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Mark And Duncans R32 Build


Duncan

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The no-cas arm is a rear toe arm from S13/S14 which has a very similar rear suspension. So similar that one of the bolt holes for it is actually on the GTR subframe. We added a bracket so that it was supported from both sides for extra strength, but it is only in that spot temporarily. Once everything is in a a good ride height is set we will do the full bump steer measurements and move the inner end of the arm up or down as required - we have a couple of cm we can go either way

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Any news on finalising the best point? Looking to get a rear GTR cradle sorted for my bus.

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yeah....what brad said lol...

final mounting points is the last piece of geometery about 2 mins before it hits the track. We know the inner end is in the right area so we will measure and adjust when the time comes.

about time you put some gtr bits in your car troy....do you want to buy a gtr sump we have about 20 lol.

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hey Duncan have u managed to weld around the entire join of every rollcage pipe? the ones for the front strut towers look pretty close to the gaurds that welding around the side and underneath would be nearly impossible? also the ones coming from the main hoop bottom to the rear strut tower point look to be tough to access also? i assume they were bars all added in last once the main hoop was finished and welded up in position?

one other question, i want to sit the front legs coming from the A pillars hard onto the side of the sill (well hard onto the base plate bent up the sill), and weld up the side of them, is this allowed if i have the base plate bent to go up the sill and on the floor area, as welding around the sill side will be tough and if i leave enough room to weld then its gonna be a fair distance off the A pillars which i dont want also. Head clearance is not the greatest im gonna have to lower the seat as it is and im pretty short.

Edited by unique1
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yeah I will have to leave Mark to confirm the exact technique because I made excuses to be somewhere else every time there was a nasty welding job to do. In fact I'd rather scrape out tar using a heat gun than weld up the cage

but the trick is, front and rear you put the bottom of the cage on little pedastal say 10cm high. they go in last so you can drop the whole cage 10cm from the roof to get the clearance to weld. Even so many of the places are a disaster to get into, and yes you definately need 100% welded. Some other guys cut a hole in the floor and let the cage drop down to the ground while welding - then weld a plate back over the hole later

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no worries mate, yer i have cut the holes to drop the hoop down and hoop is setup and front legs are pretty much sorted i am just worried about specific rules with the position of the front leg and can it be welded up the sill, i got a pic ill post to show u what i mean...

the plate spacing the leg off the sill isnt the plate i will use so dont mind the bend in it thats just to get it spaced off the 3mm or whatever the plate is gonna be. Ill have a 3mm plate on the floor and 3mm plate up the sill too for extra strength. I am just trying to avoid leaving a 20mm gap up the sill area to weld right around as it then brings the legs too far off the pillar and effects head room. Ive read through the CAMS rulebook 20 times and cant find if its ok or not.

post-40430-1238669073_thumb.jpg post-40430-1238669448_thumb.jpg

Edited by unique1
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ahh I see. well actually no bracing to the chasis is mentioned in the CAMs book, I was just talking about what people do in practice. The only thing CAMS covers is the requirments for reinforcing where it is mounted. so....weld away!

that front leg looks nice and close, is that the real position or just temporary. We normally end up with it a little further away and just use plates from the leg to the chasis to support it

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Yer thats in the position it will be mounted its a well made kit actually i bought from Rod Andrews Race Cars and got it sent here, the hoop is touching just below both seatbelt mounting spots on the B pillars which is perfect and the front leg bars are spot on and only about 10mm or so away from the A pillars at the middle of the pillars, the point where the A pillar meets the roof is about 2mm away and as close as it could get everywhere else. I havent mounted any of the other bars yet but it seems like a good deal for $800 for the lot and its CAMS and ANDRA approved design so thats a bonus. Its all CDS as i was told CM is alot of work to get past CAMS without alot of extra expense.

does Mark visit the forums often? i wouldnt mind some info on the question about accessing the welds on the difficult spots and what order to do some of the barwork going into the engine bay strut towers etc.

post-40430-1238757085_thumb.jpg

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I'm here, though not often enough for my liking. Damn work gets in the way.

As to welding the A pillar bars to the floor, I ran with 2 plates perpendicular on the floor and sides, like a bit of v channel, but wider and then welded as much as I could with the mig. There's probably a patch about a cm wide which can't be welded on the base if you run the bars right up against the side, but in my case, I ran a thick weld up the bar attaching the bar to the side which more than compensated.

