Possibly stoopid question: Spark Plugs
02-13-2018, 12:49 PM
#16
Banned
Thread Starter
Thanks Deile - this whole thing came about because I was sent/ordered 957 plugs instead of 955 plugs (that's been rectified with the NGK's as per Lupo), but my curiosity was piqued because the plug size difference was so drastic I could have thought that you could evolve the performance of the engine via different plugs. While I'm a big OE guy, I don't buy the "why didn't Porsche do it" argument - after all, those same folks thought it was a good idea to have plastic coolant pipes and a faulty IMS design! Cost, comfort, emissions, etc are all things that an OE has to consider that I may or may not value.
I had exactly the same thoughts as George in Indiana. If this works to improve the engine somehow - why didn't Porsche do it? Well - because it doesn't. OP - wherever you got the idea that it might just improve the performance - stop listening to them. They're idiots.
And you can install new plugs in 2 minutes? Per cylinder or the whole 8? Does that include torqueing them properly?
And you can install new plugs in 2 minutes? Per cylinder or the whole 8? Does that include torqueing them properly?
02-13-2018, 02:33 PM
#17
While I'm a big OE guy, I don't buy the "why didn't Porsche do it" argument - after all, those same folks thought it was a good idea to have plastic coolant pipes and a faulty IMS design! Cost, comfort, emissions, etc are all things that an OE has to consider that I may or may not value.
Good choice with the NGK plugs. Many will poopoo that decision since they are not the original OE plugs, but they are way better choice than ones that were too long. If you are willing to experiment and pay for the ramifications, I for one would be thrilled if you ran back to back dyno tests with the two different sets of plugs. IMO we need more people in this community who are willing to test the limits of these machines.
This kind of reminds me of my early tuning days as a teenager when trying to eek out the most power possible from a 2 stroke engine. Believe it or not, one of the widely shared mods was actually removing the washer from the spark plug so that it could penetrate a little further into the cylinder. It was believed at the time that it created more power due to the extra cylinder head volume taken up by the plug which increased the compression ratio. Although this is a miniscule amount, when you are talking about cylinders that are 22cc's it did seem to make a difference!
02-14-2018, 01:14 AM
#18
Banned
Thread Starter
Interesting anecdote about your 2-stroke tuning days - I figured that between displacement and better spark positioning (central vs top) it could very theoretically work, assuming your piston doesn't blow it out of the engine 
That said, people do much dumber things to try and eek out no benefit (oiled air filters, anyone?) so something as fundamental as spark and displacement adjustments seems ripe for some pioneering folks (sounds like the Mazda folks tried it out) to figure it out.
But appreciate the feedback, and happy with the NGK's - this is my wife's baby-transport so reliability and fuel economy are my primary variables (and probably Porsche engineers in designing this) so OE or equivalent is just fine for me
That said, people do much dumber things to try and eek out no benefit (oiled air filters, anyone?) so something as fundamental as spark and displacement adjustments seems ripe for some pioneering folks (sounds like the Mazda folks tried it out) to figure it out.
But appreciate the feedback, and happy with the NGK's - this is my wife's baby-transport so reliability and fuel economy are my primary variables (and probably Porsche engineers in designing this) so OE or equivalent is just fine for me
The mazda rice boys are likely idiots and the stakes are much, much lower if they ruin and engine, but that is well said. Porsche does not always get it right nor make an effort to correct equipment even when issues become widely known. There are many things that can be improved upon and I don't take much from Porsche as gospel given their track record.
Good choice with the NGK plugs. Many will poopoo that decision since they are not the original OE plugs, but they are way better choice than ones that were too long. If you are willing to experiment and pay for the ramifications, I for one would be thrilled if you ran back to back dyno tests with the two different sets of plugs. IMO we need more people in this community who are willing to test the limits of these machines.
This kind of reminds me of my early tuning days as a teenager when trying to eek out the most power possible from a 2 stroke engine. Believe it or not, one of the widely shared mods was actually removing the washer from the spark plug so that it could penetrate a little further into the cylinder. It was believed at the time that it created more power due to the extra cylinder head volume taken up by the plug which increased the compression ratio. Although this is a miniscule amount, when you are talking about cylinders that are 22cc's it did seem to make a difference!
Good choice with the NGK plugs. Many will poopoo that decision since they are not the original OE plugs, but they are way better choice than ones that were too long. If you are willing to experiment and pay for the ramifications, I for one would be thrilled if you ran back to back dyno tests with the two different sets of plugs. IMO we need more people in this community who are willing to test the limits of these machines.
This kind of reminds me of my early tuning days as a teenager when trying to eek out the most power possible from a 2 stroke engine. Believe it or not, one of the widely shared mods was actually removing the washer from the spark plug so that it could penetrate a little further into the cylinder. It was believed at the time that it created more power due to the extra cylinder head volume taken up by the plug which increased the compression ratio. Although this is a miniscule amount, when you are talking about cylinders that are 22cc's it did seem to make a difference!
03-26-2018, 09:06 PM
#19
Banned
Thread Starter
Ok still on the silly question side of things - anyone with a CTT know how to take the stupid tube off the air filter box on the passenger side? I tried just about every which way to get it off, and couldn't. As a result, I couldn't properly access the torque arm, which meant I couldn't get the spark plug cover thing off, which meant I couldn't change the passenger side plugs!
As an FYI, my MPG went up at least 1 point after changing out the plugs on only 4 cylinders!
As an FYI, my MPG went up at least 1 point after changing out the plugs on only 4 cylinders!
03-28-2018, 08:25 PM
#20
You need to slide the green ring around the hose at the air box connection away from the air box to release the pressure on the fitting. The hose will then disconnect easily. I used my hand and a plastic prying tool. Doesn't take much.
Last edited by CTTS520; 03-28-2018 at 08:26 PM. Reason: Cause I can
03-29-2018, 06:06 PM
#21
Banned
Thread Starter
Cool thanks - are you sure you slide the green ring "away from the air box" vs. towards the airbox? It seems like it will only move one way, and that's towards the airbox...
I stuck a small screwdriver in what looked like a gap between it and the hose connection and was able to pry off towards the airbox, but thereafter I wasn't able to pull the hose out!
I stuck a small screwdriver in what looked like a gap between it and the hose connection and was able to pry off towards the airbox, but thereafter I wasn't able to pull the hose out!
03-30-2018, 02:34 PM
#23
Banned
Thread Starter
So never got the damn thing off, but on the upside, I didn't break anything either. Original filter on the drivers side was still in good condition, so not too upset that I couldn't get it off and complete 100% of the spark plug/air filter change; all 8 plugs successfully changed (only one looked a little off, with more than the others carbon build up), and driver's side air filter changed.
Also swapped the cabin air filter and did an oil change.
I think the rest of the 180K service will be done at the dealer - inspections and filling of fluids and stuff.
Will report on the improvement in MPG, but given the condition of the plugs, I'm hoping to continue the +1 MPG average I saw after changing 4 plugs.
Also realized that Turbo plugs are supposed to be changed every 40K miles vs. 60K for the others. Mine were at 60K, and I would say in clear need of a change.
Also swapped the cabin air filter and did an oil change.
I think the rest of the 180K service will be done at the dealer - inspections and filling of fluids and stuff.
Will report on the improvement in MPG, but given the condition of the plugs, I'm hoping to continue the +1 MPG average I saw after changing 4 plugs.
Also realized that Turbo plugs are supposed to be changed every 40K miles vs. 60K for the others. Mine were at 60K, and I would say in clear need of a change.
