Hello all,

Ive been reading with interest posts on this forum about air intake pipes and the benefits they give. I run an x358 xjr and am developing, with a company over here in the uk, a complete cold air feed system going right to the throttle body from the air filter housing and made in carbon fibre to avoid heat soak issues (i believe the cast aluminium section after the normal plastic intake tube to be the main issue where heat soak is concerned.

Obviously this is initially being made for the xjr but as we have seen the parts have been shown to be interchangeable with the STR.

So now to my question would there be any interest in such a product (obviously dynos would be provided to prove any gains) ?

Initial pricing is looking to be between £350 and £450.

Thanks.

 

You're not going to get much heat soak except at idle... right? So why would it matter? And you could just insulate it, if you think it matters...

 

That was what i had originally believed however a test i did was take the car for a drive all quite high speed, so you would think plenty of air flow turned engine off after coming to a stop from 70 mph, popped bonnet and could not hold my hand on the cast part it was that hot! In effect the cast part is acting like an intercooler in reverse ie it retains the heat and warms the air as it is passed through.

I think that in making their cars so quiet from the outside Jaguar have virtually sealed the engine bay! Problem is amplified by the under hood sound deadening/ insulation. Give it a try and see what you think.

As colder air would be going in i was hoping for a reduction in temps coming from the charger to tie in with a stand alone charge cooling circuit which i am also looking into.

Also think the carbon would look good under the bonnet as well although this would just be nice added bonus.

 

The STR gets the coldest air it can by getting it from outside the front of the car (which is why no-one should use those underhood intakes). Some heat is added as that air rushes through the intake but far more is added under boost. At speed it is very hard to see how a lot of heat can be added as it rushes through the intake as opposed to the boost. Sounds much cheaper and far more effective either to cool the post-boost air (e.g. better intercooling) or not heat it so much (go twin screw).

 

Yes, the cast part may be hot, but the tiny amount of time the air spends in there doesn't heat it up. At least probably not measurably. The gains would be in the better flowing intake tube and a properly shielded larger cone filter. And reduced weight.

 

Smoothing out the flow was the original reason for starting to develop this intake as , from what ive seen on other posts the gains are quite high for such a small change when changing the front section. By taking it to the next level so to speak i was hoping for an improvement over just fitting the front pipe that is readily available.

I will be combining this with a post charger cooling upgrade in any case.

Thanks for your input JAgV8 and SteveM

 

If your new intake has an inside diameter of 90mm or equivalent cross section the entire length, has a smooth non-restrictive elbow at the throttle body end, and keeps temps down then I for one would be interested.

We know from the Qwiketz intake elbow that the X350 S/C car has an identical intake as the STR, so it would certainly be a product for both models.

You don't have to make it from Carbon Fibre, a plastic like Polyethylene or Polypropylene would be fine, probably cheaper to if injection-moulded or blow-moulded.

I've been toying with this idea myself, but to do it properly you need to make a complete new airbox as well. (the outlet from the airbox is another 75mm bottleneck)

Something like this would be the go;





The bigger ID of the intake tube should go hand-in-hand with an enlarged throttle body i.e. maxbore.com special...

Go for it, if you have the time & money to develop the product, cause i'm afraid i don't...

These intakes in conjunction with enlarged throttle body's (80mm up from stock 75mm) are a big hit in Oz with the Ford & Holden crowd, and they do make power!

 

Not to deter you from making one. If I had an STR or X350 XJR, I might have been interested.

Maybe you could get that section from these guys:

 

Hi cambo,

The tooling costs for injection/ blow moulding are prohibitive for low volume items like this where as the carbon (once the moulds are produced) can be made at relative low cost.

With the throttle body being 75mm (and the MAF) no gain would be had from the larger diameter piping, as with exhaust pipes they are only as good as their narrowest point/s. Increasing the size of the throttle body without a similar sized MAF calibrated would only yield a mismatch in what the ecu is expecting and the volume of air it receives. The net effect would be more acceleration for less pedal movement and a percieved effect of it being 'quicker' due to this.

The internal diameter of the piping will be the outer size of the throttle/ MAF so reducing potential turbulance this should give the smoothest airflow but as i say nothing is set in stone yet and the mockups should gve the best design for this application.

