vpannu

iTrader: (2)

Hey everyone,
I recently got some more toys put on my 04' 6mt g35 coupe but unfortunately the numbers weren't that great.

In January this was the setup:
Mods: strupp Headers, kinetix y-pipe, crawford v5 plenum, jwt intake w/ z tube. Stock exhaust.

1/17/06, 57 degrees, Humidity at 42%, SAE 0.94
Power= 248.61 Torque=240.55




Last week the dyno was done with all the above mods in addition to Crawford High Flow Cats, Crank Pulley, Unichip

8/10/06, 80 degrees, Humidity at 43%, SAE 0.99
Power=246.49 Torque=232.58


I was hoping to reach high 250's with these mods or barely gettin over 260 rwhp. If I can get some advice as to what the problem may be. Is temperature a big factor in the loss of HP and Torque? Or does anyone have a setup similar to this or knows where the problem lies in my set up where the car isn't getting its peak performance? Thanks for the tips!

HighwaySpeed

Cool, dry air is the best for engine performance.

gtmule

iTrader: (1)

Well, the correction factor should take care of the ambient temp difference. Other variables vcould be oil temp, oil weight, water temp, fuel, blah blah. Chassis dynos are pretty unrelaible. Typically on an engine dyno you can control all these variables (including ambient air condtions) to within a couple percent, this is just baout impossible on a chassis dyno. so, you may have gained power, you prolly did, but mabye had a higher water temp or.....?

Also look at the area under the curve, not just the peak #'s, see what that tells you.

davidv

iTrader: (2)

Agree. The numbers are corrected. On the first dyno you were docked 6 percent (SAE correction 0.94). On the second dyno 1 percent.

Alberto

iTrader: (14)

Silly Q, but is your Unichip tuned? If so how much, street tuned? Just A/F tuned? Timing also?

mikead_99

iTrader: (5)

From just a glance the correction is a little off. SAE standard is determined at 29.23 hg, air temperature 77 degrees F and humidity at 0% so a run at 80 and 43% humidity should have an additive factor, not a decrease.

Q45tech

6 months between runs? obviously you were running winter blend vs summer blend gasoline.

Useless to compare dyno runs unless the fuel came from same batch! Often there can be a 5% or more variance in BTU and Ried Vapor pressure.

Was one [summer] ethanolized and the winter not?

roast

iTrader: (2)

Since barometric pressure wasn't listed(temp and humidity alone mean nothing).... looking at weather records for his area, and using a SAE correction calculator, the correction factor was spot on. Higher baro. pressure + colder temps + less humidity = docked a higher percentage.

The second run had higher baro pressure than the standard 29.23(it was 29.9), which is why the air was still more dense than the standard, even with more humidity and a slighter higher temp.

mikead_99

iTrader: (5)

lol, thanks roast. I knew I shoulda done more than glance at the numbers before posting my last.