I have noticed that when revving (in neutral or park), the exhaust note sounds much better in sports mode. It has a lovely throaty rubble and a bit of a pop as it comes back down which is not audible without S mode engaged. I had thought the S mode only altered the rev limit? Does it alter any of the exhaust characteristics on the XKR - 100 models?

Cheers

 

OK, I give up . . . I checked and it's not April 1, so I'll address your question seriously . . .

AFAIK, the Sport switch only serves to change the pattern of auto trans shift points. While it doesn't change rpm directly, on my cars it serves to "hold" each lower gear for longer under acceleration, while also locking out 6th gear . . . and these conditions do raise engine rpm for any given road speed. For same reasons, I do not believe it raises rev limit either. Putting all that together, activating Sport mode will enhance acceleration performance, albeit at the expense of fuel consumption.

Of course, it is possible your car has aftermarket mods but I can think of no factory explanation for the exhaust note changes you describe while parked in your driveway. For those of us with the Mina UltraFlow option, it's much more fun taking it to the road where others can enjoy . . .

HTH. Best wishes,

Ken

 

Ken - sorry I don't get the inference in your April 1st quip? As stated, I know what the sports mode does but the X100 models have no active exhaust so the difference in tone is puzzling. It leads me to think that the S mode, changes more than just the revs/gear changing point and that there is a change to the fuel mix or air flow which is causing some unburnt fuel to pop in the exhaust system, whereas it doesn't without S-mode.
Standard exhaust fitted.

 

Sorry if my attempt at humour didn't cross international borders as intended. Don't laugh . . . it has happened on occasions before. Put simply, I wondered out loud if your post was an April Fools Day joke. Please believe I was NOT trying to offend, and if I have done so, I apologize.

For a simple push button switch that does nothing other than alert the TCM to use the alternate shift pattern, I slowly came to realize you were quite serious about features that AFAIK, are neither Jaguar engineered nor Jaguar documented.

OK, so let's start over . . . still with the proviso that your car may have after market mods beyond anything Jaguar engineered -

• no feed-in to the EFI control loop;
• no feed-in or overide of the TPS or MAF loops;
• no setting or resetting of either rpm or rev limits.

One thing you don't mention, but could be relevant, is whether your 2500rpm Park/Neutral limiter is working as intended.

Others may chime in with possibilities but frankly, I can find no Jaguar documentation, nor fairly extensive personal experience, that can support or explain your findings. I'm not saying "You are imagining it" . . . I just cannot conceive of any explanation.

 

I am quite sure the S mode has the same result as washing the car. Don't you know that cars always run better just after being washed?

Just kidding.

Doug

 

I made a brief video recording of the revving this morning. The popping is audible at the end of the 2nd rev. This only occurs with Sports mode on. Rev was up to about 1800 rpm.
See link below.

 

https://www.flickr.com/x/t/0099009/p...4/38213489232/

 

I heard no engine increase on your video.

 

That's the twin turbos spooling up. ;^)