Greddy Turbo Overheated
11-18-2009, 03:36 AM
#101
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Spark plugs and coils aren't going to help your compression. If you want to know for certain, you could get this...
https://www.rx8club.com/group-buy-center-85/tr-01-rotary-engine-compression-tester-official-group-buy-172238/
If you lived near me you could drop by and use mine for free but oh well. It works great.
thewird
https://www.rx8club.com/group-buy-center-85/tr-01-rotary-engine-compression-tester-official-group-buy-172238/
If you lived near me you could drop by and use mine for free but oh well. It works great.
thewird
11-18-2009, 01:02 PM
#102
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Toronto, Canada ^_^
I just tested a car today where the front rotor was blown. On a standard compression tester the rear would read 85+ psi even pulses on the rear and ~70 EVEN pulses on the front. When I put the TR-01 in, it read over 100 psi on the rear, and ~75 ~75 ~11. The 11 was changing between faces which means the the broken seal was affecting 2 faces. What I found odd was even though it was quite obvious on the TR-01 it was blown, on the standard compression tester it was reading even pulses all the time and would just show lower compression like your case.
thewird
I just tested a car today where the front rotor was blown. On a standard compression tester the rear would read 85+ psi even pulses on the rear and ~70 EVEN pulses on the front. When I put the TR-01 in, it read over 100 psi on the rear, and ~75 ~75 ~11. The 11 was changing between faces which means the the broken seal was affecting 2 faces. What I found odd was even though it was quite obvious on the TR-01 it was blown, on the standard compression tester it was reading even pulses all the time and would just show lower compression like your case.
thewird
11-18-2009, 01:55 PM
#103
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so the standard compression tester will not be able to tell if my car is low on compression then right?
it will always just read even pulses and lower compression?
so i really need a TR-01 in order to know if my motor is low compression.
so i should read 85+ 85+ 85+ for each rotors?
cause i know you check twice for the leading and once for the trailing right?
p.s. my motor reads 60~60~60 for front and also 60~60~60 for rear
i hope i am understand it correctly!
it will always just read even pulses and lower compression?
so i really need a TR-01 in order to know if my motor is low compression.
so i should read 85+ 85+ 85+ for each rotors?
cause i know you check twice for the leading and once for the trailing right?
p.s. my motor reads 60~60~60 for front and also 60~60~60 for rear
i hope i am understand it correctly!
Last edited by c41250n; 11-18-2009 at 02:00 PM.
11-18-2009, 07:59 PM
#104
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Well it doesn't really mean anything specifically. It just means you can't use at as a gauge to tell whether your engine is blown, low on compression, or perfectly fine. But I've never seen a standard gauge read so low for a good engine.
thewird
thewird
11-18-2009, 09:55 PM
#105
so the standard compression tester will not be able to tell if my car is low on compression then right?
it will always just read even pulses and lower compression?
so i really need a TR-01 in order to know if my motor is low compression.
so i should read 85+ 85+ 85+ for each rotors?
cause i know you check twice for the leading and once for the trailing right?
p.s. my motor reads 60~60~60 for front and also 60~60~60 for rear
i hope i am understand it correctly!
it will always just read even pulses and lower compression?
so i really need a TR-01 in order to know if my motor is low compression.
so i should read 85+ 85+ 85+ for each rotors?
cause i know you check twice for the leading and once for the trailing right?
p.s. my motor reads 60~60~60 for front and also 60~60~60 for rear
i hope i am understand it correctly!
