i have actually figured this whole shift knock thing out tonight and have started this thread to help anyone else with the same problem since it sees to affect quite a few people.

it was really simple and i cant believe none of the big time tuners on these boards chimed in with this.

you simply (at least in my case) have to tune the 0% column in the timing and fuel map above 5000 rpms. in open loop fueling the 0% column is controlled by the ecu when you recieve your utec. that laod column can still be tuned by user defined values. since the ecu is taking over at 0% load when you lift to shift it is adjusting the timing way to high.

i simply matched the 0% load to the 10% load columns timing values instead of it reading ecu it is now in line with the rest of the timing that the utec runs so there is no advance in timing thus no knock. i also tuned the 0% column in the fuel map by just adding a little fuel above 5000 rpms to add a little extra support.

this will not affect daily driving at all since there is no chance of the ecu being in controll over 5000 rpms, except when lifting to shift, because your set parameters have the utec in controll above 2000rpms and 25% throttle and there is no way to reach 5000 rpms with out going over 25% throttle.

i made these adjust and made several pulls through all gears making hard shifts and did not get shift knock at all!!! problem solved, there is no need to adjust knock thresholds or sensitivity at all.

while researching i found this guide to tuning utecs, it was written by a wrx tuner but many things transelate to us 350z guys including what i have stated above. it is a good read for all self tuners especially beginners.

here is the link http://www.scribd.com/doc/6848/UTEC-...tes-03-22-2004

 

good find, thanks alot

 

I'll have to do some experimenting.

I haven't messed with timing in the 0% column. Is the 0% column an offset of the ECU or is it absolute timing, like in the other columns?

 

it is absoult timing and an offset of fuel in the fuel map just like normal tuning. it is what the utec refers to when it goes to close loop. if unchanged the utec will just refer to the stock ecu, but you can tune user defined values in the 0% columns instead of just letting the ecu take control. give it a try and check out that link i posted it explains it as well. solved the problem for me.

 

Good info man. It's good this is out there now.

 

chefrey,

I just realized that you are NA. I'm not sure if your fix will work for me. when I get shift knock, it is in the 20-30% load columns up around 5000 rpms. the turbos are still spinning, and there are a couple psi right there as soon as the throttle starts to open again.......

I'll mess around with it though..but not today. It's rainy (sideways weather. )

 

that info should work for you since i got it from a wrx tuner and they are definately forced induction, if you havent checked out the link in my first post on this thread do so it is a utec tuning guide from a f/i wrx, i actually took the info there an applied to n/a. it should definately work.

 

if this works i know some mustangs this weekend that are gonna catch hell!

 

curious if anyone else has had a chance to try this and if it worked for them as it did for me?

 

thanks for the fixing tips man, i`ve read this guide its so so useful BTW this guide is quite old here is the latest version

http://www.wrxhackers.com/forums/showthread.php?t=2469

he wrote some info about tuning with Speed Density mode, its much more useful for FI people.

 

This works... I adjusted my tune in the 0% column this afternoon and ran some logs. Works great. I did have the Open to Closed loop Delay set to (2) to address shift knock.... Which also works, but that caused a little "shift flare" as a result. This method of tuning results in no shift flare & smoother load point transition too - thanks to Chefrey for the great find! :-)

Edit: I'm NA.

Edit Edit: I adjusted the 0% column from 5000 rpm upward. I also added fuel in the 0% column from 5000 rpm up as well. Car has never run better... :-)

 

thanks for the updated guide every bit of info helps when tuning, i have also started reading the book "How to tune and Modify engine management systems" by Jeff Hartman. it does not deal directly with utec but it gives loads of usefull background information on how everything works in EFI and the tuning world. recomend this read as well.

 

very good info.....

 

Freakin' sweet. I will give this a try too. I will be doing my regular "maintenance retune" soon and will look for any problems. Thanks for the tip and contacting me to let me know you found the fix.