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Ramping Values

Old 03-03-2006, 01:29 AM
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Default Ramping Values

Hi everyone.

I was wondering if anyone knows how to adust the ECU on the J600R to get a faster spool up time. Mine seems to be very slugish ( idol to full throttle in approx 4 seconds). Here are my current setting form the factory for ramping values.

Ramp up lo 13
Ramp down lo 10

Ramp up mid 5
Ramp down mid 4

Ramp up hi 4
Ramp down hi 4

Any help with this would be great. If my settings are correct and should not be changed please let me know.
Old 03-03-2006, 09:10 AM
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Default RE: Ramping Values

Hi Ed,


Mine are :


Ramp up lo 8
Ramp down lo 8

Ramp up mid 4
Ramp down mid 4

Ramp up hi 4
Ramp down hi 4

But I don't think I'm any faster than you are at 4 seconds.
Old 03-03-2006, 10:18 AM
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Default RE: Ramping Values

Ed,
I"m a big fan of Kelly Williams of PST North America. He is really sharp on the PST's and is a tech rep for them. The frequents this forum with some regularity. If anybody can help, it will be Kelly.

You can contact him at [email protected] .

LOL John Swanson
Old 03-03-2006, 11:55 AM
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Default RE: Ramping Values


ORIGINAL: erapoza

Hi everyone.

I was wondering if anyone knows how to adust the ECU on the J600R to get a faster spool up time. Mine seems to be very slugish ( idol to full throttle in approx 4 seconds). Here are my current setting form the factory for ramping values.

Ramp up lo 13
Ramp down lo 10

Ramp up mid 5
Ramp down mid 4

Ramp up hi 4
Ramp down hi 4

Any help with this would be great. If my settings are correct and should not be changed please let me know.

Hi Ed,
You can achieve a small reduction in the spool up/down with the following settings:

Up Lo:6
Down Lo: 6

Up Mid: 4
Down Mid: 4

Up Hi: 4
Down Hi: 4

Those are the minimum allowable settings, and that should give the best performance.

As I'm sure you an guess, the ECU interpolates its pump voltage acceleration based on these 3 ramp variables, plus 2 others that represent the switching points in the ramp curve. The "ramp switch" variables are no longer accessible to users in newer software versions though, since there's really no purpose in adjusting them from the default configuration for a given engine design... If the Ramp switches are shown, make sure the Ramp Switch Lo is 15 and the Ramp Switch Hi is 80.

Thanks,
Kelly
Old 03-04-2006, 07:53 PM
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Default RE: Ramping Values

Thanks alot for the info! I will adjust it and see how it goes. Is there any drawbacks to changing the settings?
Old 03-04-2006, 09:48 PM
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Default RE: Ramping Values

Hi Ed, You're welcome.

Pushing the engine to these kind of accelerations is pretty harmless, which is why PST set the minimums as they did in the software. Accelerating the shaft speed too hard by pumping fuel in at a higher rate can have a negative affect on long-term reliability, but these settings shouldn't get you into any trouble... This is a basic trade-off that all the manufacturers make.

Changing your setting to the ones I've noted above should give you better throttle response in the lower 15% of the curve, with a slight acceleration increase in the middle 65% of the curve when spooling up. Spooling down, it should settle to idle a little quicker.

Good luck!
Kelly
Old 03-09-2007, 01:58 PM
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Default RE: Ramping Values

Kelly, do the suggested changes (post #3) work independent of the pressure altitude the turbine is being operated at?

Mike
Old 03-09-2007, 08:33 PM
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Default RE: Ramping Values

Hey Mike,

To clarify, the ECU does not know anything about the exterior running environment, and I hope I never in some way indicated that. Furthermore, the minimum values were set according to the manufacturer's testing results, which covered a number of atmospheric scenarios and have been verified by many reps and users around the world. These settings are the 'line in the sand' that PST chose to work with in the same trade-off of reliability vs performance that every manufacturer faces. If a problem occurred under acceleration or deceleration, its likely as easy as increasing the ramp values associated with that position of the acceleration curve... That being said, I can't remember being contacted and forced to use that as a resolution to a customer's engine problem.

Short answer, yes they should work fine, but... in an extreme altitude like yours, test it out on the ground (the 'slam' test...) until you're satisfied.

Kelly
Old 03-09-2007, 08:59 PM
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Default RE: Ramping Values

Kelly replied ...
To clarify, the ECU does not know anything about the exterior running environment <snip>
Yep, that's why I asked the question: hoping to gain a sense if others might have tried those numbers "at altitude." Needless to say, I will try it on the ground 1st! But, otoh, if it ain't broke don't fix it ... [8D]

Thanks.

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