2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

redline rule?

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Old Feb 12, 2011 | 12:55 AM
  #26  
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From: And the horse he rode in on...
Not a rule.... It's more of a guideline
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Old Feb 12, 2011 | 02:46 AM
  #27  
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From: Central Iowa
Originally Posted by Evil Aviator
^ Myth.


Most aircraft engines are designed to operate around max torque rpm or max hp rpm, depending on the application. The majority of aircraft rotary engines seem to operate around 4500-6500rpm, although there are many variations due to the fact that most of the automotive type engines are installed in experimental aircraft.
Yeah I was going to say that they don't operate at 80%+ load all the time either, more like 50%-60% load since that's what they're running at almost CONSTANTLY. Running a TurboII at 60% load in 5th would have you doing like 110-120mph, cars get it easy compared to aircraft.
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Old Feb 12, 2011 | 10:40 AM
  #28  
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Useful information from everyone here, I've notice no major difference between giving a good spirited drive or redlining.
Agree with the fact that the car is meant to be driven, and drive it like a sports car. I'd drive up to 6k to get the secondary injectors working, and open up the 5/6 port.
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Old Feb 12, 2011 | 11:58 AM
  #29  
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From: Whitby
Originally Posted by wjk0817
Man, I remember when i first read on some post that red line is healthy.
So that morning, i red lined it and broke my clutch into peices.
Fail lol
HAHAHAHAHAHAAHAHAHAAHA
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Old Feb 12, 2011 | 04:22 PM
  #30  
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Originally Posted by jjwalker
Redlining the car is unnecessary.
+1

The redline is there for a reason.

Items like the clutch and flywheel are subject to centrifugal force and it's probably a good idea to keep these far from their tensile limits... If you like your ankles that is... You ever see a clutch disk explode at high RPM; not pleasant.

Stock steel apex seals tend to chatter above 6000 RPM. They skip up and down as they slide against the rotor housing. Extended operation at this high RPM will cause excess wear on the chromium coating on the rotor housings as well as the apex seal springs.



If any of your daily driving involves highway with a short entrance ramp, you probably already do this... Just attempt to merge with basic 60+ MPH highway traffic from a low speed. Your engine will be under load, you'll have to shift at high RPM, and you'll be doing a pretty normal traffic maneuver. (I do not condone street racing. Take it to the track.)


This is not just an RX-7 or even a rotary engine rule, piston engines should be loaded and revved too. They also suffer from carbon deposits... But low speed operation of a piston engine means that the connecting rods aren't ever stretched and the piston doesn't travel the entire way up the bore. This results in a ridge at the top of the bore and if the engine is ever revved to a high RPM, the connecting rod will stretch ever so slightly, but enough to let the piston travel above the ridge and damage the piston rings.


tl;dr:
Don't like a grandma... Don't redline... Just drive normally and put it under some load at high RPM once in a while... Pertains to any engine type.
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Old Feb 12, 2011 | 05:06 PM
  #31  
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From: Charlottesville, Virginia, USA
Originally Posted by SpeedOfLife
Yeah I was going to say that they don't operate at 80%+ load all the time either, more like 50%-60% load since that's what they're running at almost CONSTANTLY. Running a TurboII at 60% load in 5th would have you doing like 110-120mph, cars get it easy compared to aircraft.
Yeah, an automotive rotary engine would blow up if you took it to its mechanical redline for 2-10 minutes during takeoff and climb. Also, there isn't much point in taking the rpms past the max torque or max hp rpm because it would be producing less output at that point. Additionally, there is the issue of overdriving the propeller, so reduction gears for stock-port engines are around 2:1, while reduction gears for PP engines are closer to 3:1. Aircraft piston engines are usually designed to operate at only 2000-3000rpm, so you can't really compare their max load to automotive engines.

[QUOTE=Pele;10466637This is not just an RX-7 or even a rotary engine rule, piston engines should be loaded and revved too. They also suffer from carbon deposits... But low speed operation of a piston engine means that the connecting rods aren't ever stretched and the piston doesn't travel the entire way up the bore. This results in a ridge at the top of the bore and if the engine is ever revved to a high RPM, the connecting rod will stretch ever so slightly, but enough to let the piston travel above the ridge and damage the piston rings.[/QUOTE]
Good point.
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Old Feb 12, 2011 | 06:57 PM
  #32  
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From: Mesquite, TX-DFW
Originally Posted by Pele
+1

The redline is there for a reason.

Items like the clutch and flywheel are subject to centrifugal force and it's probably a good idea to keep these far from their tensile limits... If you like your ankles that is... You ever see a clutch disk explode at high RPM; not pleasant.

Stock steel apex seals tend to chatter above 6000 RPM. They skip up and down as they slide against the rotor housing. Extended operation at this high RPM will cause excess wear on the chromium coating on the rotor housings as well as the apex seal springs.



If any of your daily driving involves highway with a short entrance ramp, you probably already do this... Just attempt to merge with basic 60+ MPH highway traffic from a low speed. Your engine will be under load, you'll have to shift at high RPM, and you'll be doing a pretty normal traffic maneuver. (I do not condone street racing. Take it to the track.)


This is not just an RX-7 or even a rotary engine rule, piston engines should be loaded and revved too. They also suffer from carbon deposits... But low speed operation of a piston engine means that the connecting rods aren't ever stretched and the piston doesn't travel the entire way up the bore. This results in a ridge at the top of the bore and if the engine is ever revved to a high RPM, the connecting rod will stretch ever so slightly, but enough to let the piston travel above the ridge and damage the piston rings.


tl;dr:
Don't like a grandma... Don't redline... Just drive normally and put it under some load at high RPM once in a while... Pertains to any engine type.
When I was in school, we could actually measure that ridge, It is usually 1/1000th of an inch but enough to damage components. The piston rings would compress and squeeze in the cylinder bore. Over a period of time it causes the first compression ring to fail. We even had engines that got grannied, and you could barely turn them over with a wrench because of the ridge wear.
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