kb58 wrote: It's amazing to me how, in way less than one wheel revolution, the disc is already noticably cooler.
How can you tell? The darker area on the rotor is where the caliper is.
kb58 wrote: It's amazing to me how, in way less than one wheel revolution, the disc is already noticably cooler.
How can you tell? The darker area on the rotor is where the caliper is.
wvumtnbkr wrote:kb58 wrote: It's amazing to me how, in way less than one wheel revolution, the disc is already noticably cooler.How can you tell? The darker area on the rotor is where the caliper is.
No, just forward of the caliper its bright red, but even a quarter of the way around, it's already darker red. I'd have thought that with the wheels spinning so fast, the heat would be spread out fairly evenly across the disc.
great shots guys (kevin that last one is awesome). I've got a few fireball ones I need to post up. I took my girlfriend to her first race, she let me take pics for a while, but I had to keep her informed and entertained. She did get to meet Patrick Dempsey so that made up for everything.
kb58 wrote: No, just forward of the caliper its bright red, but even a quarter of the way around, it's already darker red. I'd have thought that with the wheels spinning so fast, the heat would be spread out fairly evenly across the disc.
I would think the rotation of the disc has nothing to do with the heat transferring through it. Heat = energy, you aren't applying force to the "heat".. The simple reason is that the heat is created through friction, with the disc gathering the most friction at the counter-clockwise lip of the brake pad. After that (since no more energy is being applied to the disc) it bleeds off until it contacts the pad again.
Thank you guys. Practice helps, luck pays a big part; And in my case generally for every one decent shot there were at least 8-10 crappy ones!
Settings:
1/60 s @ f/4.8 640 ISO 112 mm (70-300mm f/4.5-5.6 lens) + a bit of post processing of the RAW file all helped.
I looked into renting a faster lens for Rolex, just didn't get around to it, maybe I'll do it for Sebring.
alfadriver wrote:Vigo wrote:Not really- and it will start to burn somewhere, and anywhere down from there is hotter than no fuel. Once the engine is hot enough, fuel at +120F isn't going to cool too many things. Moreso that I would bet that all of the fuel is being injected as a vapor, not liquid- which happens about 1-2 min after the engine is first started. there *might* be another reason. But I don't see cooling as one of them. (and I still say that the photos are very cool. even if I don't agree with why they do it)no fuel is a LOT cooler than that.Only if the fuel is ignited in the engine. If it isnt then it's just like water injection.
don't the rotaries need fuel/oil mix to keep the seals lubricated? that could be why they don't want to cut the fuel completely off throttle.
Strizzo wrote: don't the rotaries need fuel/oil mix to keep the seals lubricated? that could be why they don't want to cut the fuel completely off throttle.
If they do, they have some serious technical issues that they have to deal with.
I don't recall the teams being allowed to add many fluids.
(that, and using oil to seal would reall kill emissions on a road car...)
but you could be right.
alfadriver wrote: (that, and using oil to seal would reall kill emissions on a road car...) but you could be right.
on a road car oil is injected in to the engine to help the things seal up and to help lubricate the rotor housing surfaces. This is a failure device so most race cars do away with it to and add oil to the gas. I am not sure of the rules in Grand-Am pertaining to fuel though.
at high RPM with factory everything (engine wise) my rx7 has always blown fire balls out of the exhaust.
monsterbronco wrote:alfadriver wrote: (that, and using oil to seal would reall kill emissions on a road car...) but you could be right.on a road car oil is injected in to the engine to help the things seal up and to help lubricate the rotor housing surfaces. This is a failure device so most race cars do away with it to and add oil to the gas. I am not sure of the rules in Grand-Am pertaining to fuel though. at high RPM with factory everything (engine wise) my rx7 has always blown fire balls out of the exhaust.
And there are good reasons why Mazda is struggling with the rotary engine and current emissions standards.
