thanks crossbow. nice post on the brakes.

 

Do you think you might have that backwards? Maybe it's the people who are NOT getting fade at the track that know how to drive? Put differently, if you are getting fade then you must not know how to drive @ the track...

(Go ahead, ask a performance driving instructor - you'll be surprised.)

Regards,
Gordon

 

Speedsource uses the stock rotors in their racecars... they have NO problems with braking. They have actually won a race too. Maybe they don't know how to drive at the track.

 

Yes, Speedsource is using the stock rotors but they are also using Hawk racing pads and a brake fluid with a higher boiling point.

 

The StopTech 14-in big brake kit for the RX-8 was tested in May's SCC and recorded fade free 60-0 braking in 103 ft. These are bigger front rotors, slotted (6 slots total). The car also has different wheels/tires that may contribute to this.

 

If you used the stock rotors, stock fluid, stock pads, and stock calipers...but just swapped the stock tires out for hoosiers....you'd probably stop in less then 100 feet.

Brakes stop the wheels....the tires stop the car.

 

Case closed then, StopTech used different tires. What a bum comparison. Put softer rubber on your stock '8 if you want to stop faster. Victoracers are good for a 10% reduction, I'd bet.

If you can already lock your tires, then how would more stopping torque help? Only if you're overheating your brakes... and you'd have a hard time doing that on anything less than a full race circuit (especially with racing brake pads).

 

So you're getting better mileage with the intake?

Wow, good for you.

I'm averaging around 14 with my auto. I'm afraid what the intake will do to my mileage. I may go ahead and install it and see what happens.

Thanks for the info Troy.

 

Got a question for you guys then...

Explain why these "wave" rotors can be superior to standard rotors, depending on application/useage.

 

Japan8,

I guess you decided to ignore the brake article, and the sub-articles and posts that went along with it. I'll instead assume you just missed it.

I'll post it again so you can have a better look, and quote from a specific section...

Article
http://www.mazda6tech.com/index.php?...d=19&Itemid=32

In a motorcycle or other extremely light vehicle the decrease in rotational inertia and unsprung mass might perhaps be useful (once other more efficient avenues are exhausted

. A slotted or drilled rotor will also clean off the brake pad as it passes the slots at the expense of faster pad wear. As such there are benefits for rally and dirt tracks.

On a motorcycle, unsprung weight has a massive effect. The effect of adding a single lb to the front and rear brake might have more of a negative effect then dealing with any of the negative aspects of cross-drilled rotors.

Additonally such rotors (as pictured above) are sometimes replaced on a per race basis...and as mentioned in the quotes, do have advantages in dirt/wet conditions over standard solid discs. Since this particular bike is taken out of context...I'll assume its just a racing bike, making each ounce of saved unsprung weight extremely essential for such a competitive sport.

For further information please try:
Ruiz, Stephen and Smith, Carroll. “Brake Systems and Upgrade Selection”

McCready,Tom and Walker, James. “Brake Bias and Performance”

http://www.stoptech.com/whitepapers/...erformance.htm

Corner-Carvers.com altima brake thread discussion.
http://corner-carvers.com/forums/sho...=cross+drilled

The famous Altima brake thread.
http://www.altimas.net/forum/showthr...7&pagenumber=1

 

only third link works for me EDIT of the 4 at bottom

 

Actually Mr. Smartass, I missed the article the first time around.

Before you decide to begin with the snippy comments, try asking a few questions first... I'm not rotarygod, but I'm not a moron either. I do ride motorcycles as a serious enthusiast (not a squid!) and the people I ride with are almost all race ameture and own bike shops. I posted the pic and few words on the galfer wave rotors to pique interest...play devil's advocate. Why do you think I said "can be more effective" not 'are more effective than standard rotors.

Bike rotors are hardly so heavy that they'll make THAT much difference in braking. Your brake temps, pad material, SS brake lines or not will have a larger effect. If you want to talk weight, the rider giving up eating MacDonald's in exchange for a salad (- 5-10 pounds at least) will have a larger effect. Pads are generaly the key.

The Galfer wave rotors have plenty of uses outside of racing and are NOT used in professional racing such as GP bike or World Super Bike racing. I don't recall at the moment the rotor material, but I do remember than they use carbon pads or both carbon and metalic... one set on one rotor and the othe on the other... pads effective only at high temps and pads that are good from the get go.

There have been complaints about the rotor material on the Honda CBR954 (if I remember correctly)... i.e. warping due to excessive heating and cooling in the rain. One solution used in a magazine was to trade for wave rotors. Wave rotors were a solution I considered for my bike which only has a large single disk up front (which the manufacturer change to smaller double disks on later year bikes). I had severe overheating problems during the heavy traffic commutes to work in Tokyo. I tried different brake pads with little luck at first... Race ceramic pads and SS lines got things under control finally.

