Fuel injection on the V12 engine

Talk about the E-Type Series 3
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lowact
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#41 Re: Fuel injection on the V12 engine

Post by lowact » Fri Feb 14, 2020 1:55 am

Yr ida arrangement has 110% of the stock inlet capacity so in theory it could make more power. In practice maybe not that much because HE heads are exhaust flow limited. At the same time the throttling losses would be more, normal driving u would only need ~90% of the meagre throttle req’d with stock manifolds and throttles, I imagine yr around town fuel economy is pretty poor? Reverting to efi, yr options would be ida style injector bodies or reverting to the stock manifolds, Unless the overriding interest is WOT performance, latter maybe better all round, at least cheaper?

Also, how is yr rear crankshaft seal? The Jaguar PCV system maintains a slight vacuum in the crankcase, prevents oil vapor being pumped out of the rear crankcase (rope) seal. Without manifold vacuum this is compromised?

Efi batch fueling is how Jaguar (& everybody, incl. yr XJS) did it before microprocessors got powerful/fast enough for “sequential” fueling. Sequential fueling is when each injector is fired in sequence, each injection is timed/related to the intake valve opening. For sequential fueling the ECU needs to have a dedicated injector output for each cylinder, i.e. for V12 the ECU needs to have 12 injector outputs. You also need a camshaft position sensor, batch fueling requires a crank position sensor.

Per other explanations, the benefit of sequential fueling over batch fueling is increased part-load efficiency. Sequential fueling does not enable more power. To realise the efficiency benefits of sequential fueling requires A LOT of dyno-tuning (rolling road), incl. to optimize the timing/relationship between injection and intake across the entire operating range. Otherwise, even though the car may perform perfectly ok, it may not be as good as it could, maybe no better than a blind-tuned batch fueling setup. I.e. its all in the tune. Optimising sequential fueling used to be time consuming and expensive. Less so today by using latest generation ECU’s that have adaptive/learning mode/function, able to autotune themselves on a rolling road to a limited degree.

One advantage of high end aftermarket ECU’s is that they are backwards compatible. Having capability for sequential, flex fueling and sequential (coil per plug) ignition does not prevent you starting with the simplest configuration, upgrading as yr understanding and needs develop. Adaptronic modular design is specifically to support this. I.e for 12 cyl fully sequential fueling and ignition (no other user configurable ECU does this?) I purchase an additional module, plugs in internally. Each module has it's own cpu so u can max out the configuration without degrading performance.

Another advantage is opportunity for different software settings according to purpose. For example, imo sequential fueling is best for road cars and batch fueling the most practical for race cars. So, for your car I would have two configuration files. One would be for the cleanest, most efficient everyday use. Then on race day I would unbolt the cats, load the race file and head off to the track dribbling a trail of E85…
MarekH wrote:
Thu Feb 13, 2020 9:04 am
how does your Adaptatronic talk to the CAN network on your car?
Adaptronic have 2 CAN channels, each 1 Mbps, on board terminating resistors can be switched on/off via the fully user-configurable software.
Regards,
ColinL
'72 OTS manual V12

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MLBS3V12
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#42 Re: Fuel injection on the V12 engine

Post by MLBS3V12 » Thu Feb 20, 2020 5:57 pm

Hi all,

I've a question on the oil pressure sensor. I do use the one from the XJS V12 engine on my E Type. At idle pressure read on the gauge is close from 20 lbs only. I suspect that the sender must be changed for an E Type one.

Thank you for your remarks.
Le chemin sera long!...

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Sdinse
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#43 Re: Fuel injection on the V12 engine

Post by Sdinse » Thu Feb 20, 2020 7:27 pm

MarekH wrote:
Sat Feb 08, 2020 9:04 pm
The Achilles heel of MS is in the quality of the connectors and a couple of the components on the main board are badly laid out were to need to repair a unit.
While this may be true of the kit, I went with the MS3 Pro for that very reason. It is pre-assembled, has much improved connectors(water resistant), and is contained in a much smaller water resistant case. No real need to make repairs as the MS3 Pro has proven to be quite robust despite a couple of initial wiring mishaps. I once blew the internal fuse and after replacement the unit works flawlessly. Never a problem since.

My vote is for the MS3 Pro! Support is fantastic and you can learn a lot. The auto tune function usually gets you to somewhere around 95% of what is possible with a dyno tune according to those who have BTDT. I haven't taken mine to a dyno yet, but at this point my V12 E runs awesome and I'm wondering about the value of a dyno tune since I'm not racing. I opted for late model(95) intake manifolds so that I could take advantage of modern high impedance injectors(Bosch EV14) with a large enough capacity to support E85 through a Flex Fuel sensor.
Steve
1971 SIII E Type 2+2

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MarekH
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#44 Re: Fuel injection on the V12 engine

Post by MarekH » Thu Feb 20, 2020 10:29 pm

Correct Steve.

Like I said, not all Megasquirts are equal and it is the self-build ones which, if not built well, will tarnish their reputation and drive newer users to adopt another almost carbon copy ECU which offers exactly the same features but which doesn't have mileage under its belt needed to debug it fully.

For the new user who is touting a new ECU, I'd give this simple example:- I put my MS together in the summer and found that during a 0'c winter, it performed slightly differently and needed tweaking. You won't know that or have the experience until you have been through a full 12 month cycle and a new tech with a new ECU also goes through that learning experience.

The documentation, user base and access to the developers is unparalleled with MS and (for a price) the professional editions of MS design away the flaws which are still left as legacy items in the original self-build product.

kind regards
Marek

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AussieEtype
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#45 Re: Fuel injection on the V12 engine

Post by AussieEtype » Fri Feb 21, 2020 2:48 am

MarekH wrote:
Thu Feb 20, 2020 10:29 pm
The documentation, user base and access to the developers is unparalleled with MS and (for a price) the professional editions of MS design away the flaws which are still left as legacy items in the original self-build product.
Unfortunately the rhetoric is not supported by reality if you live outside the US or the UK. I want my MS3X ECU tested and I will have to send it to either the UK or US for this to happen.

I believed the rhetoric before deciding to go MS to run my Thor full sequential Rover 4.6 and that was a huge mistake - different if there was local support but there is none - here in Aust most aftermarket systems like the Adaptronic suggested by Colin are supported with local expertise and they can do all that MS does.

MS is great if you are right into this sort of stuff but if you just want a plug and play system ready to go MS is not for you. MS Pro systems which are ready to go are more expensive (in Aust) than most other off the shelf systems.

Garry
1971 Series 3 E-type OTS

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