Datsun 280Z -77 - Build thread

[johnymd]

Which management system are you using Peter?

 

[johnymd]

As a good guild to how intake air charge temp will affect power at the crank. If all other variables stay the same and the ACT goes up 10*c then you will lose 3.3% hp at the crank. Reduce the ACT from 80 to 20 and you could see nearly 20hp gain. These are real life figures used by ford dyno operators.

 

[jonbills]

Which management system are you using Peter?

I think he's on EMU black, which does seem excellent value. Nearly as good as Speeduino

 

[peter_s]

Which management system are you using Peter?

Almost Jon, I'm running the simpler version which is called EMU Classic.

As I've said before, I'm mightily impressed with all aspects of the Classic. It's got everything you would ever need, and it costs around 800£. No wonder they have become so popular. The software is really good too.

You only need the Black if you are running more modern systems like CAN bus etc. The classic handles CAN bus as well, but the Black has got more I/O, suitable for more modern engines. The black also has one more +5V output, the classic only one. 6 cylinder sequential is max on the classic.

It seems all after market ECUs do the same thing. But there is a lot of local knowledge here with Ecumaster, and the price is outstanding.

 

[peter_s]

I think he's on EMU black, which does seem excellent value. Nearly as good as Speeduino

I read up on that one. Seems like a nice kit as well.

The EMU Classic has a few more things that will save you even more, built in MAP and WBO. I connected the vacuum line straight to the ECU, and just wired up the WBO straight to the Bosch lambda. Saved me some wiring and money.

 

[Mark N]

As a good guild to how intake air charge temp will affect power at the crank. If all other variables stay the same and the ACT goes up 10*c then you will lose 3.3% hp at the crank. Reduce the ACT from 80 to 20 and you could see nearly 20hp gain. These are real life figures used by ford dyno operators.

Going from 80 to 20 would equal a 19.8% gain if you gain 3.3% for every 10 degC.

 

[Mark N]

That would be about 400 at the crank and 133BHP/litre.
That's Ferrari FXX Evoluzione territory.

 

[peter_s]

That would be about 400 at the crank and 133BHP/litre.
That's Ferrari FXX Evoluzione territory.

The dyno reported a 25hp loss. Not 25%

 

[Mark N]

The dyno reported a 25hp loss. Not 25%

I was referring to the Ford rule of thumb of 3.3% per 10 degC.

 

[peter_s]

I was referring to the Ford rule of thumb of 3.3% per 10 degC.

Yeah, that can't be right here.

All I can say is that this is a good dyno. No overinflated numbers. The shop is always within a few hp when they dyno stock cars

 

[Mark N]

The fact that the dyno sheet mentions DIN 70020 means it is correcting to 20 degC.
The higher the temperature value input, the more it is corrected with a higher HP value.

 

[johnymd]

It is right though and as you mentioned before, DSI said you could gain up to another 20% by getting the temps down. I have just agreed with you that a drop in temps down to 20*c will see 19.8hp increase. Exactly what DSI said to you.

 

[Mark N]

It is right though and as you mentioned before, DSI said you could gain up to another 20% by getting the temps down. I have just agreed with you that a drop in temps down to 20*c will see 19.8hp increase. Exactly what DSI said to you.

You are interchanging BHP and %.

 

[Mark N]

If you use the first graph's 335.9BHP figure and multiply by 1.198 you would get 402BHP at the fly.

 

[johnymd]

Oops

 

[peter_s]

Their engines certain impress me and these power figures prove just how good they are. How much would one of these engines cost? Are they substantially more than the equivalent rebello?

You will have to check with DSI. But I think you can calculate around 10-11k GBP for a stage 4 Engine. Then you have core charges etc.

 

[peter_s]

If you use the first graph's 335.9BHP figure and multiply by 1.198 you would get 402BHP at the fly.

The ambient temp was around 20 deg, I don't know why the tuner puts the intake temp, but he does.

The 335.9 figure is crank, but it's not compensated for ambient temp.

I'll ask the tuner later when I pick up the car why he does it like that. But as I said, he is known for having realistic numbers.

Check this graph out:

 

[Alphabettispaghetti]

That would be about 400 at the crank and 133BHP/litre.
That's Ferrari FXX Evoluzione territory.

from a 55 year old SOHC L6.........

 

[Mark N]

You said he is known for accurate numbers on stock cars, which you can't really inflate the figures on.
If he is intentionally putting in a high ambient temperature, he is inflating the BHP result which will reflect well on him if the software performs the correction.

 

[peter_s]

You said he is known for accurate numbers on stock cars, which you can't really inflate the figures on.
If he is intentionally putting in a high ambient temperature, he is inflating the BHP result which will reflect well on him if the software performs the correction.

He is accurate on all cars. I will ask regarding the input of temperature, but I'm sure he has his reasons.