HPP dyno

[shogun32]

Are we possibly making more horsepower on 60 degree days in Minnesota than in states where the temps are 80 to 90 degrees ?

by definition "yes" but what matters more is how much heat you can shed out of the post-compressed (and now hot) air on it's way to the throttle body. This is where a bigger IC and greater temp differential between what's inside the IC and what's cooling the IC comes into play. If what's inside the IC is 120F (picking a random number) and you're trying to cool that down with 90F or 60F airflow, the 60F is gonna do better.

But even so, we're talking maybe a couple percentage points? That's Dyno measurement error so, who gives a damn?

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[BlueHPP]

Based on a sloppy calculation, 90F versus 60F will get you a 5% difference. Thermal differential is based on absolute temperatures. For Fahrenheit, we need to use the Rankine scale. So 90-60F becomes 550-520R. Also the amount of airflow over the ic from the cooling fans will have a large (huge?) impact. Heat transfer from a surface is a function of the temperature differential and the airflow for any design. Aftermarket ICs have larger surface areas (heat transfer) and larger thermal mass (heat capacity of the IC) so for any given airflow will transfer more heat (transfer) and respond slower to the heat applied (capacity).

 

[Hi-PO Stang]

Thanks for the responses. I am new to the turbo world and am trying to learn as much as I can. So far , I am impressed with the 2.3 HPP engine. I have not felt the effects of turbo lag yet.

 

[TeeLew]

Thanks for the responses. I am new to the turbo world and am trying to learn as much as I can. So far , I am impressed with the 2.3 HPP engine. I have not felt the effects of turbo lag yet.

That's because it's not there. Small turbos are inefficient at high flow numbers, but they spool as quickly as you can put your foot down. As strange as it sounds, the bottom end response of an Eco is better than a coyote.

 

[Hi-PO Stang]

What are the dyno numbers for the Focus RS WRC race car engine ? Who builds the WRC engine ? What size turbo on the WRC engine ?

 

[ihasnostang]

I have heard that Ford adds fuel to cool the exhaust temperature to keep the catalytic converter alive. Does anybody know if this is the reason why they way over rich the mixture later in the pull as the intake temp rise with the stock IC?
I am thinking of a turbo blanket to keep under hood temps lower but that will send more heat to the cat.

I've stated in other posts i don't believe the theory that a rich mixture cools the cat. Why would adding unburnt fuel to something that is designed to burn unburnt fuel (adding heat). a rich mixture can cool before the power stroke. Turbo blankets would probably be fine except for track days with prolonged WOT time

 

[shogun32]

Why would adding unburnt fuel to something that is designed to burn unburnt fuel (adding heat).

that's not how cats work.

 

[FreePenguin]

that's not how cats work.

I think hotter they are the more efficient they become

 

[BlueHPP]

In theory a stoichiometric mixture will yield a higher temperature exhaust stream. A rich mixture will cool the charge before combustion and after combustion as there will be more thermal mass at a lower temperature exiting the chamber. Regards to the cat question, you can overtemp a cat, just like any chemical reactor. I do not believe there are any smog considerations at WOT so running rich will not effect the smog ratings. Also gas flow at WOT is very high so probably not enough residence time or O2 to burn the fuel.

 

[TeeLew]

It's a very inelegant way to address the issue of overheating the cat.

 

[BlueHPP]

It's a very inelegant way to address the issue of overheating the cat.

Agreed but Ford has to warranty the cat for 100,000 miles, I think. Tuners can get more power but they will not have any warranty issues. I sure wish I could swap out the FMIC in D street.
I remember one story about Daytona Where they wrote about the Porsche turbos running "comfortably rich" warming up in the infield. They said if the Porsches ran too lean they would have turbo failure.

 

[TeeLew]

I doubt the ones who did that turbo trick were running a fly by wire throttle. All the Ford engineers needed to do was close the butterfly. My car went to 8.9:1 afr. That fouls plugs, washes down the cylinders, adds carbon to the entire exhaust tract, etc. There's no excuse. It's like spraying WD-40 on the rear tires to fix understeer.

 

[BlueHPP]

I doubt the ones who did that turbo trick were running a fly by wire throttle. All the Ford engineers needed to do was close the butterfly. My car went to 8.9:1 afr. That fouls plugs, washes down the cylinders, adds carbon to the entire exhaust tract, etc. There's no excuse. It's like spraying WD-40 on the rear tires to fix understeer.

Maybe (probably) it was the cheapest solution. Much cheaper than getting a better FMIC.

 

[TeeLew]

THEY HAVE CONTROL OF THE THROTTLE BUTTERFLY.

 

[BlueHPP]

THEY HAVE CONTROL OF THE THROTTLE BUTTERFLY.

Yes they do. But if they just used the throttle they might not get the exhaust stream cool enough for the cat. My information on the throttle is they do not even open it up all the way anyway. 100% on your pedal is still only 91% open or about 82 degrees of rotation. See:
https://www.mustangecoboost.net/threads/throttle-calibration-results.23213/#post-249705

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