www.jec.org.uk

I`ll open this thread as I am now awaiting delivery of an aluminum cold air intake from Mina Gallery in the States.
https://www.google.co.uk/url?sa=t&rct=j ... O_xW3Km3Cg

This is a direct performance up-rate for the OE plastic unit fitted at the factory. The ali performance part is designed as a restrictionless intake which is modified to dispense with the originally fitted noise attenuater tubes and a corrugated bellows type connector up stream of the MAF sensor. These restrictions cause internal intake manifold air disturbance and from my own experiments with the OE part, definitely rob the car of low engine speed performance and pick up.

The OE part regrettably also has a large hump built into the molding right in the place you don`t want it. Namely on the outside of a 90 degree bend where it is desirable to have a smooth airflow to keep air velocity at its maximum. The hump on the OE unit is curious as although it is close to the rear left hand corner of the header tank and has clearly been designed to clear the tank, it is far enough away from the tank to allow a good clearance without the hump being necessary. A very odd design feature to my view.

Upon buying my X350R and noticing how restrictive and turbulative the OE inlet pipe was, I attempted a "poor mans" modification to it as an experiment. Simplistically, I removed the manifold from the car and cleaned its internal parts with acetone to remove any internal grease residue. I then took a can of aerosol builders foam and one by one filled the supercharger inlet attenuater tubes with the expandable chemical. Leaving it to harden, I trimmed off the excess foam egress into the manifold with a sharp saw tooth steak knife and blended it in to the internal profile. Now, after nearly three months experimental trial, the foam is still well adhered to the inlet manifold trunking and has not been sucked out by internal manifold depressed suction flow. The effects of the experiment were very pleasing. Throttle response from a standing start was greatly improved and little if any additional induction or supercharger whine was noted. In my opinion, the fitting of noise attenuaters to the inlet manifold as an OE feature is a completely unnecessary feature which is only likely to increase fuel consumption due to parasitic inlet charge air drag and reduce overall engine volumetric efficiency. (The number one rule of successful engine tuning).

As the experiment has been so successful, I decided to buy a proper professionally produced inlet manifold induction pipe which is manufactured without attenuater pipes or the unnecessary hump on the turn of the inlet pipe bend. The kit comes as a polished aluminum pipe with two new straight un-convoluted rubber connectors, two extra jubilee clips and a connector and pipe for the part load breather arrangement. At just under £130 delivered from the States via UPS priority post, it represents excellent value for money. Indeed Tom Lenthall at TL Jaguar, told me to buy the unit as he would have difficulty making one himself for me at a similar price. Tom certainly puts his customers interests first and I thank him for that.

I`ll be doing further slight mods to the ali manifold when it arrives. I`m sure the polished finish would look spectacular when fitted to the car, but I`m more inclined to view function before and over aesthetics. Charge air needs to be kept at as low a temperature as possible in any engine bay environment. Warmed air leads to a reduction of density and oxygen content. The optimum theoretical charge air temperature is 7 degrees below ambient air temperature of the day. So one can aim and attempt for that with some limited possible success and initially drawing cold air from outside the engine compartment will help a little. If you can get temperatures down to the magic 7 degree below ambient optimum temperature level, then you have done very well technically. Refrigeration of charge air is one option but aiming to go below 7 degrees will lead to condensation issues which are not desirable.

My mod to the ali manifold is quite simple to achieve. I have bought a few metres of two inch wide self adhesive fibre glass tape with an aluminum outside surface. We already see some of this material in place in our cars to help prevent heat convection at various locations. My inlet manifold will therefore be wrapped in anti heat convection tape to attempt to keep the inlet manifold as cool as possible in an under bonnet situation. I may not get that 7 degree optimum temperature differential, but the tape will help somewhat in the quest. It may not look that pretty either. Lets wait and see what sort of a job I can make of it.

More details once this pipe arrives.

Mike

Still waiting for delivery but I know the pipe has now arrived via UPS priority airfreight in London. It has now sat for nearly twenty four hours awaiting customs clearance. Rapid transport across the States and the Atlantic and then to sit on a shelf to clear what should be a simple formality. How long can it take?!

Delivery times even from the European Union can be frustratingly slow. A pair of Bilstein dampers from Germany languished in a Heathrow transit shed for over seven days before eventually being allowed for delivery. All rather disappointing given the impressive speed of logistics operators. You would have thought customs clearance could be initiated immediately a carrier collects a parcel from a supplier to save delivery time.

Mike

Now four days for my induction pipe to pass through UK Customs....perhaps it will be dis interned tomorrow....

