mohammedtuner

hi
i have c5zo6 2001 the engine 408 i but te car on dyno jet befor two months i got 534 hp and 484 tq.
The weather was winter and cool air and the fuel rito was 12.9
until three days i but the car on dyno agian and i found the fuel rito 14.2 and horses come down to 507 hp note the summer is income heat .. after that i tune the car again and i get to 517 hp 464 tq ..
Note that the car is very excellent and I do all maintenance ..
is that normal or not ???
thank you

Horps27

Well governor...

78GEN3

danieloneil01

Same dyno? What was the AFR on the last set of numbers? Timing the same from the first and last dyno numbers?

danieloneil01

PS, cooler air = more power.

robert miller

Need a lot more info, plus if it is colder weather out side number will be better if all other stuff is the same. Robert

RED99

Different Dynos will result in different numbers, also same Dyno and different correction factor.
IAT (Air density) and Engine coolant temp will change timing which will result in different numbers itself. Going from winter to summer, the winter should show more HP for more dense air. But its all in how the tune makes adjustments for all these thousands of different factors.

Higgs Boson

what color is it and where are you? I used to have a 2001 Z06 with a 408. :-)

rjwz28

That would be awesome if all that difference was due purely to temp... see my sig for a combo that seriously dyno'd low for the sum of its parts

tblu92

Differences in ambient air temps can make huge changes in RWHP--especially on a dyno where you have no driving air to cool the IAT sensor---The IAT sensor at apprx 131* will remove 5-7 degress of timing that's huge when you only have 27-24 to stsrt with---making your car lazy and rich NOT LEAN-----If t was a colder day on the second run then yes it could bceome lean
To sort out you need to get the data from the logger to see what's happening---Intake air temps--coolant temps---knock retard==without this info you are just chasing your tail and guessing as is your tuner--
A prpperly tuned LS will eliminate all those inconsistent timing decuctions--and make tuning not a procedure of timing but fuel----Less air density take some fuel out better air density add some fuel in ( PE table) this eliminates all the crazy false IAT temps from underhood heat soaked IAT sensors----

Higgs Boson

A properly tuned LS? 27 degrees to start with? Sounds like someone hasn't looked a 2014 calibration yet....

tblu92

You can't compare the timing on a port injected LS eng to the new 2014 SIDI engines--- It's a whole new ball game with SIDI engines--
Don't know what you are trying to say---But on a LS engine properly tuned by eliminating false timing deducts-- 24* is not out of range ---with race gas or 93 oct non Calif premium you can get 27* with no REAL knock retard