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Hacking up Honda's ECU
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 Post subject: Tuning
PostPosted: Wed Jun 07, 2006 1:43 am 
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This is an article for noobs all the way up veterans still tuning on inertia dyno’s. I will go threw some very noobish stuff and make my way up to the actual tuning itself.

- AFR or air fuel ratio is referred to as a # of air to 1 part of fuel or some#:1, (like 14.7:1 which is 14.7 parts of air to one part of fuel) 14.7:1 is stoichiometric. Stoich is where you get the most complete burn and is only used for emitions. Performance tuners use AFR for heat control. Leaner AFR can get you higher power but not enough to make a difference. Example if you are on a dyno and are tuning wide open throttle or WOT and you change from a 12.5:1 to a 14:1 there might be at the most a 10 hp difference. This small difference is not enough to put your motor at risk of catastrophic failure.

- First, the reason that they refer to timing as advancing timing is because when your motor ignites its air/fuel or a/f mixture it is BEFORE top dead center. The reason for this is that fuel takes a long time to burn so igniting this mixture before top dead center, you achieve peak cylinder pressure sometime after TDC. What degree doesn’t really matter and every motor is different. More on this part later.

C/R or compression ratio- This is the difference between the amount of volume that is in a cylinder compared to volume when the piston is at TDC. Basically it is how much the motor squishes the air fuel mixture together. (Example 12:1 C/R this is a pretty high C/R for the street and a lower C/R is 9:1, this is turbo friendly)

DETONATION- This happens from a couple different things. One is a hot spot in the cylinder like a piece of hot carbon or a thin spot in the piston that ignites the fuel before it is ready. This is not that likely it usually has to do with bad tuning. Like timing if you advance timing to much you get peak cylinder pressure BTDC. If you raise the C/R you are forcing molecules closer together and that means the flame front travels faster and creates faster ignition and getting peak cylinder pressure BTDC. Same thing with a turbo or supercharger, you are forcing more air into the cylinder so the piston will compress it more because you are forcing so much more air than it normally receives. This is combated by a lower C/R, retarded timing, or both.


- Dynamometers- there is three main types of dyno’s that are used, AssDyno’s, inertia dyno’s and load type dyno’s. AssDyno’s are where you sit in your car and try to feel the difference in HP and should NEVER be used not only for safety (hard to see the road and gauges you need at the same time) but your ass can not tell the difference between 300 and 310 HP. Inertia dyno’s like Dynojet use heavy drums that the tires spin. It calculates how fast you accelerated these drums to calculate horsepower and from that get torque. Load type dyno’s use some kind of brake to slow or stop acceleration and even can even make the car decelerate. These dyno’s are superior to inertia dyno’s and is reflected by the price to use them. The RIGHT way to tune car can only be achieved on a load type dyno. More on this later.

- You need a datalogger of some type, try to get a program with both tuning and datalogging incorporated into one nice package, it saves lots of time and as far as I’m concerned this is the only way to go. Map tracing also aids in tuning.

- Wide Band Oxygen (WO2, Lambda, Uego, AF/R meter…) Sensor. The main tool used to tune along with a Dynamometer. This TOOL is used to find your AFR. If you don’t know for sure what you want to set your AFR to then keep reading this article to gain some knowledge then pay someone to tune your car.

TUNING

You have a way to change fuel and ignition maps, a datalogger with map tracing and some time at a Load type dyno. Lets go threw the steps of tuning a Honda VTEC motor.

For this example I will be using Crome Pro(because it has tons of features making it easier to tune) and a Moates Ostrich Real Time Programmer because that is what I use but this will work for any software (uberdata, Hondata, AEM EMS, Autronic, Haltec, ect.) When tuning you want to tune your AFR first and your ignition second.

Your engine will run on a 10:1 AFR all the way up to a 18:1 so set your basemap up conservative, both fuel and ignition. Also set your VTEC at 6000 rpm to tune your low fuel map first.

When you get your RTP (real time programmer) and your data logging hooked up it is time to start tuning your idle. Just watch the map tracer and select that cell it settles on and adjust the fuel up or down to where you want it. With Crome all you have to do is press (Ctrl+Up) or (Ctrl+Down) to make that cell add or subtract fuel.

Now to start tuning load... In Crome the rpm is on the left going top to bottom, vacuum and pressure is on top going from left to right. This is where having a load type dyno helps tuning. You can keep it at a certain rpm but change the Load (throttle or vacuum/boost). Start at a low rpm and work your way up. Choose a number that is in the column not in the middle of two columns; this is important because if you don’t get it exactly on the cell it will not be accurate because they use percentages of the surrounding cells too fill in between the cells when moving between cells; so if one cell gives you 10:1 and the one right next to it gives you a 16:1 and you are right between the two you would get a 13:1 AFR.

