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Hacking up Honda's ECU
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 Post subject: Great info
PostPosted: Mon Oct 09, 2006 1:40 am 
For a up in coming learner this is the best thread Iv'e seen on the forums. By using great detail I may be ready in the upcoming weeks to tune my own b16a2...I till need to learn alittle bit more. :D


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PostPosted: Mon Oct 09, 2006 3:54 am 
Just a suggestion to anyone new to tuning who reads this for the first time, after you learn more and more about tuning little by little come back and read this, trust me, im an idiot, and i get it a lot more now. =)


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PostPosted: Tue Mar 13, 2007 11:15 am 
love the article, would you be able to shed some light on timing adjustments on a dynojet without load capabilities?


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PostPosted: Tue Mar 13, 2007 7:12 pm 
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Joined: Sat Dec 17, 2005 12:54 am
Posts: 249
Location: Littleton, CO
It is possible to tune on an inertia dyno but i dont want to be responsable for people blowing up there motors... so the answere is no. Sorry.


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PostPosted: Tue Mar 13, 2007 9:36 pm 
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Joined: Tue Jul 27, 2004 3:01 am
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Location: Tampa bay, Florida
The process is mostly the same... Inertial dynos are best for tuning WOT conditions. The nice part about an inertial dyno is you can remove most of the other variables you get in street tuning - temperature, wind resistance, engine heat soak, etc... and is great for tweaking ignition timing.

The downfall is that you can't regulate the load - it is static.. Tuning partial throttle is best left for street tuning or even better.. a load-bearing dyno.


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PostPosted: Sun Mar 18, 2007 9:18 pm 
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Joined: Mon Aug 22, 2005 10:21 pm
Posts: 570
Location: Northeastern New York
Let's not forget about transient response. So many of us get all wrapped up in the biggest hp numbers when it is actually transient response that gets us there in the quickest time.

I have seen numerous times when guys like myself are underdogs since I only have a 111 cubic inch motor with 2XX hp. 0-60 I am slower than my brother's '02 Camaro but we trap the same times at similar speeds. He is making 320+ whp and 3?? torque. His is 6 speed and mine is 5. Mine is 4 banger and his is V-8. Go figure. I love it when we play and do 60 mph+ roll-ons side-by-side and we stay there... side-by-side. 8)


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 Post subject: Re: Tuning
PostPosted: Sun Jan 04, 2009 4:35 pm 
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Joined: Sun Dec 21, 2008 4:46 pm
Posts: 2
i'm bookmarking this just in case i want to try tuning my turbo accord sometime. paying $500 each time at the tuner is a lot of moolah. thumbs up.


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 Post subject: Re: Tuning
PostPosted: Tue Jan 20, 2009 12:10 am 
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Joined: Tue Nov 11, 2008 2:24 am
Posts: 17
Whoa!!!! Not trying to be an ass, but I want to post and clear a few things up that I found to be very incorrect and could potentially harm peoples engines.....

1st, afrs and timing are very much so related. You say they are not simply because the air/fuel mixture is already injected before the spark ignites it, therefore there is no way that timing changes this mixture? Well, the afr your wideband is reading IS NOT the air fuel ratio that was initially injected, it is the ratio after it is burnt!! If your timibg is way advanced, you wil burn more or the fuel in the mixture thus running more lean, and vice versa. Changing timing often times, calls for an adjustment of afrs be made. You said it yourself, for performance tuners, afrs are used as a temperature control, so to speak. Meaning, if the engine is running hot in a certain region, it is because of one of too things: 1.) too much timing advance, or 2.) too lean of an afr.

With that said, you can also richen up your afrs to make a motor run cooler due to advance timing. If there is slight detonation, you can fix it by adding fuel, or pulling timing, either or depending on the severity of the knock/detonation.

2nd problem I have with the info posted, is in the detonation section. There is not one word in there that describes detonation. Detonation is post spark, not prespark. You are referring to preignition, which basically is when a hot piece of carbon or hot/glowing/melted spark plug electrode causes the air/fuel mixture to ignite before the spark plug ignites it. This usually happens at 180* bdc (bottom dead center) of the intake stroke or 160* btdc (before top dead center) of the compression stroke. It usually ignites well before tdc, which causes EXTREME heat on the piston as it pushes up the entire last stroke against already burnt and expanding gasses caused by this precombustion. Preignition should not he taken lightly and will usually destroy an engine within seconds with no signs or symptoms, and usually on the first occurance as well. Usually it melts the piston, but is known to also melt the spark plug electrode and even the exhaust valves at times. Ways to prevent it are to use proper plugs. If you make alot of power, have higher CR's, are boosted, etc...use colder plugs. If you decide not to use colder plugs, tune accordingly to your stock plugs, meaning dont let your plugs get to hot to the point that they become a preignition source. Most if the time 1 or 2 steps colder helps. Rule of thumb on modified motors is to run the coldest plug you can that never will foul on you. If you need more in depth info on preignition and plugs, pm me.

