What did they tune your AFR to? And cat's replaced with test pipes yields about the most gains.
I know everyone can't run them; also Dyno numbers in 4th gear on an A/T will definitely read lower than 1:1 5th,,, the M/T cars have 1.27:1 4th gear to a 1.41ratio 4th in the A/T...so not as much loss on the M/T's.
Only thing is,some tuners won't tune 5th because of the 170+mph speeds.

This is my numbers on a Dynojet w/ K&N drop-in's only.https://uploads.tapatalk-cdn.com/201...4469c732d4.jpg
The torque % difference between the 2 gears was quite a bit...speed limiter kicked in @156


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Ill definitely have to contact the tuner and see what he thinks about my numbers and if maybe they`re dyno just runs low numbers. might have to do a run or two on a dynojet if I am not satisfied.

That's a local speed-shop that has a Dynojet & an educated operator...my AFR was rich@12.2'ish.
When I got tuned w/UpRev,it was set to 13:1 at wot


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I'm on the same boat, I have pretty much same set up on my 15 nismo z now my biggest concern is if there is something goes wrong with my z. I made 299whp/265ft.lb on a dynapack and and one of my buddy got 336whp which also is pretty much same set up on a dynapack but different store. Since I finished tuning session the tuner no longer reply my email like and I already send email over three times. Now I have to drive almost 180km to find a shop which have dynojet. so I'm very looking forward that you get a good number in a different dyno machine that could pretty much fix my prob either.

Your 15' Nismo is more than likely equipped with a 3.92:1 diff ratio.
Thus making it less effort on the engine to twist it up...Dyno numbers are lower on lower geared Diffs than taller gears.

Unsure if it would be 37whp difference though.


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it's very Attractive to have high Dyno HP #'s, but their primary function is to tune your vehicle,,,So many variables come into play with the magic # that tops the screen. As it calculates HP through torque,rpm's,time,etc...
Dyno's can be calibrated to throw large or small numbers-but using the same one to tune your car after mods will help you determine gains/losses better than switching to another Dyno.

re: tune
 

FWIW, I think there's something wrong, particularly with the torque curve as there's no way it should be that peaky. Although I've never used them, my reference point for best tune is Seb at Specialty Z. I recall that they were getting around 310 RWHP Uprev tune on NA 370s with CAI and Catback. I don't remember their torque numbers. In any case, I was delighted when I got 307 HP and 233 Ft-Lbs on a Mustang dyno from my tuner (Keith at AWD Tuning in DFW).

http://www.the370z.com/members/ltull...1-15-2013.jpeg