How do i tell if my 6th ports work!?
Thread Starter
Joined: Jul 2002
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From: Washington State
How do i tell if my 6th ports work!?
I need to figure out if my 6th ports work. It seems that i'm flatlining too early, i have a Racing beat SP dual long primary exhaust (w/ the 6th port actuator tubes), and a bonez cone filter intake.
I'm flatlining around 5.5 to 6k, it seems it should be more around 7k or so.
Any ideas?
I'm flatlining around 5.5 to 6k, it seems it should be more around 7k or so.
Any ideas?
https://www.rx7club.com/forum/showth...hreadid=142845
Well, I thought maybe it could be the 5th and 6th ports, but here they say it should happen morea round 4K.
~T.J.
Well, I thought maybe it could be the 5th and 6th ports, but here they say it should happen morea round 4K.
~T.J.
84SE-EGI helpy-helperton
Joined: Oct 2002
Posts: 3,584
Likes: 542
From: Phoenix, AZ
Manually operating your '6'-port actuators won't tell you whether they're opening at the correct time, since this is performed by exhaust gas backpressure when the engine is running and the exhaust develops enough pressure to open the ports. This is only about 2-3psi, but is enough that if you're below this value, even though you can move them by hand, they will not be opening as designed.
The only way to verify that your ports are opening correctly, is to mark them (with grease, white paint, etc) at the bottom of the shaft when they're CLOSED, then drive the car vigorously above 3800rpm when they should be open. When you get back home, open the hood to see if the paint mark (or whatever you used) has been moved up the shaft by the opening of the actuators. This will ensure that your ports are opening correctly, but does not correspond to the point in the torque curve at which they are opening, and then full open.
That can only be measured by actually running the car on a dynomameter or installing a remote tachometer to the engine in a position where a camera can catch the opening of the ports and the exact engine rpm at which this occurs. Yes, it's a hassle to install a video camera under the hood and all, but that's how you'll be able to tell.
Also, as discussed in other threads, you can 'feel' the '6' ports open when you're creeping up on 3800 rpm in 3rd gear. That's my easy indication that the ports are working correctly. HTH,
The only way to verify that your ports are opening correctly, is to mark them (with grease, white paint, etc) at the bottom of the shaft when they're CLOSED, then drive the car vigorously above 3800rpm when they should be open. When you get back home, open the hood to see if the paint mark (or whatever you used) has been moved up the shaft by the opening of the actuators. This will ensure that your ports are opening correctly, but does not correspond to the point in the torque curve at which they are opening, and then full open.
That can only be measured by actually running the car on a dynomameter or installing a remote tachometer to the engine in a position where a camera can catch the opening of the ports and the exact engine rpm at which this occurs. Yes, it's a hassle to install a video camera under the hood and all, but that's how you'll be able to tell.
Also, as discussed in other threads, you can 'feel' the '6' ports open when you're creeping up on 3800 rpm in 3rd gear. That's my easy indication that the ports are working correctly. HTH,
Iotus,
If I rev slowly up to the 3800 mark and then past, I can't tell. However, if I'm a little more aggressive (and carefully observing) I SOMETIMES can feel a slight change when my 6P's open. Very mild though.
As I posted before, I've got one of those "cheap" AF guages on my car. Looks tech, but we all know they are limited functionally. However, when that tach approachs 3600+, etc, the entire AF dial goes "rich". This would make sense, but of course it doesn't tell me if BOTH are opening, but at least 1 is (and probably both).
Another thing I've noticed (and you have to be careful not to wreck), is to watch my tach (spirited acceleration) as it sweep past 3500+. When those ports open, I can usually actually "see" the tach rate of change increase.
But of course, the grease works better...
jeryj
If I rev slowly up to the 3800 mark and then past, I can't tell. However, if I'm a little more aggressive (and carefully observing) I SOMETIMES can feel a slight change when my 6P's open. Very mild though.
As I posted before, I've got one of those "cheap" AF guages on my car. Looks tech, but we all know they are limited functionally. However, when that tach approachs 3600+, etc, the entire AF dial goes "rich". This would make sense, but of course it doesn't tell me if BOTH are opening, but at least 1 is (and probably both).
Another thing I've noticed (and you have to be careful not to wreck), is to watch my tach (spirited acceleration) as it sweep past 3500+. When those ports open, I can usually actually "see" the tach rate of change increase.
But of course, the grease works better...
jeryj
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EliteHardcoreCanuckSquad
Joined: Mar 2001
Posts: 2,654
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From: Toronto
Originally posted by LongDuck
Manually operating your '6'-port actuators won't tell you whether they're opening at the correct time, since this is performed by exhaust gas backpressure when the engine is running and the exhaust develops enough pressure to open the ports. This is only about 2-3psi, but is enough that if you're below this value, even though you can move them by hand, they will not be opening as designed.
The only way to verify that your ports are opening correctly, is to mark them (with grease, white paint, etc) at the bottom of the shaft when they're CLOSED, then drive the car vigorously above 3800rpm when they should be open. When you get back home, open the hood to see if the paint mark (or whatever you used) has been moved up the shaft by the opening of the actuators. This will ensure that your ports are opening correctly, but does not correspond to the point in the torque curve at which they are opening, and then full open.
That can only be measured by actually running the car on a dynomameter or installing a remote tachometer to the engine in a position where a camera can catch the opening of the ports and the exact engine rpm at which this occurs. Yes, it's a hassle to install a video camera under the hood and all, but that's how you'll be able to tell.
Also, as discussed in other threads, you can 'feel' the '6' ports open when you're creeping up on 3800 rpm in 3rd gear. That's my easy indication that the ports are working correctly. HTH,
Manually operating your '6'-port actuators won't tell you whether they're opening at the correct time, since this is performed by exhaust gas backpressure when the engine is running and the exhaust develops enough pressure to open the ports. This is only about 2-3psi, but is enough that if you're below this value, even though you can move them by hand, they will not be opening as designed.
The only way to verify that your ports are opening correctly, is to mark them (with grease, white paint, etc) at the bottom of the shaft when they're CLOSED, then drive the car vigorously above 3800rpm when they should be open. When you get back home, open the hood to see if the paint mark (or whatever you used) has been moved up the shaft by the opening of the actuators. This will ensure that your ports are opening correctly, but does not correspond to the point in the torque curve at which they are opening, and then full open.
That can only be measured by actually running the car on a dynomameter or installing a remote tachometer to the engine in a position where a camera can catch the opening of the ports and the exact engine rpm at which this occurs. Yes, it's a hassle to install a video camera under the hood and all, but that's how you'll be able to tell.
Also, as discussed in other threads, you can 'feel' the '6' ports open when you're creeping up on 3800 rpm in 3rd gear. That's my easy indication that the ports are working correctly. HTH,
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