Fitted the Porterfield Cryo front brake discs about a month ago, they are Brmebo blanks that they Cryo treat. Fitted the Porterfield R4 race pads the day before going to Rockingham and a refill of DOT5.1. It felt great on the road, massive breaking power. However on track after doing 3/4 laps at a time and leaving it 15/20 to cool or more by the end of the day got them glowing on a 2 hot lap and the pads melting. NO BRAKES AT ALL, and was a bit of a problem as I had just come to the end of the pit lane straight off the banked corner 4 at 120mph though the cones and drifted to a standstill.

 

End of story - I stopped pissing around with standard discs and have ordered the AP racing 330mm discs and pads kit from SE. If you modify past 350(flywheel)bhp do your brakes next or make a will!

 

Yours a briefly very scared 300zx driver pleased to have bought Toyo Proxes that got him round a corner with no brakes at 120mph.

 

Note from the passenger "F*cking Hell why the f*ck did you do that you b*stard you scared the cr*p outta me, you f*cking maniac!"

 

 

[This message has been edited by jvnewcomb1961 (edited 30-09-2002).]

 

[This message has been edited by jvnewcomb1961 (edited 01-10-2002).]

Now don't go and start on me my South African friend. After all you're in my country ! (and in case anyone reads this and hasn't seen the thread which indicates that this is a joke - IT'S A JOKE).

 

I agree completely that you get better braking with larger swept area AND larger calipers (well, actually, a larger pad area - it's just that that is nomally provided by larger calipers with more pistons).

 

What we're talking about here is doing part of what you suggest - the larger swept area. The kit which John has been talking about gives a much bigger swept area and, from theory (increase in radius x 2 x pi increase in swept area) AND from personal experience, this gives vastly improved braking.

 

I don't dispute for a second that adding a bigger caliper would improve braking even further. It's just that, as my earlier post said, I think John is wise to do the upgrade in stages as there's no benefit in over-engineering the brakes.

 

Re the Le Mans comparison, there is far more than the weight of the car affecting it (actually, that should be mass!). After all, the brakes themselves don't know how heavy the car is - they just know what the braking force is which they are having to apply and, more importantly, the amount of cooling they're being allowed before they're asked to do the job again.

 

I reckon that Le Mans is a pretty good test for a set of brakes, even though the Z is a heavier car. As I think I said in an earlier post, I doubt there are many drivers on this forum who have the ability or location to drive hard enought to push brakes harder than they get pushed at Le Mans.

 

Another thing that no-one has mentioned yet is improved brake ducting which I would definitely have gone for if I was into regular track days. My personal view is that they would have less benefit on the road when braking is not as hard or frequent.

 

Dave

If the 300 was to be setup for track racing where I was expecting to go for 10/15+ laps at a time then I agree it would be worthwhile parting with a larger amount of money and going for 10 pot calipers and discs better than AP's. However I have found that on motorways and normal roads when going fast the std disc diameter using the Porterfield or similar pads is excellent as attested to earlier in this post. There is a balance and to fit a full racing brake setup to the car would, in the same way as fitting a full race clutch to a manual car, make it I believe unsafe on the road. I do one or two trackdays a year and as such I am different to most 300 owners who use theirs on the roads. The idea of brake ducting is a good one, I took this up with SE and would agree that adding either some ducting from the under bumper to the calipers would be a good move so will be added to my list of stuff top do before my next trackday early next year.

 

I would be interested in anyone who has successfully gone on track with their 300 to add their comments, rather than just the "road warriors". I would add that although this debate has been rather heated at times it is a technical issue of expense, use, actual benefits and problems that many 300 owners may be finding useful. Don't let it get personal, I am trying not to....difficult as that can be at times on here.

 

Timmy - I have found that 1/4 dragging is not an issue for me, the highest speed I would expect to get on a 1/4 is under 120mph and braking from that speed was easily handled by the standard Nissan discs setup but using better pads. The issue here is not fast road or 1/4 strip use it is for on trackdays.

 

WillieO - my understanding from suppliers is that new discs/pads do not need a "few hundred miles" bedding in, manufacturers through their suppliers provide information on the correct "bedding in" braking routine and that is a series of braking actions that do this over a short time.

 

Your comment about the cornering is also beyond belief, I don't know how many trackdays you have done but instructors tell you what corners to go for flat out and those that in a heavy car like the 300 you go in slow and exit fast out of, this corner was definately a braking into corner and to do it on purpose without braking would be madness and should have put me in the gravel. I do not wish to insult you but in this case you don't know what you are talking about, however I value your comments and respect the time taken to add them to the debate - see GIO my Karma is coming back on stream the happy pills and meditation is working.

 

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Z first and anything else is secondary!

