damn thats disappointing to hear. I made a tiny change to the VVEL C (by only 2 degrees) before and it did make the change, hopefully it will work.

alright.. back from datalogging.

increasing the knock threshold by 1000 did make absolutely no change to ignition timing, it is running exactly the same ignition as before. This sucks, I am stuck

also about VVEL, I increased VVEL C by 5 and it did not make any sizable difference. Then I just discovered that VVEL B is quite close to VVEL C in the mid/top range.. maybe need to change both VVEL B and C? I will do another run with VVEL B also changed and see what it does..

made a new rom with knock threshold increased by about 8000, and VVEL B and C both increased.

hopefully it will make some difference.

but then again, I wonder if adjusting the VVEL will net any gains.. surely nissan must have spent their time trying to squeeze the most out of the stock valve system?

I think the biggest gain if you can figure it out is removing the egr function from the cam timing. The car has got to have it, if you can do that I bet you will see noticeable gains, however I dont think uprev comes close to giving you the tools to do that.

Also not sure if its true or not but there was some talk about the possibility of slapping your valves against your piston. I would tread cautiously if those tables do infact work and you end up closing your clearances between your head and bottom end.

alright.. back from another data logging.

increasing the knock threshold by 8000 did not increase timing at all, actually it did increase it by 1deg between 3200~3500rpm but i don't think that is significant enough. 8000 is more than 30% increase and it did not make any changes, I dont think this knock threshold adjustment is giving us much benefit.. if at all, or maybe it needs stupid amount? not sure how safe this can be though.


However, VVEL adjustment worked. Looks like it is running whatever is lower between VVEL B and C, you can see the log attached.

It did not increase the max VVEL timing value though, maybe its got something to do with the "valve clearance limit" table? apparently it is a safety feature to ensure the piston wont kiss the valves.

the MAF reading also seems slightly higher with the new VVEL timing, it was just a random increase I made to see whether it was gonna do anything or not.

So in short, while adjusting both VVEL B and C could not increase the MAX VVEL timing, it did make the correct changes as per the table in most areas, I think it is limited by some sort of safety mechanism. So there must be something to gain/lose from there.

It would be great if someone can share their 'tuned' VVEL timing so we can study it better..

So look at mine logs and we are only messing with VVEL B-2 why are you using both? ,

Do you mind posting your logs? :)

guess not

What are you looking for I only have them in Excel .

excel is perfect.. rpm, vvel timing, ignition timing etc during WOT would be perfect, so we can study it.. or you can send them via email too if you prefer not to post it here :D

my email is bleunetizen@hotmail.com cheers

:tiphat::driving:

st notice comparing logs that with the HFC's and M370 above 6k my car is losing timing. PRE HFC's and M370 timing was 23 Deg @6k and climbing all way to 30 @7800 ,
Post HFC and M370 timing is down to 17 @ 6K, and only goes to 21 deg @ 7500? Again I stopped at 7500 with this run cause I the AWD light was blinking( Dyno operator error) But why am I losing timing ? I'm assuming I just need my tune retouch but just want to make sure nothing is wrong. I'm up at that RPM daily.

probably better if you can dyno again at your usual place so you can compare the results?

I also find my timing reduced overall time to time, not sure what causes it, maybe heat soak or outside air temp/humidity?

Yea but that's over a month away for me, Just wanted make sure nothing is wrong.

Been to my local dyno shop today to tune my friend's 350Z, everything went smoothly and the car gained 30kw at wheels.. :ugh2: It must have been so slow

While I was there I decided to give my Ecu an another go and see if I could improve it any difference but nothing, i could not make any difference really.

No matter what I do, it wont advance more timing, yet it is dead quiet and no sign of detonation, it is no where near the detonation, I think the engine can easily advance 2~3deg+ without any hassle.. except that I CANT GET IT TO ADVANCE ANY FURTHER :shakes head:

Tried everything, playing with knock threshold, knock window, timing high det map, timing main map.

For the 350Z it is really easy, it will advance timing more and more as I tell it to and easy to find out when it would start becoming noisy, and easily find out the limit of the tune and put a slight safety margin from there.

For the 370Z, for the life of me, I cant really advance it once it hits the wall shown in the picture here.

Has anyone got any idea on what to do in search for more power in NA tune?

I wonder if it is affected by VVEL? I can't get a clear information about VVEL tune either..:confused: