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View Full Version : Does the Rev limiter vary depending on ambiant conditions?



lance
Tuesday 17th May 2005, 12:31
The Reason I ask I have a favorite bit of private road where I come off a roundabout about 40 mph in 3rd gear and GUN IT! The other Sunday ( was very warm)I hit 6400 rpm aprox and it seemed to bounce of the limiter !
Last night at about 1230 am (temp 1c) I did the same and it pulled very strongly to 6700 rpm ( may of done a bit more)before I changed upto 4th at over 100 mph!
I have managed to hit 70 mph in second gear on several occasions to , which must be over 6400 rpm!
So how does that work does the Rica & ecu decide the rev limit for a given tempreture, fuel, or is it somthing else?

volvotuning
Tuesday 17th May 2005, 13:41
You should not have a wondering rpm limit!

The rev counter is always a little slow to respond. You'll find that if you increase engine speed slowly enough the rpm limit is always the same. If not, something ain't right!

In the lower gears it may appear to have a lower rpm limit because the ECU measured rpm reaches the limit before the rpm needle does. In the higher gears it should be about the same.

Adam.

lance
Tuesday 17th May 2005, 14:02
Thanks Adam, just a couple more questions
What should my RPM limit be?
The car apears fine , and the boost is about the same as last time we measured it!
When I hit 6400 rpm it didnt want to go any more it sort of splutted b4 I went for 4th, when I hit 6700 rpm last night it hit very cleanly.
The first time the engine had been running for atleast 1 hour , the second time about 15 -20 mins , also ambiant temp was around 17-20 c the first time and 1-2c the second time!
Both times the speedo was reading 100 mph+

volvotuning
Tuesday 17th May 2005, 14:09
Don't know in that case! Can't remember what I set it at. 6800 i think.

Adam.

lance
Tuesday 17th May 2005, 15:08
Hopefully the rev counter just cant keep up with my right foot then, cos she drives lovely still!
Must admit forgot how good RICA was intill I drove a stock T5 in good condition last week and it felt a bit wheazy 3rd gear onwards in comparison!