After I found that my air intake Y pipe had cracked around the throttle body join (engine + Texas heat, I'm guessing) and finding out just how much Jaguar wanted for a new one (don't ask) I decided to replace the air intake pipe with a custom one.

So, armed with:

• A 3.0" Silicon Hose Coupler (eBay)
• A 3.0" to 2 x 2.5" Aluminium Y Pipe (eBay)
• A 30 degree bend 2.5" silicon elbow (Silicone 30)
• 3 x 45 degree bend 2.5" silicon elbows (eBay)
• A length of 2.5" diameter aluminium piping (eBay
• Heat-reflective silver tape (eBay)
• A couple of different sized threaded pipe take offs + rubber pipe lengths (Autozone)

This is what I came up with:



(Apologies for the poor quality cameraphone picture).

I'm staggered at the difference it made - the car seems to breathe a lot easier and pulls like a train. More induction noise too, which I see as a bonus

One thing I will say is that heat soak in this engine bay is really bad, which is firstly why the heat-reflective tape is so necessary, but also why I've stuck with the stock airboxes (with K&N filters).

Oh, and the 30 degree bend is the one on the far left-hand side of the photo.

I'll try and get some more details up if anyone is interested.

 

Nice job. I build/sell custom intakes for the 4.2L Supercharged XF. It's too bad the piping for the 5.0L engine is such a pain to route. Is there a breather line on the 5.0L that you had to tap into your intake piping (there is on the 4.2)?

In my opinion I'd ditch the tape and look into a way to coat the aluminum piping to reduce heat. A high temp ceramic paint might be an option. This is the first thing that popped up after a quick Google search: KBS Coatings 65303 KBS Coatings Xtreme Temperature Coating/Heat Resistant Coating - Free Shipping on All Orders @ JEGS

 

If you are getting better performance with your custom intake, I'm wondering how much the stock is compromised by efforts to reduce sound although I've always heard the intake flowed more than enough air.

And I know that heat soak is an issue from my dyno runs, so maybe I'll start figuring out some way to try and cool things down on the stock intake. Anyone have any suggestions?

 

Wow, great minds think alike! I've already got the aluminum Y and straight pipes off eBay (cxracing), but haven't yet purchased the silicone connectors.

What did you use for a connector to connect the two recirculative breather hoses (not sure it's called that) to the intake piping?

I agree about heat soak. I've simply removed the engine cover to allow the heat to dissipate a bit better. Yes, our heat exchangers are ugly to look at, but I'd rather take ugly over heat soak

 

Just be careful because without any dyno numbers we are all guessing. Many mods on many different cars have proven to be of little to no value after actual measurement.

Any car that is louder will make you think it's more powerful.

Better yet post some 1/4 miles times. I view that as a real world dyno because the dyno is also artificial in that there is no ram air into the engine.
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Yes, there's two - a small one that goes to the supercharger actuator and a bigger one that goes.....somewhere (I forget where now). I've tapped them into the silicon elbows with sealant (no welding required then) - you can see them on the engine side of each elbow closest to the Y pipe.

That is a fantastic idea, love it. It would look a lot tidier than the tape, which was functional rather than asthetic, but asthetics are important. I'll look into it

 

I've heard this too, although it must be said that there are sections of the stock pipe that are definitely a lot narrower than others. I assume these sections, along with the random plastic "L-shaped" additions to the pipe, are likely to be there to reduce induction noise, though I guess we won't know if this is at the expense of intake efficiency or power, though I'm willing to bet it is.

Possibly an aftermarket pre-supercharger chargecooler? Having said that, space at the front of the bay (where the intake is) is tight to say the least...

 

I used threaded pipe barbs off eBay. I can dig out the auction numbers if you're interested, though my measurements were a bit off and I needed new rubber hose from Autozone :P All came together well in the end though.

 

Fair point. I will try and get some dyno numbers with the stock intake and with mine when I've finished with it. I should stress though that my main reason for making this was to save the on the price of a replacement stock intake pipe after mine cracked, and even if the gains in hp are minimal, it certainly hasn't lost any!