Lets say you start at 1000 rpm, put a really light load on the motor and see where the map tracer sits and tune that cell until it is at the AFR you want. Then add a little throttle until you get the map tracer centered on the cell just right of the one you just tuned and then add or subtract fuel till you get your desired AFR. Keep moving the cell right, after you tune that cell. Do this until you get to WOT (Wide Open Throttle or full throttle)

Now you have all of your 1000 rpm tuned and it is time to go to the next cells down. On the JDM P30 rom it would be 1250 rpm. Start at a light load and work you way up to WOT just like the last row.

Do these steeps for all the rpm’s in the low fuel maps.

Now set the VTEC point at 3500 rpm and start tuning your High Cam fuel map just like you did for the low cam fuel map.

Smooth your fuel maps.

Now that you have setup all of your fuel maps it is time to go on to timing. This is where ALL of your power will be made. Also everyone says that timing affects your AFR but it does not, you have to ask yourself does timing really have anything to do with how much fuel was squirted into the cylinder; regardless of when you ignite that cylinder your AFR has already been chosen by how much fuel your injectors just squirted out.

Set you VTEC point back to 6000 rpm.

Tuning your timing is just like tuning your fuel except instead of watching your WO2, you watch how much HP or Horse Power your car is making. Start at 1000 rpm, put a really light load on the motor and see where the map tracer sits and tune that cell until you get the highest HP. If you add ignition timing you will see the HP from the dyno go up and when it stops getting higher stop or if it goes lower subtract some timing until you achieve the highest HP out of that cell and move on to the next cells until all of the cells in that row are finished. Move to the next row and repeat those steeps until your entire low ignition map is finished. Tuning timing like this is the only right way to tune timing because not only do you get peak power everywhere but getting peak HP is far from getting detonation. If you are getting detonation and tuning timing this way it is probably from a hot spot in the cylender (most likely a hot piece of carbon) so check your AFR and richen up your fuel to cool down the cylinder.

Raise your VTEC point back to 3500.

Tune your High Cam ignition map just like your low cam map.

Now smooth ignition maps.

With your VTEC point still at 3500 do a power run.

Now raise it to 6000 rpm and do another power run.

Look at your dyno charts and see where the torque curves meet; set your VTEC point where the lines meet.

That’s it, now your car is tuned.


Last edited by ickyhonda on Thu Jun 08, 2006 12:04 pm, edited 2 times in total.

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PostPosted: Wed Jun 07, 2006 5:00 am 
Only read a little because I gotta go to sleep but im sure the rest is just as great, thanks for all your help you've been a great support, someone promote this guy!


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PostPosted: Wed Jun 07, 2006 5:11 am 
Ok I couldnt wait so I went ahead and read the whole thing, I learned terms that I didnt quite understand before (WOT, butt dyno, other types of dynos) and got an idea of how to tune. Thank God I dont have to deal with VTEC and high cam but still a tiny bit confused on the whole tuning process going from a certain rpm to WOT.

Anyway, this deserves to be on Wiki =)


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PostPosted: Wed Jun 07, 2006 10:11 am 
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Great write-up.

Under "- Dynamometers-" the last statement you made is "The RIGHT way to tune car can only be achieved on an inertia dyno." I'm guessing you ment to say load dyno instead of inertia dyno.


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PostPosted: Wed Jun 07, 2006 12:56 pm 
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White_Teg wrote:
Under "- Dynamometers-" the last statement you made is "The RIGHT way to tune car can only be achieved on an inertia dyno." I'm guessing you ment to say load dyno instead of inertia dyno.


Thank you it was changed.

[quote="IntegraKarim"]Thank God I dont have to deal with VTEC and high cam but still a tiny bit confused on the whole tuning process going from a certain rpm to WOT.quote]

Ok a load type dyno uses brakes to limit how fast the rollers spin and inertia dynos use lots of weight. Load type dynos measure the ammount of force from the breaks and the speed of the rollers to get HP. This means they can keep a engine at a certin rpm if you tell it to, no ammount of throtle will make it go past this set rpm. This is like a science experiment, you only want one variable. and for a engine that runs off of two variables (manifold absolute pressure or MAP vs. RPM) and if you eliminate one vaiable by making it a constint then you only have to worry about the changes made in the variable. So if you set the dyno up on say 1000 rpm and you add and subtract throttle the tracer square will move only left and right in the 1000 rpm row. Using your foot you can center it on a cell (anywhere in the 1000 rpm row). When you center it on a paticular cell you watch for the changes you made (either fuel or timing) untill they are at the desired point.

