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dyno settings query

WazR32GTSt
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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.

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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

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  • Author
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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

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