I'ts been a while since I loged on ever since I got my STR, let me just start off by saying it's a great car I absolutly love it but i'm concerned because the superscharger doesn't whine like all the STRs that i've driven. I can't even hear the supercharger unless I mash on the gas and when I do the whine is very very faint, hardly noticable. Just woundering if there could be something wrong with it. Is there a way to silence the supercharger? Im a bit jealous at this point because I want that bad *** sound lol.

 

Hi David. As a means to lower in cabin blower whine, Jag gave the 07 STR additional underhood/firewall sound deadening insulation. You can sweeten up the whine and power with a "Mafioso" air intake tube. Want to further sweeten things? Then pop on a 1.5 or 3 lb pulley...she'll whine earlier. The air intake tube and pulley should release between 20+ and 30+ ponies and trq. Do a full exhaust mod and another 20+ ponies. Otherwise if you haven't noticed less power then all is well. Now contact Mafioso, Eurotoys, Magnaflow, Borla, etc.

 

Also, depending on how much you want to hear the wine... the Eaton S/C has 4 silencer ports on the inside. You can plug those and it'll make it about twice as loud. And saince you got it off you can clean the intercooler and port the blower as well, that'll really open up your car, and the scream. My blower on the truck sounds like a turbine engine. It's a Magnum Powers S/C, but based on the Eaton. The Eatons also have a boost by-pass on it to help with heatsoak *IAT's* , (so your not making boost at idle or cruising). It is posible that it is stuck open, and you are creating less boost, less noise. But like bfsgross said, if your not noticing any power loss, then that's prob not the case.

 

Simple solution: Mash the gas MORE!

 

^^^ +1 lol

 

Hee, hee....10-4 to Chris and Schultz. Don't be too conservative. Let loose once in a while.

 

Yeah I though this might be the case, Just didn't know for sure cuz I tried to research this topic on the 07 STR and none mention anything about using more material under the hood to hide the supercharger whine. You think If I drop a K&N filter in the airbox might up the sound a tad bit? Will a K&N be ok to use on these cars? I read in one of the XJ links on this forum and they where arguing back and forth about these filters, some saying you shouldn't and some saying it would be fine.

 

Lol I've Slipped by two cop cuisers since i've owned it one was at an intersection heading to work and I wanted to make the red light so I smashed on the gas and next thing you know I cop pulls into the truning lane and I was like damn i'm busted but he just so happened to be lookin' down at his computer. my heart was pounding lol I ocasionally let the cat loose at night heading home from work since there is hardly anyone out one the streets at that time but most of the time I just cuiz so people can get a chance to apreciate it's build... and cuz I don't want the ride to be over so quick If you didn't put miles on a car so quick I would drive it every day.

 

The SC is after the airbox, plus the stock filter doesn't markedly impact air flow, so a K&N isn't going to add whine. The pulley likely will, or removing sound-deadening material.

 

Hi David. You can drop in a flat panel K&N air filter. While in there remove (very easy: one phillips-head screw) the solenoid actuated "Wide-open throttle air intake baffle" at the bottom front of the air box. Forget about removing sound deadening material. Instead order a "Mafioso" air intake elbow.These mods will likely yield 13+ hp along with a noticeable increase in blower whine and throttle response. Of course, you can pop on 3 lb pulley and perform a similar exhaust mod as mine; earning an additional 40+ hp?

 

JagV8, back in 2000 the first mod on my truck was a K&N drop in, and let me tell you Sir, it made a big difference in sound, and a gain of 1lb boost.

I can tell you that the K&N drop in for the 3.0 flows +200 CFM more than OEM. Not saying that the OEM can't keep up with the engine requirements or that the 3.0 gains anything from the extra CFM (I don't know what CFM the 3.0 needs) just that it does outflow it, and so should improve the sound as well. My custom intake I made sounds great, imagine a blower behind it…nice! My point is that one can easily do what I did and contact the manufacturers and get the flow ratings for the STR. OEM and K&N. If it is less restrictive, it will make things louder.

I'm not trying to turn this into the K&N vs. OEM debate. To each their own. I've run'em in everything, not have a single problem. The first one my friend put on his WS6 ruined the MAF. (I think operator error-too much oil) Plus I really like not having to replace filters all the time. Just a quick clean n go.

 

How do you know it flows +200cfm more on the 3.0?

BTW, your truck experience is irrelevant as these cars are far better designed and have far better air flow.

I stick by my point that it won't markedly affect the STR's SC whine.

