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And this is probably close to as responsive as possible for the power made on a R34 GTT factory RB25det Neo, running newly developed ATR43SAT BB internally gated bolton turbo on P98 fuel. 317rwkws @21psi, 20psi @ 3550RPM.

power.JPG

boost.JPG

  • 2 weeks later...
  • 2 months later...

Why do most of the dyno grahs show power fall over at the top end?

Because most people run along the edge of the compressor efficiency curve. This means they get max turbo airflow in the midrange and also in the top end. If you get similar airflow at 5000rpm as you do at 8000rpm then this means reduced torque as you are sharing the same air over more combustion events, reduced torque means reduced power.

Most factory turbo cars don't smash the boost in the midrange or max the turbo out, hence they can hold flat torque to redline. If they didn't then you'd see the typical huge midrange torque and dropping off at redline.

And this is probably close to as responsive as possible for the power made on a R34 GTT factory RB25det Neo, running newly developed ATR43SAT BB internally gated bolton turbo on P98 fuel. 317rwkws @21psi, 20psi @ 3550RPM.

power.JPG

boost.JPG

Tao, what is the expected results on an RB25DET? Considering swapping my turbo out for a smaller one for less lag.

If I drop the exhaust or run external gate, top end torque curve would be more flat. For a good turbo configuration on a good internally gated setup. On pump fuel, The torque curve is usually an umbralla shape.

ill be running the non bb version of the 43sat iwg on my car, hoping to tune it next weekend yet that will depend if a part i ordered tonight gets here in time, if it doesnt then whatever day it gets here ill throw it on my dyno and see how it goes. stock rb25, 3"tbe, fmic, so that should give you a better idea if you can wait a week or two

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