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

the LONG awaited DYNO sheet of my car...

Old Mar 5, 2003 | 12:10 AM
  #51  
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but its not good for the motor to shift at 8200 rpms is it??
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Old Mar 5, 2003 | 01:47 AM
  #52  
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stock redline is 8k there is nothign wrong with 8200
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Old Mar 5, 2003 | 01:47 AM
  #53  
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The motors oil system I heard should soport 8500 rpms safely. I have about the same power band. When I shift at 8100 my tack drops around 6100rpms putting me in peak HP numbers. In fact the higher your tack lies after shifting the better because you can see how the HP curve increases all the way until 8k sooo basically since hp is torque x rpm then obviously the RPM increase is exceeding the torque loss wich is why your making more power at say 7k as oposed to 6k wich is why I say dig your tack in the higher rpms after shifting. Screw torque your not climbing up hill or launching or pulling a trailer. ( that statment isnt theoretically correct ) heres an example.... Racers use shorter gears to be quicker...Everyone knows that. its why ricers swap thier hondas with gsr trannies or why we get 4.3s for our 7s instead of 4.1s... Becuase our rpms are in our peak power band more often. When you shift your tack is totally dug into a higher rpm then if you stayed 4.1s
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Old Mar 5, 2003 | 12:04 PM
  #54  
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but its not good for the motor to shift at 8200 rpms is it??
Oops, i'm pretty dumb. I was asuming that it was an s4, not an s5. (I don't know why. lol)

Tim
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Old Mar 7, 2003 | 03:57 PM
  #55  
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Originally posted by von
In fact the higher your tack lies after shifting the better because you can see how the HP curve increases all the way until 8k sooo basically since hp is torque x rpm then obviously the RPM increase is exceeding the torque loss wich is why your making more power at say 7k as oposed to 6k wich is why I say dig your tack in the higher rpms after shifting. Screw torque your not climbing up hill or launching or pulling a trailer. ( that statment isnt theoretically correct )
No, your statements are all wrong.&nbsp Torque is what accelerates the car.&nbsp If you're accelerating through a lower torque range, the car doesn't accelerate faster.&nbsp Accelerating is all about torque; drag racing is all about acceleration.&nbsp The car WILL accelerate faster going through the torque peak versus trying to drive it at redline, which torque normally drops off significantly.

We've had members change their shift points to hit the peak torque range - they have all claimed the car runs faster.


heres an example.... Racers use shorter gears to be quicker...Everyone knows that. its why ricers swap thier hondas with gsr trannies or why we get 4.3s for our 7s instead of 4.1s... Becuase our rpms are in our peak power band more often. When you shift your tack is totally dug into a higher rpm then if you stayed 4.1s
Wrong.&nbsp "Gears" are not called "torque multipliers" for nothing.&nbsp You're getting everything backwards.&nbsp "Horsepower" is a non-real force that can be calculated through torque measurement.&nbsp Torque can easily be measured.

Shorter gears (higher numerically) allow the engine to rev faster.&nbsp It also minimizes friction forces "backlashing" through the driveline.&nbsp Running a shorter gear does not automatically make the car faster, but for most stock applications, this is true.



-Ted
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Old Mar 7, 2003 | 04:15 PM
  #56  
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It's horsepower just the amount of work the engine is doing...what you want is force to accelerate your car, and that is torque. You should definitely accelerate through your torque peak, your acceleration is fastest at that point!
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Old Mar 9, 2003 | 09:16 AM
  #57  
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Maximum acceleration in any given gear is at peak torque. For best acceleration you want to maximize torque at the wheels, not the engine. As reted pointed out gears are torque multipliers. When you shift to a higher gear you lose some mechanical advantage. In some cars you shift at the redline because the wheel torque (at redline) is still higher than wheel torque in the next highest gear at any rpm.

I have not worked out the shiftpoints for the rx-7
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Old Aug 26, 2005 | 01:52 PM
  #58  
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Originally Posted by Kahren
btw this is a stock FC dyno witha HEALTHY FC putting out 128 at the wheels







this is the diffrence btw from before and after the port PLUS teh addition of a header and pineappple 6 port valve sleeves(also as u can see my 6 ports werent realyl working right and had so much carbon that they werent really movign properly)





Sorry for bringing up the dead but, could you post these comparison charts again? I'm about to rebuild the engine in my 91 vert.
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