Rev Limiter
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Instructor
Joined: Oct 2003
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Rev Limiter
I have a 1990 964 with a rev limiter that kicks in at 7200 rpm. I openend up the DME box to find what appeared to be a stock chip starting with the numbers 12xxxx.
It aslo looked like this was the first time the box had been opened. Everything I have read says the cutoff should be at 6800 rpm. Could someone advise on this? I do not want to blow up the motor.
It aslo looked like this was the first time the box had been opened. Everything I have read says the cutoff should be at 6800 rpm. Could someone advise on this? I do not want to blow up the motor.
Agent Orange
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Has the tach been opened in the past? If someone played with it and didn't insert the needle properly, that could be the issue. Simple way of checking is to see if it idles around 840 RPM. If it does, disregard my post. If not, that may be the issue.
Drifting
Joined: Jun 2006
Posts: 3,441
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From: Dallas/FortWorth Texas
Stock valve springs are not up to the task of running up to 7200 rpms. As someone else commented, best to get a replacement chip with 6800 limit if your current chip is allowing you to run up to 7200.
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Nordschleife Master
Joined: Dec 2001
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From: Kingston, NY
I think you first need to determine if it is actually reving to 7200. What is the full number on the chip? If it is a factory chip, then I doubt it is overreving, but rather thr tach may be optimistic.
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For the Hammer-challenged around here -- can ScanTool's numbers be taken as gospel?
(ie, insofar as accurately reporting what the ECU is perceiving in the engine's world?)
Just hoping that's a 'low fruit' case before going off to get some 3rd party-device's take on engine rpms.
(ie, insofar as accurately reporting what the ECU is perceiving in the engine's world?)
Just hoping that's a 'low fruit' case before going off to get some 3rd party-device's take on engine rpms.
Burgled
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From: Altamonte Springs, Fl/Gwynns Island, Va.
For the Hammer-challenged around here -- can ScanTool's numbers be taken as gospel?
(ie, insofar as accurately reporting what the ECU is perceiving in the engine's world?)
Just hoping that's a 'low fruit' case before going off to get some 3rd party-device's take on engine rpms.
(ie, insofar as accurately reporting what the ECU is perceiving in the engine's world?)
Just hoping that's a 'low fruit' case before going off to get some 3rd party-device's take on engine rpms.