Thread for discussion on the following posts, I have started this thread to keep this subject out of the thread it popped up in as it was off topic for that thread. Quotes from Monkeyboy relating to brake upgrades: "If you use that argument, then really really big brakes on the front mean you don't need any rear brakes. It doesn't work like that." (relates to a comment that rear brakes require less cooling due to fronts doing more work) "I just think that the common notion that just bigger on the front will always result in better braking can be misleading to a lot of guys just starting out and find that their braking distances can actually increase because hydraulic pressures to the rears are reduced in proportion to the braking effort applied to the front circuit. When you imply that the rear rotors will run cooler because the fronts are used more really means that the rears are no longer supplying as much braking effort to the tyres in the way the system was designed. In normal driving, street, it is already easy to lock( when I say lock, I mean in our case, going to the point where abs is activated) the front wheels with the stock brakes. Once a brake system is capable of braking traction, no amount of larger brakes will have any advantagous effect in reducing braking distances. If this is the case and you put larger brakes on the front only and do not address the now brake pressure proportion imbalance that has been created, any street driving that results in the front wheels locking means that because you have managed to lock the front wheels, the reduced braking pressure to the rears results in reduced braking efficiency of the rear wheels. They are no longer working as hard and hence not stopping your car as quickly as it has the capacity to do. If talking about track days i.e., high speeds, you have a bit of an advantage with larger front brakes because they are able to deal with higher temps and offer higher clamping forces where the stock brakes will be overwhelmed. Having said that, your car's brake system will still be operating in a state of imbalance until the appropriate increase in rear brakes is addressed by the addition of larger brakes. A front bias of 80% which is an average effect of front brake upgrades on Z32s will create the illusion of better brakes because the fronts go into abs quickly, meanwhile the rears have less pressure applied to them and you get almost no if any improvement in overall braking performance. My advise to anyone contemplating brake upgrades is to speak to brake specialists and be very careful, as usual, about changing anything as complex as the brakes based on partial knowledge and advice". "It is misleading to make the point that the rear brakes are bigger so you only need to add big brakes to the front. The car's brakes have been designed to provide the correct braking balance for minimum stopping distance. Altering one side of the equation imbalances the system by effectively reducing the involvement of the rear brakes in the process of stopping the car. I can't understand how you offer the 2/3 - 1/3 example and then advocate the shifting of this ratio". "I know that most guys start their brake upgrades wth the fronts only but it is poor advice to not include the caveats of doing the fronts only. It's very important to remind people that they will have an unbalanced system until the rear brakes receive the attention needed to redress this imbalance. Your point about the use of a bias adjuster is only applicable if used to reduce rear bias. Seeing that this discussion is about the upgrading of front brakes only, the addition of a bias adjuster can only further reduce rear pressures which is the opposite of what is needed here. My problem is that I don't think some readers are getting the correct picture from what a lot of people say about front brake upgrades". It is the opinion of some forum members (including myself) that it is acceptable to upgrade the front brakes of the Z32 without upgrading the rears. It is at least my (others as well no doubt) opinion that the addition of larger front rotors & calipers will benefit the braking performance of the Z32 with no adverse side effects. This is obviously as a primary upgrade to improve the system, there are options to upgrade the rears once the cars performance dictates this is required. At some stage you would look at the entire system with twin master cylinders etc once you start to get really serious with your racing - not normally something you would do with a street car. My own personal opinions as to why this is an acceptable practice: R33 GTR rotor upgrade with spacers for calipers: Zero hydraulic modification, the calipers & master cylinder remain the same so hydraulic performance is not altered (rear braking remains the same for the pedal pressure applied). Bigger rotors = more braking power for the same pressure applied to the calipers (so long as pad size etc remains constant) = braking bias is increased at the front. R33 GTR caliper & rotor front upgrade (Brembo/350Z track etc) Hydraulic modification: two of the pistons on each caliper are slightly larger than the original calipers, this increases pedal travel minutely (1mm or so) & increases available braking pressure to the front. This does NOT alter what is available for the rear in any way shape or form, rear braking remains exactly as it was for the pedal pressure applied. The bigger rotors, bigger pads & increased available pad pressure all combine to increase the front braking bias. Braking bias change, the Z32 has the exact same braking system for the 2+2 & the 2+0 even though there is a weight & balance difference between the two models. Nissan obviously were not concerned with slight alterations from the "perfect" braking bias. When upgrading brakes we do so normally because we intend to use the car beyond its original performance envelope (IE track use etc) if we intend to