Originally Posted by The Real Roadrunner
actually, being pedantic the diameter is actually 296mm for the r33gtst (and i think r32gtr). I have no idea where 297mm comes from
R33 GTR discs, they are normaly used with a brembo caliper but you can use an r33 gtst caliper on them also. just need a cutdown EVO brembo pad or a aston/jaguar pad with filed out pad pin holes.Originally Posted by jak
cheers
linden
Originally Posted by WHITCHY
Originally Posted by The Real Roadrunner
actually, being pedantic the diameter is actually 296mm for the r33gtst (and i think r32gtr). I have no idea where 297mm comes from
Last edited by barned01; 18-11-2007 at 07:34 AM.
Rear discs
Peewee
1985 MZ12 Soarer - 1UZ Powered
2013 86 GTS
That's correct...Originally Posted by CrUZida
The R32 GTS-T has 280mm Fronts with 297mm Rears, and both the R32 GT-R and R33 GTS-T have 296mm Fronts with 297mm Rears...
what about some r33gtr front disks. dont they measure 324mm?
OK... what you all have failed to mention is why big brakes are required... and this has been covered before. More power does not equal bigger brakes needed. Momentum is a product of mass by velocity squared... so we need to look at the mass of the vehicle, and the practical top speed. The 1100kg mass of the RA28 is your friend here, and the speed will be limited by a number of factors other than the accelerative capability of a 700hp engine. You still have a live axle rear suspension setup, and a rather primitive mcpherson strut front setup... so best case scenario, you will probably hit 250 before the car begins to get unstable and you either slow down or crash.
So, based on the GT celicas being capable of around 200kph, your only adding 50ish kph and maybe 100kg of mass... so 334mm brakes start becoming overkill, and will start hindering more than helping. In all honesty, if the 290mm VL turbo disks using slotted DBA rotors and a set of RX7 series 5 or 6 callipers and good pads wont slow you down effectively, nothing will. As for the back, it only does less than 30% of your braking, so they dont need to be anything near as good as your front brakes... which will probably unweight your rear end to the stage of them being useless anyways.
Also, you mentioned drilling things to 4 by 100pcd... RA28s use 4 by 114.3 pcd. Going to a 5 by 114.3 stud pattern though will increase your rim choice and improve thier availability... and is the same used on Supra and 5 stud hilux.
EDIT: the more unsprung (brakes, diff etc) weight you have, the earlier the car becomes unstable, and the less speed you will get, therefore the less your brakes need to perform.
Cheers, Owen
1977 RA28 with 1JZ-GTE (Was 18R-GTE)
Lancer EVO Brakes into old Celica/Corolla/Corona
Doing the things that aren't popular... cause being popular and being good are often distinctly different.
the reason for drilling to 4x100 (or 5x100 for ms65 hubs) is to attach them to the rear of the hub therefore giving more room for the calipers to sit behind the wheels.Originally Posted by o_man_ra23
pad size/rotor dia = stopping power
larger dia/thicker discs = greater thermal mass = more times you can stop b4 the discs/pads start to get too hot reducing braking efficiency.
OC could probly do all the calcs for you but basically what im trying to say the bigger the brakes the harder it will stop and will stop you more often b4 they overheat.
ill agree that more unsprung weight is a bad thing but if thats the case buy some decent forged rims to offset the problem, then you can have your cake and eat it too (to an extent).
the 324mm setup i did for a customer is practically the same weight as the C/H/P setup that most ppl run, more rotational weight (due to the large discs) which impedes acceleration slightly but reduced stationary weight (alloy calipers) which knida makes up for it.
cheers
linden
Originally Posted by WHITCHY
IC about the PCD... my bad on that. I know Brett_Celicacoupe had all the calcs, and after going through them, the VL turbo/RX7 setup is pretty hardy to begin with, and will be reasonably light too. I agree the CHP setup is pretty heavy due to the callipers, and would personally advise against it unless your doing a 1G conversion and are on the cheap.
And my big buff on the reasoning for wanting to not increase the unsprung weight is due to road holding capabilities of the RA28 suspension... you dont want to hinder it any more than you have to. Personally for my SA23 I dont intend on reaching much more than 200kph, the car will be built for every day driving and tight track racing... so it should never reach huge speeds. My planned SA28 however... will probably use RS200 Altezza suspension to enable higher speeds... but thats a whole nother world of hurt (especially to the back pocket!!)
Cheers, Owen
1977 RA28 with 1JZ-GTE (Was 18R-GTE)
Lancer EVO Brakes into old Celica/Corolla/Corona
Doing the things that aren't popular... cause being popular and being good are often distinctly different.
This is vastly oversimplifying the matter. You could have an RA2x with a 500hp 1UZ which weighs about the same as a stock RA2x, and yes the stock brakes will pull it up just fine - but the difference is the 500hp allows higher speeds, and more importantly it will allow you to accelerate much faster between corners than the old 18R-C. This means the brakes will suffer heatsoak far sooner than a stocker. Trust me, I experienced this phenomenon first-hand when I stuffed a 2JZ in my Supra with no supporting mods.Originally Posted by o_man_ra23
Long story short, more power DOES mean bigger brakes are necessary/advisable.
Norbie!
www.norbie.net
Thats also a vast oversimplification Norbs... my original intent was not to say that an upgrade was not necessary... but a car that has been increased to 700hp will most likely only required a very slim amount of extra braking capacity than one with 500hp (all other things equal). Especially in this case where there are other factors limiting the speed gaining capabilities. Also traction will try and reduce the amount of acceleration between corners, as traction is the limiting factor when you talk about power to weight ratios.
Cheers, Owen
1977 RA28 with 1JZ-GTE (Was 18R-GTE)
Lancer EVO Brakes into old Celica/Corolla/Corona
Doing the things that aren't popular... cause being popular and being good are often distinctly different.
I think the point here is that stock RA2x brakes are barely adequate for the asthmatic 18R-C, so even with modest power upgrades a brake upgrade is well advised.
FWIW the MA61 brake upgrade was one of the best things I did to my RA23, and it's far from a powerhouse!
Norbie!
www.norbie.net
Yes, it needs to be upgraded, but going overboard IS a bad thing...
I would suggest that if the VL turbo upgrade is not enough, you need to look at more than just your brakes (suspension and steering system will have an effect on the performance of your brakes as well as tyre choice, tyre pressure etc)
Cheers, Owen
1977 RA28 with 1JZ-GTE (Was 18R-GTE)
Lancer EVO Brakes into old Celica/Corolla/Corona
Doing the things that aren't popular... cause being popular and being good are often distinctly different.
ill post some pics next week of the setup. we are in the prosses of making custom adj stut tops so shit is everywhere.
324mm rotors
x130 struts
mx85 hubs
koni adj shocks
we are using an ae71 r and p
How about, to match that 700hp motor you simply go custom one offs.
Wilwood 320 x 32mm rotors and Six Piston Superlite calipers. Will fill 17" rims rather nicely.
How do you plan to use all this Jak?
Regards
Rodger
well, if u run 9's, u need a chute to pull you up properly.
and i will probably take it to ek raceway every now and again.
im just matching the brakes to the power level.
not sure exactly what the power levels gonna be yet, but will be 1jz and will have a gt42 which is huge for a 1j btw.
Jak
'77 RA28 Celica - Repairing Rust...
'84 AE71 Daily Driver/Race Car
'91 MX83 - Fastest Standard Turbo 1JZ Powered Vehicle In The World -
10.74 @124 Mph
http://www.youtube.com/watch?v=H2ido6yirZ8
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