Power curves

[Oakenvalley]

Hi all,

When I see dyno graphs of built Audi 2.2 and 2.5 liter inline 5 cylinder engines it seems the torque curves are very narrow. Commonly a flat peak of torque of about 2000rpm width. Sharply rising before the peak and dropping more slowly after the peak. With a turbo giving that characteristics it seems pointless to raise the stock rpm of the engine even further. Below is a graph I found of the 2.2 (2.1?) Audi Imsa engine. That looks like a nice linear curve. Does anyone know how similar characteristics is achieved?

[newsh]

Big turbo

[SteveH]

Tuning! You don't have to go for the big hit low down if you prefer a linear curve.

[Error404]

Clever people and lots of money. Thats what you can expect from a works developed package.
Very few poeple are able to put any scientific decision marking into their setup - its normally based on budget, and for good reason.
I expect Audi Sport spent a few million Deutschmark developing the IMSA GTO motor.

[larsaskogstad]

Its easy

[larsaskogstad]

Something like this would be nice. I know of a setup here in Norway with extreme good curves but I can't share it yet, owner doesn't want me to share it weirdly enough . This pic is KRB tradings car/old car , not sure what he has now

[larsaskogstad]

Seems like today its newest Precision turbos or Borg Warner EFR for the early spoolup. Combined with correct cams and calculated length of intake headers etc etc. so many factors. I guess it depends what you are going for.

[Airwolf]

But what exactly are you looking for with your engine? Street use ? IMSA engines are RACE engines. I had a great power and torque band on my 2.2 with EFR turbo and pretty wild cams for my street setup. Drove great!

[larsaskogstad]

But what exactly are you looking for with your engine? Street use ? IMSA engines are RACE engines. I had a great power and torque band on my 2.2 with EFR turbo and pretty wild cams for my street setup. Drove great!

What EFR did you use? How early spoolup?

[Airwolf]

EFR 7670 , Full boost @3500rpm 98 octane

[larsaskogstad]

Not bad not bad

[newsh]

Something like this would be nice. I know of a setup here in Norway with extreme good curves but I can't share it yet, owner doesn't want me to share it weirdly enough . This pic is KRB tradings car/old car , not sure what he has now

Something like this would be nice for drag racing.