Jump to content
SAU Community

dyno settings query

WazR32GTSt
 Share

Recommended Posts

WazR32GTSt Grand Master

WazR32GTSt

Posted
Posted

g'day

i have a question about "dyno dynamics" dyno's and their settings...

i have seen that the intake temp is the main setting that seems to vary from graph to graph when different people put their power figures up

so my question is...

what would the power difference be for a car run with an intake temp of 14deg versus an intake temp of 30deg on the settings? (assuming everything else is constant...)

would this be significant, or just a couple of killowatts?

obviously its not an issue, i was just thinking...

(its almost exam time so i have plenty of time on my hands and will do anything to procrastinate!)

cheers,

Warren.

Link to comment
https://www.sau.com.au/forums/topic/74943-dyno-settings-query/
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted

Shoot Out Mode (SOM) compensates for temperature differences. So a guy in Tasmania in winter should get the same power if he was in Cairns in summer.

The old rule used to be 5% change in power for every 8 degrees change in temperature. I have no idea what DD apply for SOM correction.:P

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

it makes a difference on a turbo car is the sensor is in the engine bay as the sensor see's...

eg: 50 degrees due to a pod and no CAI... but then it goes through an I/C on a turbo car so the car is actually seeing a different temp and shootout is applying a correction that isnt quite correct.

Its different for an N/A car.

I've seen a 10-15rwkw difference in my car using shootout with the sensor inside, and outside the engine bay.

WazR32GTSt Grand Master

WazR32GTSt

Posted
  • Author
Posted

reason i asked is that when i got my car dynoed it was about 15deg outside, and the temp was measured at the intake manifold, so the real temp getting to the cylinders

but on dyno days i see them placed at the air filter and temps of 30deg

so let me rephrase my question...

- dyno in shootout mode

- car in same workshop, same day, same time of day

- car gets power measured with IT set to 15

- then car gets power measured with TI set to 30

same figure?

Sydneykid Grand Master

Sydneykid

Posted
Posted
reason i asked is that when i got my car dynoed it was about 15deg outside, and the temp was measured at the intake manifold, so the real temp getting to the cylinders

but on dyno days i see them placed at the air filter and temps of 30deg

so let me rephrase my question...

- dyno in shootout mode

- car in same workshop, same day, same time of day

- car gets power measured with IT set to 15

- then car gets power measured with TI set to 30

same figure?

Use the 8 degrees = 5% rule of thumb.

Need more info though....

1. What is the ambient temperature (AT)?

2. What is the rwkw reading at the 15 degrees Inlet Temperature (IT)

:(

JAGR33 Grand Master

JAGR33

Posted
Posted

Interesting question this, was trying to apply this theory to two.60l's thread where she made 466 rwkws in shoutout (8) mode, but when asked to provide a graph in non shootout mode the reply was "there's no difference".. WTF??

Anyway as an example my car made 335rwkws (Racepace dyno dynamics), and then backed up with 360rwkws in shootout mode!!!!

Haven't got a printout of the 360rwkw (shootout mode) run, so sorry can't compare temp readings...

Although next week i'm getting poncams installed and a retune so I'll get Ben to do a run in shootout mode aswell as normal mode... STAY TUNED!!!

Sydneykid Grand Master

Sydneykid

Posted
Posted
Interesting question this, was trying to apply this theory to two.60l's thread where she made 466 rwkws in shoutout (8) mode, but when asked to provide a graph in non shootout mode the reply was "there's no difference".. WTF??

That could be true, if the Ambient Temperature and the Inlet Temperature are at the temperature that DD have selected as their "reference temperature".

Anyway as an example my car made 335rwkws (Racepace dyno dynamics), and then backed up with 360rwkws in shootout mode!!!!

That's normal, and precisely what I would expect if the Ambient and Inlet Temps are hotter than the "reference temperature". It is exactly the same as dynoing your car in summer (335 rwkw) and then again in winter (360 rwkw).

Although next week i'm getting poncams installed and a retune so I'll get Ben to do a run in shootout mode aswell as normal mode... STAY TUNED!!!

That should be interesting:cheers:

WazR32GTSt Grand Master

WazR32GTSt

Posted
  • Author
Posted
Use the 8 degrees = 5% rule of thumb.

Need more info though....

1. What is the ambient temperature (AT)?

2. What is the rwkw reading at the 15 degrees Inlet Temperature (IT)  

:rofl:

1. the ambient temp was about 15deg

2. the car made 132rwkw at 14deg inlet temp

if its 15deg outside, even with a FMIC surely i could not be seeing 15deg at the inlet manifold? would have thought realistically the inlet air would have been about 20deg

but if i were at a dyno day instead of having booked tine on the dyno the probe would be elsewhere and definately not measuring 14deg... maybe the probe wasn't even hooked up? and it was jsut set at 14deg?

hmmmm

Munna Rising Star

Munna

Posted
Posted
1. the ambient temp was about 15deg

2. the car made 132rwkw at 14deg inlet temp

if its 15deg outside, even with a FMIC surely i could not be seeing 15deg at the inlet manifold?  would have thought realistically the inlet air would have been about 20deg

but if i were at a dyno day instead of having booked tine on the dyno the probe would be elsewhere and definately not measuring 14deg... maybe the probe wasn't even hooked up? and it was jsut set at 14deg?

hmmmm

Thats the problem with dyno days sometimes they dont take the time to set the cars up properly as it takes longer between runs.

