A Quick question for anyone with an answer,

Is there any advantage in putting either a drop in high flow filter such as a K&N or BMC in my 1995 xjr

Or even replacing the box with an open pod set up?

 

Quite a few posts on DIY CAI and units by Mina, etc.... seems the general consensus is that the traditional CAI is of minimal value unless you can find a way to really isolate the hot air from under the hood.

I found this to be a good idea:

https://www.jaguarforums.com/forum/x...5/#post1007809

.

 

Hi Michael,

Plus 1 on Al's recommendation of Andy Stodart's timing advance bracket.

Given that a filter that can pass more air can also pass larger grit into the engine, I've personally avoided the K&N drop-in type filters. Also, the oil that is necessary to improve the filter's dust-collection capacity has also been known to foul the MAF from time to time.

A simple mod I made on our '93 was to replace the tapered air cleaner box inlet snorkel with a straight hose, significantly increasing airflow with just a minor increase in induction noise. Actual performance gains may not be measurable, but there is a sense that the engine is more responsive, especially in the mid-range:

Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

 

Something I just noticed, on the XJ40 there apparently (via Don's photos linked above) is a panel in front of the airbox and a hole that the snorkel protrudes through behind the headlights.

On the X300, there is no such hole or panel. The snorkel just pokes down behind the headlights and is an open space shared with the cavity behind the headlights and engine compartment.

So on the one hand the X300 OEM snorkel does pull in "cool" air directly from the front of the car (via gaps in the headlights, etc), but on the other hand it also can still suck in some warm air from the engine compartment.

But the snorkel restriction is still there as it tapers as on the XJ40 example as well.

So there is likely still some opportunity for improvement. There also may be some increased opportunity to do something creative with the air intake routing since that bulkhead behind the headlights is not present.

.

 

Al, which hole are you talking about? If you're talking about the black hole that looks like it's going into the fender wall then yes the x300 does have the same hole. The xjr snorkel from the air box does not go into that hole but the regular xj6 airbox does. I compared the top of tge airbox with the snorkel and confirmed that the elbow has a different angle. Has something to do with the extra space that the supercharger takes up that moves the factory airbox a light bit.

 

Ah, that is interesting. I didn't notice that.

 

Well there is one way to get cold air into the intake, if you're truly committed:

 

Well, the links didn't work.... but yeah, this isn't a big deal. But Don's hose solution looked pretty interesting and simple.

.

 

The snorkel is the biggest restriction and can be eliminated with minimal effect on noise. The area of the paper element is too small and can be replaced by an aftermarket part, but measures must be taken to ensure only cold air enters the intake. See my garage for photos of one solution.

 

Ah OK, there the pics are Not sure why they weren't working for me yesterday.


But yeah "committed" would be the right terminology for sure, lot of time and monetary investment for that solution.

Looks very clean, but I'm not sure I like it on the XJ. Maybe on an XK, which BTW, is that what those "nostrils" are from? I prefer more concealed and "sleeper" solutions, but that is still a nice implementation and looks practically factory.

As an aside, I wonder if the "nostrils" in this example really do anything?

Based on their placement, I am curious if they would actually exhaust air more effectively than "suck" in air as the air flows over the hood. One would have to do some airflow analysis to really know as these things can be tricky and counter intuitive sometimes (think cowl induction, or high pressure areas around rotating tires, or hood "scoops" and rams that don't even work) so you never know until you measure.

Definitely interesting.

.

 

...and of course upgrading to an Eaton M112 from our stock M90


Andy, I see that you have what appears to be a K&N (or similar) oiled cotton cylindrical filter on your installation. Have you had any issues with that filter and its associated filter oil foul your MAF? Also, any concerns about fine grit passing that filter and causing wear?

I've considered something like a K&N but some concerns have been raised here on both of those points.

.

 

Here is what was said about that particular install from the website I pilfered it from:

 

Well, I truly am not being argumentative ..... but "of course" he's going to "see heat rise from the vents at a stop" due to simple convection from under the engine

What I'm curious (although not highly curious, as in I'm not going to put a lot of time into it ) about is: Are these vents actually some sort of "induction" (tied to the intake) or just hood penetrations venting hot air? And if they are induction, at speed does their placement benefit from high pressure (help with induction) or suffer from low pressure (fight induction) due to airflow? I suspect the latter.

From that quote about seeing the heat rise, I suspect they are just "vents" through the hood.

What website are they from? I'd like to learn some more just because it is a neat modifiction.

Might not be everyone's cup of tea (e.g. Not sure I'd like it on mine), but still good work. Still smart looking installation regardless.

.

 

Ah, found the forum post at Roadfly:

07 XKR vents n a 2000 XJR

 

I put one of the large spectre cone filters in. The adapters fit it right over the maf tube and it reaches to the relay mounting bracket. So its pretty stable without a bracket as I havent made one yet. No perceived performance gain. The guy that runs the dyno hasnt sched me in yet. Just found another one across town. But Im stuck going by feel til then. The supercharger whine is a fair bit louder. But doing this has to be the absolute opposite of cold air induction. I have been staring under the hood trying to imagine simple solutions to the cold air source. The xjr6 has a large rubber shielded port in the driver side wing that opens into a cavity in front of the wheel well. A body mod of some kind of a side vent would be interesting. A naca duct would probably work well. Another solution would be a box that surrounds the filter with an open top and rubber seal that traps up against the hood. Large naca duct there would prob do the trick as well. Both ideas require body work. The Easy choice would be pull the bright lamp and fashion a grilled hose to replace it and run back to the box. If you used stainless mesh to match the hood intake grilles it might look acceptable. Not sure the legalities of the loss of one bright lamp. Dont use mine anyways.

 

I did some more looking for examples online. It appears the headlight removal seems to be popular amongst club racers of the xj6, r, & s community. So I think this is the way I'll go. My plan is to fit some grills in the bright lamp houses that closely match the large front grilles. (i'll do both sides to balance the look. But the passenger side is loaded with mechanicals behind the lamps). I have seen a few ready made options as small headlamp stone guards. The next issue is the headlamps are secured to a plastic web board that the main hole behind the bright lamp isnt that large. I think its ok. So ill plan to use a plastic tube behind the stone guard but inside the chrome ring that runs back to the web board. It doesn't seem too difficult to isolate the intake filter area via a formed aluminum panel. But the relay group will need to be relocated and the harness is short so it isnt going very far. I think this is doable.

 

You mean like this X308 solution?

 

Is that serious?

.

 

ummmm wow. well that inspired another concern. what to do with all the driven water that comes in. will it soak the filter without a baffle if some form.

 

Big Power - Big Air