Since I had to remove my Xede and send it to Vishnu to take care of the overheat protection and firmware issue, my car is now back to a TBE and drop-in filter only. I never logged data from my car w/o the Xede. So I did a log today to see the difference in AFR/boost with and without the Xede. This is a third gear pull of two overlayed runs. The dotted line is with the Xede and the hard line is without the Xede.

The boost falls to 15.5 psi by redline w/o the Xede while with the Xede it stay at 18.3 psi. The Xede reduces taper from 4K rpm all the way to redline. Peak boost is the same, however. Spool up is faster wit the Xede and I did notice that in daily driving.

The AFR also suffers horribly after 5K rpm w/o the Xede and this is with a conservative 11ish AFR.

 

thats great nj!
are you gonna do a log with pocketlogger just to see the diff??

 

I alreday did but I have not downloaded it from my palm. I will post it ASAP.

 

Here is an excel graph between the stock timing map and the custom timing map on my 05 Evo. notice that there is more timing pulled with the custom map than with the stock map. It makes sense since boost has increased and AFR was leaned with the custom map. You will also notice that this glitch in the middle of the timing curve where both the custom map and the stock map back the timing 1 degree then advance it up again. It happens around 5300 rpm which corressponds to point 10, 11, 12 on the chart. I have seen this in almost all the timing logs that I have done. now I see in the stock timing curve.

 

great nj +1!!

so do you think 2* degrees of timing being pulled back is still acceptable as 1*??

 

I was thinking about doing this myself....thanks for saving me the trouble.

Nice job.

 

This is were things get dicey and interesting. You need to know if your car is knocking and pulling timing or not.

The Evo has a knock sensor on the back of the block. The knock sensor is nothing but a rubber microphone that picks noise from the engine block. This noise is transmitted as either as a fequency or a voltage (I am not sure which) to the ECU. The ECU reads that noise/voltage and with other inputs pulls timing when it believes that there is knock.

Here is the problem in this approach. When you mod your car with TBE/intake/bov/big trubo/larger pipes/solid motor mounts you increase noise. So now you have the knock sensor hearing more noise and transmitting this noise to the ECU. The ECU, in turn, thinks that this noise is actual knock and pulls timing. But the noise could be phantom knock.

From what I read, the best way to listen to knock is to use your ears. You can create a device from old people's hearing aid and attach it to the block and attach a set of headphones to your ears. This way you can tell what is knock (which has a specific noise) from simple noise. Another way is to create a detection can from a metal pipe that is rolled and flattened on one end and attached to the block and attached to a hose and to your ears at the other end.

Most of what I read seems to indicate that logging knock voltage on a modded car is not adequate to detect knock.

Barring th creation of listening devices to hear knock. You can take preemptive steps to protect from knock. Lowering your AFR is one sure way to reduce knock. You and I know that Shiv's over-the-shelf maps run lean. So go to the MAF/Fuel map and add 4% fuel to the entire map. Zero out the cells that turn positive. Set your AFR target at 11.2:1 across the power band with taper at the end.

Another way is to run 93 octane gas instead of 91 octane. I am currently mixing 100 and 91 to get 93 in CA.

Finally do not boost more than 22 psi peak on 93 octane gas.

 

thanks nj!
what iam doing is using the 91oct map with 93oct gas just to be on the safe side!

 

I would also urge you to lower your AFR. Just add 4% of fuel to the entire map and zero out the cells that turn positive. I know your car will not make as much power as before, but it will be safer. You can compensate for the loss of power by maxing out the boost table from 6000 rpm on.

 

thanks nj,i left my afr#S fluctuate between 10.9-11.7 this is in 3erd gear WOT!

 

If you take a look at the stock ECU timing curve, then the values that you are seeing make perfect sense. Looks like you are falling somewhere between the 200 and 220% Load column when the ECU is running the show. At 200% Load the timing values on a stock '05 ECU are 8 (4500 rpm), 10 (5000 rpm), 9 (5500 rpm), 13 (6000 rpm).

l8r)