TB993tt

The technicalities here are way over my head.......But isn't the mass air flow g/hr just part of the formula for how much power an engine can make ?

I remember when I tried Kevin's stage 3 K16s he told me to ask the sceptical guys at RS what they thought of the fact that the Stage 3s could flow XXg/hr due to the large compressor - Rather than enter into a debate the reply was the predictable "we will test it on the engine dyno"
Simialr thing with Tal's engine when it originally rocked up to RS with a set of Garretts which on paper gave all the right flow numbers but on the engine dyno would give in the 600s - out came a pair of whopping K27EVOs and the missing ~200hp materialised.
Point being it is the temperature of the mass of air that that is being flowed which is more important (to produce real hp) than the actual mass # ?

Jussi

Engine's air flow is most important factor in producing power..
Mass air flow or Volume air flow is same thing, mass flow can be translated to volume flow when knowing temp, airpressure etc..
Very simple basics: if you want to make 600hp engine, your engine must get 900CFM flow. Your engine flows NA mode as calculations from cubic size * RPM / 2 * VE. And so on..
So flow is power, like a flowerpower
And when you force air by turbos more than engine normally (NA) takes, that's overboost and overflow and also just an air flow !
And when engine flows, ECU are adjusting right amount of gasoline at right moment and time etc to make as much horsepower it can BUT still it corresponds to this amount of air. (that adjusting ratio is also know as AFR)
VE is value efficiency which tells how much your engine can utilize from this flow. It is something about 90%.
Of cource, air temperature and density affects to these flow values (g/s) in ECU calculations but these MAF flow values are very important and their can be compared to each others car when we are testing these values in appr. similar temperatures and altitudes.. because there is no power without flow and how much flow means how much horsepower you can get from your engine..
So if you have OBD tester or similar device, please log that MAF values against RPM, load, throttle and show results

Edited : of course, Intercooler's capability is also very important thing when getting serious power from system. But these above flow calculations/stories are still upperlimit of system or in other words they determine max values. Hotter air(worse IC) just lower results..
So, good IC can just minimize losses, it can't itself produce more power from nowhere.

I hope my explanation(sorry for bad english) makes clear this topic to you

fast951

Does anyone have the transfer function for the MAF in question? A Bosch part#?

Based on the MAF signal, you can determine the air mass. This will give you a rough idea of te HP your engine is making.

The effect of the change in air temps is captured by the MAF and is reflected by the MAF signal..

The Intake Air Temp sensors (IAT) in the MAF are used for cold/hot start. Some MAF sensors can be installed after the IC (vs. in front of turbo). Some systems use the IAT in the intake manifold for ignition control (ex. IC heat soak = elevated intake temps = higher chance for detonation).

Jussi

I think part number is 993 606 124 01
and Bosch number B3130-128512.

And that MAF DON'T support over 550 hps.
If there is much more powerful engines they just don't use MAF to control these powers..
Jean or Kevin : or what do you think about transfer function's max value
5V @ 1545.8kg/h ?

But I ask again, can someone log or check their MAF values against RPM when acceleration hard, TB?

TB993tt

Told you already - car is away for surgery, will get max MAF values when I get it back.....

Jussi

Thanks TB, sorry that I hurry you.

Maybe also somebody else can check those values if they have real +500hp with MAF based system?

Jussi

Because I have got many useful information from this forum and these people here, thanks!, I can also share my solution for this MAF problem with powerful TTs.

So, if you want to keep your car on MAF based system(like stock Motronic) and you _really_ have +650 horses..
you can buy and do cheap solution: install Ford Lightning MAF !
It is about 96mm ID instead of stock 82mm version.
When stock one gives about 5.7 volts and confuses ECU (if you have about 700hps), this baby gives only 4.99 volts.
It gives almost same Volt values from idle (about 1.1 vs 1.0 V) to cruising speed Volts (about 2.3 vs 2.3. V) - where their curves intersect and then it gives lower output until that max 4.99 vs 5.7 V.

It is quite easy to swap with simple pipe working
(from 90mm to 100mm expander)
and it uses same +12V/ground and that 0-5V signal/ground wiring.

