of the weight savings comes from (it weighs alot).

#17

Igor wrote:

[quote]I told Tony (cage builder) what class(es) I intend to run, and we discussed cage design a bit, but I went along with his recommendations (guy knows more about the subject than I do, plus has more experience building cages on E30s then I). He feels that rear shock towers on E30 are ‘weak’ (relatively speaking) point, and wanted to insure structural integrity by tying them to the cage ( I am being careful how to ward this as I don’t want to make it sound as if it is a performance enhancement – from my research cage is legal in SpecE30 ).
It took me few weekends of on-and-off work to get the interior out, and to clean up adhesive. It’s PITA job, and I ended up using ‘goo-be-gone’ and plastic scraper to get it off.

Igor[/quote]

While it’s probably true that the towers are a weak spot, that would only be a problem with certain suspension set ups, namely rear coil overs where the load actually comes into the shock tower. Even with stock style set ups I would find it hard to believe (without real data) that the SpecE30 set up would affect it, pretty light springs/shocks.

A very nice looking cage though!

#18

That’s where I don’t agree. A rollcage is basically a truss (which gets its strength from the foundation). Why would you use a structurally weak point as one of the foundation points? I can see trying to reinforce the shock tower, but the way to do it is anchor the cage to a strong chassis point (probably the trunk floor area right at the base of the tower) and extend a support plate up from that anchor to the shock tower.

As for protests, I wouldn’t worry too much. I’ve already got a "gentleman’s agreement" with some of the local NorCal SpecE30-in-the-works guys not to protest each other on stupid non-performance stuff. So, we should be safe for a little while.

Post edited by: traqrat, at: 2005/11/18 13:28

#19

traqrat wrote:

[quote]That’s where I don’t agree. A rollcage is basically a truss (which gets its strength from the foundation). Why would you use a structurally weak point as one of the foundation points? I can see trying to reinforce the shock tower, but the way to do it is anchor the cage to a strong chassis point (probably the trunk floor area right at the base of the tower) and extend a support plate up from that anchor to the shock tower.

As for protests, I wouldn’t worry too much. I’ve already got a "gentleman’s agreement" with some of the local NorCal SpecE30-in-the-works guys not to protest each other on stupid non-performance stuff. So, we should be safe for a little while.[/quote]

Sorry, which post are you replying to?

#20

Ooops.

I’ve edited my reply to include the original quote.