Im sorry man, but I do not get where you get your misinformation. It is not false, and spark plugs do not "simulate" better quality fuel. The ONLY way a colder plug will help you at all if if you are knocking from terrible fuel, and it HAPPENS to stop it, but if the fuel is that terrible to begin with, it probably will not help. You are also under the assumption that in stock form, the engine/ecu is holding back on giving you as much advance as possible. This is all assumption, which in my experience is all false.

Are you telling me if I go to work, slap my fit on my dyno, do a baseline pull, and then put some 6 or 5 cold range spark plugs in there, I'll see an increase in horespower?? Not true. Sorry.

Im not trying to be a dick, I just hate misinformation on the internet, this website in particular, because i love my fit and their fellow owners... Ive been in the japanese performance industry for about 6 years now, the shop manager at a shop that makes some of the fastest hondas in the country, and Im efi101, efi advanced, and AEM EMS2 certified, if you want qualifications...

 

This is not misinformation. And I don't mind if you're going to be a dick about it, I can be as well.

You don't have to actually have pre-det for the ECU to pull timing or enrich the mixture.


Through my own OBD2 logger I see a healthy change in timing and AFRs between grades of fuel and when I changed spark plugs.


On the stocker 6 range plugs on stock gap on 87oct E10 pump gas I would see timing advance under cruise in the high 30s, usually 37-38* @ 45mph in 5th and at WOT towards Redline advance would be in high teens like 17-18

On 93 under the same condition I would regularly see 40-43* with WOT timing was in the 19-21* range.

On 93 with NGK 7's on stock gap last time I had the logger on the car Cruise advance was between 45-47* and WOT was approaching 25*

And what you said is false. Not only that but you don't seem to understand that I am talking about using a 7 range plug. Going to a 5 would be going to a hotter plug. The Fit uses 6 stock.

In addition to my experience in the matter, Oscar Jackson from KW will tell you the exact same thing as will many tuners. When I said simulate a better fuel that is essentially what is happening.

It is the same reason I use 7s 8s and 9s in high boost applications and then further vary the gap depending on fuel and dynamic compression.

A hotter plug will create a hot spot in the combustion chamber, in addition we have a 10.4:1CR on our L15A's and there is no getting around that.

So how often do you tune, being the manager? I can definitely appreciate that you are AEM and EFI101 certified but I have to wonder why you think that on a car with an 87 minimum recommendation, a 10.4:1CR and 6 range plugs stock that simply using a colder plug which as you admit will clean up any knock were I experiencing some, would not allow you to run more advance?

And this is not hearsay I personally have seen the results in datalogs, other scan gauge users boosted and NA on here will attest to this as well as the guys at Jackson Racing/Kraftwerks.

If you are going to have the Fit on the dyno to find out, try different runs with 5s 6s and 7s and while using different fuels on each.

You might be surprised at how adaptable the stock ECU is.

 

A colder plug will not increase hp unless you are already experiencing pre det.

 

You don't have to experience actual detonation for the ECU to use a less aggressive timing and fueling scheme.

A colder plug will allow you to get away with more timing.

When the engine is in good health as in no CELs or mechanical issues, the ECU always runs aggressive as conditions allow.

You are making a mistake in assuming that without actual detonation the engine is always running MBT timing for whatever fuel you are using.

This is not true at all or we would all be seeing 25-27* @ WOT and 50* under cruise in the cells that allow for it.. regardless of what fuel, weather or plugs we are running.

Most people here are running 87oct which is the minimum acceptable rating for this engine. You can switch to 93 and pick up a bunch of timing and lean out.

For basically the same reasons you can then switch to a colder plug and pick up yet more timing.

It is that simple.

I even provided you with my actual spark advance numbers from what I have seen in 3 years of owning this car. I have no reason to lie about this, and I hate misinformation arguably as much or more than you do.

And there is a sh!t load of it scattered through out this forum.

This is not misinformation.

You will acknowledge that on an engine experiencing knock that a colder plug will alleviate this.

But when we are talking about using regular 87 in a high compression engine, you as a tuner should know that it is not likely the ECU can get away with its most aggressive tables (like the ones the ECU uses with 93oct and greater) on a 6 range plug on the minimum recommend fuel rating.

So 87 and colder plugs would be comparable to running 91 or 93. Just like running 93 with colder plugs would simulate a better fuel.

I have demonstrated this with actual numbers from my OBD2 port and there are several others here with scan tools who see the same results, including boosted and NA Fits.

So besides merely telling me I am full of it, what do you have in the way of evidence to support your claims?

 

Im not going to argue with you over the internet, its ridiculous. that is all for this thread, sorry original poster for messing it up with arguing.

 

Whats ridiculous is you jumped on me for spreading "misinformation" without any evidence or support for your claim.

