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

Compression test done.. numbers REALLY high??

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Old Dec 4, 2006 | 02:14 PM
  #26  
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i get around 400psi on the compression gauge with my DD
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Old Dec 4, 2006 | 03:43 PM
  #27  
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Originally Posted by slpin
i get around 400psi on the compression gauge with my DD
What the hell do you drive, a pipebomb?
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Old Dec 4, 2006 | 03:49 PM
  #28  
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Originally Posted by fusion-turbo
Count I guess you can do math? 250RPM is what it says in the FSM, so 250 revolutions equates 250 RPM at the ROTORS right? If so, there should be 750 puffs. Divide that by 60 (seconds in a minute) and 750/60=12.5. So you should see 12.5 puffs a second if the motor is rotating @ 250RPM. Hmm, that seems like alot.... this is of course, theory... HAH
ooooor you hook it up to a Mazda compression tester (a bunch of members did this on an Ottawa Cruise) or hook up digital tach or timing light with RPM reading while doing the test....................
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Old Dec 4, 2006 | 03:50 PM
  #29  
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a turbo truck that makes three times the torque idling than an rx7 at peak
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Old Dec 4, 2006 | 04:01 PM
  #30  
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spazz!
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From: Knightdale, NC
Originally Posted by slpin
a turbo truck that makes three times the torque idling than an rx7 at peak
Har har. How much does it weigh?
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Old Dec 4, 2006 | 04:11 PM
  #31  
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From: California
should be around 6000lbs
according to international harvester, the engine is about 1200ish lbs...
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Old Dec 4, 2006 | 04:16 PM
  #32  
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spazz!
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From: Knightdale, NC
You pull tree stumps out of the ground for fun?
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Old Dec 4, 2006 | 04:27 PM
  #33  
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Originally Posted by classicauto
ooooor you hook it up to a Mazda compression tester (a bunch of members did this on an Ottawa Cruise) or hook up digital tach or timing light with RPM reading while doing the test....................
I vote this way MUCH better Counting was still fun without the mazda tester tho
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Old Dec 4, 2006 | 04:39 PM
  #34  
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Originally Posted by darktritium
You pull tree stumps out of the ground for fun?
oh, when i find one, i know i will
it will be too tempting

how do i stop myself from looking at turbo upgrades?
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Old Dec 4, 2006 | 07:55 PM
  #35  
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From: Knightdale, NC
Originally Posted by slpin
oh, when i find one, i know i will
it will be too tempting

how do i stop myself from looking at turbo upgrades?
You keep looking at turbo upgrades for your Redwood Stump Destroyer?
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Old Dec 4, 2006 | 08:35 PM
  #36  
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From: I come from a land downunder
Originally Posted by fusion-turbo
Bought an Autozone compression tester.. pulled out the valve on the dial so it wouldnt hold a reading.. warmed the motor to normal Op temp and tested my compression. Pulled the EGI fuse, held the throttle wide open and cranked the motor.

I saw about 115 psi rear rotor and about 118-120 front! The motor is a j-spec used motor with about 60k miles on it... now i hear most people saying they have about in the 90's to low 100's.

What gives? Is this normal compression?

Dude i have a jspec and my mechanic did a compression test the other week it is supposed to be between 100 and 120 on the turbo, shame my rear rotor was at 15psi lol
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Old Dec 4, 2006 | 11:33 PM
  #37  
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From: atlanta ga
Originally Posted by fusion-turbo
Count I guess you can do math? 250RPM is what it says in the FSM, so 250 revolutions equates 250 RPM at the ROTORS right? If so, there should be 750 puffs. Divide that by 60 (seconds in a minute) and 750/60=12.5. So you should see 12.5 puffs a second if the motor is rotating @ 250RPM. Hmm, that seems like alot.... this is of course, theory... HAH
no.

you turn the ecc shaft 1/2 revolution and you get compression from one rotor face on one rotor another half turn you get compression from the next rotor on its face, and so on and so forth.

the rotors spin at 1/3 the speed the ecc shaft does.
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