The wave rotors used in ameture racing are NOT used on short tracks as they will overheat. There isn't enough time between heavy braking for the rotor and pads to cool off. The extra material of "normal" rotors is needed to quikcly dissipate the heat (as noted in the article about brakes in general).

Lastly about inertia. The wave rotors do little for braking as I said earlier. What they do improve is handling. With the reduced weight at the wheels the bike becomes more... flingable... readily able to change direction. Weight transfer plays a bigger role on bikes. The opposite of cars, bike's front brakes won't lock up first... the rear will. As such proper supsension setup is also crucial in braking on modern motorbikes.

 

I do admit my original response was a bit...rude and I apologize for that. I guess I'm just used to people just skipping over anything that requires more then a few brief seconds of reading, and continuing to hammer in points which don't make any sense.

I don't ride a motorcycle, nor do I have much knowledge or understanding of their functionality. I only know what I've read, and thats miniscule at best. So I'll let you handle your part of the discussion.

I guess I came on strongly because I don't really see how a 2-wheeled lightweight motorbike relates to a four wheeled 3,1000 lb sports car.

Perhaps you were just trying to illustrate a situation where such a device gave more benefits then negatives?

Are you arguing that cross-drilled rotors are a decent investment for someone looking for performance braking in a 3,000 lb car?

redrx8, I edited the links so they should work now. Thanks.

 

Ok.. no problem then.

Bing... you hit the reason I posted that. yeah... other than the fact that they have 4 cycle engines (not always with bikes!)... there really is little overlap between the two. I was just trying to show a situation where these types of rotors actually do prove to be useful. But as you can see even then it's not always either!

 

My turn!

Ya I definitely see your point, and thanks for making it. I should have known I was being intrapped by a bike question and should have backed off. Oh well I was in a "man I wish I actually owned a mazdaspeed rx8" mode.

On a side note, since your a bike guy....

http://www.suzukicycles.com/Products/SV650SK4/

What do you think of this bad boy? I'm currently on a weight loss binge (exercise + eating less 5 lb cakes) and if I meet my goal I'm looking for a fun bike (will be taking driving courses) to zoom around on the weekend .

 

crossbow,

Hey... everyday on the forum I am so envious of you guys with your 8's... and just the fact that the majority of you can commute to work by car instead of a packed like sardines, in a hot stuffy, full of smelly, perverse (bad if you're female) salarymen train. As you can guess... I hate it a lot.

Damn... you hit me with an easy but hard one to answer. You'll see why in a minute.

The good 'ol Suzuki SV. I haven't read about it recently... since my SV400S died. Damn crank bearing when out on it... $2,000 repair.. suffice to say this is going to be sold for parts on yahoo (no ebay in Japan).... the bike only costs $3,000- $4,000 used.

Anyway a REALLy good site (like this one!) to check out on the bike is http://www.svrider.com . The feelings on the present model bike were mixed when it came out... the old model based off the JDM only 400cc model was loved by all. It had a crappy suspension that was easily and cheaply upgraded. Despite the bad suspension (and of course was better after the upgrade) this bike can take bigger faster bikes in corners with the right rider. It is such an easy bike to ride and ride well. All things being equal, of course a brand new supersport bike like a CBR600RR or R1 is better handling... but most of us aren't Valentino Rossi or Nicky Hayden.

The riders on the SV forum are as passionate helpful (maybe moreso?) than here on the RX-8 club forum. Definitely check it out.

The older 99-'01 model was carburated and put out a little less power than the current fuel injected model. What people especially love about the older one over the new is the looks. My feeling... I like them both. I especially like FI over carbs... easier to tune and upgrade. Playing with jets and mixture screws sucks. Plus the new one has a cool digital speedometer. Handling is similar they say between them, so rest assured that you will still get a great handling bike in the new 650. The 1000 was a bit disappointing to many... doesn't handle as well, but it doesn't seem to be THAT bad. If this is your first bike, I especially recommend it. It is easy to learn on... it's easy to ride... very forgiving. Many experienced rides have left "faster" supersport bikes for the SV and never gone back. A few did eventually because... well when it comes down to it... the SV is like the 8... most want more power. Thus numerous bore-up kits and the anticipation and disappointment with the 1,000.

I will probably never buy another Suzuki. The SV was my second... my first was an old Bandit 400 (license limits me to 400cc). It had valve problems. My SV engine died...and there are reports that it happens with the 650's too. Not a totally odd occurance it seems. That combine with the plain fact that although Honda's cost more, you get it back in quality and fit & finish. My next bike will be either a RVF 400 or (get a bigger bike license) VTR 1000F or a CBR600RR.

So you can see the mixed bag for me. For you... I'd say hell... go for it. I can't think of any better bike to start out on.

 

I read 31000 lb sports car - holy smokes!!

Now THAT would be interesting. How many HP would it need to equal the -8's times? Stopping that sucker would need some real brakes. LOL

 

Japan8,

Thanks for the site and recommendations! Appreciate it...now to just lose a bit more flab so I don't overweight the poor crotch rocket .