Horsepower readings from OBD Fusion

[jmazzabufi]

i have a 2012 A5 quattro 2.0 TFSI.
Claimed horsepower 211.
I made several runs getting on the highway after setting up OBD Fusion and show: (not at the same time)
Max of 256 horse.
Max boost of 39 psi
Max torque of 275

How accurate is the horsepower calculation? I know it's not a dyno reading at the wheels that would be the most accurate.
I'm getting Stage 1 soon and this will give me a baseline at least.

[Jeff V.]

I'm no TFSI expert, but 39psi is heavily modded race car territory for most cars...

[Sgibb16]

39 psi is way off.

stage II i could see being about 256 hp though.

[jmazzabufi]

Yeah i thought so.

Oil temp matches exactly to what the car gives me in the dash. Intake air temp seems right. The HP, torque are calculated? best effort?
I'll use it as a baseline for Stage 1. I should get higher numbers - wrong, but higher and then figure the HP gain from that and add to the 211.

Same with a cold air intake - the air is 20 degrees hotter than the outside air.

[JamesRS5]

At 2.5 bar (39psi) boost pressure I think you'd be replacing the pistons and big end bearings by now. The HP sounds low if you're stage 2, you should be up at 320ish. Is this an at the wheels reading?

[jmazzabufi]

It's stock right now. So it should be "claimed" 211 horsepower.
I don't know if there's another "boost" reading that's showing on the dashboard. It's also the setting that comes with the default dashboard. Both show those high psi numbers. mostly negative readings as i cruise around.
Getting Stage 1 soon. so if this reads 45 HP higher, after stage 1 it should read even higher than 256 and I'll subtract that new HP number minus 256 to get the additional HP Stage 1 gives me and add it to the 211.

[Jeff V.]

The ECU doesn't report a human readable, decimal number to the OBD port. It's just an 8 or 16 bit whole number. The software then has to apply a math formula to it to change it into a number we're more familiar with. I'm thinking it's this conversion formula that might be wrong. So when it should be multiplying by 2, it's multiplying by 5 or something. Hence your inflated boost number.

What does it read when you're parked and idling at normal operating temperatures? Even though 'negative psi' isn't really a thing, it might show something like -10. Or if it switches over to inches (or mm) of mercury, it'd be 16-20 inches (~410-510mm)

The horsepower number is just a guestimate. It can't get all that accurate without knowing things like the frontal area of the car to calculate air resistance. Even if you put lead blocks into an A5 to make it weigh as much as a Tahoe, the Tahoe still needs more horsepower to accelerate to the same speed in the same time due to its greater frontal area.

[jmazzabufi]

yes, it's a -10-ish number at idle.
I got Stage 1 today and got a max of 327 HP.
so, subtract 327 from 256 = 71 additional HP.
That seems about 10 too high. Boost was in the 50's - lol.
It's still good for baselining changes. Obvious increase with Stage 1 whether i had the OBD or not.
Next is a cold air intake. The air can be 20 - 30 degrees higher than the outside temperature with the stock intake.

[jmazzabufi]

ok, they say the BRAKE SPECIFIC FUEL CONSUMPTION needs to be changed. Does anyone know what that is for the 2012 2.0???
Also the VOLUMETRIC EFFICIENCY % ????

[doug97gxe]

are you sure your boost calculation is right? I was getting 30 PSI (3.0T Supercharged) and i got help here

http://www.audizine.com/forum/showth...1#post11970824