TRM Spec e30 rollcage build photos

[matt]

Hey guys, this is a car TRM designed and installed the cage for. It was installed months ago, and has garnered some serious praise from tech inspectors and racers alike since its owner's racing debut in August.

It's a bit more expensive than most people are paying for cages that are just fabricated, but having a cage that's engineered is worth it to a lot of racers. (bolded for an important distinction) Of course a well engineered design can't make up for crappy craftsmanship, but this cage is certainly one of the most well built as well.

I've also edited in some comments to distinguish this cage from some others we've seen around that contain some not-so-awesome features.

Note how the dash bar runs behind the dash and steering wheel... far above the driver's knees. (Here is a different cage for comparison. Note the dash bar location, just because they were too lazy to remove the dash to install the cage.)




Of course all the welds are neat and tidy, made in one pass with a properly sized welder. (Lots of cages are done with smaller 115V welders that don't have the juice to weld .095 tube in one pass.)


Check out the close fit to the B-pillar. (Comparison here) Obviously closer to the chassis means farther from the driver, which makes a tight fitting cage safer.


Foot protection is an optional extra on a lot of cages. By the way, I've also seen cage fabricators weld in tubes with the wiring stuck behind them, which I think is pretty hilarious.


This is a node: a point where multiple tubes meet. This allows loads to be transmitted along the length of the tube to compress it instead of bending it. (Compare that to this cage, with poor nodes. (Tubes don't all meet at the same point.)




Owners comments: http://www.tehdriven.com/forum/showp...9&postcount=21

Custom roll bars (from the main hoop back) are also available, installed only at this point but we're thinking about coming out with a weld in kit for the roll bars. Cages can also be built to any class rules and customized for driver size and car setup (rear coilover reinforcement for example) on a one-off basis.

Thanks for looking!

[e30 gangsta]

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

[iflytii]

A few comments:

Are you not allowed to take the sunroof cartridge out in spec-e30? You can save a LOT of weight and gain over 1.5" for the cage by taking it out.

Your plinth blocks could be be better designed by following the profile of the rocker and welding the vertical 100% if you aren't going to use a base plate under the plinth.

Some gusseting in the door x, the horizontal to b-pillar and the a-pilar to cross piece would be a nice addition but obviously a decision for the owner (added cost).

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?

Overall the cage looks great! My comments were very "nit-picky" :D

[matt]

Keeping the sunroof was a preference of the owner, we did suggest otherwise.

Gusseting to the chassis like you're suggesting is illegal is Spece30 racing. We may go back and add some gussets between different tubes, and we may actually add a couple of bars.

The rear was tied in to the rear spring upper perches (well, the trunk floor above them since cutting the sheet metal there is illegal) because it's stronger than the shock tower mounting points (which only need reinforcement when using true rear coilovers, which are also illegal in SpecE30 racing.

[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

[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?

[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.

[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]

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.

[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]

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.

[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]

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...

[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.

[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.