In the meantime in preparation for the arrival of the pipe kit, I removed the upper inlet plenum chamber and set to work. The air cleaner box lid needs to be removed by un-clipping to the right of the box. The lid is then slid and lifted to the left. The left hand side of the lid engages slots which run on flat "pegs" on the lower air box case. The issue is that those flat pegs are this shape in profile ¬. The down stand part is a nuisance causing the air box lid to have to be lifted high on the right hand side whilst being pushed downwards on the left. I`ve previously cut off the down stand to leave a long version of this profile -. This makes air box lid removal easy.

The part load breather pipe on the top of the N/S rocker cover is removed by squeezing the fitting on the breather pipe where it locates to the outlet on the rocker cover lid. The plug and cable to the MAF sensor needs removing by pushing down on the plug clip release and at the same time pulling the plug off the MAF. Not so easy if this plug has slight corrosion on the pins and initially refuses to move.

That done, removal of two Jubilee clips, one securing the outlet of the old plastic inlet pipe to the upper plenum and one securing the upper plenum via a rubber collar to the throttle body is required. The first clip is easily accessible with the pull off top plastic engine cover removed. The clip around the rubber collar to the upper plenum is more difficult. An 8mm hex socket driver on a spring drive with screw driver like handle is needed. The clip is buried right at the back of the engine and removal and replacement can be a cuss with the plenum itself causing an obstruction. With that clip released, the plenum is lifted out of the collar and slid forward a couple of inches towards the front of the engine where upon it disengages from a stout steel pointed ended mounting peg. The upper plenum can then be lifted from the car. I had two ideas in mind this morning. One was to wrap the plenum in heat shield tape to insulate it from heated generated by the engine and the supercharger outlet plenum which is mounted directly under the upper plenum. Hot inlet air is not a good idea and leads to engine detonation if not controlled by anti-knock sensors. Induction of hot air via an inlet pipe is non productive, decreases oxygen content and lowers air density through heat generated within the engine bay. My mission today was to clean up the outer surfaces of the upper plenum and wrap the plenum in anti-heat soak aluminum backed, self adhesive, fibre glass tape. This would help lower inlet air temperature and aide the volumetric efficiency of the engine. My second job was to clean out the internal plenum of rough casting flash and smooth out internal roughness within the casting thus gas flowing the plenum and easing parasitic air flow drag and achieve a faster flow through the induction system. A garnet wheel on an electric drill swiftly removed the rough internal finish to leave the areas I could reach, nice and smooth. Every little helps in the quest for improved power and torque. Moving onto the external surfaces of the plenum, this was tackled using an angle grinder to flatten out the aluminum surfaces and the further sanded with a dual action sander to fine off to a better finish. The manifold was then blown with compressed air before being water washed. Hydrochloric acid was then used to remove dirt and grease, followed by another water wash, a blow dry with compressed air and a final dry off with a cloth and a spell in front of an infra red heater.
That completed, I spent a good hour cutting, sticking and trimming the aluminum backed self adhesive tape to the plenum. The plenum and other parts were then refitted to the car. What results? After a ten minute fast run, the plenum appears to run cooler than previously noted. Previously warm to the touch, it is now rather cooler. As regards the gas flowing to the plenum, perhaps a mite quicker on pick up but realistically I wouldn`t expect much gain until the decent tuned inlet pipe arrives from the States and can be fitted.

I`ve probably done as much as is practically possible to the inlet side of this car now short of porting and polishing the internals of the supercharger. I`m in no hurry to do that as other mods will be more productive. Looking to the future, sports cat fitting would de-restrict the exhaust system which currently utilises 600 cell units. Fitting sports 200 cell components is the next project together with an X-pipe fitted to the intermediate section of the exhaust to again provide lowered gas flow resistance than is possible with the standard H-pipe arrangement. Another £1300 needed to have that occur!

More as and when the induction pipe arrives.

Mike

No sign of the pipe leaving Customs yet.....

Better news though on the upper plenum chamber minor gas flowing. A couple of runs out today and I have to say the result of the recent internal clean up of the plenum and the wrapping with the anti-heat soak bandage has been little short of astonishing. Whilst the temperature of the bandage on the exterior surface was quite warm, removing the inlet trunking again, revealed the ali plenum itself to be at a much lower temperature. I`ll get my infra red heat detector out to confirm effectiveness soon and see just how much lower the internal temperature is compared with the outside. Previously before wrapping with the bandage, the temperature felt by hand was the same inside and out.

