I have been working on improving the dual intake for the XKR for the past few weeks and I am happy to say my prototype works! I have never seen the Mina version but read quite a few comments here how it did not work or there were MAF sensor issues, etc. I'll post some pic of mine when I have the aluminium tubing finished and installed, hopefully this week or next.

Basically, I did not like the idea of small snorkles pointed upwards near the top of the inside of the bumper, the intake boxes, the turbulence caused by so many rough and irregular surfaces or the 6 Hemholtz resonators featured on the Jag design. I wanted something larger, direct and smooth with large K&N inverted top cone filters directed forward at the lower right and left bumper ducts. Another benefit is less air flow restriction in front of the radiator where the snorkle flares used to be.

Besides working with no errors, I definitely feel the motor is breathing better, IATs are lower, super charger whine is more pronounced and the car gets to redline and speed much more swiftly.

HOWEVER I can NOT recommend this to anyone who drives their car in rain or water, rain would be okay but driving into deep water/puddles, etc could cause water to get sucked up into the motor.

More to come...

 

Mine picks up the occasional unbalanced MAF fault with just the snorkels removed. Just one of those things that makes me glad a tinted the warning lamps. Looking forward to pics and maybe a parts source list.

 

I am sure you guys know this, but it has been proven that increasing the induction sound/noise tricks the brain into perceiving an increase in performance, much like louder exhausts do the same.

Only real dyno testing of A(Stock) vs B(modified) preferably on the same day will reveal any performance gains, or not. I have spend solid days( I always rented dynos by the day, not hour) running hundreds of dynos testing induction systems, exhaust systems, S/C systems etc, and you will be surprised at what really works vs not.

Also to consider, and this is assuming the 5.0L Air intake is similar, which it appears to be, the stock XKRs and XKR-S made up to 542HP with the stock system, so there is proof it can flow the amount of air needed to produce that kind of HP. One would assume the lower powered 4.2 would have plenty of breathing room already.

BUT, it is fun to experiment with different things and I find the learning curve fun!

Cheers,

Dave

 

Of course I have no empirical data from this particular mod, but I do have plenty of dyno runs.

Can’t speak for induction noise as I can’t hear it inside the car with a Snell helmet on, windows down and exhaust loud as hell, I can only go off of how it feels and it does feel different. Despite what people say about how great the Jag design is, when you’ve made as many changes as I have there is always room for improvement especially with an air pump motor and increased tolerances. Jaguar didn’t build this cars to be sold with the maximum they are capabale of and they deliberately muted the intake and exhaust to make it a gentle grand tourer.

 

Mina is no longer selling its intake system. Years ago I bought the Mina system for a 4.2 XKR hoping to fit it to a 4.2 XK. No fitment as the XK (single air filter) has a larger diameter MAF sleeve/tube 3.5" vs. 3" for the XKR. The OEM airbox has the MAF sleeve screwed to the top of the airbox.
We all know that the Jaguar intake system is hyper sensitive to imbalances and intake leaks. Mina used a new aluminum MAF sleeve, and I think they had downstream sealing problems with it. The shape of the downstream sleeve flange is critical.
In addition, a 3" diameter aftermarket MAF tube/sleeve is hard to find.
Perhaps a better solution/alternative is to try to use the OEM sleeve and make some sort of adapter to mate it to a 3" tube upstream of the sleeve, but even then "balance" is still an issue to be resolved.
I applaud A/B dyno testing. It is still the most accurate method of any measuring improvements, provided you use the same dyno on similar air temps.
I have constructed a system for my 4.2, and will do an A/B dyno testing - some day. It uses a K&N RG-1002RD air filter.

 

Thank you very much for the update on the Mina version, I have never seen one so I had no idea how they were made. The ones I have built are significantly more expensive than Mina's unfortunately. I reached out to Chris multiple times but never heard back from him.

I indeed reused only the MAF sleeve and both sides are still identical so balance is no issue. I have put several hundred miles on the crude prototypes and an intense weekend at the track and absolutely no issues, the custom fabricated tubing should be even better.

 

Basically, supercharged systems that "suck through" (Jaguar) are more responsive to intake tract mods than those which "blow through" (old-fashioned Paxton). This means there is potential improvement everywhere - like boring out the throttle body (Maxbore.com throttle body boring service and repair).
There was nothing exotic about the Mina system other than the MAF sleeve. The sleeve mated to a 90 degree rubber/silicon elbow (easily found on line). The other end of the elbow had a short metal straight section, which provided a purchase point for the air filter. The air filters supplied by Mina were cheap small K&N knock-offs. The whole contraption was held by a piece of strap metal tucked under the clamp of the air filter and reaching up to the rear mounting hole on the chassis for the airbox - EZ PZ.
I am not worried about water immersion and subsequent hydro-lock. I think you'd have to have water over the top of your fender for this to happen. My own experience with a similar homemade intake on a Cadillac CTS-V, which I had for 95K miles - only once did I "enter" water deeper than 4" at speed; and water was not injested - but the car did stumble because its intake was momentarily blocked.

