Is it good to travel at 3k?
10-14-2009, 11:28 AM
#12
4th Gear Member
Join Date: Feb 2007
Location: Austin, TX
Posts: 1,139
No worries man, it's good to ask questions so you can find this stuff out! You don't need to worry about supplying enough air to your motor. I'm not sure what exactly happened to your friends car but it wasn't because he didn't have a good fan in front of his intake. Maybe it wasn't enough air moving over his intercooler and the compressed air going into the motor got to hot for it to handle, but it wasn't a lack of air to the engine itself.
The reason is (and Cliffy can explain this in a more technical way than I can) that your engine draws air through the intake tube and MAF at MUCH faster speeds than you can ever drive, so hooking your intake up to a ram air scoop (or sticking a fan in front of it) will not have any noticeable effect on the performance. This is why FI is required to be able to force more air into the motor. Only those devices can compress the air fast enough to be able to get more in than the motor does stock. Hope that makes sense!
The reason is (and Cliffy can explain this in a more technical way than I can) that your engine draws air through the intake tube and MAF at MUCH faster speeds than you can ever drive, so hooking your intake up to a ram air scoop (or sticking a fan in front of it) will not have any noticeable effect on the performance. This is why FI is required to be able to force more air into the motor. Only those devices can compress the air fast enough to be able to get more in than the motor does stock. Hope that makes sense!
10-14-2009, 12:59 PM
#14
Well, see I was just wondering because I have heard about revving engines at idle and spinning a rod. It's a known fact that you SHOULD be moving at a speed that gives the proper air to amount for the high RPM you are at. I have a friend who blew black smoke from his WRX STI because ECS tuning did not have a powerful enough fan for his high RPM run. Something got seriously messed up in his engine.
Stop treating me like an idiot, I just had a simple question.
Stop treating me like an idiot, I just had a simple question.
Last edited by BraMas; 10-14-2009 at 03:32 PM.
10-14-2009, 04:54 PM
#16
Banned
Join Date: May 2007
Location:
Posts: 4,064
Well, see I was just wondering because I have heard about revving engines at idle and spinning a rod. It's a known fact that you SHOULD be moving at a speed that gives the proper air to amount for the high RPM you are at. I have a friend who blew black smoke from his WRX STI because ECS tuning did not have a powerful enough fan for his high RPM run. Something got seriously messed up in his engine.
Stop treating me like an idiot, I just had a simple question.
Stop treating me like an idiot, I just had a simple question.
Thats why I had to replace the turbo fan behind my radiator... when I was idling and revving the engine it wasn't blowing 170 mph air and tripping the CEL for a lean condition.
10-14-2009, 05:18 PM
#17
Gentleman's Relish
Join Date: Feb 2005
Location: AZ
Posts: 13,090
Well, see I was just wondering because I have heard about revving engines at idle and spinning a rod. It's a known fact that you SHOULD be moving at a speed that gives the proper air to amount for the high RPM you are at. I have a friend who blew black smoke from his WRX STI because ECS tuning did not have a powerful enough fan for his high RPM run. Something got seriously messed up in his engine.
Stop treating me like an idiot, I just had a simple question.
Stop treating me like an idiot, I just had a simple question.
2) The whole spinning a rod from free reving is possible but not beause of 1). Rather, it's simple physics. When en engine is not underload (free reving/spinning) everything with a gap (crank to main, crank to rod, rod to piston, piston to skirt, valve to rocker, etc) gets banged around. That banging around is what spins a rod bearing...not A/F at idle or a/f at any RPM.
3) Your friend probably got rid of both rev limiters. The redline one and the free rev one. The other thing is he probably had a bad tune or he overheated his car. Again, that has nothing to do with RPM.
Seriously..go out to your car, start it up, let it warm up, and press and hold the gas peddle. The car will cut/sputter at about 3500 RPM. This is your free rev limiter. Under driving conditions only the redline limiter exists.
10-14-2009, 08:05 PM
#18
4th Gear Member
Thread Starter
Join Date: Jul 2008
Location: Connecticut
Posts: 1,140
Thanks, I appreciate the help from those who didn't waste space posting bullsh*t. I did not know this, and now I do. Every circumstance that I have seen where someone does something stupid to their car and causes some kind of motor damage, has let me to believe the OP.
For the rest of you, congratulations, because you just revealed a lot about yourself to me. At one point in your life, you did not know the answer to this question either. People who try to make others feel dumb, usually have far worse complications in their life. It's facts, sociology is a University requirement at my school. Face palm, kiddies.
For the rest of you, congratulations, because you just revealed a lot about yourself to me. At one point in your life, you did not know the answer to this question either. People who try to make others feel dumb, usually have far worse complications in their life. It's facts, sociology is a University requirement at my school. Face palm, kiddies.
10-14-2009, 08:59 PM
#19
4th Gear Member
Join Date: Mar 2009
Location: NC
Posts: 1,909
Thanks, I appreciate the help from those who didn't waste space posting bullsh*t. I did not know this, and now I do. Every circumstance that I have seen where someone does something stupid to their car and causes some kind of motor damage, has let me to believe the OP.
For the rest of you, congratulations, because you just revealed a lot about yourself to me. At one point in your life, you did not know the answer to this question either. People who try to make others feel dumb, usually have far worse complications in their life. It's facts, sociology is a University requirement at my school. Face palm, kiddies.
For the rest of you, congratulations, because you just revealed a lot about yourself to me. At one point in your life, you did not know the answer to this question either. People who try to make others feel dumb, usually have far worse complications in their life. It's facts, sociology is a University requirement at my school. Face palm, kiddies.
+1
However, claiming something, and "not knowing" are two different things. For example, you said you were pretty much cretin, which it most certainly was not.
So, If you say "i don't know.. why does this.... blah blah" would be completely understandable. But calming something that is just not true makes you look a lot worse.
and to the OP's question, the only way you would possibly EVER see a problem with HIGH rpms and overheating is if you literally rev your car up to 5-6 grand and put a brick on the pedal and let it run for 8 hours. Even then, the radiator fan might be enough to keep the engine cool.