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I am lucky enough to have the ability to make pretty much whatever I want so I have been toying with the idea of a dedicated ITB kit that could bolt straight on to a V12 HE using all the original injectors, fuel rail, sensors, etc, etc
My aim would be for anyone with some practical aptitude to follow some instructions and install it in a day with no ECU mods necessary. VERY early days on the design front, but I have plenty of spare time at the moment and would like some feedback.
Here's a short version that should fit under the hood of my '87 Sovereign:
And here's one that if my maths are correct, should be an absolute torque monster, but with the tradeoff being limited top end power:
Throttle linkage would use the original tower with off the shelf webber rods and arms.
Obvious points that need attention are filters and actual clearances, as well as plumbing for vac and idle air system.
I like the look of the idea, seems a better proposition than the Mangoletsi / Webcon manifolds plus IDF throttle bodies
What's the expected price point for such a setup?
The Webcon manifolds are £600 a set and six pairs of IDF throttle bodies will set you back £1200 plus hardware, then another £500 or so for ram tubes, etc...
Thanks.
Not sure on price, too early to tell. It was just going to be a one off for myself until I thought about it a bit. I would imagine the full kit with everything needed for install would be north of AUD$3,000, but I'm just guessing at the moment.
Even though I have some spare time on my hands, this is a project that I don't expect to finish before next Christmas. I've given myself 12 months to do a full top to bottom job on the car and making these would be close to the end. That might change if I get some interest though.
Anything that is a simple bolt on upgrade that will have demonstrated improvements is good in my book. Personally I'd like to see an alloy air box on the end of those that can be plumbed straight to a cold air supply.
Otherwise awesome work, wish I had your skills!! I have the ideas but not the skills, which always proves expensive ;-)
Addendum: Not sure if it was deliberate, but I'm also liking the idea of red anodised with silver trumpet.
would not mind if they were more vertical and two piece that bolted and went over the center of the engine giving more pipe length for more lower rpm torque..
as for Idle air... you would have to place a port for it on each one below the butterfly and have a tube to plum them together to the AAV and idle air control valve ..
would like them as I would not have to sadly cut a hole in my bonnet...
Jonathan: The lower port on the pics is for exactly that AAV and MPS scenario. I was thinking a tube rail to join all the ports with sensors etc at the back. I would just need to make sure the tube diameter and MPS takeoff location weren't giving a false signal to the ecu. The small port above the butterfly would be for ported vac rail.
A two piece so that people could bolt their own runners/horns to is also doable, but here's the problem from a simple bolt-on kit point of view:
Pipes cannot cross over without using an alternate ignition system and throttle tower which would put most amateur enthusiasts out of the picture. Not to say it can't be done, just that it wasn't my first intention. Going over the top of the cam covers like the longer version above is really the only high torque option.
I like the idea and do have a crossover version drawn up somewhere (a crashed laptop left me with files in backup drives and folders all over the place). My intention is to get my Sovereign in show condition as a daily driver and then go crazy on an XJS with aftermarket ECU/ignition, bored and stroked to 7.3l and setup as a road driveable track car. In that scenario a crossover is a definite consideration.
Well with what ever you come up with... In 12 months I will have been saving to the side some $ to AU... and it will look cool when I open the Bonnet... I am sure it should work fine too... :-)
1992 xjs came with a different fuel rail set up and more clearance in the center of the hood
Less hoses... and polished up they look good...
going to rebuild my injectors soon and polish the rails and the air injector rails
the difference on the install would be the three places to bolt down the rail...
I think I could figure out a mounting for my rails...
Last edited by Jonathan-W; Nov 19, 2015 at 12:22 PM.
Jonathan,
Differences like that are good for me to know and something I'll add to the list.
Cheers
Bruce
Let me know if you need any measurements from the rails...
I at least provide you with that if you need it...
oh, the pictures were done in PAN and I did not keep my hand at the exact same height so the bending of the rail in the picture is really the deviation of the height to the rail as I panned the phone down the rail...
never done that before... If I wanted to do it again I would set up a rail parallel to run it down to minimize the deviation.... and get a better picture...
when you are done it should look something similar to this
which, if you buy this kit when made... buy a valve cover gasket (as you are going to want to clean up and detail your Valve cover) and a exhaust manifold gasket set as you should be wanting to also clean them up and apply some ceramic coat to it to make them look good and keep the heat transfer down https://www.vhtpaint.com/products/flameproof/ many colors available ( and make it look COOL too)
Last edited by Jonathan-W; Nov 20, 2015 at 01:33 PM.
This is where I was heading before deciding on the ITB route:
Basically I'll be going a step further and pulling the engine out for a full overhaul and cosmetic job. Everything that I can chrome or polish will be done. I also plan on fully rerouting all the wiring in the engine bay to a modern waterproof fuse/relay box where the battery would normally be. Battery is going in the boot. New interior, new paint, new wire wheels, new gearbox. This is going to be my 40th birthday present to myself. Then it will be on to the XJS project for my 45th, or maybe an XJ13 replica if $$ allows.
nice pic of engine , but i sure dont like those rubber hoses going to the fuel injectors, they been known to burst fuel onto hot exhaust manifolds, the rest is history!
mine hi-pressure O-rings top and bottom of injectors!
Sounds like I need to draw versions to suit different scenarios. Version one is purely a bolt in aimed at owners that either don't have the skill, or don't have the inclination, to completely redo the ignition/fuel/vac/idle system. As an update I don't think weber linkage will be practical. I've been sketching up options and clearances and it seems like a bit of a hash job so far. I can do custom linkage for similar money no problem, but was hoping to use off the shelf where possible so I don't end up being a parts store
Version two can be for owners that want to get rid of the dizzy and use billet fuel rails etc.
Since I myself want to keep the rest of this particular car close to standard I'll get that one done first. When I get to my planned XJS build or XJ13 replica I'll be going all out as well so version two will happen then.
On that thought if anyone has any opinions about injector location let me know. It seems that Jaguar have them in the perfect place for a road car as it is. If the throttle bodies cross over to get length then the injector position would need to be in a completely different place. I know jenvey have the butterfly and injector all the way up the runner, but I'm not sure that would suit anything other than a dedicated track car??
Injector position doesn't matter too much, the only reason Jenvey have them on the throttle body is because they already had them like that.
The rubber pipes are fine but can give up when they haven't been changed for 25 years!
Certainly a cheaper option than a conversion to sealing ring versions especially if purchased new.
Question, why bother with the butterflys at all, just mold the trumpets onto a plenum and attach the std throttle body on the end. Like a really cool version of what AJ6 did and gave up on years ago. Much cheaper and easier to make.
V12 Individual Throttle Body - Bolt-in-kit
