As Jaguar went to the trouble of fitting a motorised flap and engineering the system to operate it, as well as test and monitor it. We can assume that there are worthwhile gains to be had from doing it this way. If a hole would have been better, they surely wouldn't have bothered with the more complicated solution. Especially given the propensity of motor manufacturers towards saving penny's.

 

As Jaguar went to the trouble of fitting a motorised flap and engineering the system to operate it, as well as test and monitor it. That there are worthwhile gains to be had from doing it this way. If a hole would have been better, they surely wouldn't have bothered with the more complicated solution. Especially given the propensity of motor manufacturers towards saving penny's.

That is a fair point, but all vehicles, including these, are designed to be sold and used all over the world, in all conditions with as few differences in build as possible.

There are lots of parts on a lot of cars that are unnecessarily complicated because they have to comply with different regulations in different parts of the world.

I have fitted a Caldoofy intake because the original one was unnecessarily complex with lots of different size resonance chambers when all it needs is a straight pipe.

Thank you for your reply although it didn't really answer my question.

 

The flap opens at wide open throttle and some do remove it, the aperture is below the filter element so the air passes thru the filter as normal. The debate on removal runs that the air will be warm from the engine bay and the air will be taken from the path of least resistance. I wangled a duct from the rad grill behind the headlight and it terminates right outside of the flap. Given that you might be shifting a bit when you mash it and if you have your hand out the window at speed its gets proper cold i theorise that when my flap is open its getting rammed with ice cold fast air.

 

Thanks FlatCap, I thought of making up some sort of duct so I might look into it a bit more when the weather warms up.

 

You can see my ram air trumpet top right of the grill

 

The removal of said flap is 'called' the Wide Open Throttle Mod on here.

I removed mine well over a year ago.

You only remove the flap leaving all connections etc in place.

Easy enough done when the filter box is out of the car.

Is there a noticeable difference? In all honesty I don't know.

Perhaps I should reinstall and take note of how my car sets off from rest or kickdown at 30, it's this latter point that has had me thinking it is quicker and perhaps the addictive whine of the S/C begins sooner.

As for the stock air intake to the box, I've allus thought it a Heath Robinson oh bollocks we need to have somat affair, an afterthought.

There's nowt remotely airtight about it so it'll be bleeding in warmer air as well.

Rich

 

Thanks for the reply.

I agree with you on the air intake, in fact the whole set up from air filter box to plenum isn't great which is why I fitted a Caldoofy intake pipe.

I had the filter box out today to replace the filter and noticed the solenoid looked very scruffy and I'd be surprised if it still works.

I understand it generates a "hidden" fault code that doesn't illuminate the EML or causes restricted performance when the solenoid fails.

The solenoid is no longer available so I guess I'll remove the flap now I know it doesn't cause any other issues.

 

Mine has been off for years. 160k miles. I got blocked by a car turning off the road yesterday and when it cleared I floored it. Dropped into first and spun the tires until the traction control kicked in, then launched. Don't think the flap missing has hurt it at all.

 

My old one was long gone when I bought the car. Probably wil do it to the Daimler, any diference, who knows...

 

The principle of delivering smooth cold air the the engine is a corner stone of tuning, there are other enhancements withing the airbox that are cheap and easy to do, working on the principles of marginal gains.

 

0 restriction plenty of performance benefits.

 

Not keen on the cheesy chive so all red for me

 

Gotta be worth 15 RWHP

 

Apparently the only time warmer air gets into the airbox with the flap removed is at stationary or walking pace. If the airbox is the same as the STR, it's a very good design according to Count Iblis.

 

I have fitted a Caldoofy intake because the original one was unnecessarily complex with lots of different size resonance chambers when all it needs is a straight pipe.

I believe it was designed like that to reduce & minimise the s/c whine.