Initially this intake will be to go onto the standard airbox but already we have been discussing enclosed filters with its own cold air feeds ala CIAS focus RS system.

Once again thanks for your input and ill be posting up progress soon once i get the car back from the body shop.

 

SteveM thats the reason i use these forums :-) pictures like that could save hours of development (and if the parts are resonable cost) i would just need to add a front section that would fit. Do they report any gains with that setup as it looks pretty much the perfect setup ie straight airflow with nothing toslow it down.

Thanks again.

 

That picture is from a race team and I have no idea who they are or how to contact them. Maybe others would know.

Regarding the intake diameter, there are significant gains going to a 3.5" diameter over a 3" on a x308 XJR, which also has 75mm TB and MAF. I'm sure it would affect the newer V8 the same way.

 

Yes ive read that on some other posts just cant understand why that would be the case! it goes against the fluid dynamics theories and alot that i have learned over the years, however i am not closing my mind to any possiblities at this point and we will be exploring different size tubes in metal first to see what differences there are.

 

If you are going to all the trouble of hand-making a carbon fibre intake then make it capable of flowing more as well as reducing temperatures. 90mm is a good size and if you make a new airbox as well then no problem to fit a bigger MAF (the ECU will learn?).

I am thinking bigger picture here, a wünderbar intake to go hand-in-hand with the https://www.jaguarforums.com/forum/p...59/#post243827 since the kit for the STR & X350 S/C cars is very close now...

 

While logically appealing, it is not quite the whole story and the discipline of fluid dynamics will explain all the reasons why a bottleneck is not the whole story.

 

The racecar CF piece is most likely using a different engine management setup as there is no MAF.

 

Quick update, car is out of the body shop now and booked in to the fabricators on 3rd Nov to develop the intake. Watch this space.

 

Not to mention all the other parts that must be relocated and rebuilt just to fit that sucker in over the radiator and under the hood.

 

While that racing intake would be nice the one we are making will fit the standard car without relocation of parts, obviously as that intake is direct straight and has no MAF to interfere with airflow it will flow better than ours but time will tell cant wait to see what the finished article will be like, we are making 2x pipes 1 in 3 inch and 1 in 3.5 inch to directly compare the 2 different sizes on the rollers.

Thanks for all the interest/ feedback so far.

 

Looking forward to your results from 3rd November, this is exciting stuff.
I reckon you could have a 1/2 dozen pre-orders for the 3-1/2" system, if the price is right.

As you may know my XJR has the Qwiketz intake elbow fitted. Sunday afternoon I went for the last drive of the year on the German Autobahn before winter hibernation, and did about 100 miles at speed, lots of full throttle, 120mph cruising and a short run peaking at 160mph.

After one of these high-speed runs i pulled off the Autobahn into a rest stop, popped the bonnet & put my hands all over the stainless steel intake elbow, & also the cast alloy tube between the charge coolers. It was warm, but certainly not "so hot I couldn't touch it". Maybe around 55°C (most people automatically pull their hand away from something at 65°C, if you are tough you can hold onto something at 70°C)

OK it was not a hot day around 14°C ambient. I'm sure if the ambients were in the 30°s it would be a different story.

I believe (without any scientific evidence to back me up) that a plastic or CF intake will help somewhat in hot weather conditions. But on cool days it won't make that much difference. What is more interesting for me is a bigger inside diameter!

Really hope you can get something done here.

 

I am running an intake elbow with a 3.5" diameter vs. the 3" of the Qwiketz/Mafiaso intake; I have no exact comparison of the two so I can't speculate if mine is any better or not. As mentioned, we are limited by the diameter of the throttle body and the MAFS. I believe JagV8 is correct in saying that the real advantages are going to be had from cooling the air intake temp as close to the point of combustion as possible by going with a twin screw or killer chiller type of setup (although SteveM made a good point about the air not being in that section of piping long enough to get that hot). I'm not sure any more gains are possible by modifying the intake system any more than has already been done, and for ~$700 I would expect about 25-30 whp gains; which I just can't see from a bolt on tube. I hope to be proven wrong on the dyno, but at this point I remain skeptical. At the same time, it is nice to have some people interested in producing aftermarket products for these vehicles.