Connecting 4point Harness In R33

[Kaido_RR]

Hey (dont know if this is in the right section)

Just wondering if anyone has any pix of how they have connected there 4-point harness in an r33

cheers michael

[Duncan]

Well its a bit tricky - to mount them properly they are only meant to be 10 (or 20 cant remember) degrees from horizontal. So if you have a cage you attach it to that - if not you should put it to the parcel shelf - but you would need to wled additional reinforcing to the parcel shelf since its just 1 piece of steel.

In practice a lot of people just use the original bolt holes from the rear seat belts - but these areway too low and probably more dangerous than just using a lap sash seatbelt since they are not designed to work at those angles

[Victory]

Installing the belt anchor points in the rear parcel shelf are a major challenge in a R33 Coupe. This is because the panel drops down at the side and you need to mount the eye bolt suspended in the air.

I solved this problem by using a piece of 50mm angle that I then cut most of one side out to fit on the parcel shelf (refer photo). The eye bolts closest to the centre go through the speaker and child restraint mounting bolt point. This is the overlap of about three pieces of body metal so it is quite strong especially when you use a 90 mm washer on the underside.

The end of the angle is then supported via brackets to the back panel below the window and also down to the back of the rear seat.

This then has the two eye bolts in the exact location to line up with the front seats. The trick though is to put the parcel shelf in place (holes pre drilled for the eye bolts) then install the eye bolts and tighten them up followed by the rear trim and seat.

My problem is that after all of this work in my GTS-T I have to start all over again and do the same for my GTR.

[Roy]

Im not convinced that is a great way to do it. Has the car been to an event that required a CAMS scrutineer to inspect it? Did it pass?

The theory seems ok, but i have a few concerns, namely the material you have used for the angle. It looks like galvanised thing gauge angle? The kind used on sheds and flashings etc, not for structures. (Completely different strenght steel and thickness)

[Roy]

Also, just generally. Ppl seem to like usign child restraints. Just remember that the inertia from a grown adult if well and truly above that of a child in a capsule...so you are well beyond the design limits of them. Just look at the lengths Nissan go to on the std points

[Victory]

The angle is 2.8 mm thick and galvanised so that it will not rust.

I mounted it in the child restraint bolt hole as that is where the panels of body metal overlapped so that apart from being in the right position it would be the strongest part of the parcel shelf.

The car was scrutineered by CAMS officials at a Renault Skid Pan Day and they had no problems with it.

Do you have any better suggestions and how did you mount your 4 point harnes?

[Trust33]

what brand of harness did you use?

[Victory]

I picked up a pair of ERG 6 point harnes from R & R Speedsports Pty Ltd in Greenacre. I am running R33 GTR seats in both cars so I do not use the crutch belts.

The other problem is finding the eye bolts with the short eyes to fit the seat belt mounting point on the console side of the seats. Most performance shops do not stock them (refer attached pic) however I found some at Gary's Motorsport Tyres Pty Ltd.

[Roy]

The angle is 2.8 mm thick and galvanised so that it will not rust.

I mounted it in the child restraint bolt hole as that is where the panels of body metal overlapped so that apart from being in the right position it would be the strongest part of the parcel shelf.

The car was scrutineered by CAMS officials at a Renault Skid Pan Day and they had no problems with it.

Do you have any better suggestions and how did you mount your 4 point harnes?

Im not having a go, just in case thats what you thought. Different ppl have different ideas and approaches and through disucssions and a few evolutions of tweaks then perhaps a better solution is sometimes stumbled upon.

Being a steel geek for a second. The steel used in your pic does not appear to be BHP 300Plus steel, the strong structural stuff that meets certain quality and metallurgy standards. If the wall is 2,8mm then thats an indicator that it isnt, as 3mm is the thinnest 50x50 comes in. Another tell tale sign is the radiaus of the outer shoulder where its bent. The structual angle is usually a sharp 90deg edge, not a rolled shoulder. When BHP hot roll the stuff thats how the edge is produced. Your angle looks as though it may be extruded galvanised sheet, not realy a structual thing.

So if the above observations are correct, then your good design and execution is let down a tad by material selection. If im wrong then tell me top put the beer down now and put my head in the oven

On the actual installation, thats pretty good. Only, You have said you cut most of one side out to fit the parcel shelf. So i assume you mean the toe or side of the angle has been removed so that in a section of the length its more flat bar then angle iron?

If so that sux but is necessary as Nissan farked us from the factory. But adopting another approach means it may not be necessary.

How about on the boot side behind your battery etc you use some angle iron crammed up into the top corner with holes drilled so that it will pick up the std child restraint points. Now if angle iron of a certain size doesnt readily lend itself to the geometry and location then flat bar (BHP Grade 300PLUS) can be used. Does it have to span the enture underside, maybe not, but the weight difference would be jack all and i would rather see the load uniformally placed along the whole area, not a point load.

So by doing the above you are adding rigidity and strength to the mounting point along the whole parcel shelf.

So this doesnt really help the outer points. So two out of 4 are sitting out in limbo. So now rather then using cut down angle, i would simply roll the angle so the the toe sits up vertically. This way you havent cut the angle whereby introducing a weak point where it will want to bend in an accident and you are also able to make it the full width. This has the added bonus of sandwiching the std parcel shelf steel between the two peices of angle. If the toe of the angle is too high for the belt to pass over, and you dont want to put the eye bolts in the horizintal then you can cut out a letterbox style opening in the upwards facing part of the angle. It wont affect the strength as much as removing a section.