Suitably encouraged, I wrapped the MAF sensor mounting tube ( the so called air flow meter housing) in insulation bandage and part of the upper air box case. Then I ran out of tape. Fortunately I`ve ordered some more and this will be with me shortly. There should be sufficient to wrap the entire air box and the new intake tube. I`ll also stick some atop the front mounted large coolant feed pipe to the thermostat housing and see if I can insulate that pipe in an attempt to stop heat soak from directly heating the cold air intake pipe which is immediately above it.

Perhaps the most spectacular thing to have occurred is the now instant and very rapid improvement of this cars performance. It was very much above my expectations. The gas flowing of the upper plenum together with the insulation wrapping has produced a spectacular improvement and I`m somewhat taken aback by the result. Today, I also removed molding flash found at the exit of the upper air box lid on the air exit outlet. Paired off with a sharp Stanley knife blade and then sanded flush with a scrap of P280 sand paper. Cleaning up of inlet pipes of excess material certainly appears to give excellent results.

Now I`m becoming really happy. From a car which was a sloath when purchased to an outrageously quick piece of machinery. Well pleased with more to come.

Mike

More did in fact come today. But still now what I was hoping for. With all my customers now gone AWOL during this cold weather and with my frustration building, I pulled the upper and lower plenum off for something to do..... The intention was to remove a well known large restriction to airflow within the neck of the bi-pass section of the pressure plenum. Removal is easy enough after removing the upper plenum. Four nuts and four bolts secure the pressure plenum to the inter-cooler bricks with tow metal and rubber gaskets sandwiched between the two bricks and the plenum pressure outlet. Four more bolts secure the base of the plenum to the rotor body of the supercharger. One Jubilee clip around a rubber tube secures the plenum bi-pass to the rear of the charger. The small rubber pressure pipe feeding input to the fuel pressure unit is also removed. The stub pipe onto which it locates is clearly visible in the above image. This was the pipe which fell off just after Christmas and caused so much grief. Best secured with a small cable tie to stop that antic. A pull upwards and the plenum is off but not before clamping off and removing a coolant pipe which goes to a bleed/fill pot which is curiously cast as part of the plenum. It is quite unnecessary as coolant bleeding is easily accomplished via a bleed screw on the header tank. I may well remove that part of the casting at a later date as it takes up valuable maintenance space and gets in the way of spanner swinging. I`ll not miss it if removed from the scene. A large square re-usable thick neoprene gasket is sandwiched between the plenum and the top of the charger.

As advised on an American tuning forum site, I found the bi-pass to be severely and seriously restricted with an un-machined and crudely finished excess of metal. It had to go, as did two sharp corners on the other end of the bi-pass within the centre section of the unit. This shot shows graphically the excess material to be removed. The thick O section of metal was about 1/8" wide and had to be removed and blended to remove this constriction to reasonable airflow. Half a handful of ali swarf was removed in the process. So out with my Silverline cheapo windy compressed air driven die grinder kit from Toolstation. Excellent value at under £20 but only having 1/8" or 1/4" shank grinding stones rather than tungsten burr removal bits. Hardly ideal for the job but good enough. I must get a set of tungsten burrs. They would have made the job rather easier. Available on ebay for around £15 and destined to be my next tool buy. My little 10cfm compressor manages to drive the unit reasonably well but sometimes runs out of puff. A 12-14cfm would compressor would be more suitable.

I cleaned the plenum of grease with spray cleaner washed off under a water tap before beginning the rework. A blow off with compressed air dried it off. An interesting if noisy couple of hours followed with dockside passers by descending on me wanting to know what the heck I was doing and why so much noise way emanating from my floating heap. The XJR in the car park with once again the bonnet up and half the engine missing, clearly provoked interest. I suppose it advertises my skills! Then they bring me all their marine junk to fix!! Only this morning I pressed an anchor straight with the bench press for a chap who had an argument in his ten ton boat with the harbour wall.....buy you a pint in the pub he said. I just saved him £140. Don`t you love them?! A bottle of Malt would be appropriate.

Once complete, the job had the bi-pass neck cleaned out and a couple of other restrictions removed. The internal surface of the plenum was lightly smoothed out and all in all, the work achieved was quite pleasing. Not a mirror finish job but certainly an improvement.. All parts were refitted to the car having been blown out with compressed air and water washed under the tap before being blow dried again. A final wipe out with a cloth ensured swarf had all been removed.

