After adjusting timing I get knock on shifting. I just keep dumping fuel and it seems to get better but I'm still what I consider to be fairly conservative timing. Is there another setting that could help me out in this. The knock occurs as the revs fall between gears and the AF floats between 12-13. Timing is in the mid 20's moving to high 20's in the uppers.

On a side note my UTEC is outputing .5 degrees less than I enter at all times, common or anomaly?

Thanks!

 

I get 'false knock' on my Utec all the time while shifting. I just ignore it.

 

i get "shift knock" too. I have my utec setup to pull huge amounts of timing when it senses a knock, so the shift knock kills my performance if I am trying to perform a 1/4 mile pass.

for example, the dofference between shift knock on my 3-4 shift from one run to the next was 4 mph....just in the last 1/8 mile!!!!!

 

So is there a way to tune it out?

 

i get the shift knock too, i just learned to ignore it

 

So I'm I the only person that is worried about it. I can see ignoring a single knock but I had 13 consecutive on a shift and the UTEC pulled 10 degrees timing. That would seem to be something to worry about.

 

Log the knocking and post the log.

 

I believe the .5 degree difference is UTEC pulling your whole timing curve after detecting knock. I did some runs, and saw UTEC pull my timing curve each time because I was getting knock in the upper revs.

 

it bothers me, too.

I noticed that I get the shift knock in the high rpms of my 30-40% columns (3-4 psi) . This is an area that would only be reached during a shift as the turbo is spooling back up.....

I may try to lower the timing in that region to see if that eliminates it.

 

You need to drop timing in those RPM/Load areas to prevent the knock counts. I have tried to listen to it through the knock cans but am unable to hear if it is a "phantom" or not. To be safe reduce your timing in those areas. It does not effect performance significantly (if any at all) from my testing.

 

Why don't you just implement a threshold cutover delay? If it is real knock, this may solve your problem.

Basically, the UTEC allows you to set how long it should stay in open loop before returning to cars stock ECU map. For example, lets say your threshold is 65% throttle and 2000rpms. The UTEC will only apply its map when both of these factors are true. When you shift, the throttle goes to 0% and one factor becomes false. Because we have an electronic throttle, the UTEC will see this and it will switch back to the cars stock map. If you set a delay, it will ignore the momentary drop in throttle and stay on its own map. You do this by crank cycles. If you are shifting at 6600 RPM, that is 110 crank cycles per second. If a shift takes two seconds, then you need to enter 220 cycles for the threshold delay. However, this would be pretty high for street driving where you shift at lower RPM points. For the street, you also will modulate the throttle over and under the threshold point on a regular basis.

DEFINITELY CHECK MY MATH ON THIS. However, it very well could be your solution. I also would run this by Jermaine (i.e. user BlackTuner).

I implemented a slight delay to try and get rid of a bog that I am experiencing. It really did not help, but it did not make things worse either. Then again, I am NA.

 

I was thinking this would be an appropriate solution but wasn't sure on it's impact performance wise. Thanks for the idea.

I thought about that but I don't think it will make a difference. I never leave the open loop threshold.

I've seen a few logs of tuned cars and the timing seems to be set lower around the 4750 mark for most people so I'll just increase everywhere else and see if that gets rid of the problem.

 

I have seen the knock count on shifting, but it logs it in a vaccum condition...such as -8.7psi, for instance. This type of knock is definately phantom, and could just be the sound of the throttle plate snapping shut, or a weird exhaust transition on decel. If you see 13 counts of knock under a pressure situation, then that is something to be concerned with.

 

It is under pressure, or so I would say. It happens around 4600-4700 as the rpms fall between gears. Everything is fine until it shifts so my assumption would be that because the engine has no load while shifting that it is causing the knock. Does that sound right? Straight gear pulls don't give knock, it's only on a run up throught the gears. I think I'll back the timing down to 24-25 from 4500-4750 and see if that remedies the situation.

 

on your logs, what is the PSI shown when the knock occurs?

 

My car is NA at the moment. I too was getting shift knock after I set my Open Loop TPS Threshold from 65 to 25 in the Open Loop Fueling Menu. I 'tuned' the shift knock out by increasing the Open to Closed Loop Delay from 0 to 2. So far this has really smoothed it out. Hope this helps...

 

I've noticed mine does this sometimes too, after comparing my logs to my parameter settings. My hypothesis for this is that the UTEC may need a slightly faster processor (CPU) to keep up with rapidly changing conditions... I was told the UTEC currently uses an 8 bit processor (which is 80's - 90's technology hardware-wise)...

 

The frequency that that 8 bit processor is being ran at is the important part. I would think that an 8 bit processor would be fine for the application, as long as they are running it at a decent speed (>20mips).

 

It was an internal setting that I never noticed. It was just pulling .5 across the board once knock was detected.

I'm not sure what you mean, the only PSI reading I see is for MAP which I'm am not using.

Anyways I made some adjustments to try and reduce the knocking and what ever I did really started doing bad things so I'm scraping it all and starting over before I nuke the motor. I never logged knock with just A/F adjustments so I'm going to try that and see if I get any before moving on to timing again.

 

I've also noticed that as UTEC transitions from one load point to the next, that the timing can be "off" by a little bit.

Example: If load point 50% has timing of 24, and 60% has 25 -- As UTEC transitions from 50% to 60%, the timing will read around 24.5 while it's transitioning.

It's the 3rd column in you log. If you're NA, it'll read negative. Ie. Vacuum.

If you're going to start over, here's a 350Z TurboXS base map (for NA with Breather Mods). It's a little conservative, but not *that* bad tune-wise, and will help get you going... This is the one I started with...