TPColgett posted the only thing making a difference was running 93 with colder plugs. Running 93 alone made no difference. I don't know what other mods they tried.

I agree, it would be interesting to see if running cooler plugs with 87 increases power 2-3 HP alone...

 

you will NOT see the same gain with 87 octane and cooler plugs.

87 simply burns too fast compared to 93. And if the combustion event is too small, even perfectly timed, it is not as effective as a slower more powerful burn of 93 on colder plugs.

The reason its more powerful is not because of the temps, but because it takes longer to burn. Start burning BTDC by a few degrees, and you can crush that new explosion and perhaps even double the pressure that a stock setup on 87 octane might produce.


What you get is a motor that tends to respond a bit quicker, hungers for rpms a bit more, and gives a solid few horsepower extra.

But fuck that horsepower. Google some of these cold plug dynos and look at the torque increases.

Torque>Horsepower

You calculate horsepower FROM torque!!!!!!!

And our cars could use 3 digit torque. GODDAMIT HONDATA, GTF into the shop and finish our flashpro!!

 

Intuitively, I'd say faster burning fuel needs less advance to achieve ideal MBT. Perhaps this is why while scangauges show greater timing advance dynos don't show any difference using premium.

Disregarding burn rates and focusing on just the fuel's ability to resist pre-ignition (knocking) it's logical that when knock is detected and timing is retarded that lower MBT is achieved. Building on this it's logical that a higher anti knock rating will achieve higher MBT. That dynos don't show any difference using premium is an endorsement of Honda's designs.


If I felt that need in an economy car I'd question my purchase. But ok. I'm not sure how "bit quicker" and "hunger" can be quantified objectively.

I really tried hard on this, but couldn't come up with any. Can you help?

The only references I came up with suggest increasing horsepower by 50-100HP through other modifications requires a cooler plug by one range to avoid pre-ignition detonation.

Yessir, but RPM is equally important to measure power, or we'd all be racing steam engines. The calculation is simple:

HP = Torque x RPM ÷ 5252

which is interesting as you can see on any dyno where torque and HP are superimposed, that they equal each other at an RPM of 5252.

The question has come up for GD's where Hondata ECU tuning is available, what gains these show against stock with minor modifications (short of forced induction). I'm curious too.

 

Ill see if I can find some dyno's that show it well. I meant dynos overall, not jsut honda.


Yes, you will find all sorts of power increases for heat ranges. Some say every 50, some go every 100hp

I really dont think there is a good rule, other then if you are having trouble killing detonation, its probably time to get a step cooler

EDIT Found one. Honda accord V6, changed to one step colder plugs from Denso


No info on whether the old plugs were worn at all. Grain of salt I would say. Shows 3 hp increase

EDIT Here is a thread on getting different plugs. I think this guy replaced crappy plugs, because he claims all sorts of smoothness and whatever. http://www.6crew.com/forum/showthrea...RESULTS-ARE-IN!

yet another EDIT If this accord dyno is indeed accurate, it does show a balloon effect on the torque in the midrange. Would be a good candidate to increase fuel savings

 

thanks for the link.

It says he got a 5hp increase just by putting a blower in front of the car for the 2nd pull, and then a 4hp increase from the "weapon X" plugs on the 3rd, but it went down to only +2hp on the 4th. This on a 200HP car. I think 2HP is well within a margin of error. Also he doesn't talk about cooler plugs or heat ranges at all, just the change to shiny new plugs. Sorry, I only read the first page, is there something more there?