I would be pretty suprised if GA allowed the Mazda teams to spike their fuel, but since many of these GT cars are mostly made of round tubes, who knows what they let them do....
HiTempguy wrote:kb58 wrote: No, just forward of the caliper its bright red, but even a quarter of the way around, it's already darker red. I'd have thought that with the wheels spinning so fast, the heat would be spread out fairly evenly across the disc.I would think the rotation of the disc has nothing to do with the heat transferring through it. Heat = energy, you aren't applying force to the "heat".. The simple reason is that the heat is created through friction, with the disc gathering the most friction at the counter-clockwise lip of the brake pad. After that (since no more energy is being applied to the disc) it bleeds off until it contacts the pad again.
Not what I meant. The heat is being applied at one point, and as the the disc emerges from between the brake pads and into the air, it immediately starts to cool. My point, was that it was impressive that the disc could cool from "bright red" to "dark red" in well under 1/2 of a revolution. Sigh, I was simply trying to point out something interesting, not pound it to death... oh well.
In reply to alfadriver:
I add 2 stroke oil to my fuel in my RX-8, I did the same in my RX-7 and it is still running strong at 245,000+ miles the last time that I spoke with the current owner.
In reply to pilotbraden:
I'm not saying people don't. But I'm quite sure that Mazda can't count on that. Very much not allowed to.
I would have figured that a better solution would have been found, especially for these 3 rotor race cars.
Still, they would need an allowance from GA to allow them to spike the fuel with oil....
2-16 Mazda RX8 (Prep 2) 2-16.1 20B Cosmo three rotor (Mazda Spec parts). 2.0 liter, 9.7 compression ratio, 3-52mm throttle bodies, maximum of 6 injectors, maximum fuel pressure 4.2 bar, intake manifold is free. Maximum RPM 8800. Call GRAND-AM for parts list at386-310-6500. 2-16.2 Minimum weight 2260 lbs or 2350 lbs with DP transaxle. 2-16.3 Six-speed transmission. 2-16.4 Maximum body width is 73.5 inches. 2-16.5 Engine set-back 5.125 inches from spindle centerline to 1st spark plug. 2-16.6 Complete rear wing height w/ end plates cannot exceed roof height. 2-16.7 Fuel capacity 24 gallons May use oil in fuel. May machine the blue fuel rig restrictor to an inside dimension of 1.200 inch with square edges. 2-16.8 Allowed larger/higher exhaust position. 2-16.9 Tire sizes are 285/645R18 front and 305/660R18 rear. 2-16.10 2009 Mazda RX-8 “R3” bodywork permitted with 3” maximum front splitter dimension.
All rotaries inject engine oil in small amounts into the engine to lubricate the seals, in carbed cars you can see two narrow clear tubes running from a small pump on lower passenger side into the base of the carb.
I remove this oiling system as I firmly believe that pre mixing 50:1 ratio with synthetic 2 stroke oil is far superior and the oil is designed for this purpose. Personal preference was Amsoil.
Without this lubrication the engine will fail when it gets hot under hard use. It will also wear the engine extremely quickly.
Ok.
Oil lube it is.
Glad that the entire class is so close to real cars.... but I digress. the pictures continue to be cool.
I would wager that Idemitsu is the brand that is premixed. Probably in the sump as well.
http://www.idemitsu-usa.com/default.asp?msg=wso&lwd=1
Absolutely love these pictures!
As far as why the Mazda shoot flames like that, ill offer my limited expertise...
1) upon decel timing gets thrown through the roof....so spark may actually occur late enough that it just barely ignites the mixture before it is forced out of the exhaust....basically, not creating any power but shooting the mixture right out of the exhaust. 2) I'm sure they turn off decel fuel cut in order to lubricate the apex seals. Most motors go super lean under decel...Id imagine the rotaries do the opposite for this reason.
These are just my theories....I need to read more.
In reply to Matt_Smith:
kinda like the 2-stroke saabs with the one-way clutch
You'll need to log in to post.
