MazdaManiac

iTrader: (3)

I think you are just bringing too much irrelevant info (for this particular discussion) to the table.
Port timing and volume is interesting and all, but in this instance, I think all we are looking for is hard data for this particular scenario.

Brettus

iTrader: (2)

IAT from just before throttle plate
some readings from first test
3000 rpm in 2nd gear through 3rd and to 8000rpm in 4th -( if any one has a better test that is easy to do on public roads i'm all ears)

Aux ports closed
Max MAF : 300g/s (sits at 295 from 6800 right through to 8000rpm)
Boost pressure : 9.5psi constant
ambient temp : 25C
Start IAT temp : 40C
end IAT temp : 43C

What I was going to compare was the speed of temp change hopefully at same maf , ambient and start temp ......

Kane

iTrader: (1)

Seems like a useful run - now try it with ports open and we'll see.

I would like to participate... but motor is still too new and I am under 6 inches of snow; I miss Hawaii

olddragger

iTrader: (3)

isnt your intercooler more efficent the hotter it gets? Just trying to think of this as apples to apples.
Wouldnt the intercooler efficentcy have to be a constant?
This is interesting. Especially if the 2nd run with the ports open shows no temp change.
Whats the bet gentleman? ---significant change are no significant change?

Arggggh---Thanks to your info i certainly have a better understanding of why MM has advocated the use of bigger injectors in the P1 spots instead of the P2's. Appreciate that.

Brettus

iTrader: (2)

Tried to do the second run yesterday but ran into laptop/software issues and was unable to measure IAT .

Wish Hymee would get IAT onto dudelogger - would make it much easier for me ....

Brettus

iTrader: (2)

I did manage to get MAF info however which demonstrates the loss of power that happens when aux ports open .

I believe more power is lost than what we see on a dyno because dynos typically get their readings at a much slower acceleration rate than what we see on the road ....

MazdaManiac

iTrader: (3)

It would have been useful if you extended your run out to at least 8200 RPM.
That is where the potential loss would occur from having the AUX ports closed.

Brettus

iTrader: (2)

the point of the exercise was to see what the delta T was with the same MAF . I can fiddle the wastegate to achieve identical maf from 7000 onwards with either setup .

MazdaManiac

iTrader: (3)

I'm sure you can.
But data is data.

TeamRX8

iTrader: (25)

Funny that he started off this thread referencing you, and now in turn is arguing about your answer(s)

MazdaManiac

iTrader: (3)

I'm used to it.
That is pretty much the basic paradigm of this entire forum.

Brettus

iTrader: (2)

not really . I'm just not one who blindly follows the teaching of others without trying to understand what is really going on .

Kane made a very good point which throws doubt into my mind - I don't mind if I end up proving myself (and MM) wrong if I at least learn something from it .

olddragger

iTrader: (3)

Learning--sometimes is half the fun of it all.
I wish I had a fully equipped garage/lab to do a lot of the tests I would like to do--properly.
Best i can come up with is a multi tester, stethoscope, timing light, thermometer ,vacuum/boost , obd2 stuff and a somewhat understanding tolerant wife.
OD

Brettus

iTrader: (2)

Well - it is doubtfull i'll be able to do the tests I wanted to because my laptop is about to meet it's maker - aka the sledgehammer .

gregs

iTrader: (7)

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Brettus

iTrader: (2)

/\ ah yes - I know that feeling well

TeamRX8

iTrader: (25)

Well there's learning something, and then there's believing you learned something when in fact you got it wrong ...

Good luck

Brettus

iTrader: (2)

very true - I try to avoid the latter with good logical process and testing but there is always the possibility of getting it wrong if you don't have the facility to do exhaustive tests under controlled conditions .

I maybe started off the thread over enthusiastically but at least I did label it "discussion" .......

FWIW : I have looked back on previous logs I did (aux. ports open) some time ago which show a very similar delta T to the aux ports closed test I did so I'm not expecting any great ZOMG revalation from any testing that I do.

TeamRX8

iTrader: (25)

It started great; asking a question

you went off track when the asking questions stopped and countering replies began

olddragger

iTrader: (3)

the art of diplomacy is being lost in the world of text-ing

Brettus

iTrader: (2)

I did a little digging and came up with this formula for calculating the temp diff.
I'm not 100% sure this is correct but i'll plug in the numbers anyway :

T1 x (P2/P1) x (1/ compressor efficiency) = T2

So for my particular example taking the pressure at the turbo outlet ,reading efficiency off the chart in my first post (not 100 % correct because It is off the chart but the difference should be about right ) and keeping MAF the same :

Aux ports open
25C x (26.7/14.7) x (1/0.65) = 69C

Aux ports closed
25C x (29.2/14.7) x (1/0.60) = 82C

From this it seems it is better for me to leave them open ......

Kane

iTrader: (1)

Looking good bro.

That seems about right to me.

Spoolin8

iTrader: (2)

So let me get this straight for all the people that want a simple logical answer. Your saying instead of closing off the aux ports its better to simply run them always open for better efficiency and lower temps. Is this correct?

Kane

iTrader: (1)

No, it just means that more flow at a lower PSI is overall better temperature wise.

You still have to tune around it, which can be hard.

If you leave them open all the time you lose a lot of air velocity down low.

Brettus

iTrader: (2)

Think I had better edit my first post --- LOL