 

Again thank you for the further clarification, mine is a bit more complex than that, besides the large premium K&N filters, I have replaced all of the plastic OEM resonated ducting with custom fabricated aluminium 3" piping. I also do not believe water ingress will be an issue, but I wanted to warn anyone who may follow this, the intakes are much lower now than they were.

 

so are you planning to release these for sale at some point assuming they pass all the road testing and what not?

 

Interested to see this...

 

x2

 

Pics aren't the best, these are the mock ups I've been running for over a month with no issues. The fabricated ones are 3" aluminium and also replace the distorted and turbulent factory plastic tubing.

 

Interesting. I'm curious what the air filter area comparison is. Those cones look smaller than the factory deep pleated one.

 

It seems the "distorted and turbulent" factory plastic tubing does more than we think?

Here is some info from a recent thread here... https://www.jaguarforums.com/forum/x...design-201035/

3D scan of Air Intake system on 5.0 ...



Cheers,

Dave

 

Dave, JLR spends far more time on comfort related NVH dynamics versus performance dynamics. I'd lay money that those bumps are purely to help the engine pass the drive by noise levels and eliminate some 'unpleasant' noises from the blower coming back through the intakes.

Using the bumps for performance only works under certain conditions due to the speed of sound changing with temperature. I found that out on my Helmholtz resonator project. My cars exhaust drones louder in the winter when it's burr cold out. It has much less drone on a warm day. I needed to shorten one of the resonators due to the tow bracket being in the way so I'm sure that's the one that's out of tune. Fascinating stuff.

 

The stock filters are approximately 6-inches x 9-inches, the K&N cones are larger than they look at 5.5-inches X 18.8-inches NOT including the second intake in the middle of the filter so well over DOUBLE the surface area. Also the untreated cotton material on the cone is far less restrictive than paper OEM filters.

 

Hi Dave,

I have a 4.2 so a bit different from your 5.0. There are several issues with the factory intake, one the inside surface of the plastic is not smooth, it is rough and textured, plus the flexible "accordion" joints are not smooth at all. Second, the factory tube are not round, they vary in all sorts of shapes to accommodate their locations. And third, the resonators are more for acoustic purposes rather than return pressure waves, particularly with a 3" round tube.

 

FWIW, I only posted the information from that thread and YES it is fascinating stuff, I disagree that JLR spends more time on comfort than performance. If they weren't high performance vehicles we wouldn't be talking about them, or even owning them, right? Seriously though, I am not sure if you are aware how these things work at a large professional company, but there are various different groups working on different aspects of a vehicle to the BEST of their abilities. You can bet the Comfort Group worked to the best of their abilities, given the constraints they have to work with, and you can also bet the Performance Group works just as hard, if not harder to do the same.

I am in the same camp as you about the various small chambers being sound attenuators more so than for anything else. BUT, the bottom line is that everyone here is just "guessing". The guys that designed this stuff are way smarter than we are concerning this, or at least have way more experience because they are educated and trained to do it everyday, for a living.

Have a great evening,

Dave

 

..... with this ONE PRIORITY.......
Make it as cheap as possible.

 

Hi Jeremy,

Yes, I assumed they were different which is why I specified it was from a 5.0L, but the concept is all the same and there may be something to learn by comparing the two of them. I would guess the 5.0L system has some improvements since it was revamped when they came out with their latest and greatest (even to this day) new wizz bang engine that was and still is their flagship engine today. So it would be safe to assume they took a long second look at the air induction system and if there were improvements to be made I am sure they made them. It would be interesting to see the 2 systems side by side and if they are pretty much identical then it also tells us that the lesser powered 4.2 systems has all the airflow it needs, even if modified tot he same power level of the 5.0L.

I am very impressed to hear the inside of the air tubes are textured, that tells me a lot about the JLR "Performance Group" and that they are on their toes. You seem to think that is a problem, I implore you to do some research on boundary layers, especially if you are designing air intake systems. I big hint for you is a golf ball.

The flexible joints are a necessity, something has to give between the moving/vibrating engine and the rigid chassis where the air tubes/filters are attached. That flexible joint has to be somewhere if the system is going to last very long. Since they are using texture inside the pipes I am sure they are smart enough to use the most efficient flexible joint that is feasible. Again as I have said before these guys/gals do this stuff for a living and know more about such things than we can ever guess about. Of course they have restraints in design that end users do not have, or think of, and given amounts of money and time anything can be improved. But it is never as simple as it may appear to be.

Changes in shape aren't that big of a deal as long as it is done the proper way with thought into the transitions in and out of those shapes. It happens everywhere in an air intake tract on every engine I can thing of. The air changes shape everywhere all the way down to the shape of the intake ports. If keeping it perfectly round all the time was the best way to get performance then all of the engines would have perfectly round intake ports, etc, etc. For the life of me I can't think of a single engine that does with the exception of my lawn tractor, pressure washer etc. In the end it is all about how you handle the air flow more so than the shape of such.

Again, I agree that I have always thought those chambers are just for sound attenuation, but like everyone else here we are just guessing and don't really know for sure. I will say judging from that 3D scan, they put a lot of thought into optimizing what ever they were trying to accomplish. Anything beyond that is pure speculation.

Have a great evening too!

Dave