I wonder weather or not Jag / Ford at the time decided that it was important that the XKR did not sound as good or better that the Aston.. well just my two cents.. sure it is has already been mentioned....

But here is my real question..

Removal of fuse 19 and addition of this resonator bypass.. with it make a difference, or is the money wasted..??

resonator bypass called
"Ersatzrör fur Vorschalldämpere" in the picture.

 

The Performance Active Exhaust option for the XKR (standard on the R-S) replaces the centre boxes with a crossover section and has larger outer exhaust outlets. It's louder than the standard XKR exhaust and gains a few horsepower. You may be able to buy it as a complete unit.

 

I went from a 2011 XKR 175 to a 2013 XKR with dynamic pack/performance exhaust. I find a big difference in the 2 cars. The dynamic pack and performance exhaust really make the cars performance. The performance exhaust is more high pitched and F1 like in sound. With the dynamic mode (checkered flag) and "S" turned on the active exhaust is engaged on the 2013 XKR with dynamic pack and performance exhaust all the time. The dynamic pack adds XKR-S suspension and dynamic tuning to the standard XKR. This is my hooligan mode--and fun mode.

 

I have both a 2013 XKR-S and a 2012 XKR. The XKR has the standard active exhaust and though I thought it would be good enough it IS lacking in sound and "rap" until you get up to 4000 RPM but NEVER equals the RS. I rarely ever get up to 4000 RPM because lets get serious!!!!!!! WHY WOULD I DO THAT TO MY CAR!?!?!. The XKR-S sounds great just going 0-10 MPH in stop in go traffic for god sake.

DGL, is the Performance Active Exhaust "LOUDER" in S mode than in D mode simply because the RPM's get higher or does it need to be in S mode to open the flaps all the time vs D where they are still closed?!? Understand the question?

Loth

 

My workshop manual doesn't cover the Performance Active Exhaust - however, the standard XKR Active Exhaust does not go full-open if you select Sport or Dynamic modes. It only goes open full-time if you switch to manual shift, and that is in either Drive or Sport.

Of course, the rules may be different for the Performance version, though that is not my experience from the 'prototype' version installed in my XKR 75.

 

So the only way to get my car to open the exhaust valves is to go manual? Even at a certain RPM it does not open? Ngarara can you give me some more info overall about my standard active exhaust...how exactly does it differ from the RS performance exhaust?

 

Well, in either of the auto-shift modes, the valves are open up to 1000-1100 RPM, then they close and don't reopen until 3750 (if you're on 80%+ throttle) or 4000 (if you're on less). That's what the workshop manual says - however, it doesn't cover the Performance Active Exhaust, so my guess is it only covers MY11 cars. So I can't be absolutely certain about your later cars.

The Performance Active Exhaust deletes all the centre boxes and replaces them with a crossover system. There's pictures of both here:

XKR & XKR-S Exhausts

According to Jaguar, the outer (bypass) exhaust outlets are also slightly larger.

 

I read something from Jaguar about the active exhaust valves being tied to throttle level. I forget where I've seen this but it was from a Jaguar manual. Could have been the shop manual. Not show if this relates to the dynamic pack/performance exhaust packages and the XKR-S.

I always drive my car with dynamic mode on and rotary shifter in "S". I tried the car in "D" a few times and never noticed a difference in the sound; however, the rpms were very low. The valves seem to be always open with dynamic mode on; this could be because of the dynamic pack option combined with the performance exhaust. It sounds so much better than my old 175--higher pitch F1 like. With the car in "D" the rpms stay very low unless you use a lot of throttle. My car still has below 1,000 miles, so I don't exceed over 4K rpm's. The next time I have my car out I'll check all combinations using dynamic mode on/off with rotary shifter in D/S. It should behave the same as your XKR-S. Loth, your new XKR should sound the same as my old 175. The dynamic pack option with performance exhaust option is hard to find, unless, of course, you buy the XKR-S, which you also own.

 

If one takes out the mid pipe with the 2 resonators and replaces them with the X pipe this could make a big difference and shouldn't cost too much

 

So let me ask this...why on manual are they open? So you can hear the engine better and shift accordingly? in that sense is it just a function and the fact that you like the extra loud sounds just a added bonus?

 

I really think I could go on FOREVER talking about the Jaguar "sound" and exhaust systems...lets face it - its part of the "experience". I for one cant live without a car now that doesnt make that roar!!

 

I'm guessing, but: they assume that, if you're in manual, you're in "press on" mode and want a more interesting audio accompaniment. I doubt that the car gains any performance benefit until the higher RPM range when the bypass pipes are open anyway.

 

My thoughts too.. Replace the resonators and just have the straight pipe, should produce a sound similar to the XKRs... in theory...
.

 

I had my car out today and tested the different combinations. The dynamic mode switch, indeed, turns on/off the active exhaust on my car. Is this the same as your XKRS Loth?

 

Interesting… this might have been a change as part of the Performance Active Exhaust, or it could just be an MY12+ feature for all XKR models.

I need to have a play with Dynamic Mode on the 75 to see if its 'semi-prototype' exhaust system works the same way. I presume you're just switching Dynamic on & off at constant RPM and hearing the exhaust note change.

 

With the car iin "D" on very low rpm's, less than 2K I would turn the dynamic mode on and slowly increase throttle. The sound is significantly louder with dynamaic mode "on". When the car is coasting at about 30km/hr in "D" the sound level is so low during driving the difference is not noticable. As soon as the throttle is depressed the difference when dynamic mode is "on" is obvious. The shfter never had to be in "S" to open the valves.

 

Hmmm.... I'm confused!!

 

Try it on your XKR-S. You should get the same results as I did. Let us know. The dynamic mode switch on my car with the dynamic pack and active exhaust should work the same as your XKR-S.

 

Well this is for the 4.2L XKR but I thought someone reading along might find this useful.

 

The Active Exhaust settings are different on the 5.0 models - the throttle angle only affects whether the bypass valve opens at 3750 or 4000 (3750 if over 80% throttle).

The Performance Active Exhaust deletes the two centre mufflers and uses a simple crossover pipe.