Jump to content
SAU Community

Recommended Posts

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

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • If you take the top half of the intake off you can unbolt the flap off the shaft and leave the shaft in there blocking the hole. Then you can remove the little vacuum canister off from under the manifold and get a spare vacuum line to run to the ECU. I can take some photos of it later. Probably best to get the vacuum source to the ECU sorted first though. Mine all worked mint with the base map from the GTT an I've pretty much let the closed loop sort the fueling and took 1 degree out of the whole timing map.
    • This IS something you also have to configure in Haltech (or at least I did in the past when going from onboard-to-ECU map sensor and an external MAP sensor in haltech land).
    • I'm hoping it's something as simple as the ECU is looking for an external MAP sensor, but he is trying to use the onboard MAP sensor.
    • You won't need to do that if your happy to learn to tune it yourself. You 100% do not need to do that. It is not part of the learning process. It's not like driving on track and 'finding the limit by stepping over the limit'. You should not ever accidently blow up an engine and you should have setup the ECU's engine protection to save you from yourself while you are learning anyway. Plenty of us have tuned their own cars, myself included. We still come here for advice/guidance/new ideas etc.  What have you been doing so far to learn how to tune?
    • Put the ECU's MAP line in your mouth. Blow as hard as you can. You should be able to see about 10 kPa, maybe 15 kPa positive pressure. Suck on it. You should be able to generate a decent vacuum to about the same level also. Note that this is only ~2 psi either way. If the MAP is reading -5 psi all the time, ignition on, engine running or not, driving around or not, then it is severely f**ked. Also, you SHOULD NOT BE DRIVING IT WITHOUT A LOAD REFERENCE. You will break the engine. Badly.
×
×
  • Create New...