Once again results have been worth the effort. The car has a lovely idle and pick up is smooth and a little creamy. The throttle seams extremely linear and rather nice. There is a small but noticeable improvement between about 30 and 50mph. Essentially there is a small improvement in torque. At full throttle I don`t think there is much to write home about. I was reworking the bi=pass which is predominantly at its most active during low to mid range use. What I have learned over the past couple of months with this car is that changes made in the tuning process take some time to be learned by the adaptive part of the engine management computers.That takes time to filter down, then all of a sudden, the car improves when you are least expecting it. Interesting, eh?

Sorry no images of the car part built up during this afternoons work. It was getting dark when I had it all back together. Pics when the light comes back again.

Mike

Mike

An update. The Mina pipe has cleared Customs and will be delivered on Monday. This makes the total delivery time scale for delivery to me as twenty one days.

Additional fees for import VAT of £9.54 and Parcel Force delivery at £8.00 this side of "The Pond". I suspected this might be the case with Mina freight and duties only applying to US internal costs. UK delivery and VAT liability is not mentioned on their site when ordering. The total cost for the intake pipe delivered is therefore now approximately £148.

Mike

So finally delivered but not without the usual PF delivery nause. Checked the tracking service to find that delivery had apparently been attempted and a card left in our post box. Not so.....off I went to the local depot to find out what was going on. Promised a call back which never occurred. So at 18.30 I rang the depot again with a big moan. Forty minutes later, the part arrived in a seven and a half ton lorry. Special delivery. Ha,ha, I won!! Fitted this morning after wrapping in self adhesive anti heat soak tape. Not an easy job taping around a ninety degree bend. Shame to cover up a nice shiny pipe but engineering excellence before aesthetics as always with me. Kit supplied with two rubber joining collars and four high quality Jubilee clips. Also a part breather tube and end fitting plus another smaller Jubilee clip. So far so good. Then difficulties arose which I`ve emailed Mina Gallery to attempt to sort out.

The length of new aluminum inlet pipe which links to the "air flow meter" or MAF mounting tube is about an inch to short. Either that or the rubber collar is short. Depends on how you see it. That puts the collar which joins the MAF mount tube to the new inlet pipe at the limits of security with the risk that when the engine is revved, pt rotates a little to the left due to torque reaction. There is a risk that the collar may be pulled off the pipe or the MAF mounting due to tension as the air box is fixed solidly to the car body. Not good. Either a longer pipe or a longer collar would be better. Hence the email to Mina Gallery and hopefully an understanding response.

A second issue concerned incorrect sizing of the part load breather pipe to the rocker cover stub pipe. A quarter of an inch in diameter too large. Not happy about that either so mentioned in my email. I`ve got around the issue by fitting a thin wall three quarter of an inch high piece of plastic tube between the rocker cover pipe outlet and the Mina connector with another Jubilee clip as belt and braces.

Its all in the car now and working although security of the joint collar at the MAF mounting tube and air box top concerns me and the issue needs to be addressed properly for the future. Rather disappointing all in all. The job feels like a cobble up. The devil is in the detail and Mina have not, in my opinion, developed parts too well. I`ll be interested in what they say in reply to my mail. Bit of a shame. The car has slightly more supercharger whine from around 1500 rpm and surprisingly gear changes seem to occur a little earlier. There is also a little more lower down grunt which is what I`ve been chasing since buying this car. Around town the car seems exceptionally placid and has a slightly stronger pull at lower revs. I`d say there must be a small increase in torque having taken place, hence the quicker gear changes.

Was this unit worth the £148 total expenditure? Sort answer. No, not really. My DIY mod with a can of Poundland builders squirty foam and a steak knife trim up of blocked up OE unit noise attenuater ports was vastly better value! That was true engineering development!

I suspect gains from this pipe may come into play once I port out the supercharger. That will happen once I have all the necessary tools up together for my windy powered die grinder kit.

Mike

Good news from Mina regarding the two issues I experienced with the intake pipe fitting.

Mina will send an alternative breather pipe connector elbow and also an extended intake pipe to MAF rubber tube collar. This should take the tension out of the installation.

Once again the "adaptive" part of the engine management system seems to be kicking in. A couple more trips out made with the car again becoming more responsive to the throttle especially at lower rpm. I remember someone saying that having driven a modern Jaguar briskly and come to a halt, if you keep your foot on the brake pedal for thirty seconds having switched off the ignition, changes to the ecu are saved as a particular driving style. Can anyone confirm?

Gaskets now ordered from XJK for the throttle body, EGR valve and throttle body elbow to the rear of the supercharger casing in preparation for a planned super-charger porting session.

