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bravenrace
bravenrace New Reader
5/23/08 7:13 a.m.
nickel_dime wrote: The higher the octane rating in gas the faster it burns and it is more explosive.

Actually, the higher the octane the higher a fuel's resistance to burn. That's because higher compression engines make more heat during compression and need a fuel with a higher flashpoint to prevent pre-ignition or detonation. That's also why putting higher octane fuel in an engine that doesn't need it is a waste or money.

Strizzo
Strizzo HalfDork
5/23/08 8:16 a.m.

another myth about higher octane is that it burns slower, which is why you need/can run more timing, to give the fuel more time to burn.

GameboyRMH
GameboyRMH GRM+ Memberand Dork
5/23/08 10:31 a.m.

Cars nowadays are more efficient, faster, more spacious and better looking than those in the late 80s.

Salanis
Salanis HalfDork
5/23/08 11:53 a.m.

Hybrids save money, and the environment.

NYG95GA
NYG95GA Dork
5/23/08 6:38 p.m.

The government is there to help you.

LopRacer
LopRacer New Reader
5/23/08 6:45 p.m.
GlennS wrote: V-Teck stickers add 5hp. Type R stickers add 10.

And Yellow stickers are good for 10hp a piece, you can also double up with a yellow V-tech sticker and get 15hp.

phillyj
phillyj New Reader
5/23/08 7:17 p.m.

acetone will improve gas mileage

Jamesc2123
Jamesc2123 New Reader
5/23/08 8:19 p.m.

All big cars are safe, all small cars are dangerous.

Sport bikes are faster than any exotic by any measure of speed.

Volksroddin
Volksroddin New Reader
5/23/08 8:19 p.m.

My truck is faster becouse its 289ci in it and I got really big tires

Salanis
Salanis HalfDork
5/23/08 10:08 p.m.

My truck is outperforming your sportscar because I can make the rear wheels spin.

Nomad
Nomad New Reader
5/24/08 12:20 a.m.

correction: "I can make the rear 'wheel' spin"

donalson
donalson SuperDork
5/24/08 1:11 p.m.

classic muscle cars where MUCH faster then the "fast cars" today

Volksroddin
Volksroddin New Reader
5/24/08 8:50 p.m.

my car is not low on oil, the little oil light is not on........

Salanis
Salanis HalfDork
5/24/08 8:54 p.m.

The bigger your rim is, the better the car will perform. Get the biggest rims you can fit.

neon4891
neon4891 Reader
5/25/08 7:04 a.m.

a Sunfire with a wings west body kit can beat anything

RealMiniDriver
RealMiniDriver Dork
5/25/08 11:22 a.m.

correction: "Sunflower"

joshx99
joshx99 New Reader
5/25/08 12:05 p.m.

Rotaries are unreliable.

maroon92
maroon92 New Reader
5/25/08 2:22 p.m.

rally specific,

AWD is ALWAYS faster!

wcelliot
wcelliot New Reader
5/27/08 8:22 p.m.
RealMiniDriver wrote:
Volksroddin wrote: the Volkswagen beetle was made by hitlers desighn.
Maybe not Hitler's design, but he comissioned Ferry Porsche, who already had a design in the works.

Almost. Hans Ledwinka of Tatra had the design in the works. He and Hitler fell out and Hitler turned to his competition Dr. Porsche who promptly infringed Ledwinka's patents in building the VW. VW lost a patent infringement lawsuit after the war....

Bill

wreckerboy
wreckerboy SuperDork
5/28/08 7:12 a.m.

Myth: There are questions where the answer is NOT "Miata."

alfadriver
alfadriver New Reader
5/28/08 8:58 a.m.
bravenrace wrote:
nickel_dime wrote: The higher the octane rating in gas the faster it burns and it is more explosive.
Actually, the higher the octane the higher a fuel's resistance to burn. That's because higher compression engines make more heat during compression and need a fuel with a higher flashpoint to prevent pre-ignition or detonation. That's also why putting higher octane fuel in an engine that doesn't need it is a waste or money.

Actually, no it's not. Octane does not drastically change the burn rate, it changes the fuel's natural point where it spontaniously explodes (which is what knock is). You got the part about detonation. Octane does not effect pre-ignition that is not knock (normally caused by hot spots that can start normal style combustion, but many times, pre-ignition can cause knock). Oh, and knock/explosion is NOT normal combustion....

But, like you say, if the engine doesn't need knock protection, it's a waste of money.

Octane is not resistance to burn, but resistance to explode on it's own.