John (Nukem) Newcomb

www.geocities.com/jn300zxtt

Ok here are my experiences i have had with my car and brakes.

 

I had a brand new set of g-force discs fitted to my car when i got it, stock size ect cross drilled, i fitted greenstuff pads to them and after about 30miles, of to the Nurburgring i went on my holiday, i warped them stupid in one lap lol, and they really were not up to the job, the pad seemed alright on that occasion.As for braking power, the car seemed plenty powerful enough.

 

I changed these for a set of 3G brakes that were slotted (still have the slotted rears on my car) and greenstuff pads, i used these for Trax at silverstone and after my 5th lap i arrive into copse and nothing, no pedal pressure whatesoever, fried the pads, but i found this time the braking power was not as i would have liked, more so because of the brake fade.

I went to kemble later that year with a whole bunch of 300's (best event so far this club has arranged by a long shot)

i had redstuff pads with the 3G brakes (bremobo cast discs) Perfect day out and i did 3 sessions of 15 minutes and had no braking problems whatsoever, what i did find was that the braking distance and pedal feel both suffered and i was not able to realyl get on the brakes and feel 100%comfortable with them.

Changed the front over to Brembo 328mmx32mm and Skyline 4 piston calipers (which are huge) All i can say is the difference in braking is like night and day, i have managed to lock up my ABS with this lot, brakepads are redstuff again. I am very confident on the brakes with this kit, more so than ever before, as for te track, well ive done the ring with this kit and no fade whatsoever, they seem to get alot better and just almost come to you (that sounds wierd lol) No fade no problems after repeatedly heavy braking over and over.

So i conclude this (if your even still reading lol)

A: stock discs braking power is plenty fine for everyday use and fast driving on the road

B: I am very happy having gonewith the big brake setup and would not change back no matter what. Besides stock discs behind anthing bigger than 17inch wheels look crap

Thanks Warren. The only stage that you missed out in the past years unfortunately was using the larger discs but with the standard 300zx 4pot calipers, which is what I am intending to try out next. Otherwise my experiences go along with yours. I have to say that from recent past experience I would now never use either EBC greenstuff or redstuff pads again in my 300zx they just don't work for me, I think the Porterfield pads are great though and are fine even from first use of the day.

Well this topic was / is an interesting one. Loads of info and experience!

No insult taken John either. You're right too, I've never done a track day. Like to try it but I'm afraid I'll stuff the car or someone else! I'm good on Karts tho. I know someone who did track days like a drug and for him the brakes made more of a diffence than outright acceleration. He was into shearing off the discs but outbraked everyone on the track. Think he ended up with BMW M5 discs on a Sunny GTIR.

Look forward to your reports on the upgrade

Willie

LO chaps, back from the volcano so karma level is good (except when right wing fascists get my goat - no not anyone here just that other lot).

 

2p on brake stuff. Theory paper so no damn use for practical guys like you.

 

Brakes exist to convert kinetic energy into heat. (i.e. slow you down by getting hot.)

 

Kinetic energy rises as the square of the speed. So if you are entering a corner in trackday mode (at say 80) instead of pipe flat cap and braces volvo mode of 40mph, you have FOUR times as much energy to get rid of (not just twice).

 

So brake setups which might be well OK for fast road - or even strip use (one big grip , then trundle to the back of the queue and cool down while waiting for the next run) might be just not up to it after you give them lots of high energy brakes one after the other.

 

(Not an engineer, just opinionated!)

Aand another thing to add to GIO's opinions, me too! Everything in sports car design is a compromise. You can fit the most massive discs to absorb and dissipate the maximum energy but you will also increase the unsprung mass something fierce. The designer had a certain optimum unsprung mass in mind and people like us put anything up to 19" 245 section tyres on the front as well as huge thick heavy discs. So while you might make it stop well the ride and handling will eventually suffer as the front shocks and sus geometry struggle to keep the wheel and tyre on the road and vertical when you hit the bumpy stuff.

Willie

For what it’s worth, I'm currently running standard size Paget 8 groove discs with race pads and standard calipers following a recommendation from another Z and several Scooby owners. I have to say that they are excellent for both normal and fast road use with none of the warming problems you normally get with race pads.

 

On the down side, I recently took the car to Knockhill and although they stood up extremely well, only slight fade at the end of a hard 15min session, they generated so much heat that the dot 5 fluid boiled in the pits! I went to start next session – pedal to the floor and bugger all brakes – eventually came back though.

 

The next day whilst changing the fluid to DOT 5.1 I noticed the front wheel nuts weren’t as tight as I expected. Turns out the heat was so great that the powder coating on the inner face of the wheel had melted and squeezed out!

 

In summary, the set up is excellent for road use but I’ll be sticking to ¼ mile stuff from now on!

 

Colin

 

 

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