Rev 2 explanation

[SNDa]

The search function on the forum has gone down temporarily and the answers coming back from the temp google search aren't quite hitting the spot, so apologies in advance if this has been done to death:

1) what counts as a rev 2 value? I notice from Baz's postings that it is a mechanical over rev but I'm not sure what that means? is it red lining it in every gear?

2) what counts as a rev 1?

3) how many rev 2 values are alright (say as a percentage of total ECU time)

Thanks

[hutchingsp]

My very basic understanding is that a Rev 2 is what happens, if, for example, you try and shift from fourth to second at high speed (sure someone will jump on me if I'm wrong).

[slippydiff]

hutchingsp said:

My very basic understanding is that a Rev 2 is what happens, if, for example, you try and shift from fourth to second at high speed (sure someone will jump on me if I'm wrong).

Correct. My car had a few Type 2 over revs when it was checked out by Reading. They happily issued the warranty on it despite them.
When asked if they were an issue for future warranty claims, they said not (but they also told me my PCCB's were fine as well........................)

Type 1 over revs are acceptable/expected, as the rev limiter protects the engine against damage so it really shouldn't be a concern that a lot of them would effect the engines long term durability.

[steve rance]

SNDa said:

The search function on the forum has gone down temporarily and the answers coming back from the temp google search aren't quite hitting the spot, so apologies in advance if this has been done to death:

1) what counts as a rev 2 value? I notice from Baz's postings that it is a mechanical over rev but I'm not sure what that means? is it red lining it in every gear?

2) what counts as a rev 1?

3) how many rev 2 values are alright (say as a percentage of total ECU time)

Thanks

[steve rance]

A Rev range 2 incident is when the engine revs over it's limiter. typically is is the result of gear change error, ie; 4th to third rather than 5th on an up change or 5th to 2nd rather than 4th on a down change. The ECU records the number of ignition cycles (6 to one engine revolution) that occur in this rev range. Most engines have some rev range 2 incidents but if they add together to be more than say 5 seconds of engine time it is not good news for a potential buyer. Reve range 1 is the number of ignition cycles that the engine is held on the limited and as such is relatively harmless to the engine.



Steve R

[slippydiff]

steve rance said:

SNDa said:

The search function on the forum has gone down temporarily and the answers coming back from the temp google search aren't quite hitting the spot, so apologies in advance if this has been done to death:

1) what counts as a rev 2 value? I notice from Baz's postings that it is a mechanical over rev but I'm not sure what that means? is it red lining it in every gear?

2) what counts as a rev 1?

3) how many rev 2 values are alright (say as a percentage of total ECU time)

Thanks

[slippydiff]

steve rance said:

A Rev range 2 incident is when the engine revs over it's limiter. typically is is the result of gear change error, ie; 4th to third rather than 5th on an up change or 5th to 2nd rather than 4th on a down change. The ECU records the number of ignition cycles (6 to one engine revolution) that occur in this rev range. Most engines have some rev range 2 incidents but if they add together to be more than say 5 seconds of engine time it is not good news for a potential buyer. Reve range 1 is the number of ignition cycles that the engine is held on the limited and as such is relatively harmless to the engine.



Steve R

Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo Echo

[london GT3]

steve rance said:

The ECU records the number of ignition cycles (6 to one engine revolution) that occur in this rev range.

Are there 6 ignition cycles per engine revolution or 3 per engine revolution?

[SNDa]

Thanks for the responses. taking it to opc this saturday for 111 check. will ask for the rev range 2 value then.