 

I looked at the CFM charts via the manufacture for the OEM replacement one it had when I bought it, and the CFM charts for the K&N drop in I replaced it with.

I hear you, apple to oranges, but in my case I was just trying to compare fruits. lol The Eaton on the truck I figured was just as in-efficient as the Eaton on the STR. But my point was that with only a filter change the noise was dramatically different.

I'm sure this can EAISLY be tested. I know a few members on here have the K&N drop in. So who ever you are, please chime in and post results since the OP seems to be more interested in sound then performance the normal discussion of K&N vs. OEM should not be an issue. Just slap in a OEM filter, rev it a few times, then K&N and post results. Like JagV8 said, my Lightning is not a STR so I’m speaking in speculation albeit educated.

 

Ooh, now I'm interested! Where do I find those charts please? Never knew they were available. I'm a bit surprised jag would release them for their filter......

 

K&N on thier web sight then just make sure you are looking at YOUR filter, they have charts for everyone they make, I got nothing from Jag, nor do I think they'd give it up, but look up the manufacture on hte replacment filter, then google. I ended up calling, they told me to look on the box. I did, and the CFM rating was on it. What filter are you using? I'll look into it if you'd like.

It's kindof like the ZF fluid, Arm n a leg from Jag, but the Lincon with the ZF is a few bucks... It's all about the manufacture, not the Dealership.

 

I'm using a genuine OE filter.

If the car doesn't need more than the stock cfm there'd be no improvement, right? The tech stuff I've read refers to pressure drop across a filter (typically at WOT) not cfm. Are the tech articles wrong?

The ZF fluid was about the same price everywhere for years then dropped. Cheapest I've seen (until apparently LS) was LR.

 

If I get time I'll do an anecdotal test of my K&N drop in vs. an OEM filter - I think I still have it somewhere. Although I do have the Mafioso intake. Not sure how I would measure sound differences other than just observation.

For what its worth, when I have added a K&N drop in to any of my turbo cars there is a noticable increase in intake noise (aka: suck) - not as much as with an open element (no airbox) but noisier for sure.

 

Yea under WOT, I'm sure the OE filter flows more than enough for the engine, or the manufacture would not have good engineers. lol I believe in most applications a K&N will not increase power, because in most applications a manufacture will use a filter that flows enough. For my truck under WOT and high RPM the K&N flowed much better resulting in sound and boost. It’s a big topic on SVTPerformance, at least it was years ago when I was an active member.

I'm not sure about pressure drops, that is not something I looked into. Once I found the difference in flow capabilities I just went logical on it, (don't mean I'm right, lol) But if it flows more, then the blower don’t have to work as hard to keep the same amount of flow, and since it’s mechanical will still spin the same, so able to push more air right? Keeping lower IAT’s, more timing, faster E.T. over OE. How this relates to the STR I could be way off, like I said, the only real relevance is the Eaton. A guy like you who knows more about this stuff then I do could probably brake it down into lay-mans terms for me.

Or it will forever be a debate based on opinions that can never be resolved. The only reason I went with the K&N on my 3.0 S-Type was for the re-use, and the sound. (My intake tube probably makes more of a difference here, but I put them in at the same time.) the flow charts I looked up at a later time due to someone questioning and poking me in the eye for using a K&N.

Last but not least, not sure about the ZF. I’ve yet to change mine. But when I first joined this forum I did some searching on here. I thought I read that from Jag it was like $60-$70 a qt, but the Navigator that has the same transmission calls for Moto-Craft fluid at $7-$8 a qt. The MSDS for both were from the same manufacture. Same product, two labels. Again, this is from my shady recollection, and I easily mix things up.

JagV8, you got me so confused, I’m questioning everything I thought I knew about this car. Lol Fix me!

 

A K&N a/f makes more noise than OE filter on both my Ford Expedition and Jag...more suck...more noise. Blown cars both need and enjoy more intake air suction.

 

It makes sense for any maker of a modern car not to use a restrictive air filter. That's when using the rest of the stock things - intake, blower (if any), etc. If you change intake / pulley / blower / etc then of course it may be that the filter can become a problem, though it can't be much of a problem unless you make a really big change to the overall intake system or the stock filter/airbox is/are really useless.

The reason air flows through the filter is that there's a partial vacuum on the engine side of it. That's why people measure the pressure drop across the filter. (Ideally it would be zero.) The easy way to get less pressure drop is to have bigger holes and/or more holes overall (i.e. overall more area of holes) but a better way is to have a larger area of filter to achieve that. You want good filtration as engines don't love particles of grit etc! (You already know what K&N do.)