That all said, thats some thinking i would be looking to apply. But main thing is make sure you are using the right material, or just grab a harness bar from Sparco/Meridian Motorsport etc etc. Off the shelf and easy to install, albeit a few dollars extra

[Victory]

Being a steel geek for a second. The steel used in your pic does not appear to be BHP 300Plus steel, the strong structural stuff that meets certain quality and metallurgy standards. If the wall is 2,8mm then thats an indicator that it isnt, as 3mm is the thinnest 50x50 comes in. Another tell tale sign is the radiaus of the outer shoulder where its bent. The structual angle is usually a sharp 90deg edge, not a rolled shoulder. When BHP hot roll the stuff thats how the edge is produced. Your angle looks as though it may be extruded galvanised sheet, not realy a structual thing.

Roy

I would suggest that you are correct in that I may not have used the best form of angle with the best strength characteristics, but it is what I had at the time.

My main idea was to attempt to spread the load over as much of the parcel shelf and surrounding panels as possible. I have seen cases in the past with just the eye bolts mounted through the body metal with the large washer and nut underneath. In an impact they did not pull through the panel but there was a degree of distortion on the panel.

[Kaido_RR]

cool thanks everyone, keep the ideas coming (pics help alot)

ohh and if it matters i have a nismo 4 point harness (willans)

edit: i use the car for street use, so is there an easy way to install it so i can take it out quickly when im not on the track

[Victory]

Michael

That is the idea of using eye bolts. It allows you to quickly click on and off the harness as required.

The problem though is that once you have experienced the extra support that the harness provides you will want to always use them. I now do not feel safe in a normal lap sash belt and use the harness all the time.

The other thing is that you have so much more feel of what the car is doing under you in corners with a harness that you become one with the car. This may sound like a lot of crap but the extra feel makes you a better driver because you can feel what the car is doing.

[Kaido_RR]

Michael

That is the idea of using eye bolts. It allows you to quickly click on and off the harness as required.

The problem though is that once you have experienced the extra support that the harness provides you will want to always use them. I now do not feel safe in a normal lap sash belt and use the harness all the time.

The other thing is that you have so much more feel of what the car is doing under you in corners with a harness that you become one with the car. This may sound like a lot of crap but the extra feel makes you a better driver because you can feel what the car is doing.

thanks for the advice i was worry i would use the harness all the time too if i put one in so, that why i wanted to be able to remove it.

[Kaido_RR]

hey,

ok i went about fitting the harness today, now im not sure if where i've mounted it is ok.

for the 2 side points, i mounted them at the back of the seat rails (the 2 bolts at the rear of the harness) now im not really happy with these to point as the bolts aren't long enough and even thou they are tight i have a feeling the seat rail may be abit loose.

the 2 top points, i didnt get time to fit but i was thinking about using the, the 2 bolts from the rear seat belts.

now is this ok? as im just tring out ideas for the moment, to find the best opinion.

thanks michael

ps stock gtst seats look silly with a harness, i think its time for a gtr seat

[Kaido_RR]

wannabe racer or poorman racer lol

i think i need bucket seat asap!

[Roy]

That works...but like Duncan mentioned in an earlier post is that the angle isnt ideal.

Think about it this way. When you suddenly move forward in your seat, (frontal impact or heavy braking) then the inertia of your body will put the harness in tension. When its in tension it will want to trace a straight line from where its mounted. So what it will do is place a large verticla load on the back of your seat. So what can happen is your seat is damaged in a big accident...but the big concern is that same vertically down load that wants to compress the back of your seat also wants to crush your spine. Not good.

So its well worth the effort to mount the harness so that it is about parallel with the ground (ie off the parcel shelf)

[Kaido_RR]

That works...but like Duncan mentioned in an earlier post is that the angle isnt ideal.

Think about it this way. When you suddenly move forward in your seat, (frontal impact or heavy braking) then the inertia of your body will put the harness in tension. When its in tension it will want to trace a straight line from where its mounted. So what it will do is place a large verticla load on the back of your seat. So what can happen is your seat is damaged in a big accident...but the big concern is that same vertically down load that wants to compress the back of your seat also wants to crush your spine. Not good.

So its well worth the effort to mount the harness so that it is about parallel with the ground (ie off the parcel shelf)

cheers for that info roy, i plan to fit it up right before hitting the track, as i want it to help me not hurt me. just wanted to trail fit it

[Beer Baron]

the lap belts should not be mounted as far back as you have them. as it is now they are going over your lap, then they have to wrap around to behind the seat. that's not good.

[Kaido_RR]

the lap belts should not be mounted as far back as you have them. as it is now they are going over your lap, then they have to wrap around to behind the seat. that's not good.

where is the best place to mount them?

[moobaque]

where is the best place to mount them?

Its all pretty bad until u get yourself a proper seat...the shoulder harness staps are probably going to be tight around your neck because of the lack of guidance through the stock headrest, and obviously as mentioned the angle is all bad in the event of a crash... specially with a reclinable seat! (your spine wont be happy)

as for the lap belts connection that far back, it wouldnt be an issue if running throught the guides of a proper racing seat but as your not the points need to be closer to you. this may require putting an eye bolt through ur transmission tunnel on your left side but you should be able to use a stock bolt hole, like the anchor for the bottom of the standard seat belt, or worst comes to worse an eye bolt though the floor (with a plate on the back to spread the load)

Ive had a harness bar built for my street car to i get a much more preferable harness angle for the shoulders. Havent got a pic handy but ill post one up tomorrow if you interested in the concept.