I spelled out how and why for you, an alleged certified AEM dealer that "makes some of the fastest hondas in the country" and you can't even say anything other than "no" or basically acusing me of lying in three seperate posts?

I smell BS. The OP is long gone, only two posts, both of them in here.


If you are going to apologize to anyone it should be me at this point unless you can explain why this is "ridiculous" and wrong.

Be aware you are not the only tuner in the country turning out fast Hondas. Nor are Honda's the "be all end all" of tuning knowledge.

Everything I have posted about this in here applies to pretty much all gasoline engines and is elementary really.. So a quick explanation of how I am wrong should suffice instead of just calling it "misinformation" and implying I am lying.

I gave you actual logged data, the ECU doesn't lie.

 

I don't disagree with you at all on the physics of tuning, we both have the same understanding of tuning. All my original disagreement was about is that I disagree that adding a colder plug to a stock fit running 87 octane will not increase horsepower.

According to you you do see an increase in ignition timing on same fuel, same setup by simply running 1 step colder plug, correct? If that is the case, then maybe it does, but I have never seen it in any other car. We tune to make the best VE of any setup, and if the car requires, we go a step colder.

 

I tune essentially the same way it sounds like.. try to jam as much air as possible in the cylinder, then start to play with target Lambda and Timing till I can find a safe happy medium that makes power.

As far as the plugs vs. power.. I and other Fit owners on this board who have made the switch see the same trend.

I should also be more specific since I have the opportunity to chat with another tuner... when I refer to gains in power I am talking about torque production in the low and mid range, not necessarily greater peak power.

Then obviously after VE max, where torque output peaks, cylinder pressure and temps start to fall off a bit toward redline and the effect from the plugs is less profound.

So instances where nearly all gas engines are knock prone... like between shifts on an auto trans, getting back on the gas after engine braking or sudden aggressive throttle input at high rpm or near VTEC switchover the plugs can add a layer of safety and in some cases allows us to get closer to MBT.

But of course this all varies car to car, even between identical cars.

I see the plugs as one way to get more area under the curve on our stock NA L15As. When I am out in the country or in a state with no 93oct like I normally run and I have to switch to 87 or 89, the first time I get back to a highway on-ramp and open the tap I can actually feel timing being pulled.

During a commute if you drive like a granny, of course you will likely not notice any increase in power, instead there might be a small gain in fuel economy because (to an extent) more advance can make for a more efficient burn.

Then in a best case scenario... if the plugs bring combustion chamber temps down low enough or to some sort of tipping point where both timing can be ramped up and the mixture can be leaned because all the fuel that was used to cool and slow the reaction is no longer necessary.. you stand to see quantifiable changes in efficiency.

That is all I am saying. I consider it a neat little tweak and some have found success with it.

I wouldn't recommend it to someone and feed them a line "you will automagically gain like 2-3whp dude!" without clarifying that any gains from the plugs will likely be in areas that will not appreciably increase peak HP @ WOT.

But instead they do their "magic" in other areas of operation providing more street-able power, specifically low and mid-range torque.

For what it is worth there are other members here with scan tools similar to my OBD2 logger that have reported the same findings.

I am glad we could reach an amicable disagreement!

Maybe if you have time share some of your projects with the FF community!

I for one would be interested.

 

Humm i won't say there is merit at putting colder plugs in a car that doesn't need it!! But those IK20\22 plugs are shorter then the stockers... Shorter in that case helps the engine breathe better as they are not sticking right in front of the intake valves!!



They works for me!!

Marko!!

 

diamond is correct...

on a relatively stock motor colder plugs aren't going to do much if anything...

combustion chambers have a target temperature range... go to cold and it'll rob power because the burn won't be complete, go to hot and it will predet and rob power...

as long as colder plugs keep the chamber temps in that range, it will increase timing advance and promote a more complete burn... a touch more power...

 

A colder plug won't rob power by itself... What may happen is simply that it won't reach a temperature high enough to ''Self clean'' the plug so it will missfire when it's gonna be jam packed with carbon deposits!! A hotter plug will more then likely do pre-ignition, scaring away the computer and robbing ignition advance and\or enriching the mixture! A factory plug could be too hot for certain conditions as the do compromises at the factory! It's probably just fine for mild climates at low loads but may be too hot at extreme temperatures at Wide Open Throttle! In those cases, a colder plug could mean more power and\or less chances of damaging the engine!!

Marko!!

 

yup

 

Just clarifying something. From the earlier posts, my understanding is that replacing exhaust will not yield great results, as the ecu will adjust to the changes.
What realistic gains can be expected from from a cat-back, without touching the ecu?
Thanks,

 

Little to none. Possibly an adverse effect. Loss of torque through less back pressure, and no complementary modification on the intake side to increase mass flow.

More noise though.

 

Good info More money to spend on tires, wheels or shocks. Keeping the car in stock class for autox limits any changes to the intake, so for now that will remain unchanged. Thanks.