Quote:
Originally Posted by Dan Stokes
To answer a couple of your questions:
1) Yep, this was on a DynoJet chassis dyno. A dyno with a PAU (power absorbtion unit) is preferred but the inertial Dynojets can be useful. They can only take measurements at WOT/full rack (depending) but they can be helpful.
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To expand on this, a Dyno Jet is typically an inertia dyno where a large drum of a known inertia is accelerated by the test subject to X speed then HP / TQ calculated by how long it takes to accelerate. This is more for measuring capability's of a drag car / road race car between corners as acceleration over time is critical. This is also how some flywheel manufacturers can claim their light FW gives you more HP.
As speed levels off, the load on the engine drops and eventually will just be frictional losses in the vehicle / dyno.
A loading dyno ( PAU ) is more for towing a trailer up a hill / max speed ruins / down a long road race straight. This measures torque directly than calculated HP from there. Adding a light FW does nothing on this type of dyno.
Quote:
Originally Posted by Dan Stokes
BTW - I got an Email from Goran this morning. We says I'll be safer at 20ish. PSI boost than at 16 given the smoke output at 16. Darn, more HP!
Dan
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Did he give reasons for that? While smoke does not = power, I'd be more inclined to reduce fuel levels to trim smoke.
I'd also be inclined to record rack position during an on the road run to determine if the rack is pulling back. Not sure if your pump has this but some industrial diesels use a torque limiter to pull the rack back in addition to the standard RPM limit.