Hmmm, I'm not so sure I agree with that, sounds like Ricer science. Also I'd like to think the quite obvious gains I've noticed are not purely placebo!

Quote:

Originally Posted by tbird6

Better yet post some 1/4 miles times. I view that as a real world dyno because the dyno is also artificial in that there is no ram air into the engine.

I have to say I disagree with this - with a 1/4 mile time there are so many other variables at play which affect each run such as wheelspin off the line, ambient air temperature, phase of the moon etc. At least with a dyno if you're comparing two things (such as a stock air intake and a modified one) you can rely on everything else remaining reasonably constant.

 

Be careful with tapping into the silicone couplers. It's hard to keep those leak free after a ton of heat cycles. A port welded on to the aluminum pipe is the best idea but it's likely too expensive and fitment might be an issue. Keep an eye on it.

I am still working on building intake scoops to help direct the air into the duct work from behind the grill. It's a common mod on BMW's and they have similar duct work that pulls air from up above just behind the grill. I think it would be a easy bolt on piece worth adding to any XF. Here is what they look like on a BMW:

 

I would agree about tapping silicone couplers. I'd suggest trimming an inch off one of the driver's side 30* couplers and using a longer piece of straight aluminum tubing to give you a place to put in your tap.

I bet a BMW intake scoop could be easily modified to fit a Jag. Might make your life easier.

 

Another option is header wrap. I can speak from experience with turbocharged engines that wrapping the charge pipe in header wrap REALLY cuts down on heat transfer into the charge pipe. Obviously the intake doesn't contain charged air, but why allow it to absorb more heat than necessary. The benefit of using header wrap is you can wrap the entire intake to hide all the connectors. But always use titanium header wrap. Fiberglass wrap degrades too quickly.

 

check out what they do on late model Corvettes.

the air filter is in front of the radiator and leads directly into the over radiator ducting.

 

Unfortunately we have very little clearance between the Throttle body and radiator, and also little clearance between the hood and the top of the radiator. Personally I'd rather re-route the stock intakes so that instead of drawing air from behind the centre grill they'd be drawing air from the lower side grills. The driver's is blocked off, and the passenger one appears to be for the oil cooler (or intercooler, I'm not sure). It would create a more direct path for the incoming air into the air boxes and should free up some breathing.

 

Your parts list show you used 3" and 2.5" pipes and couplers. I measured my N/A 5.0 TB at 3.5" OD and the air box outlet at 3" OD. Is the Supercharged parts really smaller than the N/A parts?

 

Yes, you're totally right. Good spot! I can't edit the post now for some reason

 

Check this out, a company that made one for a customer. All custom welding.
http://www.fluidmotorunion.com/archives/18194

 

Does any of these help the standard V8 aspirated engine ?

 

I know people have been looking for a custom intake for the 5.0 SC for a while now, so I called these guys this morning. Said it was over $700 for the job because it was a one off. Told them they should get on the forum and they might get some business. He said if they could get 10 orders they could get it down in the $500 range. I'm not sure I'm ready to do something right now, but if any of you are, there might be a way to do so at a somewhat more reasonable cost.

Would love to see a dyno run before and after on this to see if it's justified, or whether the noise is contributing to the placebo effect. It's funny...if it was $300 I'd just buy it. But for $500, I kinda want to see some proof.

 

I know the OP put that intake together more out of necessity than a desire for more power / sound. $500-700 is a lot for an intake anyway, especially when I have been told by Jag techs that the intake system is really finicky with these cars. I don't believe it is the weak link in the chain in terms of what is holding back more power either. Plenty of people here have made 110+ more hp with supporting mods and the stock intake. What I would REALLY like to see is for someone to get the cajones to do water or meth injection.

I used to remove the silencers / snorkels from the intake systems on my old cars, but from looking at diagrams of this one I had a hard time figuring out if one exists or not.