Keep giving me feedback like this so I can elaborate on things that you dont understand.


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PostPosted: Wed Jun 07, 2006 5:55 pm 
It probably sounds dumb that I dont understand that part but its probably also since i havent physically gotten started on my car. I wont have access to a dyno for a while so i have to ghetto dyno it.

When you talk about the tracer moving across squares, was is the tracer? Does it mean while i have everything hooked up, say im at idle holding it at 1,000 rpm, will i see information change in crome? Thanks


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PostPosted: Wed Jun 07, 2006 6:56 pm 
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I just want to say that tuning the whole fuel map, rpm by rpm, load by load, this puts TOO much work on a turbo setup. you can do it, but let the car cool down and dont stay long on the cell you adjust, or you will melt something.
You can also deactivate the vitec to tune the non vtec map and put the vtec very low to tune the vtec map, sometimes having a very low vtec can unleash some power which you dont expect to have. This is even more true with funky cam shafts.


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PostPosted: Wed Jun 07, 2006 8:03 pm 
Well thank God I dont have VTEC so i dont need to worry about that, when you say it puts a lot of load on the turbo setup, you mean when im sitting in my car and just revving, is it possible to tune that way or would i have to be on a track or dyno, cause im not ready for a dyno, i wanna try something at home first.


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PostPosted: Thu Jun 08, 2006 12:15 am 
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Synoptic wrote:
I just want to say that tuning the whole fuel map, rpm by rpm, load by load, this puts TOO much work on a turbo setup. you can do it, but let the car cool down and dont stay long on the cell you adjust, or you will melt something.
You can also deactivate the vitec to tune the non vtec map and put the vtec very low to tune the vtec map, sometimes having a very low vtec can unleash some power which you dont expect to have. This is even more true with funky cam shafts.


You are not in boost that long remember you go from vacuum to boost and back down to vacuum. If you are melting anything tuning, your car it not set up for the power you are trying to get out of it. Pro race cars where the motor is built and tuned on engine dynos tune the same way and the HP they are getting out of their cars is tremendous.


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PostPosted: Thu Jun 08, 2006 12:24 am 
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IntegraKarim wrote:
Well thank God I dont have VTEC so i dont need to worry about that, when you say it puts a lot of load on the turbo setup, you mean when im sitting in my car and just revving, is it possible to tune that way or would i have to be on a track or dyno, cause im not ready for a dyno, i wanna try something at home first.


On the crome website there used to be a walkthrew video but it does not work anymore. Basicly a map tracer is a box that shows where your ecu is taking its fuel and ignition point from. So if you are at 10 psi and 6000 rpm it will highlight the cell at 10 psi and 6000 rpm.


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PostPosted: Thu Jun 08, 2006 12:53 am 
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Icky I have to say that this is a very good post. It should be put on the wiki for the noobs that have no previous expereance. Good job! Not sure if this would help or confuse a noob, but maybe alittle on C/R. Just a thought.


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PostPosted: Thu Jun 08, 2006 12:04 pm 
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civic_r87111 wrote:
Icky I have to say that this is a very good post. It should be put on the wiki for the noobs that have no previous expereance. Good job! Not sure if this would help or confuse a noob, but maybe alittle on C/R. Just a thought.


Done. Plus some info on detonation.


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PostPosted: Wed Jun 14, 2006 2:13 pm 
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In your post you say that leaner means higher HP, what is the factor limiting how lean can you run?? EGT?? how can i tune a car in an intertia dyno?? i know that i can** hold the car at certains rpms... is there a method like the one you posted?? thnk you. GREAT POST!!

**edit: sorry i mean CANT hold the car....


Last edited by luisma on Thu Jun 15, 2006 6:18 pm, edited 1 time in total.

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PostPosted: Thu Jun 15, 2006 6:07 pm 
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luisma wrote:
In your post you say that leaner means higher HP, what is the factor limiting how lean can you run?? EGT?? how can i tune a car in an intertia dyno?? i know that i can hold the car at certains rpms... is there a method like the one you posted?? thnk you. GREAT POST!!


1: It also says not enough to make a difference. The reason that you may want to go richer is that your cylinder and head might not be able to cope with the heat of going lean. So stay rich.

2: You can't. Well you can, but it will not give you the best power or reliability.

3:The only method that i know of to keep a motor at a certian rpm is a Load type dyno.

4: Your welcome! Just giving back to the people of this site for all of their help when I needed it.


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PostPosted: Fri Jun 16, 2006 9:16 pm 
I have to say "Thank You!" - that answered more of my questions than trolling and searching on the site for the past 2 months has. This is sticky and wiki worthy!


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