use the brakes for motor sport it is normal that more braking is required in the front due to the heavy braking required. (under braking the centre of gravity for the car moves forward & places more weight therefore grip on the front wheels, heavier braking moves it further - note how the rear of the car pitches up & the front down = C of G shift). Therefore an increase in braking at the front percentage wise is a good thing for extreme use & not a serious concern for normal road use. NONE of the kits I have seen normally installed as a front only upgrade shift the braking balance/bias so far as to cause any possible trouble. NOTE: The R33 GTR (fitted the Brembo brakes all round) actually runs a very similar sized caliper & rotor on the rear when compared to the Z32 300ZX - virtually no gain from changing these performance wise. Interesting to note that being 4WD they can increase the braking vastly on the rear when compared to a front engine rear drive combination. This just adds more weight to the notion Z32s were fitted with large rear brakes compared to what would just do the job. I'm concerned that there has been a comment made that suggests a vehicle with upgraded front brakes will take a longer distance to stop, first of all this is utterly ridiculous & here is why: You know what I can't be arsed anyone with common sense knows if you apply more force to the pedal you stop faster (until you break traction & skid), improving braking efficiency simply results in less pedal pressure required for the same braking force :bash:
I cant see a problem with upgrading to 324mm fronts with stock calipers(what it should've been from the factory). not sure about the brembo calipers and leaving rear stock. I went with STOPTECH for the fact its big brakes are designed to work same as/or better than factory bias
re: R33 GTR rear brakes, I'm guessing being 4WD increasing rear braking would reduce the initial turn in understeer experienced by all AWD cars when braking into the corner? I run the brembo front, stock rear combo and haven't found any bias issues under heavy braking into corners. Should have came this way from factory. As for pedal feel the brembos have a much more linear feel than the stock front calipers. Braking distances reduced and with two piece rotors no extra unsprung weight was gained over stock either. Definitely a worthwhile upgrade and while you can do the rears too, I agree it is not needed.
Rear GTR Brembo's are so close to stock I can't justify the $800 for a different sticker on my rear calipers... A few mm larger rotor and a slightly larger pad.
That all sounds cool mungyz. The only comment I would add is that it is that bigger brakes will have less fade and given that the rear brakes on a 300ZX are relatively oversized the brake balance will probably be better with an upgrade to the front rotor under race conditions.
I think it's a gain of 4mm all round in both diameter and thickness + extra pad surface. I suppose the extra thickness w/ bigger cooling vanes might be handy over long periods of track abuse but for weekend warrior street cars it's definitely not needed.
Agreed Plenty more I could babble on about but I didn't see the need. There is a good article in the tech section on how brakes work for those who might want to learn more/other things about brakes Interesting it reads almost word for word about weight shift under hard braking.
Mungyz, I agree with you - to a point. I don't the improvement can be open ended on improving front brakes only. I have upgraded my fronts to 332mm Stoptechs with Stoptech 4 pot calipers, without uprading the rears save for a switch to slotted rotors. If, however, I was going to fit top-of-the-range 6 pot AP calipers over 355mm rotors to the front, then I think some further improvement to the rears would be warranted, probably to 4 pot calipers. I'm no mechanic or engineer, this would just be my personal choice based mainly on what high performnce car manufacturers tend to fit with big brake upgrades.
Agreed, as I said at some point the cars performance will dictate more than just an upgrade to the front Pretty much what we are talking about here (from what I gathered) is he basic first steps of improving the brakes, one of which is upgrading rotors & calipers. Funny no one seems to grizzle about people replacing the front pads with high performance ones & not the rears, no one seems to grizzle about replacing standard front rotors with slotted ones & not the rears. Yet upgrade your front calipers & rotors & you are the spawn of satan brining about the end of the world in a cataclysmic ball of unbalanced evil
I have the 355mm disc with 6 pot AP calipers on the front. I recently replaced my old rear pads with some Hawk ceramic pads and the braking ability of the car has improved greatly. I think too many people overlook the importance of fitting the right pad to the application. I know I was guilty of that with my rear selection.
Sadly this is the best I've got of the fronts: As for the pictures of other types of kits most vendors websites have nice pics of the kits available. UAS have some nice pics as do Z1, Caz & concept z.
My sentiments exactly. Z32 is fairly heavy up front, the harder you brake the more weight is transferred forward too.
Seems fairly obvious most of us are on the same page, the proof is in the pudding. Front brake upgrades have been a proven upgrade for many cars for years, some require more than just rotors &/or calipers, years of development with the Z32 has proven just the fronts is fine for a start. Obviously most people will change the rear pads for a more suitable spec than stock & some will add slotted/ dimpled rotors etc but essentially the stock size rear brakes can go a long way into the high performance zone.
Anyone have experience with Wilwoods? While we are on the subject - does anyone have experience with Willwoods? How do these compare to Brembo, AP etc?