But unless the all the sensors are in the correct positions ect. the results mean nothing.

Example

Ice performance Dyno 195 rwkw

All sensors in correct positions ect. 22 deg day in shootout mode.

Local Dyno comp 156rwkw

no sensors in airbox, no fans infront of the cars, 40 deg day, no shootout mode

car ran great no pinging at all.

RPMGTR Community Regular

RPMGTR

Posted
Posted

Shoot out has some pretty generous enertia values (esp shoot 8), hence the higher numbers. Intake temp is also corrected back to 20C, so placing the sensor in behind the rad will give a substantial 'improvement ' also.

We like to use ambient air for Intake temp and 0 enertia. When done in this manner, the cars perform as per the hp calculators. When using shoot numbers, the cars underperform........

JAGR33 Grand Master

JAGR33

Posted
Posted
Shoot out has some pretty generous enertia values (esp shoot 8), hence the higher numbers. Intake temp is also corrected back to 20C, so placing the sensor in behind the rad will give a substantial 'improvement ' also.

We like to use ambient air for Intake temp and 0 enertia. When done in this manner, the cars perform as per the hp calculators. When using shoot numbers, the cars underperform........

That's the answer I was looking for!!!!!!!!!!!!!

Hence some dyno figures getting around which are truly over the norm....

Emre Proficient

Emre

Posted
Posted

The difference explained to me by a DD rep quite a while ago:

Inlet Temp - Ambient Temp / 5 = x% difference.

Ex : It's a 25 degree day and the probe is placed in the engine bay and reading 55 degrees.

55-25/5 = 6% will be added to the measured power in shootout mode.

Sydneykid Grand Master

Sydneykid

Posted
Posted
The difference explained to me by a DD rep quite a while ago:

Inlet Temp - Ambient Temp / 5 = x% difference.

Ex : It's a 25 degree day and the probe is placed in the engine bay and reading 55 degrees.

55-25/5 = 6% will be added to the measured power in shootout mode.

Isn't that only half the story? That's the correction for Inlet Temp being above Ambient Temp, but what about Ambient Temp being above DD's reference temp? Based on RPMGTR's post wouldn't it apply additional correction for the Ambient Temp being 25 degrees compared to DD's reference temp of 20 degrees?

Keep in mind Shoot Out Mode doesn't always ADD to the power readings. If the Ambient and Inlet Temps are less than DD's reference temp then it will show LESS power.

:P

WazR32GTSt Grand Master

WazR32GTSt

Posted
  • Author
Posted
Agree with you...

The point i was making, is the discrepancy on where the temp probe is placed and the effect it has on the readings.

There was a dyno sheet where the IT was 82 degrees, a while back.

true...

i remember seeing a thread comparing optimx to bp ultimate

ultimte made about 10 more rwkw, but also had an IT 10-15deg higher than the optimax reading...

hmmmmmm... bit sus to me

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • dbm7
      R34 Skyline climate control unit transistor

      By dbm7 · Posted

      Bit of a pity we don't have good images of the back/front of the PCB ~ that said, I found a YT vid of a teardown to replace dicky clock switches, and got enough of a glimpse to realize this PCB is the front-end to a connected to what I'll call PCBA, and as such this is all digital on this PCB..ergo, battery voltage probably doesn't make an appearance here ; that is, I'd expect them to do something on PCBA wrt power conditioning for the adjustment/display/switch PCB.... ....given what's transpired..ie; some permutation of 12vdc on a 5vdc with or without correct polarity...would explain why the zener said "no" and exploded. The transistor Q5 (M33) is likely to be a digital switching transistor...that is, package has builtin bias resistors to ensure it saturates as soon as base threshold voltage is reached (minimal rise/fall time)....and wrt the question 'what else could've fried?' ....well, I know there's an MCU on this board (display, I/O at a guess), and you hope they isolated it from this scenario...I got my crayons out, it looks a bit like this...   ...not a lot to see, or rather, everything you'd like to see disappears down a via to the other side...base drive for the transistor comes from somewhere else, what this transistor is switching is somewhere else...but the zener circuit is exclusive to all this ~ it's providing a set voltage (current limited by the 1K3 resistor R19)...and disappears somewhere else down the via I marked V out ; if the errant voltage 'jumped' the diode in the millisecond before it exploded, whatever that V out via feeds may have seen a spike... ....I'll just imagine that Q5 was switched off at the time, thus no damage should've been done....but whatever that zener feeds has to be checked... HTH
    • 25RBGT
      Got this r31 silhouette flood car to rebuild.

      By 25RBGT · Posted

      First time we have seen lights 
    • Wazmond
      WGNC34 - floor mats

      By Wazmond · Posted

      I think Fitmit had some, have a look on there (theyre Australian as well)
    • soviet_merlin
      Howdy Y'all

      By soviet_merlin · Posted

      Hah, fair enough! But if you learn with this one you can drive any other OEM manual. No modern luxury features like auto rev-matching or hillstart assist to give you a false sense of confidence. And a heavy car with not that much torque so it stalls easily. 
    • soviet_merlin
      WGNC34 - floor mats

      By soviet_merlin · Posted

      Actually, I'd say all three are the automatic option. Just the different trim levels. The manual would be RSFS, no? 
×
×
  • Create New...