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Discussion Starter #1
Ok, I heard somewhere that D15B has a more agressive cam as compared to the one on a Z6. I wanted to know how true this is and would it make any difference if i change my z6 cam to a d15b one? Also if right what kinda timmings issues can i run into? thanks in advance
 

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i agree... i think it will be a bolt on thing.... im pretty sure ud feel the difference too.. in performance.. but by how much? ur butt dyno will tell u hehe

cuz all z6 aftermarket parts work for my jdm D15B vtec head..
 

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If u do that I would sugest remapping your ecu as a P08, cause the timing advance/ignition maps are different from a P28.... might run a little better... maybe not... you will have to configure/try on a dyno... but I think it might play a rold in the game of power!
 
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JaredKaragen said:
If u do that I would sugest remapping your ecu as a P08, cause the timing advance/ignition maps are different from a P28.... might run a little better... maybe not... you will have to configure/try on a dyno... but I think it might play a rold in the game of power!
ok see thats the thing, remapping the ECU is kind of a problem where the car is located, plus there is no dyno available either, lol i know i know you could say the car is in the middle of the sahara desert and im going there in a few weeks. What the middle of the saharan desert does have is a shit loads of engines of all types, so maybe i can get another ECU to work on this one? has anyone tried that??
and what about a cam gear, can that help me optimize the timmings?
 
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Discussion Starter #8
Cuong-Nutz said:
you could buy any civc ecu and have it rechipped with the p08 maps.
so u suggest i put in a p08 cam and p08 ecu in a z6 and expect gains?
correct me if im wrong
 

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Altyman said:
Is it the same when applied to a Y8 head?
neither a d15b nor a d16z6 cam will fit in the y8..

and no, not ALL z6 and d15b parts are the same.. rods yes, everything else is different.

if they were the same then why swap the z6 cam for the d15b :hammer:
 

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since you're going from 1.5 to 1.6L, the p08 maps won't be ideal even with the d15b cam. The p28 will work fine, but it will most likely see more gains from actual tuning.
 
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makku said:
since you're going from 1.5 to 1.6L, the p08 maps won't be ideal even with the d15b cam. The p28 will work fine, but it will most likely see more gains from actual tuning.

ok so now , considering no ECU tuning facility, and no dyno
how can i actually tune without these 2 things :p
i mean is there anything else i can do to make it better without these 2 being there
 
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SOHC_Rules said:
u can get a chipped ecu and street tune or u can just get an apexi vafc or something
From what i have learnt here, the VAFC's wont let u alter timings which is what you need to do with changed cams, correct me if im wrong.
 

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Here's a great write-up from my local board. I didn't copy over the two charts for Ignition and Fuel maps:

"AFCs (Air-Flow Controllers) are simple hacks. That's why they work with pretty much any EFI system. Basically what it does is take a reference voltage that an ECU uses to calculate how much air is coming in to your engine and change it. It works with MAP sensor based systems like Hondas as well as Mass-Airflow systems like Nissans etc. Because it's a simple hack something has to suffer somewhere. Because the ECU chooses fuel values and ignition values based on air-flow and RPM, this hack not only modifies your fuel curve, it modifies your ignition curve as well.

Below are sample maps from a B18B P75 ECU. You can see the maps are identical in size (10x20) and the MAP values and RPM values that run along the top and sides of these maps are identical. Inside the maps are ignition values in degrees and fuel values calculated from fuel map values and multiplier numbers specified in the Honda ECU.

As you can see in the ignition maps, the less manifold pressure the ECU sees the more ignition is applied. The more manifold pressure the ECU sees the more fuel is applied. Here in Arizona our atmospheric pressure reading is around 958 mBar which would put us between the 8th and 9th columns of these maps. Essentially when leaning a mixture out with an AFC your ECU sees less airflow. Let's say you start running incredibly rich at 4300RPMs. If we take the point at 4325 and atmospheric pressure (958) we get between 29.75 degrees and 28.50 degrees of advance and a fuel value somewhere in between 553 and 589. Let's say we start leaning the mixture out because we have upgraded from 240cc stock injectors to 270cc injectors. As we use the AFC to lean the mixture out the ECU sees a lower manifold pressure and starts moving to the left on the maps. Now let's say we have leaned it out enough that the ECU is seeing 760 mBar as our current manifold pressure. The ECU is now selecting values from the 6th column instead of the 8th and 9th. We are now running 33 degrees of advance and a much lower fuel value, 434. Now leaning certain points out and richening others would give you an ignition curve that's all over the place...

