Guys what’s the simplest way to get that whine, mines almost silent 2009 xkr

 

Squeeze 'em and you'll whine!

Sorry, I couldn't resist. The pandemic made me do it.

Seriously, the simplest thing to try is removing the Engine Appearance Cover. It's lined with plastic foam that absorbs sound. Will you be able to notice any difference? Maybe, but that depends on your engine RPMs, exhaust noise - did you pull Fuse 19? - and if your XKR is a coupe or convertible.

 

It’s a coupe , I did pull the fuse but I have put it back in

I’ll try removing it tomorrow , was wondering about the k&n drop in air filters ? I’d love a air intake kit but Im not spending that right now

 

In that heat look to have the supercharged oil changed it evaporates over time

 

There are many threads on this Forum debating K&N filters. I'm opposed because i installed a pair on my old V12 MBZ 600SL and saw no obvious difference except to my wallet. Sure, K&N advertisements claim HP gains but they're only at high RPMs, so there's little bang for the buck in my opinion.; And then there's the issues of the oil mucking up the MAF sensor and throwing CELs.

My 1960 Corvette came from the factory with an oiled foam plastic air filter. Four years later, GM used the identical housing on the Pontiac GTO but replaced the filter with a pleated paper element. Why? Because the paper element was more efficient.

So, if you want to put 1960 technology in your XKR, it's your car, your money, and your choice. Unless you're going to track your XKR and need to squeeze every drop of HP out of the engine, I believe you're better off staying with the factory air boxes and a matched pair of paper filters.

 

Filters won’t do anything. The biggest improvement is going to be to get rid of all of the resonators on the intakeS that silence the charger whine. Did it to mine and all of the whine came back.

 

What Jahummer said. Take a look at the OEM intake tubes; they are a hot mess. DooDads and Whoozits all over the place for no apparent reason. Cut those off, seal up the holes (or make new tubes) and that whine will return.

 

My pop loved this guy i grew up listening to him on the record player , Happy days a legend

 

Take the engine cover off.

You can also take the 2 silencer bags out. They are wedged under the SC outlet pipe. However this requires some work to get to. I took mine out when I was doing the SC overhaul but only because they were fouled up with oil.

I do notice a bit of a whine now. I also have a smaller pulley installed.

 

I have heard with the pulley you don’t need to tune , is that right ?

thanks for the help I’ll take a look at it all today

 

Some will argue that a tune is needed for optimal performance with the new pulley, regardless of size.

I have a 2.5LB pulley with no tune, from Eurotoys - no issues or codes thrown. Check with the manufacturer/seller to see if a tune is needed before your purchase.

 

Spinning the supercharger faster lowers the torque curve without a tune. Depending on the supercharger and engine, a tune can help with the increased boost by changing how the ECU manages the extra boost instead of blowing it off when hits the stock limit for boost.

 

Smoother intake tube and cone filters will do the trick. My supercharger sounds like a police siren sometimes.

 

But you have a 5.0LSC XJ, not a 4.2L XKR like Mtomlin the OP. That's like comparing apples to oranges.

See Post #6, above - Clean up the intake tubes, use the OEM matched air filters, and remove the Engine Appearance Cover. No need to modify the intake with new tubes or a cone filter.

 

Agree with Jahummer..
It's not an argument pulley without a proper tune for it is money wasted . ECU in our cars is pretty smart , Even on a stock car limiters will kick in at certain times and especially with a pulley power will be kept in check thus making your smaller pulley irrelevant.
4.2 Xkr with a proper tune will be entirely different beast of a car, it's not an exaggeration, I get such feedback from customers with 4.2 XKRs all the time.
​​​​​And as far as manufacturers of the pulley, they just want to sell them and never recommend the tunes Well and to be frank they don't even know that you need an adjustment in ECU, but it is a must. Pm me on the tune

 

Thats what I couldn’t understand . I have pulley swapped many cars zlr1 , zl1 , procharger Jeep Srt’s and always tuned them for it.

I just assumed maybe the base map allows for the increased boost in the jag , but if it doesn’t then it needs tuning

what software you guys using ? I have Hp tuners , but I can’t see that working

 

There is no specific software. Denso ECU and tuning for it on our cars is pretty complicated , only few guys in the world have actually cracked it, I'm one of them . See my signature