Reading spool from a dyno chart
09-02-2010, 04:59 AM
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Reading spool from a dyno chart
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?
Can you infer full boost from a dyno chart based on when the tq curve begins to flatten out after the upswing?
09-02-2010, 05:43 AM
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Re: Reading spool from a dyno chart
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.
09-02-2010, 05:46 AM
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Re: Reading spool from a dyno chart
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
09-02-2010, 06:03 AM
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Re: Reading spool from a dyno chart
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.
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.
09-02-2010, 06:23 AM
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Re: Reading spool from a dyno chart
09-02-2010, 06:29 AM
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Re: Reading spool from a dyno chart
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.
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.
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