Now for VAFCs or any other type of VTEC controller. They simply provide +12v to the VTEC solenoid at whatever RPM is specified. Some of you may think this is great. BUT (There's always a but isn't there) the VTEC controller does not communicate with the ECU in any way, shape, or form. The ECU has two separate sets of maps that it uses for VTEC applications. A low cam set when VTEC is not active and a high cam set when VTEC is activated. When ECU engages, the ECU switches maps to provide the engine with the correct ignition curves and fuelin for the higher cam lobes. Even though you can specify when the VTEC engages with a VTEC controller the ECU still switches maps at it's stock programmed point. If you set VTEC lower than stock you are in high cam while still running on the low cam maps until the ECU's programmed point. If you set VTEC higher than stock you're in high cam maps while you're still in low cam from the ECU's stock point until the VTEC controller's set point. Adjusting the VTEC point with a VAFC can cause a lean or rich condition and force you to use the VAFC to adjust fuel during the tuning process, which would adjust your ignition timing (as mentioned above) even more. Now, not only are you not in the correct maps, but the VAFC is changing the MAP sensor voltage and your ignition curve is going all over the place."
 
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DirtyDEF said:
Here's a great write-up from my local board. I didn't copy over the two charts for Ignition and Fuel maps:

"AFCs (Air-Flow Controllers) are simple hacks. That's why they work with pretty much any EFI system. Basically what it does is take a reference voltage that an ECU uses to calculate how much air is coming in to your engine and change it. It works with MAP sensor based systems like Hondas as well as Mass-Airflow systems like Nissans etc. Because it's a simple hack something has to suffer somewhere. Because the ECU chooses fuel values and ignition values based on air-flow and RPM, this hack not only modifies your fuel curve, it modifies your ignition curve as well.

Below are sample maps from a B18B P75 ECU. You can see the maps are identical in size (10x20) and the MAP values and RPM values that run along the top and sides of these maps are identical. Inside the maps are ignition values in degrees and fuel values calculated from fuel map values and multiplier numbers specified in the Honda ECU.

As you can see in the ignition maps, the less manifold pressure the ECU sees the more ignition is applied. The more manifold pressure the ECU sees the more fuel is applied. Here in Arizona our atmospheric pressure reading is around 958 mBar which would put us between the 8th and 9th columns of these maps. Essentially when leaning a mixture out with an AFC your ECU sees less airflow. Let's say you start running incredibly rich at 4300RPMs. If we take the point at 4325 and atmospheric pressure (958) we get between 29.75 degrees and 28.50 degrees of advance and a fuel value somewhere in between 553 and 589. Let's say we start leaning the mixture out because we have upgraded from 240cc stock injectors to 270cc injectors. As we use the AFC to lean the mixture out the ECU sees a lower manifold pressure and starts moving to the left on the maps. Now let's say we have leaned it out enough that the ECU is seeing 760 mBar as our current manifold pressure. The ECU is now selecting values from the 6th column instead of the 8th and 9th. We are now running 33 degrees of advance and a much lower fuel value, 434. Now leaning certain points out and richening others would give you an ignition curve that's all over the place...

Now for VAFCs or any other type of VTEC controller. They simply provide +12v to the VTEC solenoid at whatever RPM is specified. Some of you may think this is great. BUT (There's always a but isn't there) the VTEC controller does not communicate with the ECU in any way, shape, or form. The ECU has two separate sets of maps that it uses for VTEC applications. A low cam set when VTEC is not active and a high cam set when VTEC is activated. When ECU engages, the ECU switches maps to provide the engine with the correct ignition curves and fuelin for the higher cam lobes. Even though you can specify when the VTEC engages with a VTEC controller the ECU still switches maps at it's stock programmed point. If you set VTEC lower than stock you are in high cam while still running on the low cam maps until the ECU's programmed point. If you set VTEC higher than stock you're in high cam maps while you're still in low cam from the ECU's stock point until the VTEC controller's set point. Adjusting the VTEC point with a VAFC can cause a lean or rich condition and force you to use the VAFC to adjust fuel during the tuning process, which would adjust your ignition timing (as mentioned above) even more. Now, not only are you not in the correct maps, but the VAFC is changing the MAP sensor voltage and your ignition curve is going all over the place."

Excellent info but just need to clarify myself so i know i understand everythin correctly,

so VAFC's can alter ignition timings, thats good. Now what I didnt understand was when you change the VTEC engagement point, can you alter the stock VTEC map starting point to compensate for that using the VAFC's?
 
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