Gt-r's Past Their Used By Date?

[32vspecII]

a nice evo is $40-$50K ditto the sti. now if you are patient and willing to break someones balls on price then you could find a pretty damn good 32 GTR for $25K. now you have $20K to spend on it. I reckon you can get a $50K 32 GTR going just as quickly as a $50K Evo or STI.

you could bust some balls and get an evo 6 for 25

so would the 50k worked evo be quicker than the gtr . its something to ponder

[Roy]

If you want ferni im pretty confident i can get you some 340 x 32mm Performance Friction rotors that are 42 vane (from memory...have to check) that would work nicely with Brembo and 18" wheel

[Sydneykid]

The brembo would surely be the better option though as it woudl saddle the rotor better

That's the theory, but the real world is that I personally can't feel any difference. With the same compound pads in both applications, I can lock up the 245/40/17 "R" spec tyres anytime I like in a 20 minute session. The pedal feel is the same, logically the power booster is masking whatever small differences there are.

Which calipers? Whats involved in getting these discs to fit with the brembo calipers? I'm running stock sized 324x30mm (i think?) DBA5000 with my R33 GTR brembos...

I bought some calliper adaptors that didn't fit and then modified them slightly, 10 minutes in the mill was all it took.

I used the DBA 5000 series GTR hats with 343 mm rotors, machined down (in the lathe) to 336 mm.

The pads have to be ground down (on the linisher) 0.75mm from new to give clearance for the 32 mm thick rotors.

Next I am going to try some slightly larger pads, it will spread the load accross more surface area and therefore reduce the spot rotor temperatures slightly. Plus I am looking for a little more feel, which the increased pad to rotor contact area will give me. I am checking the Bendix master catalogue for a pad that is slightly larger, which I will trim to shape on the band saw.

The medium term aim is to have a standard Skyline calliper with adaptor, two piece rotor, brake line, brake fluid and pad combination that will give better performance than the current grossly overpriced brand name setups that we use on the race cars. One that is both cheaper to buy and cheaper to maintain, because the race team budget is finite and I think I can get better value for money interms of faster lap times using the (saved) money elsewhere.

cheers

[Roy]

That's the theory, but the real world is that I personally can't feel any difference. With the same compound pads in both applications, I can lock up the 245/40/17 "R" spec tyres anytime I like in a 20 minute session. The pedal feel is the same, logically the power booster is masking whatever small differences there are.

I was more thinking that the Brembo caliper swallows a 324mm rotor from the factory. So the 340mm jump is only 16mm bigger. Not near as dramatic as the 44mm jump when using the R32 GTR caliper intended for use with the 296mm rotor. The inner radius of the Brembo caliper is more likely better meaning the pad will fit better against the face of the rotor. Dont know what the proper term is but i say the brembo will saddle the 340mm rotor better.

So from that perspective it should be better...no other reason though, um well maybe pad area as thats something for nothing

[Beer Baron]

let's not discourage cashed up 33 and 34 GTR owners from buying big AP kits gary. I want a set of reasonably priced standard brembos...

[Sydneykid]

I was more thinking that the Brembo caliper swallows a 324mm rotor from the factory. So the 340mm jump is only 16mm bigger. Not near as dramatic as the 44mm jump when using the R32 GTR caliper intended for use with the 296mm rotor. The inner radius of the Brembo caliper is more likely better meaning the pad will fit better against the face of the rotor. Dont know what the proper term is but i say the brembo will saddle the 340mm rotor better.

So from that perspective it should be better...no other reason though, um well maybe pad area as thats something for nothing

Yep, that's why I am looking for a slightly larger pad. The R32GTR N1 Brembo calliper has a pad that is only slightly bigger than the pad in the standard R32GTR Sumitomo calliper. Mostly inwards, towards the rotor centre.

If I get a chance tonight I will post up the Bendix pad profiles, you can easily see the small difference.

cheers

[Sydneykid]

let's not discourage cashed up 33 and 34 GTR owners from buying big AP kits gary. I want a set of reasonably priced standard brembos...

In the circuit race off season, we have back to back tested 324 mm x 30 mm DBA5000 Series two piece rotors with the same pad compounds using Sumitomo and Brembo callipers and the difference is not discernable. Not by me, anyway, that’s driving and reading the data logs (same longitudinal G forces).

Right now the 336 mm x 32 mm rotors with the same pad compounds using Sumitomo callipers are out performing the 324 mm x 30 mm rotors using Brembo callipers. The rotors and pads are lasting longer and running at lower temperatures (according to the temperature paint).

I honestly believe that the difference between the GTR Brembo brakes and the GTR Sumitomo brakes is ALL rotor diameter and pad compound. People replace their rooted 296 mm rotors, water contaminate brake fluid, spongy rubber hoses and worn out, crappy pad compounds with new Brembo stuff. Is it any wonder that the brakes are better? It’s not a fair comparison.

cheers

[Beer Baron]

In the circuit race off season, we have back to back tested 324 mm x 30 mm DBA5000 Series two piece rotors with the same pad compounds using Sumitomo and Brembo callipers and the difference is not discernable. Not by me, anyway, that’s driving and reading the data logs (same longitudinal G forces).

Right now the 336 mm x 32 mm rotors with the same pad compounds using Sumitomo callipers are out performing the 324 mm x 30 mm rotors using Brembo callipers. The rotors and pads are lasting longer and running at lower temperatures (according to the temperature paint).

