2011 Jaguar XF premium 5.0

just need help on something I made a custom cold air intake and took the original 2 out (stock). Question should I leave the stock on or the new custom one on that I made cuz I’m not seeing a whole change do I need to make a dual custom cold air intake cause I have just the one single intake but I’m not seeing a difference in power maybe less.

please help. I also straight piped my exhaust if that helps or not.


thanks!

 

I think you've probably made things worse with this intake, if I could give some constructive feedback:

1. How well are the hose clamps sealing on the pipe? Hard to tell from the pics but any leaks past the MAF sensors are going to be a real problem - and get some hose clamps on the other end of the pipe, they're not that expensive
2. Definitely not sure about having one MAF sensor up from the other one in a single pipe - these are intended to be mounted either end of a Y pipe from the factory - which has (a least on my supercharged engine) different lengths to the throttle body, so the MAFs are likely tuned for airflow accordingly. Granted these are both in a single pipe so differences between the two should be neglible, but it's still hard to know the affects on this.
3. Again my engine's supercharged but I have two filters close to that size. Is it possible the filter is too restrictive?
4. You've lost the factory cold air feeds, which just means at this point your engine's sucking hot air from the engine bay. Doesn't make much difference on 1300hp drag cars but on a road car (especially naturally aspirated) this hot air can be quite a significant detriment and kind of removes the point of having a "cold" air intake.

Honestly, I'd be looking to create a Y pipe that allows you to use the existing lower halves of the air boxes with the factory cold air feeds, and original MAF mounting positions.

I've done this but also added carbon fiber heatshields around the airboxes, and additional cold air feeds from the bumper air vents up behind the headlights to the airboxes:



Honestly I'd love a single carbon fiber Y-pipe but I'm having trouble finding someone who'll make me one for a vaguely affordable price! There's been loads of discussion about whether a metal pipe actually heats the air up with general concensus appearing to be that it doesn't make much difference, but a) I think carbon fiber looks the mutt's nuts and b) I bet it does make a small difference, carbon fiber is a much better heat insulator than metal.

 

To make things worse - in this setup the open PCV will cause either a HUGE vac leak if only one breather is disconnected/plugged with a cone filer or a big risks of leaking seals/excessive oil use due to the increased crankcase pressure.
Also, in this setup a maf positions/tube diameter are wrong and it will cause wrong maf readings and mixture problems.

 

I appreciate the feed back I do! It’s my first jag and I’m just testing the waters but I’m gonna go ahead and fix it and proceed with fixing the entire issues but doing a dual intake instead of single and connecting the both the hose to the intake. Thanks for the feed back it helps!


also with the tubings I’m assuming getting the same size correct? You’re talking about the one on the right side not the one with the filter head attached right?

 

My current setup is a 3.5" Silicone coupler on the throttle body with a 3.5" -> 2x 3" Y Pipe (if I remember correctly it's this one from cxracing), and then a length of 3" carbon fiber pipe to each air filter, with various silicone bends joining them all together. The MAF adaptors are 2x 3" (or 76mm) MAF adaptors for Toyota, which has the same bolt pattern and entry hole as the MAFs on our engine - like these ones on eBay.

I've also got different size hose connections sealed into each carbon length of fiber pipe for the supercharger vacuum valve and the breather connection - you can get these easily enough online, these were intended for mounting inside silicone hosing.

A final point - air leaks past the MAFs are really bad and can cause all sorts of OBDII codes as well as shitty idle, and it's always worth resetting the engine management after you make changes to the air intake so it can relearn setting - I've done this via a pretty extensive Autel code reader, but not sure if you can just disconnect the battery for a while to achieve the same result.

 

Also, random point, but your coolant is pretty low in those photos. Top it up so it sits between the level marks and see if it stays level over the next few days of running - if you have a leak, now is the time to catch it, these aluminum blocks don't take overheating well

 

Can I ask how long are those two carbon fiber pipes and if I may ask about the cost of this whole setup ? What are the filters you are using ?