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NSW supra club Member
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Discussion Starter #1 (Edited)
Guys,
Im posting in this section as i believe i would get a fair/honest reply and seeing as this section is for racing etc you guys would know all the ins and outs etc...

Im wanting to change my harness setup and buy some new ones, 3" ( not sure wich ones yet ) and the mounting points as well.
I have a drawing here and would like to see if anyone can tell me if this setup looks ok/safe?




The (red) would be a decent size round/square bar welded to a plate at least 3mm thick, connected to a part of supras chassis (yellow) that would also be bolted down, it already has 3x threaded holes there where i circled (yellow).

Eye bolts would be either welded or bolted to the bar.
Or would looping the harness be a wiser choice?

The angle in the picture may look huge, but i dont believe its more then 40deg, its just the weird photo.

I know i should have a roll cage, and i would like to but dont want to make the supra a race car just yet, or weld to it, or have holes drilled through the body etc.
Its a casual track day with a few events being run by cams that i attend, and just dont like using the stock seatbelts with the buckets.
No serious competition or anything like that, and i dont use harness when on the road, i have my stock belts for that.

Current belts are 2" 4point, but im wanting to go either 5/6 point 3".

Now,
I have an idea about a second version of mounting the bar, but i dont like the look of it as it would be right in the middle of the rear view, wont be able to see through the rear window (its hard enough as is).
So, if i can get away with the first idea with the lower bar, it would be my prefered choice.

Here's the second idea:


May be better? and angle is pretty straight, but i dont like the look of where its at etc...

I have tried to see what the angle would be like by drawing the lines across with my first idea/picture etc, to me it seems to be less then 40deg? that is the max i can go with CAM's rule.
So, to ME, the first idea with the bar lower and out of view/sight seems to be within specs and doable, no?


So, any thoughts, opinions?
EDIT: P.S. Or should i just buy the sparco harness bar and be done with, would it be just as strong? strong enough? ( it would save me a lot of headach just buying that ).
cheers
 

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Hey Danny,

I think the first one is no good, as the it has more chance of breaking your back! I would like to know this too!

I always thought the second option you have is teh correct way. I think we need to see an engineer to see where is best.
 

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NSW supra club Member
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Discussion Starter #4
Shane,
I realise the second option with the bar up higher would be better, how much better i dont know, how much safer i dont know!
I know that cams says not more then 40deg, so anything up to that is allowable, therefor the first design with the lower bar would pass,
Why would they let you run up to 40deg if it was not safe? thats what i would like to know.

Thanks for that link, Nick.
From reading that, schroth says recommendation is up to 20deg, and up to 40deg but only on certain race seats that are approved by schroth!

Any bar thats more then 200mm from the seats should have the harness crossed over, thats easy enough.

Looking at the sparco race bar positioned in a supra in some of the pictures, look very close to being more then 20deg angle!

Seem's i may end up doing the second option with the bar way up higher, just for piece of mind if nothing else!

cheers guys.
 

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Not Enough Grip
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I was going to post the link to the Scrothracing guidance but Nick beat me to it.

It appears that you are measuring your angle from the provisions in the seat for the harnesses...is that the exact same point that the belt will be sitting on you? I have read many many posts about this topic on Rennlist in the racing section as well as many discussions at track events and some of the points that may help are that you need to have the seat in the position where you are going to be driving, sitting in the position you will be when on track, and with any safety gear such as your driving suit on and a HANS device so that when you measure the angle it is exactly where it will be when you are on track.


:soapbox:
Personally I would never get into a car on track with harnesses and no rollover protection. Any time I have a student that has a harness bar and harness without roll bar installed, if the stock 3-points are not available I will not get into the car. Way to much risk in case of an incident, even if that is a remote chance. At an event I was at last month, there was a 5 series BMW that had a mild little spin right in front of the car I was instructing in and it ended up hitting a small burm and rolling over. This was at point on the track that I would have never expected to see a car roll over at, but stuff like that happens.
</end :soapbox: >
 

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Yeah, what they said!

Ditch those 4pts and get 5/6pts, for sure. Roll bar will be much more safe than a harness bar, mainly because of possible crushing of the roof during a rollover. Better to have a bar supporting the roof than your head (and broken neck) in that situation!
 

