TRM Bolt-in Roll Bar pictures

[Mike B.]

Who is McMahan?

[Charlie]

that old TC Kline bar is one of the nicest I've ever seen for an e30. You should get your hands on one of those and copy it!

McMahan still builds the "TC Kline" cages & bars out of his shop.

-Charlie

[matt]

LOL, no need. This one is just the way I like it in terms of fit. I would love to see some comparison pics though. I would guess they didn't do the B-pillar mounting plates the way we did, because it's a PITA. But it's the right way to do it.

[1990m3]

that old TC Kline bar is one of the nicest I've ever seen for an e30. You should get your hands on one of those and copy it!

[matt]

It will be more in line with the prices on the old TC Kline bars.

[BrandC]

I'd be interested in the roll-bar if it beats the competitors pricing (Kirk, Autopower). It'd be for DE's, not any heavy-duty racing.

[matt]

It WILL PASS a NASA tech inspection.

[155///MPH]

Well that's fairly assumptive don't you think? Using that logic, if its the right way to go why don't all cars use the same method? DTM cars use short harnesses and WRC cars are being required to use shorter harnesses for 2008.

If you would take the time to understand what you quoted you would see that I didn't admonish the design as wrong or right. I simply stated that I would not be comfortable with that setup in my race car given the way that I understand the way harnesses work.

Also, most series in the US that I can think of require modifications of FIA legal cages in order to be legal to race with. All of this was irrelevant to the OP seeing as stated that he wouldn't be using a H&N restraint and wouldn't be using competition grade harnesses.

Go ahead and build it to meet FIA specs, just don't be surprised when it won't pass a lowly SCCA or NASA tech inspection.

[techno550]

Not my car, or safety so go for it. I wouldn't feel comfortable with my belts being mounted that far back. That has no bearing on whether it is correct or not, but I wouldn't buy a roll bar designed like that.

I suppose you feel all of the FIA GT cars are unsafe?

[whiltebeitel]

This sounds really good to me. Any ideas on a ball-park price range?

[SpecE30DRVR]

Seriously that brace is hardly "connecting the shock towers for reinforcement" as was stated earlier.

Not my car, or safety so go for it. I wouldn't feel comfortable with my belts being mounted that far back. That has no bearing on whether it is correct or not, but I wouldn't buy a roll bar designed like that.

Mine is still farther back than I would like. I'm not sure if you could even get belts long enough to reach that far back. I would just run a bar through the X.

hard to see but you get the point

[155///MPH]

Seriously that brace is hardly "connecting the shock towers for reinforcement" as was stated earlier.

Not my car, or safety so go for it. I wouldn't feel comfortable with my belts being mounted that far back. That has no bearing on whether it is correct or not, but I wouldn't buy a roll bar designed like that.

[Massive Lee]

That's the picture we've all been waiting for, Matt. :nice:

The shoulders usually being at the same height as the bend in the main hoop, then we can clearly see (now) that the angle fits the regulation. Nice work.

Lee

[matt]

Lee, I see what you're saying about the angle... The angle is fine but the pictures make it hard to see. I've attached a pic that should clear things up a bit.

[techno550]

A few notes. The bar is above where the down tubes meet the top of the rear wheel wells. probably around ~6 inches or so below the window line. How high is your cross tube/ harness bar there? Right around or just below the window line and how far in front of that rear point? what is the difference in angle?

The FIA cages generally don't have a bar in the main hoop for the harnesses. They usually don't like anything in the main hoop plane unless its a rally car. This includes a diagonal. They generally prefer the diagonal be in the plane with the downtubes.

for the belts

In the downwards direction, the shoulder straps must be directed
towards the rear and must be installed in such a way that they do
not make an angle of more than 45° to the horizontal from the
upper rim of the backrest, although it is recommended that this
angle should not exceed 10°.
The maximum angles in relation to the centre-line of the seat are
20° divergent or convergent.
If possible, the anchorage point originally mounted by the car
manufacturer on the C-pillar should be used.

That is from the FIA Sport / Technical Department, as of 29.03.2007. (FIA appendix J article 253. FIA world touring car champoinship safety equipment)

That same article then goes on to say

Anchorage points creating a higher angle to the horizontal must
not be used unless the seat meets the requirements of the FIA
standard.
In that case, the shoulder straps of 4-point safety harnesses may
be installed on the rear seat lap strap anchorage points originally
mounted by the car manufacturer.
For a 4-point harness, the shoulder straps must be installed
crosswise symmetrically about the centre-line of the front seat.
A safety harness must not be installed on a seat having no head
restraint or having a backrest with integrated head restraint (no
opening between backrest and head restraint).
The lap and crotch straps should pass not over the sides of the
seat but through the seat, in order to wrap and hold the pelvic
region over the greatest possible surface.
The lap straps must fit tightly in the bend between the pelvic crest
and the upper thigh. Under no conditions must they be worn over
the region of the abdomen.
Holes may be made in the series seat. Care must be taken that
the straps cannot be damaged through chafing against sharp
edges.
- If installation on the series anchorage points is impossible for the
shoulder and/or crotch straps, new anchorage points must be
installed on the shell or the chassis, as near as possible to the
centre-line of the rear wheels for the shoulder straps.
The shoulder straps may also be fixed to the safety cage or to a
reinforcement bar by means of a loop, and may also be fixed to
the top anchorage points of the rear belts, or be fixed or leaning on
a transversal reinforcement welded between the backstays of the
cage (see Drawing 253-66).

The drawing has the harness bar behind the B pillar bar in the downtubes, including if you are "silly" enough to put a diagonal in the main hoop plane. unfortunately, being here in the US, we are forced to have a diagonal in the main plane. At this point I generally revert to an X, but still put the harness bar rearward when possible.


so, I guess I'm trying to say... its not that low... and it should be back there.