We swapped these new kg/h values to ECU and made dyno tuning..
now my car works excellent also with higher gears and speeds.
I made simple acceleration test with 1650kg, +21 celcius, AWD, hot engine(driven quite hard 200km before test), stock fuel,
from 100 to 200 km/h..... time was about 6.5 seconds
from 60 to 130 mph, it was about 7.5 s

troppo

thanks for the great info! Is that with a stock IC? Approximately what power level are you running?

Stummel

sounds like a strong engine.

Is that GPS timed or from the speedo?

Jussi

I still use a stock IC because it is very efficiency. I have made some test in 21 celcius: cruising 100 km/h intake temp. is 24-25, so just 3-4 degree rise.
And when accelerating hard till 260km/h, temp raises to 45 max.
Maybe that 13000 euros Secan is better but not needed..
I wait what result vrus will get with that new cheaper IC model..

I have done measurements with our own software which uses OBD data and external datalogger channels..

Powerlevel with max 1.3bar setting is about 500kw

TB993tt

js
Thanks for sharing your results.
I know you will realise that what you have apparently achieved goes against what I have been told by the (IMO) best Porsche turbo builders in the world

It would be great to explore into what you have and seriously validate it since the acceleration numbers you have given (for the weight) do indicate a peak hp perhaps begining with a "6".....

The first area of conflict for me comes with the intercooler. The stock I/C is an excellent unit but my understanding is that it is good for about 570hp max.45DegC is around what a standard 408 car will heat up a standard I/C at 300kph (20DegC ambient) according to the tests we did recently, so surely an engine producing the amount of BTUs as yours will heat the air up some more

Even if you are managing to keep the temperatures down by a cocktail of other efficiencies, your 500KW/680hp seems to be pushing it when GT2 EVO racers needed the full house $24K front to back Secans to achieve their 630+hp ?

I would naturally turn next to your data measurement system, I obviously only trust the ones which I have tested myself - can you give as a snapshot of a run up to 240kph showng some Gs etc so we can see how valid it looks ?

I know you like a debate and are very knowledgable so it would be great to discuss your achievements here in more detail

Red9

Do you have a part number for Ford MAF? What model is it used on? Thx

Jussi

Hi, I used that MAF, picture in second page:
http://www.jimwolftechnology.com/wol...WIRINGINST.PDF

There are also bigger model from Granatelli like here
https://www.jegs.com/webapp/wcs/stor...0002_833056_-1

Jussi

Don't believe your Porsche builders anymore or maybe they don't tell you all..
Stock IC has good efficiency but of course, Secan is better and EVO racers use them because they don't have to care about money and even little better is better.
I know many Porsches which have +600hps and they use stock IC. But I also know that some of them have upgraded their IC with better ones like with Bob's(Mode Inc) big IC and got even better results..
Check Turbokraft's project from their Gallery page. That guy(Chris, originally from Germany) actually selected my tuning components and he has done many similar project and easily can achieve 700hp when using big Garretts.
Protomotive also uses Garretts and makes good cars like Markski's 996TT
My turbos are good for 400hp each, maybe 750hp together.
They don't loose power/boost even in higher rpms, like I have 1.3bar still in 7000rpms and engine revs freely till 7500 but we limited it 7250 to save it little
But very important, actually the most important thing is how good ECU tuner you have. I have one of the best tuner in world and that helps a lot

TB993tt

Yeah I seem to recall the "Bob's (Mode Inc) big I/C Garrett turboed engines"........thats right, about 400hp each ?
Only problem is when a car with this spec was plugged into RS Tuning's engine dyno and the Motec Europe race mapper attempted to find the 800hp he couldn't manage more than 600hp......
Mr RS had to hand him a set of RS spec K27EVO units off the shelf which allowed the 800hp to be found, and I won't even go into why "that" 800hp is not the same as RS's "800hp" I suspect you are too far gone ....
We won't even talk about the power curve with such big turbos

Glad you're happy, but don't dis' people who have built up their reputation the hard way