Mike

A little more porting work done today as I had a couple of hours free. I removed the upper intake plenum again today, predominately as I wanted to have a good look at the work that will be required to remove the throttle body, its elbow and also the charger in the near future.

Whilst the plenum was removed which is only a five minute job, I decided to try out some of my new windy grinder tools that arrived recently. Namely the tungsten burrs used to cut aluminum. I also wanted to find out which grinding stones worked best in awkward areas and which ones gave the best finish.

I spent an interesting hour or so further fetling the lead from the plenum to the cold air inlet pipe and also the outflow which links by a rubber collar onto the throttle body at the rear of the engine. Pics of the plenum can be seen in the first few shots attached to my first post on this thread.

It has become increasing obvious as I`ve worked away cleaning out the plenum and also the lower pressure manifold recently that blunt obstructions on inlet leads really do make a big difference to the way in which the 4.2 R performs.....especially at low speed. Every time I have cleaned up the internals of parts, I have had a small but noticeable result. So today I removed the blunt entry on the upper plenum and worked like a man possessed to really smooth out the plenum exit onto the throttle body. All corners radiused and smoothed, rough finish faired out and everything as made as nice as possible. My polishing work still leaves a bit to be desired by way of appearance and like any skill, there is a learning curve involved but I`m told that an ultimate high finished surface is not that critical.. Obstruction removal I am told is more important. That said, a large amount of unfinished material is left after factory manufacture and a reasonable attempt at improvement certainly has a positive effect. What can be and needs to be worked is easy to see.

That is as far as I can go now until the charger is removed. This will probably be in a couple of weeks once I`ve had a short spell in hospital.

Mike

Mnnn...I`m a bit narked.

As mentioned above, the Mina cold air pipe/rubber coupler is just about an inch short where it joins with the air box lid outlet. I suspect the length would be fine for the S-type R or 4.2R XF models but a little more length on the pipe or the coupler is required for the wider XJR. As it is, the coupler only locates on about the last 12mm of the cold air intake at it has caused air leaks and insecurity issues which result in faulting on the ecu. I`m having to clear the fault reguarly with my diagnostic tool which is irksome.

I previously advised Mina Gallery in the USA of the difficulties and they agreed to send a longer reducer collar and the correct part breather elbow. Despite a chase up email via their site, the parts have not arrived or has my last mail been replied to. Disappointing after-sales service indeed.

I`m now rather annoyed and exasperated and there appears little more I can achieve to seek redress. Sadly our legal system carries no weight overseas. Now becoming rather naffed off, I ordered a 75 to 80 x 100mm black silicone reducer coupler from Viper in the UK for just under £25 including VAT and delivery. I`ve been patient and polite and have trusted to Mina to sort out the issue. Now I`m less than amused.

I don`t like publicly having to write a post like this or condemn a supplier. In this case, due to a totally apathetic response from Mina Galley Inc, I`ll not buy from them again.

Total costs for this pipe and remedial part needed to get the unit to an acceptable standard now stand at £173. I have a good core product marred by poor development and dreadful back up.

Mike

Having ordered another collar from Viper in the UK for £25 which has now been sent to me, I received an email from Mina saying their replacement extended collar would be dispatched today! My expenditure of £25 therefore effectively becomes un-necessary. So it looks likely that I shall end up with two collars (if the Mina one ever arrives). Perhaps though it is no bad thing. I could use the second collar on the plenum end of the pipe. This might also give an improved seal at the plenum end of the pipe due to the ability to double Jubillee clip the collar to the plenum and at the airflow meter.

The sadness is that Mina really did not do their R&D thoroughly leaving the end user ie me, to sort out the issue.

Call me cynical, but I suspect that I will be liable for a delivery charge payable to Royal Mail before the Mina replacement collar arrives with me. No doubt there will be the inevitable wait whilst the collar makes its snail paced way out of UK customs.

Buying from US sources is in my experience slow, fraught with freight niggles and often seriously frustrating. I`ll now avoid buying outside Europe for those reasons. If it can all go wrong, its almost certain to do so!

Mike

Hi Mike,

Like everything else you get what you pay for with international shipping. Post office is always going to be the slowest, air freight is generally next but couriers such as United Parcel Service, DHL or Fedex can usually deliver within 48 hours, sometimes 24 hours depending on origin country. You will pay a premium for that level of service but get full tracking and customs clearance facilities. Delivery guarantees are also available.

Next time you need something urgently ask the shipper to price it up for you. it just may be worth it to take out the 'how long is it going to be' scenario from the equation..

Just a thought.

Rod