I honestly believe that the difference between the GTR Brembo brakes and the GTR Sumitomo brakes is ALL rotor diameter and pad compound. People replace their rooted 296 mm rotors, water contaminate brake fluid, spongy rubber hoses and worn out, crappy pad compounds with new Brembo stuff. Is it any wonder that the brakes are better? It’s not a fair comparison.

cheers

yeah, I agree with that 100%. but for me, I'm running good condition DBA4000 rotors (currently have 2 full sets on the go), using nismo braided lines. using RBF600 fluid (and change is regularly), and currently have 4 or 5 full sets of pads to chose from. The only thing I need to do is put a seal and boot kit through the front calipers (may do it this weekend) and then I've run out of stuff to do with them. BUT yes, I will do the bigger rotor option over buying brembo gear, simply because it costs lest, and delivers are bigger and thicker rotor.

Gary, I do have one question. why did you machine down to 336mm instead of say 340? or even leave them at 343? is it to fit a certain type of rim over them? or could the calliper not accept the 343 or even 340 rotor?

[fuzzy_scuz]

But is it quick

I don't know

[Sydneykid]

yeah, I agree with that 100%. but for me, I'm running good condition DBA4000 rotors (currently have 2 full sets on the go), using nismo braided lines. using RBF600 fluid (and change is regularly), and currently have 4 or 5 full sets of pads to chose from. The only thing I need to do is put a seal and boot kit through the front calipers (may do it this weekend) and then I've run out of stuff to do with them. BUT yes, I will do the bigger rotor option over buying brembo gear, simply because it costs lest, and delivers are bigger and thicker rotor.

Gary, I do have one question. why did you machine down to 336mm instead of say 340? or even leave them at 343? is it to fit a certain type of rim over them? or could the calliper not accept the 343 or even 340 rotor?

A couple of reasons;

1. Rim clearance, I knew that 336 mm would clear the 17 x 8's (we have 16 wheels), I wasn't sure about 340 mm or 343 mm.

2. I had pads, in our usual compound, with a radius suitable for 336 mm

3. (the real reason) I already had calliper brackets for 336 mm

There is that availability answer again, it was there, so I used it. Machining the rotors to 336 mm was easier than designing and making new calliper brackets from scratch.

cheers

[Beer Baron]

thanks, I just wanted to make sure there wasn't some glaring problem with a 340 or 343 that I had overlooked

[ferni]

If you want ferni im pretty confident i can get you some 340 x 32mm Performance Friction rotors that are 42 vane (from memory...have to check) that would work nicely with Brembo and 18" wheel

Interested. But i would need brackets or something to fit the rotors wouldn't I? What are the rotors worth. I run 18" rims so thats not an issue, just getting them to fit/work with standard brembos is.

[Roy]

What is anything worth. The rotors, hats, adaptors etc would be in the ball park of $800 and you can use your old brake lines and pads. Problem is do the Brembos swallow a 32mm thk rotor with fresh/think pads?

[ferni]

800 for rotors/hats/adapters sounds reasonable, what about replacements discs only when needed.

As for 32mm rotor, seems like SK is running 32mm by shaving off .75mm (so 1.5mm total) from new pads, which isn't much.

[Sydneykid]

800 for rotors/hats/adapters sounds reasonable, what about replacements discs only when needed.

As for 32mm rotor, seems like SK is running 32mm by shaving off .75mm (so 1.5mm total) from new pads, which isn't much.

Yep, couple of minutes each pad on the linisher. Or better still, order pads with less material, for example there are 3 thicknesses available in the pads we use. The backers are high tensile so no flexing there.

cheers

[Roy]

800 for rotors/hats/adapters sounds reasonable, what about replacements discs only when needed.

As for 32mm rotor, seems like SK is running 32mm by shaving off .75mm (so 1.5mm total) from new pads, which isn't much.

Reasonabvle? Fark me dead you are a hard man to please. I think its a steal...but you have to remember its 2nd hand rotors, though they have only done about 20-30 laps

[djr81]

Has anyone tried the Stoptech ST-40 caliper?

From their blurb it is a 4 piston, 2 piece caliper.

Piston sizes are 38 & 44mm (although other sizes are available) which is the same as the Brembo.

Importantly the pad is larger at 131mm long. Apparently it is a FMSI D372 pad if that means anything to anyone. You can get a good range of compounds.

Caliper weight is 3.6kg which is pretty close the the Brembo weight.

The only thing that I cant see is the mounting holes/arrangement but they offer kits with the requisite brackets.

Rotor ranges are 28 to 35 mm & 328-380 diameter.

Can be bought with hatted rotors.

Australian vendor is C-Red.

It sounds like what I have been looking for, but has anyone tried them?

[Beer Baron]

lol, how is it that every GTR thread these days seems to end up talking about brakes? haha

I have never seen the stoptech bits in person but they certainly know how to write good marketing speil! and their prices are not too bad.

[djr81]

lol, how is it that every GTR thread these days seems to end up talking about brakes? haha

I think it is because, despite the number of different brands of caliper on offer, none of them are particularly suited to running with 17" rims. Most of the 4 piston calipers are too small in piston area & the 6 pistons are mostly designed to run with 355mm or larger rotors.

[Beer Baron]

add to that we are all too tight (or sensible?) to spend $10K on an AP or Brembo kit!