Gman57

I'm getting my 07 Z51 vert set up for racing and noticed the seats do not accommodate 4 or 5 point seat harnesses. I'm installing a roll bar system to attach the shoulder belts but it looks as if i will have to go around the seat apposed to through the seat like most.
Will this be ok? Will it pass tech inspections?
Thanks in advance for your input.

Bill Dearborn

A number of BMW and PCA events are not allowing this type of belt set up anymore. In 2004 a Boxster driver was killed in a PCA event at Watkins Glen and this type of belt system was possibly a contributing factor in his death since his shoulder harnesses came off his body during the first impact with the guardrail and he had no upper body restraints when the car hit the guardrail the second time.

You would be safer with the stock setup than using the current one you are planning. If you don't mind modifying your seat you can get the grommets shown in the picture and have an upholsterer install them. They are only $15 for a pair. I have seen them installed in a new Z06 and they look like they were installed at the factory.



This is where to order them:

http://www.hmsmotorsport.com/store/s...c/seat-grommet

You can also find some very good instructions on how to install harnesses by clicking on the Competition harness link and a harness name then going to the bottom of the page under documents. Joe Marko (the owner) supplies belts and installation to several top Nextel Cup drivers and quite a few BMW and PCA club racers and is an expert in this area.

Bill

gkmccready

In another thread it was pointed out that modified stock seats with the grommets suggested will not pass tech with a lot of clubs in '08.

AU N EGL

No - shoulder harness may not go around the back of the seat
No- those will not pass tech.

Harness must pass though the seat back. Many car clubs will not allow OEM seats that are modified for shoulder harness, Many clubs will only allow Seats that are designed for harness to be used. and must be equal on both sides.

Your roll bar, What are you looking at? That may be an other issue and not pass tech.

The roll bar must be at least 2" above your helmet
one continuous bar from b pillar to b-pillar
two downward supports
One diagonal brace in the main hoop
One additional bar may be added at shoulder level to attach harness.
FIA padding with in 12" of were a helmet or body part may have contact.

Swing out door bars are frowned upon, but not illegal.

A properly fitted roll bar in a convertible in most cases would not allow the top to go up.


The seat backs in the C6 are much different the the C5. The C6 seat backs have one large piece of steal or aluminum, so Harness holes are not easy to install. The C5 seat back had a steal hoop which all the seat springs and leather were attached too.

That photo above may not pass the PCA clubs techs either. The roll bar does not have FIA padding on.

Bill Dearborn

As of 2007 these grommets had passed tech inspection at both BMW and PCA events in the Northeast. One way to know for sure is to call HMS and speak to Joe Marko since he is the seat belt expert both clubs depend on for technical advice in the Northeast.

My 03Z seat back frames are not steel. The seat bottom frames are steel but the backs are fiberglass and flex like mad. Have never seen a bare C6 seat so I don't know if there is any real structural difference between C5 and C6 seat frames.

Bill

Gman57

Thanks guys the more info I can get the better!!!!!

AU N EGL

Good to hear

There is a big difference between the C5 and C6 seat frames.