It needs to be done with a rotary specific setup...either a Mazda service tool, or an aftermarket tester designed for a rotary that can read the values needed
Anything else is basically useless...unless it shows little to no compression...then you know for sure its F**Ked
11-20-2009, 06:50 PM
#111
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no you cant always notice a bad coil from driving. you may not get a cel you may not hear any misfires.
i do feel like this is starting to go in circles.
whens the last time you changed your coils?
ive had a set go bad in 35 000km when i changed them i noticed better gas mileage better engine response and a quicker start. i thought the coils were fine but figured id change them anyways and was surprised how much power i had lost with out realizing it. i track my car often and would like to feel that i know when my cars down on power i was even running decent lap times and passing faster cars. needless to say when i went back i ran even better times.
https://www.rx8club.com/showpost.php...04&postcount=7
i do feel like this is starting to go in circles.
whens the last time you changed your coils?
ive had a set go bad in 35 000km when i changed them i noticed better gas mileage better engine response and a quicker start. i thought the coils were fine but figured id change them anyways and was surprised how much power i had lost with out realizing it. i track my car often and would like to feel that i know when my cars down on power i was even running decent lap times and passing faster cars. needless to say when i went back i ran even better times.
https://www.rx8club.com/showpost.php...04&postcount=7
Last edited by nate340; 11-20-2009 at 07:11 PM.
12-08-2009, 10:26 PM
#113
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Alrite, just did compression test, front 70psi and rear 68 psi.
But my question is my machanic said you only need to check the leading for conpresion!
Also since the compression is so low, how could my car idle normal and drives perfect, it's just hard start when it's hot??
Any input welcome!
Thanks
But my question is my machanic said you only need to check the leading for conpresion!
Also since the compression is so low, how could my car idle normal and drives perfect, it's just hard start when it's hot??
Any input welcome!
Thanks
12-09-2009, 10:17 AM
#118
Turbocharger Guru
What kind of vacume are you pulling at 1K RPM?
How good is start up when cold?
If you are using a compression tester (possibly a cheapy with a removed check valve) you are just checking the bounces to make sure they are even.
Make sure the comp test is done in the Trailing side. Also remove the opposite side plugs that way the engine can turn a little faster on the start.
The engine needs even compression. Doesn't always have to be the highest :D. I ran an 11.21 at 127 on ET streets with 80-30-30 on the rear and 90-90-90 on front. The car still runs awesome at the higher RPMs.
How good is start up when cold?
If you are using a compression tester (possibly a cheapy with a removed check valve) you are just checking the bounces to make sure they are even.
Make sure the comp test is done in the Trailing side. Also remove the opposite side plugs that way the engine can turn a little faster on the start.
The engine needs even compression. Doesn't always have to be the highest :D. I ran an 11.21 at 127 on ET streets with 80-30-30 on the rear and 90-90-90 on front. The car still runs awesome at the higher RPMs.
Last edited by Bryan@BNR; 12-09-2009 at 10:20 AM.
12-09-2009, 01:31 PM
#119
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hum....we were using a cheapy with a removed check valve to check the compression, and we only did it on the leading side for front and rear.
here is his procedures, so he unplug all the coils, use the stick to hold the gas pedal down, remove the check valve on the compressor, and took out both leading plugs.
so is it a wrong procedures??
here is his procedures, so he unplug all the coils, use the stick to hold the gas pedal down, remove the check valve on the compressor, and took out both leading plugs.
so is it a wrong procedures??
12-10-2009, 06:29 PM
#121
There is a compression tester you can purchase specifically for the rotary that will pick the RPM and also cycle 3 compression numbers so that you get a reading for each face. If you blow a seal, it'll hurt the compression on 2 faces. For a whole engine, you'll have 3 compression values for each rotor (6 total). The tester for a rotary probably runs a couple hundred bucks. See if someone in the area has one. I kind of want one just to have for future use.
12-10-2009, 06:39 PM
#122
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hum.....so what is the correct procedure to check the compression?
do i check on the trailing side only, or the leading side only?
also, do i need to press on the gas while testing it?
do i check on the trailing side only, or the leading side only?
also, do i need to press on the gas while testing it?
12-10-2009, 07:16 PM
#123
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The correct procedure is to use a proper rotary compression tester. Leading and trailing don't make much of a difference, I have tested both before.
thewird
Last edited by thewird; 12-10-2009 at 07:23 PM.
