I can tell Peter that you are excited - enjoy.
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Datsun 280Z -77 - Build thread
- Thread starter peter_s
- Start date
Mark N
Club Member
It is called the K factor in the manual and relates to speed at 3000rpm in the gear for the dyno pull.
http://www.dynomet.dk/quickguide Dynomet for Windows.pdf
Peter, I would have thought that temperature value should be ambient temperature, not inlet temperature, as the manual says to input it and atmospheric pressure before the pull.
peter_s
Club Member
No, it's the inlet air temp just outside the intake. It was up to 80 at one point.
DSI also said there are 10-20 more hp to be had if you let it cool down a bit, with the same tune
peter_s
Club Member
It's like when you get a kid and you can tell your friends it's a boy or a girl, and what it weighed.
"It was 300whp and the torque curve looked like this"
Mark N
Club Member
It should be ambient temperature and pressure according to their other manual:
http://hamownia.info/instrukcja/index_en.htm
The dyno will then correct back to 20 degC and 1013mb for the DIN power figure.
http://hamownia.info/instrukcja/index_en.htm
The dyno will then correct back to 20 degC and 1013mb for the DIN power figure.
Alphabettispaghetti
Club Member
5 rpm less...
Alphabettispaghetti
Club Member
hi- I’m not disagreeing with the figures at all. I just want to know what I’m looking at. I’m use to other Dyno brands.
peter_s
Club Member
It's nuts really. DSI knows what they are doing!
Alphabettispaghetti
Club Member
I’d bet the fi you’ve got is worth nearly 10%.
Dsi seem to take the ‘Kameari’ method and design use for parts and put them together nicely.
Seikoking
Well-Known Forum User
My exact thoughts too. I love seeing the data and this is very pleasing to see. I was looking at the Datsun Spirit site recently, but I was only dreaming to be fair! It looks like their power claims are not unfounded, nice.
Seems there may even be more to come from your engine too...I really look forward to future posts.
Really great stuff.
Mark N
Club Member
When the temperature was at 80 degC, did the dyno figure increase or decrease substantially when that temperature value was input into the system?
Mark N
Club Member
Using inlet temperature instead of ambient will hugely affect your dyno figures.
For example, if you input a 55 degC ambient temperature, it will net you around 60RWHP when corrected back to the DIN value of 20 degC.
If the actual ambient temperature in the workshop was less than 20 deg C it will net you even more.
This calculator shows the effect of temperature and atmospheric corrections (Standard is the same as DIN)
https://robrobinette.com/Dyno_Correction_Calculator.htm
For example, if you input a 55 degC ambient temperature, it will net you around 60RWHP when corrected back to the DIN value of 20 degC.
If the actual ambient temperature in the workshop was less than 20 deg C it will net you even more.
This calculator shows the effect of temperature and atmospheric corrections (Standard is the same as DIN)
https://robrobinette.com/Dyno_Correction_Calculator.htm
peter_s
Club Member
It is the air intake temp. And it compensates up for it. However, the dyno said there is 14hp to gain from a colder air flow at the intake, it didn't recalculate the number and bumped up the number in the graph.
DSI said the same thing, the engine will deliver 10-20hp more if they have let it cool down.
peter_s
Club Member
It was not a part of the calculation. The car showed less power on the rollers.
Instead of hp figures you should just announce that the power is 'sufficient' like Rolls Royce did for many years. I like that idea it avoids a lot of argument.
Manufacturers will guote specific figures like 323 bhp and 0-62 mph 5.2 s. People 'hang on' those figures to impress mates. Its like saying because you have a fantastic cooker you can cook fantastic meals.
peter_s
Club Member
I kinda like having the real no bullshit numbers that you can backup
And I do think this is a testament to what the guys at DSI are doing. The numbers and curves are exactly that they expected. So being able to reproduce this putside their shop is pretty nice.
And I state again, it's just not the engine, it's a complete system that needs to work in harmony. I've done everything Eiji has recommended, and he recommend things that needs to be done so his engine can flow. Headers, ITB, fuel injectors, trigger wheel etc. Do it right and everything will work as it should.
I've also had a great shop with tons of experience that put it all together in the end. Those guys are amazing and know what they are doing