I have the boost pressure over RPM values from my A5 B5 (well, complete only in a few days when car is back from shop). Within a certain error range, can I get horsepower and torque stimates from that? I now that timing, Octane, fuel and airflow all have an impact as well, but a good estimate would suffice at this time.

I would assume with the wealth of dyno charts in the hands of tuners, that someone has put together a table what can be expected?

Considering that boost pressure and RPM are the most readily available data, I would like to put an excel and graph together (Bost over RPM, Torque over RPM, HP over RPM).

 

i would imagine you could figure it out doing some basic math.. Do some research and find out approximately the energy loss due to turbo'd vehicles, for example I think due to friction and mechanical loss it is somewhere around 20-25% energy lost.. Now take the fact I think atmospheric pressure is around 14.2lbs at sea level, you figure 7lbs which is roughly half of atmospheric pressure would with no energy loss give you 50% more power I guess you could take that 50% gain subtract the 20-25% (take 25-30% and multiply it by the wheel horsepower and get a value) then take number and add it to the wheel horsepower to get a range you are looking at.. Note there are charts to roughly estimate how much horsepower is lost due to elevation soo you can then use that to refine your value.. I just thought this up and think it would work, now I don't know the exact value of energy lost that was used as an example soo do some research and thinking and you can get the value.. you wouldn't need to subtract power lost from the tranny and diffs if you use wheel horsepower values.. hope this helps.

 

also to get a rpm value take a dyno chart of a stock a4 and do the above throughout the rpm range to find apprx horsepower for that rpm...

 

You can get hp numbers by using the MAF readings.