I doubt weather/dyno variance is much if any factor here. You can see the dyno uses STD corrections which accounts for temp/humidity plus it's a fixed-mass inertial dyno not subject to the huge variances brake based dynos are known for. The gains/losses of his mods should be greater than the dyno variance in any case.

I would take a look at the timing curves before/after the mods. I am definitely seeing some knock retard on those plots. Cams can induce some phantom knock if they are noisey. Try shutting knock control off completely and setting hi and low det maps equal. Also make sure you have a solid 12.5 a/f thru out the pull.

 

Did i just read that you're swapping out the MREV2 because you lost 2 HP at peak and gained torque all through the curve?

Not complaining, just trying to be clear there? Chances are, with cams, you might make more power with the complete intake revision you're ordering, i assume you're after just peak numbers?

 

I'm guessing you mean improperly lashed, maybe a bit loose?

Curious as this is the first time i've heard any stories about phanom knock on our vq's...
A friend's built sti engine has phantom knock like a ****... I don't want to deal with that at all.

 

Just being F/I on a stock block will induce phantom knock. I know because I have it . Ended up shutting down knock control completely on my track map and got an extra 4mph. It doesn't get talked about too much because uprev F/I has only recently started to take off in popularity and nobody really pushes the limits quite yet.

 

Sweet another thing to worry about.
"fuuuuuuuuuuuuuuuuuu"

 

depending your goals I wouldn't jump straight into boost. If you are wanting an extra 100-150 hp then go for it but if you just want to be up at 300hp I would stay NA for sure.

Have you thought about going to a different fuel? E85 has proven great results for some imports that are NA. You can get the extra cooling from the fuel and then push the timing limits from the octane.

Increased compression would be nice like you said but requires a tear down of the engine which sucks. If you do up the compression then I would for sure use e85.

 

I got da phantom knock! Ya, I'm not sure if it's the knock sensor or the oem knock map but our engines show tons of knock for no reason. My built engine is pretty noisy as well (on a knock sensor, not audible). I had to tweak the haltech knock map a bunch due to random strange noisy areas.

 

I think even the Nissan engineers got fed up with it, which could explain why the stock map has knock control disabled below 2k rpm and above 5k rpm or so.

 

Ask the tuner to look up a RECENT base Z33 run and see what the numbers are. My guess is the dyno is just not set up the same. The key is get a recent output from the dyno under similar factors.

Otherwise, you may have an issue. Although cams don't add monster power on their own they normally give a pretty health bump once tuned.

 

did you ever check the old dyno sheet? this one is showing smoothing of 5 which is going to cut your numbers down more than a lower smoothing amount.

 

Hit this one on the nail man, We are dealing with an unhappy customer right now because he put the wrong cams in his Titan and he's trying to say we didn't tune it correctly. I always recommend always doing a little head work with cams. Good luck !

 

I too have the mysterious phantom knock....I have Osiris so I have a tune w/ knock sensor on and knock sensor off; I think I'll get rid of the knock sensor on tune....

I wonder if there's anyone out there FI/built engine that runs with their knock sensors on?

 

I doubt anyone making serious power is tuned with the knock control on, at least above 4500rpm. It's just too sensitive.

Ever notice how almost every VQ35DE N/A dyno chart has a slight dip around 5k or so?

 

seriously? all of us making big power do. Of course with the limited software provided by osiris you can't tune the knock threshold so you will have to invest in a better tuning solution like proEFI or haltech. I honestly can't think of someone putting down high HP that DOESN'T have knock control enabled on their car.

On that note, it's impossible to have a generic knock map for any built engine. Every engine has unique sounds and needs to be setup properly in order to work. That goes with any car on the market. It's really not THAT hard to tune a knock map as long a the tuning solution used has that freedom.

 

I was speaking specifically of uprev, not other systems. Uprev knock control seriously sucks ***** as I was trying to explain.

 

oOo, yes it does. I'm not sure why they couldn't program a map to adjust the sensitivity like other platforms that use the OEM ecu. Seems like osiris is horribly limited compared to other oem ecu flash programs (for other cars of course).