TRM Spec e30 rollcage build photos

[techno550]

I agree with you on the harness bar. It's a glaring deficiency, since any significant side impact load will not be transmitted through the harness bar and thus increase the likely hood of large deformation.

The harness bar is at the appropriate height for the seats. (and thus the harnesses. Its called a harness bar for a reason, right?) Lower and it would hit the node for side impact protection... but not properly locate the harnesses for the driver. The point of the cage is to protect the driver, and all cages will have some sort of compromise. One solution could be the cross bar beeing lower and mounting the harnesses to a harness bar much farther back on one of the X's. The rules do not allow for such, so this was the best compromise as forced by the current rules.


That said, its not a required bar, and is not only legal as placed, but quite good.

another cage design to note would be

Thirding this. The big "X" sort of made me go "wtf"? seems odd that you would have the impact travel at an angle. Really seems like it would deform a good bit.

Any reason you didn't go Nascar bars on the driver's side?

-Charlie

Nascar bars are good "crush structure". that is their purpose in Nascar. Outwardly bent bars of that sort of magnitude will bend easily. They will bend in as far as they are out without any further stretching. This means the nascar bars can come into the car as far as they were sticking out... and thats generally a bad thing in someting as small as an E30. For side impact protection, the X is king.

[Charlie]

I agree with you on the harness bar. It's a glaring deficiency, since any significant side impact load will not be transmitted through the harness bar and thus increase the likely hood of large deformation.

Thirding this. The big "X" sort of made me go "wtf"? seems odd that you would have the impact travel at an angle. Really seems like it would deform a good bit.

Any reason you didn't go Nascar bars on the driver's side?

-Charlie

[Axxe]

Nice looking cage. The welds look very well done.

To say this is the best SE30 cage only points out that you haven't seen that many cages in many of the cars that have joined Spec E30 this year.

with that said... this is a nice one.

FWIW: The only part I question is how the harness bar fails to connect in the center. With the horizontal bars as they are a side impact is going to transfer the load to the center at a point that is not triangulated. It seems to me, this is going to create a weak point in an area you'd want to be one of the strongest.

I agree with you on the harness bar. It's a glaring deficiency, since any significant side impact load will not be transmitted through the harness bar and thus increase the likely hood of large deformation.

[matt]

In all honesty I haven't really seen any other e30 cages in person. I need to make it out to some nasa events more often. I just took a quick search around spece30.net and found some other examples. There are obviously plenty of other nice ones around (but I didn't feel the need to link to them). Bill told me a few of the tech inspectors said very nice things about the cage at his first race weekend a few weeks back.

No comment on the harness bars, I'll talk to Mike and see if I can get him to reply on that one.

Thanks, Lee. To be perfectly honest, I didn't design or install the cage. (I removed and refitted the dash though...)

[Massive Lee]

Hi Matt.

Very nice work. I obviously like the welds, but also how you made your boxes, so that when the cage is tacked together, you can move it to the back and lower it by about 5 to 6 inches, liberating a lot of room all around the upper tubing to do the 360º welding. When welded, move it up and onto the bases, finish to weld the tubes on the bases. Nicely thought.

Keep on the good work.

[Scott///M]

Nice looking cage. The welds look very well done.

To say this is the best SE30 cage only points out that you haven't seen that many cages in many of the cars that have joined Spec E30 this year.

with that said... this is a nice one.

FWIW: The only part I question is how the harness bar fails to connect in the center. With the horizontal bars as they are a side impact is going to transfer the load to the center at a point that is not triangulated. It seems to me, this is going to create a weak point in an area you'd want to be one of the strongest.

[matt]

Heh. I wasn't really asking for opinions. I'm really looking for customers. :giggle:

I honestly don't know what Bill paid. I don't think he got any sort of discount, but it was quite a complicated deal.

Like I said, it's slightly more expensive than a custom cage from the average fabricator. It's worth it to some racers, it isn't to others.

It's probably possible to get a legal cage in a car for ~$1000. I wouldn't recommend it...

[155///MPH]

I've seen scary cages in pro cars let alone SE30.

I agree with Ben, asking for opinions on cages on line is asking for it. Something could always be "better". Its a good cage but declaring it king of all SE30 cages is a stretch.

How much of a discount did Bill get for all of the advertising his car is doing?

I can't speak to the cost of this cage, but mine is very similar with a little extra detail work (floor pan rust repair, etc) and it came to right at $2k.

[matt]

Have you ever seen a better one in a spec e30? I sure haven't. And a lot of the ones I've seen are scary.

Keep in mind a mod class cage will be a lot different. Different in a lot of "better" ways that we're prevented from using by the spece30 rules.

[Ben Carufel]

When it comes to cages, everyone has an opinion.

Looks nice. Doesn't look like the best cage I've ever seen, but it looks nice. I'm thinking at the moment that I'll eventually put in a full-CF dash and have the front bars redone to extend through the dash, as well as raise the front bar like yours.

[matt]

Do you have any pics of how the rear was tied in? I think I read somewhere that rear sheet metal was finished off too, got any pics of that?

I looked today and I actually don't have any pictures of the rear part of the cage at all. Sorry. I will ask the owner to snap a couple.

Yeah, that's my car and my ongoing, seemingly never ending cage. :D

The plinths definitely took a long time (longer than expected) to get the profile perfect to fit the rocker but I think it was worth the time. I really like the overall shape of yours better since it's a little more compact. If I had to do over again, I would probably do exactly like you did but with the notch to fit in the rocker.

Yeah, metal fabrication can be a PITA.

[iflytii]

OK gotcha. Yeah, we can definitely add those bars. I wouldn't call them gussetts, they're really just extra bars. My understanding is that these are gussets.

Connecting the chassis to the cage in more places would be nice, but rules dictate otherwise.

That's a nice cage, it looks like. Your car?

We may also look into changing the design of the plinths... these were cut by hand. If we get a lot more e30 cage work, we'll have them waterjetted to match the chassis better.



Sent you a PM.

Yeah, that's my car and my ongoing, seemingly never ending cage. :D

The plinths definitely took a long time (longer than expected) to get the profile perfect to fit the rocker but I think it was worth the time. I really like the overall shape of yours better since it's a little more compact. If I had to do over again, I would probably do exactly like you did but with the notch to fit in the rocker.

[matt]

My gusseting comments were intended as "between tubes", not chassis to tube reinforcements.

edit, a couple pics would better describe what I was "trying" to say. :)

gusset between b-pillar and the horizontal leading from the a-pillar
http://img.photobucket.com/albums/v521/iflytii/roll%20cage/progress_3050607.jpg[/IMG]

gusset between the a-pillar and the horizontal connecting the a-pillars
http://img.photobucket.com/albums/v521/iflytii/roll%20cage/progress_2050607.jpg[/IMG]

OK gotcha. Yeah, we can definitely add those bars. I wouldn't call them gussetts, they're really just extra bars. My understanding is that these are gussets.

Connecting the chassis to the cage in more places would be nice, but rules dictate otherwise.

That's a nice cage, it looks like. Your car?

We may also look into changing the design of the plinths... these were cut by hand. If we get a lot more e30 cage work, we'll have them waterjetted to match the chassis better.

I'd also like to know?

Sent you a PM.

[Mastrcruse]

How much would a cage setup like that cost? If car was brought in with no interior or dash?

I'd also like to know?

[iflytii]

My gusseting comments were intended as "between tubes", not chassis to tube reinforcements.

edit, a couple pics would better describe what I was "trying" to say. :)

gusset between b-pillar and the horizontal leading from the a-pillar


gusset between the a-pillar and the horizontal connecting the a-pillars