Eric

bravenrace
bravenrace New Reader
5/28/08 9:06 a.m.
alfadriver wrote:
bravenrace wrote:
nickel_dime wrote: The higher the octane rating in gas the faster it burns and it is more explosive.
Actually, the higher the octane the higher a fuel's resistance to burn. That's because higher compression engines make more heat during compression and need a fuel with a higher flashpoint to prevent pre-ignition or detonation. That's also why putting higher octane fuel in an engine that doesn't need it is a waste or money.
Actually, no it's not. Octane does not drastically change the burn rate, it changes the fuel's natural point where it spontaniously explodes (which is what knock is). You got the part about detonation. Octane does not effect pre-ignition that is not knock (normally caused by hot spots that can start normal style combustion, but many times, pre-ignition can cause knock). Oh, and knock/explosion is NOT normal combustion.... But, like you say, if the engine doesn't need knock protection, it's a waste of money. Octane is not resistance to burn, but resistance to explode on it's own. Eric

You and I mean the same thing. How about this - It's the fuel's resistance to start burning. I understand what you mean, and that is what I was trying to say. It's the way it was defined when I was in school and it stuck. Technically, yes, it's the fuel's resistance to flash, or start burning. But I don't agree on the pre-ignition, though, as a higher octane fuel will allow higher combustion chamber temps without flashing than a lower octane fuel will.

alfadriver
alfadriver New Reader
5/28/08 9:47 a.m.
bravenrace wrote:
alfadriver wrote:
bravenrace wrote:
nickel_dime wrote: The higher the octane rating in gas the faster it burns and it is more explosive.
Actually, the higher the octane the higher a fuel's resistance to burn. That's because higher compression engines make more heat during compression and need a fuel with a higher flashpoint to prevent pre-ignition or detonation. That's also why putting higher octane fuel in an engine that doesn't need it is a waste or money.
Actually, no it's not. Octane does not drastically change the burn rate, it changes the fuel's natural point where it spontaniously explodes (which is what knock is). You got the part about detonation. Octane does not effect pre-ignition that is not knock (normally caused by hot spots that can start normal style combustion, but many times, pre-ignition can cause knock). Oh, and knock/explosion is NOT normal combustion.... But, like you say, if the engine doesn't need knock protection, it's a waste of money. Octane is not resistance to burn, but resistance to explode on it's own. Eric
You and I mean the same thing. How about this - It's the fuel's resistance to start burning. I understand what you mean, and that is what I was trying to say. It's the way it was defined when I was in school and it stuck. Technically, yes, it's the fuel's resistance to flash, or start burning. But I don't agree on the pre-ignition, though, as a higher octane fuel will allow higher combustion chamber temps without flashing than a lower octane fuel will.

It's not really start burning- it's spontaniously explode- knock is a very singular combustion state, where the flame front travels at the speed of sound, as opposed to normal combustion where the flame is more a function of turbulance and whatnot. Knock is the state where the fuel/air mixture explodes on it's own- right time, pressure, and time. Octane rating is the resistance to that.

If it's the resistance to start burning, then people might think that you need a more powerful ignition to light high octane fuel, which isn't correct, either.

As for the pre-ignition- you are mixing up physics. Higher octane fuel will allow for pre-ignition w/o knock. They are only loosly related- pre-ignition is proper flame front speed but ignited by something other than the spark plug- normally a hot piece of carbon build up. Octane will help reduce the likelyhood that this pre-ignition leads to knock, for sure.

BTW, don't use the word flash- that's normally reserved for a liquid to gas phase thing. You are using it in replacement for burning.

And I'll repeat that burning and exploding are not exactly the same thing.

ae86andkp61
ae86andkp61 GRM+ Memberand New Reader
5/28/08 6:03 p.m.
maroon92 wrote: rally specific, AWD is ALWAYS faster!

True, true...I love it when the fast 2WD cars threaten to beat the AWD cars. :nice:

I usually get these from either kids who bought WRX's and then became interested in "rally" or from non-car-people who have watched some TV and played some video games, but never actually been to a rally event.

-All/most rally cars are AWD.

-You need AWD to participate in rally events.

-Subaru is the biggest figure in the history of rallying....I mean, who would ever rally a Ford, Saab, Peugeot, Datsun, etc?

Salanis
Salanis HalfDork
5/28/08 6:19 p.m.
ae86andkp61 wrote: ....I mean, who would ever rally a Ford, Saab, Peugeot, Datsun, etc?

I will if you bring the supply. :twisted:

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