From how I understand it, advancing the timing on our ECU raises the maximum value that the ECU will try to run at as long as there isn't any knock detected. 93 has a higher threshold for knock and can benefit from letting the ECU advance higher than the stock limit (anyone know what this # is?)

 

The dynojet dyno numbers are usually all over the place due to user inputted correction factors and non vehicle loading.

On average for the Mustangdyne and Dyno-dynamics (true-loading dynos), the 350Z will put down about 205-210whp. We had a stock 350Z with extremely heavy 5-zigen wheels put down 197whp the other day. This is pretty much inline with the manufacturer's ratings, with the STI doing about 220-225 and the EVO 8 doing about 210whp.

Just FYI on the Mustangdyne you do not turn off VDC as all four wheels are rolling just as they would on the street.

Cheers,

Gary
Gruppe-S

 

We have not taken a good look at the 350Z ECU yet (just got the reflash software), but ECU's such as the Subaru ECU's have ignition timing multipliers. Basically your ignition timing is the result of a function of knock detection (or lack thereof).

Therefore when the use of higher octane fuel is applied, based on the ECU "sampling rate" your stock ECU will gradually (or rapidly depending on settings) advance ignition timing up to a maximum threshold provided that it does not detect any detonation. As soon as it detects detonation it begins to retard timing based on pre-defined formula.

Based on what I have seen with the 350Z / G35, I would be willing to bet that there is definately an aggressive and fairly rapid ignition timing multiplier.

Cheers,

Gary
Gruppe-S

 

On crappy 91 octane California gas, my car pings a tiny bit during the hot summer days, and I can feel it pull back the timing when I'm really pushing hard. On those days, 92 or 93 octane should help bring back the zip that gets otherwise lost due the heat-derived-pinging. I can't imagine a relatively stock Z engine needing more than 93 octane under any circumstance, though. The only full-proof way to test if 91 octane is insufficient for you is to hook up a scantool and watch the knock sensor status while driving. If they never activate, then a higher octane won't do anything for you. If they do, then a higher octane might help.

 

I'm a little surprised by these numbers. Isn't that a ~27% drive train loss for the 350Z. Compared to ~25% for the STi and ~24% for the Evo. I was always under the impression that AWD vehicles would have more loss, not less.

 

Yeah--does anyone know the true drivetrain loss on a 6mt Z?

I'd imagine (based on my calculations) its about 17%.

ravi

 

I think it is somewhere in the 15%-18% range. Every dyno is different, but for the most part, the 16-17% range is a good number to work with. From my experience with the mustang dynos (from my reading past forums) they report EXTREMELY low numbers no matter what car is ran on them. That is why you can't compare dyno numbers between different cars and dynos.

For the most part, the thought that AWD has more drivetrain loss is correct. You have another transfer case that will result in power being lost.

 

Hi,

Yup, basically every dyno is different . The popular loading dynos that most tuners have (the Mustangdyne and the Dynodynamics) all result is fairly lol numbers relative to the dynojet, and even more so to the Dynapacks as you are dynoing the hubs only.

In terms of calculated drivetrain loss, it's really hard to peg a drivetrain loss number, because a manufacturing's rating is often calculated very differently (and influenced more by the advertising department).

A good example is the 280HP rated 2003 G35 6-speed grounds 210-215whp stock compared to the 287HP rated 350Z which does about 207-210whp.

On a side note we installed Helix prototype headers, Helix cat-deletes, Gruppe-S Y-pipe, Injen intake, and RSR exhaust on the 350Z and put down 212whp and 214 ft/lbs of torque - a very respectable 15whp gain, with solid gains throughout the power band.

Cheers,

Gary
Gruppe-S

 

+1

 

just to add to the octane debate, in the september (or was it october) 2002 issue of SCC, they did a dyno of a 350z on regular 91 octane gas and then on 100 octane gas

it gained 4-5 peak hp at the wheels and 2-4 throughout the powerband