Some Technical Questions

[Russman]

Hi All

Got a few questions before I get stuck into my brake upgrade.

I have bought some R34 Gtt front calipers (310mm rotors) to put onto my R32 Gtst.

Will they fit straight on without mods?

Is my brake bias going to be affected?

Thanks,

Russell

[Roy]

The only way to find out is to bolt it on and see.

But on the face of it, bias wont be overly affected. The R34 calipers run the same sized piston as the R32/33 etc so the only real difference is running the bigger rotor that still fits inside the 16" wheel.

As for bolting straight up. You will find that the R34 caliper uses bigger bolts so will need to drill out your hub.I havent done it personally but understand its not that big a job

[Russman]

Thanks mate.

I look forward to getting it done.

[Russman]

Has anyone done this before?

Am I best to drill out the hub and fit the larger bolt or can I get a hub off an R34 skyline and fit that?

I don't want to drill them out and then find out that there is not enough meat around the hole and make it dangerous.

[BHDave]

I've done it. As roy said all you need to do is drill out the holes.

I've had r34gtt brakes on my r32gtst for a good 3 years now with no problems. You're only increasing the size of the hole by 2mm, 16mm-18mm from memory.

[Russman]

Yeah I had read 18mm somewhere but I wasn't 100% sure.

Did you grind off the shroud behind the disk? Also did you just drill it in place or did you use a proper drill press?

Thanks for the info.

[BHDave]

The backing plates are untouched on my car. The fit was perfect.

I did the dodgy method and drilled on the car. It took 2 people to hold it all steady and drill it though.

[Russman]

The backing plates are untouched on my car. The fit was perfect.

I did the dodgy method and drilled on the car. It took 2 people to hold it all steady and drill it though.

Hmmm.. The backing plate fouls the new larger disk. I'll grind it off anyway for better cooling.

I think I'll just drill it on the car too. I'll probably stuff something up taking the hubs off!

Now I just need to get the correct size bolt because the callipers I bought didn't have the bolts! Anyone have some? Do you know what size the bolt is?

[Roy]

Yeh, get rid of the dust shield...i have ran without one for years with no probs...meant to help cooling as well

[BHDave]

For the bolts i just took an r32 caliper bolt for length and the r34 caliper for a sample to get the right diameter/pitch bolt. Shame the place i used to get all this shit has closed, damnit!

Then measured the bolt to get the right size drill bit. though 18 does ring a bell.

[meanman]

I am in the same position. Own a Cefiro and have R34 calipers and rotors.

So just drilling it out while they are still on the car works..... sounds alright then.

What about the rear calipers? Is it the same or is it just the front that use the bigger bolts?

The bolts came with the brakes except for one *sigh so now I need to find one bolt aswell. Anyone know where you can pick these up from?

[meanman]

I still havnt finished it. Ive measured the size of the R34 bolt and its 14mm but Ive been to bunnings and Repco but they dont sell 14 mm drill bits. The biggest drill bit they stock go up to 13mm.

Where can you get 14mm drill bits from? I also measured it in imperial which came to around 3/5" which again I could not find.

THIS IS SOO ANNOYING. Might just sell the calipers and get me some R33 calipers.

Any help will be much appreciated.

=> Russman, how are you goin?

[Russman]

I'm gunna try and get the bolts this week. We'll have to go to a fastners place. Bunnings and repco/bursons don't really have that stuff. the R32 bolts are 48mm long and I'm taking in the caliper to get the right thread. Make sure they're high tensile stuff. I didn't really think about drill bit size... what are the original hub hole size?

Don't sell em. shouldn't be too hard...

[meanman]

Just spoke with a friend about this and he said I should explore the option of a "Helli Coil" or "Heli Coil" Dont know exact name/spelling.

But basicly take it to Repco or a fabricator or something along those lines and ask for one.

We all know now that the original bolt and hole on the car is smaller then the new bolts and hole on the new calipers. My friend said these Heli coil things are basicly a plug that you will be able to thread into the new caliper which is hollow and has a thread on the inside.

Thus you use your old SMALL bolts which will then be able to screw into the new calipers..... Sounds interesting and obviously get it in high tensile stuff so it wont break.

Will check this out tomorrow hopefully. Will let you know when I have got around to it.

[Russman]

Just spoke with a friend about this and he said I should explore the option of a "Helli Coil" or "Heli Coil" Dont know exact name/spelling.

But basicly take it to Repco or a fabricator or something along those lines and ask for one.

We all know now that the original bolt and hole on the car is smaller then the new bolts and hole on the new calipers. My friend said these Heli coil things are basicly a plug that you will be able to thread into the new caliper which is hollow and has a thread on the inside.

Thus you use your old SMALL bolts which will then be able to screw into the new calipers..... Sounds interesting and obviously get it in high tensile stuff so it wont break.

Will check this out tomorrow hopefully. Will let you know when I have got around to it.

I thought helicoils were used basically when you stuff a thread and it gives you a new thread, not to make a thread smaller?

Anyway I got the bolts from a fastners place but I got 50mm bolts and that doesn't include the head so it's about 58mm not 48 that I need so I'm going today to get the 40mm bolts which should be right.

edit: Got my bolts now, M14 x 40. just need to get some brake pads and a 14mm drill bit and I should be all set!

[Russman]

I've finished one side and all is going well. I'll be doing the other side on monday and plan to put up a DIY here on SAU.

Hows it going meanman?

[discopotato03]

If you can get a step drill it will stay pretty much on centre , self aligns .

Cheers A .

[meanman]

I've finished one side and all is going well. I'll be doing the other side on monday and plan to put up a DIY here on SAU.

Hows it going meanman?

Havnt done anything have slacked off on this. My bad, did buy Cusco coilovers and fitted them fine:D

Where did you get your 14mm drill bit? Where did you get your bolts from? im missing one.

[Russman]

If you can get a step drill it will stay pretty much on centre , self aligns .

Cheers A .

I doubt a step drill will have a long enough step to drill one size for the width of the hub.

Havnt done anything have slacked off on this. My bad, did buy Cusco coilovers and fitted them fine:D

Where did you get your 14mm drill bit? Where did you get your bolts from? im missing one.

14mm drill bit and bolts I got from a bolts and fasteners place. drill bit cost $25 and bolts were like $15 for 4. You will need a M14 bolt that's 40mm long. Good luck.

Anyway I'm all done and drove it around last night and it's all good. I'll post some pics when I get some time.

[neo32]

just got my 34 gtt brakes on my 32 put ebc red stuff pads

stops insane now

did new braided lines