Spark Plug Concern in Regards to F/I
01-30-2005 | 06:48 PM
#26
Registered User
Joined: Feb 2003
Posts: 1,080
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From: South Florida
This by the way hints at another advantage of a good electronic boost controller. The solenoid typically changes the air pressure seen at the wastegate so you can "fool" it by giving no pressure up until you reach your target and then letting it see full pressure all at once. This allows the turbo to maintain full boost up until it needs to stop, and then quickly stop building...another "area under the curve" problem that you can't really solve with a simple mechanical spring.
There was a good article floating about the internet describing how this all works but I can't find it right now.
jds
There was a good article floating about the internet describing how this all works but I can't find it right now.
jds
Originally Posted by MazdaManiac
That is how a boost controller works - it has a solenoid and it has dwell and duty cycle control over the wastegate actuator.
The actuator itself is just a rubber diaphragm attached to a piston with a rod mounted in it at a 90° angle to the action of the diaphragm.
When it is pressurized, it extends by an amount controlled by a spring. It is the spring that decides the minimum opening pressure of the actuator - the boost controller can then increase that opening point by modulating the amount of pressure that the actuator actually sees.
Ideally, you want a spring that allows the actuator to open completely all at once and at a low pressure. However, this isn't possible. It will typically "crack" at a starting pressure and be completely open at another pressure that is usually 100% above the cracking pressure.
So, aim for a fully open pressure that is 75% of your target boost when selecting an actuator (in reality, finding an actuator that is set for your desired opening pressure is like looking for a needle in a haystack - they are seldom "rated" or marked in any way, so you need to test them with a pressure gauge and a pump. At $75 a pop, that can get to be difficult).
The actuator itself is just a rubber diaphragm attached to a piston with a rod mounted in it at a 90° angle to the action of the diaphragm.
When it is pressurized, it extends by an amount controlled by a spring. It is the spring that decides the minimum opening pressure of the actuator - the boost controller can then increase that opening point by modulating the amount of pressure that the actuator actually sees.
Ideally, you want a spring that allows the actuator to open completely all at once and at a low pressure. However, this isn't possible. It will typically "crack" at a starting pressure and be completely open at another pressure that is usually 100% above the cracking pressure.
So, aim for a fully open pressure that is 75% of your target boost when selecting an actuator (in reality, finding an actuator that is set for your desired opening pressure is like looking for a needle in a haystack - they are seldom "rated" or marked in any way, so you need to test them with a pressure gauge and a pump. At $75 a pop, that can get to be difficult).
02-01-2005 | 07:15 AM
#32
Rangers Lead The Way!
Joined: Mar 2004
Posts: 1,330
Likes: 2
From: Athens, Georgia
I just bought a spare set of factory spark plugs for my RX-8. You know what.. they are the same damn spark plugs that they use in the 93's... I am amazed.. all this crap about different plugs when I could have been using '93 race plugs the whole time.. argh..
02-03-2005 | 07:11 AM
#34
Absolute Rotary Madness
Joined: Mar 2004
Posts: 1,291
Likes: 0
From: Thessaloniki, Greece
I just saw this thread, interesting...
As you can see in my signature, I have the GReddy plugs with the code RE10.
I'm not an expert, but I changed them because I had some starting problems (never flooded though). A friend had them on his car and recommended them to me. Since then I have no problems at all, even at cold weather (3-5 degrees C). Maybe someone can comment on this. They are made from iridium and they were considerably larger than the stock (size matters right
) Here's a pic too.
As you can see in my signature, I have the GReddy plugs with the code RE10.
I'm not an expert, but I changed them because I had some starting problems (never flooded though). A friend had them on his car and recommended them to me. Since then I have no problems at all, even at cold weather (3-5 degrees C). Maybe someone can comment on this. They are made from iridium and they were considerably larger than the stock (size matters right
) Here's a pic too.
02-03-2005 | 10:25 AM
#36
Originally Posted by RotorManiac
I just saw this thread, interesting...
As you can see in my signature, I have the GReddy plugs with the code RE10.
As you can see in my signature, I have the GReddy plugs with the code RE10.
02-03-2005 | 11:03 AM
#38
Sorry, I speak it much better than I can write it. :p
Are those the same plugs for the leading and trailing? Colder plugs don't get as hot (by definition) so at lower RPMs and rich A/Fs they get fouled.
Are those the same plugs for the leading and trailing? Colder plugs don't get as hot (by definition) so at lower RPMs and rich A/Fs they get fouled.
02-03-2005 | 12:56 PM
#40
Well, the "hotter or colder" issue is about resistance to detonation. In short, if you decrease the engine's resistance to detonation (pre-ignition, knock, whatever - that is a whole other discussion) via the introduction of high combustion pressures and/or temperatures, a "colder" plug will help negate the possibility of detonation to some extent by removing more heat from the combustion chamber. However, the penalty is the plug, being colder, is unable to burn off the film of un-burned fuel that accumulates at low RPM, low load conditions.
The "trailing/leading" question was directed to the number of the plugs you installed.
The rotary engine uses two plugs per rotor - one fires before the other to complete the combustion process.
In a stock Renesis, the trailing and leading plugs are different. I was wondering if you replaced all four of the plugs with the Greddy RE-10s or not.
The "trailing/leading" question was directed to the number of the plugs you installed.
The rotary engine uses two plugs per rotor - one fires before the other to complete the combustion process.
In a stock Renesis, the trailing and leading plugs are different. I was wondering if you replaced all four of the plugs with the Greddy RE-10s or not.
02-03-2005 | 08:36 PM
#45
Absolute Rotary Madness
Joined: Mar 2004
Posts: 1,291
Likes: 0
From: Thessaloniki, Greece
Originally Posted by MazdaManiac
Interesting. That shouldn't work very well, if at all.
I may have to get a set of those to experiment! Efharisto.
I may have to get a set of those to experiment! Efharisto.
please do experiment with them, and tell me what you think Jeff! these plugs are not so expensive, you should find them less than $150. Until now they work well:o hope the same for you!
02-03-2005 | 10:08 PM
#46
Originally Posted by RotorManiac
Parakalo please do experiment with them, and tell me what you think Jeff! these plugs are not so expensive, you should find them less than $150. Until now they work well:o hope the same for you!
please do experiment with them, and tell me what you think Jeff! these plugs are not so expensive, you should find them less than $150. Until now they work well:o hope the same for you!The stock trailing plugs are 9 and the leading are 6 or 7.
Seems to me that running a 9 in the leading would be the coldest I would go.
So, maybe I will get a pair of RE-9 and have a go in just the leading plug first.
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