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Not Enough Grip
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NSW supra club Member
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Discussion Starter #9
Joshua,
With regards to how/where i sit.
I pretty much sit right against the seat, so however the angle the seat is thats how i sit, and with the helmet on my head is a touch forward, not much as it touches the headrest all the time.
So the 40deg angle should be probably even lower then what i have drawn in that picture with the lines.( that picture assumes i sit on a right angle ).

I see that mustang picture on the main forum, cant see the other attachments they linked up as it exceeded the limit, but wow...very lucky!

Now, who here would recommend a place online that has good roll bars for the supra's? where i could order online and a realistic turn around? then pray they ship worldwide...
A 4 point with crossover and a harness bar would be more then enough for me.
Bolt on would be ideal as i can do the work myself and be able to remove it if it ever came to that.
Also, the design would have to mount to the body frame/chassis, not like that mustang that had it on the floor!

I have ordered Schroth profiII-6 harnesses, these seem to get a pretty good rep.
 

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maximizing slip angles
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Autopower makes a bolt in 4 point cage for the Supra.
 

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NSW supra club Member
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Discussion Starter #11
Yea i seen them, and was interested but when i went to email them, i couldnt find theyre email address!
I wanted to asked about any difference being RHD here where i am and where do the legs bolt onto(floor or part of chassis).

They list distributors but who do i ask, and who would ship international!
Obviously i would like some trustworthy...

cheers
 

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Highway Demon
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ioport racing is one of their largest distributors. I dealt with them and they are nice guys. I have the 4 point bolt in roll bar. The main hoop mounts to the floor right in front of the backseat bench in the corners of the backseat foot wells. The aft bars go back and mount to the wheel well arches. The aft bars go through the stock rear speaker mounting location. There is no cutting of the factory panels needed to install this roll bar due to its routing through the stock rear speaker location. Mine luckily for me was given to me as a gift but it did not come with the harness bar, as mine was made more for street cars. Not sure if you would be interested in the Autopower roll bar since it is a bolt on that uses sandwich plates to the floor and rear wheel wells.
 

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NSW supra club Member
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Discussion Starter #13
Thanks for the info, i might see if i can ask them a few questions.
After that link Joshua posted of the mustang, i am not really keen on having a bolt in cage that bolts to the floor pan, as it seems its the weakest link!

cheers.
 

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Hey Danny,

As you know I got a container coming from Japan. I think a Cage like mine will be good. Its a Cusco Saftey 21 9 Point. The front legs bolt to the chasis instead of teh floor.
 

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Not Enough Grip
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A 9 point cage for a car that is going to be driven on the STREET? Better start getting used to wearing a helmet everywhere :confused:
 

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NSW supra club Member
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Discussion Starter #16
Shane, i only see a 6 point?
Also, everyone here is saying anything more then a 4point is illegal here in NSW, even then you have to engineer it, so id find out if your going to use that.
Id be happy with a 4 point with harness bar and a crossover.

Do cusco make 4 point that doesnt bolt to the floor?

The back main loop still seams it will be attached to the floor pan?
 

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Autopower makes a bolt in 4 point cage for the Supra.
Anyone have any thoughts about an autopower bar? i'm looking to increase safety but do not want something permanent. do you know if they bolt into the floorboard or some other more sturdy area?

Thanks.
 

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NSW supra club Member
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Discussion Starter #18
as above, 95jza80tt mentioned that his autopower mounts to the floor, so im not keen on that.

Ive finished making my harness bar, i'll take some pictures tomorrow, just waiting on my harnesses.
 

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Highway Demon
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Hey Mazman this is OT but I just wanted to say thanks for the write up you did for the custom airbox. I had a buddy of mine that had full access to a machine shop make one for me in his spare time a long while ago. The only major change I did was to wrap the entire box exterior with heat resistant material instead.

 

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as above, 95jza80tt mentioned that his autopower mounts to the floor, so im not keen on that.

Ive finished making my harness bar, i'll take some pictures tomorrow, just waiting on my harnesses.
Thanks. Would bracing help and make things sufficiently safe?>
 
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