I'm having a mental block here, but I was thinking about how the SMART timing table is set up...

The x-axis is RPM and the y-axis is "knock" as it is read by the knock buffer. The table is then set up so that at various rpm levels if the knock being read by the buffer exceeds the nominal value for that RPM timing is pulled.

My question is this...

Shiv said that the "0" line was determined by running the engine through it's rev range while on low boost and very rich (read, a situation with no chance of knock) The input value from the knock buffer was logged versus RPM, and the "natural noise" of the engine is then determined. That curve is then determined to be the "0" line in the SMART timing table.

The only way the Xede will ever venture below that line is if the knock levels are lower than that, but if that's the natural noise level of the engine with NO knock, how could the knock sensor ever read lower....

And to that end, can the Xede ever really add timing????



- Steve

 

Well I know when speaking to Dustin his car set-up to run positive timing without a problem, but then again he has Shiv to set-up and check-up the car all the time. I am hoping maybe Shiv can set-up the Smart timing tables on the dyno to have some positive timing.

 

My take is that the zero line is calibrated to WOT. Thus at part throttle conditions the noise can (and is) below this line permitting positive timing advance.

Several of us (covertly exchanging mail) have noticed remarkable results from the smart timing system with the advance table. Specifically in stop and go driving, fuel consumption is sufficiently lower as to pay for the upgrade.

Second the engine's torque delivery is greater at low RPMs such that less throttle (and clutch slip) is required to launch the car. This translates not only in an easier to launch Evo, but lower wear on the clutch.

For these reasons I consider the smart timing upgrade to be the best development for 2005.

 

 

That makes sense then... and also explains why I never see it go positive at WOT. I havn't paid attention to the SMART timing table at part throttle, but I did notice a huge difference when I recently changed to the table with advance after I got my new creader. Just as you said, driveability is much improved.

 

Dumb question from me:
Will leaving a Creader plugged in all the time (and thus keeping OBDII in not ready status) negatively effect fuel economy?

 

Nope. Leave it plugged in all the time. OBD-II system will still be fucntional. Just no P0300s anymore.

shiv

 

As of now I am running off the shelf smart-map with my custom tune boost, timing and fuel numbers. I was just wondering where can I download smart timing map where it has positive timing? I want to give it a try. I have good creader.

 

Doesn't the SMART system also add timing when you are running, for example, a 93 Octane map with race-gas in the tank? Unless I missed something, I'm pretty sure that's how the SMART setup on my car was able to extract an extra 15whp across the board when we dynoed it using this scenario.

l8r)

 

Igor,

Look here and you'll find what you're looking for. You have to manually input the values, but that's what you want.

- Steve

 

Technically, no, unless one of these two scenarios are true...

a: Your motor is "quieter" than Shiv's "0" line, and with race gas SMART ventures below the "0" line at WOT.

b: Your motor was always knocking just a little bit so that your SMART timing table was always pulling about a half a degree of timing throughout the rev range.

Either of these scenarios would allow the race gas to quiet down your car pushing the SMART table to run in a lower row of cells.

Correct Shiv, or am I way off here? I'm trying to learn...

 

Thanks Steve, I am going to try it today and see how it works for me.

 

I just re-did my Smart timing map to be more aggresive then drove the car around for 10 min, could already feel the difference at partial throttle. We will see how it hold up during the week since I drive the car almost everyday.

 

Good deal, glad to see it worked out for you.

 

Better than I could have explained it!