With the main hoop, you should be able to weld all the way around. If you can't, move it or bend it in a bit so that you can.

With all the other bars, I was able to weld all the way around with the exception of one little spot on the rear strut towers. But here again, it's attached to a plate and the plate is welded all arond and the bar is welded so strongly to the plate that it's not a problem.

Rule of thumb is weld as much as humanly possible, but having a spot unweleded is not the end of the world. Before I get harrassed by everyone for saying it, my last cage built by Bond roll bars didn't have the top of the main hoop to rear strut towers welded at the main hoop and it worked fine. I only discovered it after smashing the car and removing the roof.

Last bit of advice, from your picture you've got a bar clamp holding the A pillar bar in place. Make sure that the bar clamp is not forcing the bar in place. It should sit naturally in place. If not, bend it a little until it does. It should not be under strain beforehand. Not absolutlely sure of the mechanics, but the cage builder I was working with was adament that it should not be under strain.

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Thanks for the reply and advice Mark, i have only got that clamp holding the pipe up so it doesnt fall over while its sitting there (unwelded at the moment), its naturally gonna sit in that position which is good. I am able to access around the hoop no probs, its just the front engine bay strut tower ones and a couple of extra bars i was thinking would be tough to access with the mig.

so do u weld the front legs/hoop/rear sections in completely and then add in the bars from the front legs to the rear of the engine bay strut towers last of all?

also a different question for you guys regarding the mounting of the drivers seat... did u have to remove that factory braced section that runs across the floor on both sides of the gearbox tunnel to lower the drivers seat lower? its gonna be right in the way i think as head room is not the greatest with a helmet on.

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well actually....we haven't really resolved the seat mounting yet. Both Mark and I are not short and have troubles in our other cars with helmets banging on roll cages. the problem is the seat needs to slide so whatever we come up with has to utilise rails.

so at the moment it is using bride rail bolted into the stock mounting points. we also didn't put a diagonal in the roof section to keep good clearance.

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Sitting in Adelaide airport lounge with flight about to be called any moment, so if this post get's interrupted, I'll continue later.

Procedure is to locate main hoop with base plates or triangles, a pillar bars and the bar crossing the top of the windscreen (I strongly recommend you bend this bar at both ends to put it up to the room and out of the way as much as possible.

Tack weld it in a few places, then when you are happy with it, cut the tacks for the main hoop and drop the bar so that you can get to the top seams. Weld everything that will be hard to get to and then put the main hoop back in place and weld it all in place.

From here on in, tack everything. Don't weld it all up unless you wont be able to get to it again because of another bar. You will find that there are a lot of places, particularly in the rear where multiple bars meet. Only weld it once everything is in place or you will have welds on top of welds which will weaken it and make it harder to cut the bars.

Make sure all your bars fit without bashing them into place and if you are using Chromoly, make sure to tig weld as much as possible as mig makes the bars brittle.

As for the front bars, no way around it, it's a pain in the ass. I used a plasma to cut little holes then ran a string line to center it, cutting little bits away as necessary until the string did not foul on anything. Then using the string as a center I cut a hole just about the right size. Lots of trial and error and plates to cover the holse back up. Welding was hard and mostly done with the mig.

Hope it helps.

mark

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thats great help Mark, i got instructions with the kit on order of doing things so most is explained it was just at what stage to do those engine bay bars i was unsure of. I have that top of windscreen bar in the kit and it is bent on both ends which is a good idea by the sounds of it. The whole lot is CDS so mig is what im using as we just bought a brand new machine to do the job.

Well i guess its a matter of getting stuck in now, over the easter weekend we will get a fair bit done i hope and then i can focus on some other stuff and get this thing running :P

sorry for filling the thread with unrelated info to your project too!

Edited by unique1
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  • 3 months later...

NOTE:

You may have noticed this thread has been moved.

SAU Admin have decided to run a new section for "Projects, Overhauls and Build-ups"

As such your thread is a prime example of what we wanted to house in this section.

We have left links in the sections you originally posted also to allow easy access to the threads new home.

Any issues, please feel free to pm myself or N1GTR.

Cheers Col

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