Detonation is the more common term heard when speaking of tuning timing. The correct definition of detonation is when the unburned "end gas" ignites due to too much heat and pressure in the cylinder. Detonation occurs AFTER the mix is ignited by the spark plug. Detonation is definately something to worry about, but nowhere near as severe as preignition. Detonation usually breaks things if severe enough, such as ringlands, and it often pits the outer crowns of the piston and is also known to pit the spark plug. So another rule of thumb....if it's melted, its preignition, and if it's mechanically broken, its detonation. The famous pinging sound you hear from detonation is from the structure of the parts in the engine that actually ring when this detonation of the end gas occurs. Detonation is pretty much a secong explosion in the cylinder, and it WILL break things because it creates a very large spike in cylinder pressure when it happens. Depending on the motor setup, you could run with detonation of seconds or months, it all depends. Another sign of detonation besides the famous pinging, like i said before is pitting of the spark plug. it will even sometimes have silver flakes on it, in which case is very bad because that is probably peices of the piston that broke off during the detonation.

What causes detonation? Several things do such as CR, cylinder size and shape, spark plug location, etc.....but those are already engineered into the motor so no worries there. The reasons you want to worry about are timing, afrs, and fuel octane. Too much timing advance causes detonation because it ignites the a/f mixture too soon, this basically lets the cylinder build too much heat and pressure, which causes a spontaneous second combustion of the end gas I spoke of earlier. Too little fuel cause more heat, and more heat causes a spontaneous second combustion of the end gasses. Too low of a fuel octane allows the end gas mixture to resist combustion poorly, causing a second spontaneous combustion. I could go more in depth upon request......but it serves a good purpose to understnd what is happening and why, when you alter things in your ecu.....aka, tuning.

Putting all of this together, one can EASILY see why afrs do correlate to timing. If you make too much heat, then you need to remove it. Either add fuel or pull timing, OR use higher octane gasoline....

for questions pm me, i am very willing to help out on this thread for street tuning, and not so much dyno tuning


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 Post subject: Re: Tuning
PostPosted: Tue Jan 20, 2009 2:08 am 
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Joined: Tue Nov 11, 2008 2:24 am
Posts: 17
And I do remember seeing a question earlier in this thread about tuning at the same rpm all the way to WOT without the use of the dyno.

I will go ahead and answer this quesiton just so people can use it to their advantage if they do not have acccess to a dyno.

So, here goes. Timing should always be tuned with load. The origianl poster, ickyhonda, made that very clear and he couldnt be more correct!! Best option would be the load dyno, but the option that I often use is to simply find yourself a hill thats a decent length and drive up the darn thing. You would be suprised at exactly how much of the rpm band you can tune all the way to WOT simply using hills. Because basic physics says, and everyone knows, that the steeper the hill, the more load is put on the motor!! Just expiriement with it some.....you will not have a display to show you horsepower numbers, but you will definately be able to tell a difference in throttle response and overall daily driver friendliness. Worried about detonation, well, a simple solution is to use a set of det cans. I made an electronic pair for $25 bucks and they work AWSOME!!!

So yes, it is very possible to tune pretty much all of the timing tables by using hills to your advantage!!


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 Post subject: Re: Tuning
PostPosted: Fri Apr 03, 2009 7:01 am 
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Joined: Mon Jun 09, 2008 11:36 pm
Posts: 1
Awesome


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 Post subject: Re: Tuning
PostPosted: Fri Apr 10, 2009 1:24 pm 
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Joined: Fri Apr 10, 2009 1:05 pm
Posts: 1
thank you so much. this is a awesome write up


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 Post subject: Re: Tuning
PostPosted: Wed Oct 21, 2009 5:10 pm 
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Joined: Sat Jan 17, 2009 7:24 am
Posts: 6
Great write up. Thanks for posting for us noob's


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 Post subject: Re: Tuning
PostPosted: Tue Jan 11, 2011 8:42 pm 
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Joined: Wed Aug 18, 2010 5:42 pm
Posts: 13
Location: France
great topic, nice explanation of pre ignition and detonation. I am very interested on this cause i have an high comp d16, and need to learn as much as possible before trying to tune it a bit so it doesnt explode... thanks guys


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 Post subject: Re: Tuning
PostPosted: Thu May 24, 2012 8:20 pm 
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Joined: Sat Jan 30, 2010 1:10 pm
Posts: 2
Location: Bangor, Northern Ireland
Wow thanks for the lessons guys 100% awesome!!!


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