TheShodan tried to PM you but your box is full...

Can you infer full boost from a dyno chart based on when the tq curve begins to flatten out after the upswing?

 

It would be just before that "upswing" on the torque curve. the upswing typically shows where max torque is made, and just below that point is where at a give pressure level, the turbo has reached its efficiency. that's the better way to get an IDEA of where max "spool" is for a given pressure.

 

Thanks. Can you clear a space in your box, I have a PM I want to send that ask specific questions about someone's setup. Don't want to call anyone out before I get my facts straight

 

When you look at a dyno graph that shows boost, you'll notice max boost is reached a hundred or two rpm before the torque drops/flattens. As soon as you hit target pressure, the WG opens. When it opens, backpressure drops in the manifold to free up extra power (from scavenging).

Anyways, I don't try to interpret peak boost from a dyno graph to compare turbos. Instead I try to compare rpm's that they both hit the same whp before they hit full boost. In most cases, 200whp is what I look at. I've noticed that it's largely based on manifold design and displacement. It does not show transient response, however, which can be totally different if you compare a 300whp and 500whp cars that hit 200whp at nearly the same RPM.

 

That's my question, how do you interpret peak boost RPM from a dyno graph?

 

That's not a bad way to compare between two turbochargers. peak boost is just before the upswing, but the CONSISTANT area of boost is the point where you've described.

Peak boost rpm is not exact on a dynograph. that's a tall order. you can get a closer range, but not exactly, unless you're right there with the cursor on the computer looking at the full spectrum of data comparing boost to rpm.

 

good info fellas, i just learned something new.

 

Can anyone illustrate an example of what the TheShodan said on a dyno sheet?

 

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