Another option instead of the carbon plenums + div ECUs
Discussion
Engineer1949 said:
the comment on multi injectors being a better way to meter the fuel is on more modern engines valid but as the 14cux only does bank firing not sequential it is negated i feel the four barrel system may well be an improvement time will tell.
john
I'm thinking the same. V8d is porting out a edelbrock manifold to match the stage 4 heads. Don't think power or drivability will be an issuejohn
Engineer1949 said:
the comment on multi injectors being a better way to meter the fuel is on more modern engines valid but as the 14cux only does bank firing not sequential it is negated i feel the four barrel system may well be an improvement time will tell.
john
When you try sequential it feels different , best thing I did in overall enjoyment john
OleVix said:
Engineer1949 said:
the comment on multi injectors being a better way to meter the fuel is on more modern engines valid but as the 14cux only does bank firing not sequential it is negated i feel the four barrel system may well be an improvement time will tell.
john
I'm thinking the same. V8d is porting out a edelbrock manifold to match the stage 4 heads. Don't think power or drivability will be an issuejohn
Using this type of single point throttle body injection kit will deliver better results than fitting a carburettor but all things being equal you can't compare it to multi point port injection, even semi-sequential multi point port injection.
But it's not all doom and gloom, so I'll come back to that all things being equal statement in a bit.
These single point throttle body injection systems are closer to carburettors than you think, with jets replaced by a high mounted injector or injectors the fuel distribution disadvantage of a single choke carburettor remains, these system are in effect an electronic carburettor.
Back in the day if you wanted to make power the first thing you'd do is replace a single choke carburettor with a multi choke carburettor or better still multiple twin choke carburettors the ultimate incarnation of the practice would be a choke for each cylinder which is why a D-Type Jag has triple twin choke Webers on its six cylinder XK engine. These days we all get very excited about independent throttle body injection, the truth is this is just good old multi carb/choke practice re-imagined for the modern age.
All this sounds like I'm completely dismissing these single point throttle body injection systems as a bad idea, while such systems do have their drawbacks and all things being equal they can never be as efficient as efficient as semi-sequential multi point port injection system, I want to be clear in the case of our cars they do offer two significant benefits.
1.Any fuel delivery system available on the market (even a carburettor) is massively easier and more convenient to tune than the 14CUX, and these carb replacing single point throttle body injection systems are designed to be super easy to set up and get good results from.
2. As these single point throttle body injection systems are designed to to fit straight on an inlet manifold designed for a carburettor you get to use it with the excellent Edelbrock Performer 2198
Both points deliver real benefits, but it has to be said if it's in fine fettle and working correctly the closed loop 14CUX semi-sequential multi point port injection system will all things being equal beat the single point throttle body injection on fuel metering and especially fuel to port distribution.
As I keep hinting the elephant in the room is in the case of our cars not all things are as equal as they should be, the 14CUX & the single plane inlet manifold it works will sees to this
The problem the 14CUX introduces is it's design brief was heavily lead by the need to meet ever stricter emissions targets and to work with AFR sensitive catalytic converters, as such most of the 14CUX efforts are centred around achieving the stoichiometric AFR of 14.7:1, which is way leaner than the RV8 wants to idle at.
The Rover V8 likes to idle rich, so rich it would soon start to poison the cats, so with the 14CUX trying t hit the way too lean idle figure of 14.7:1 and the fact it's nie on impossible to stop it doing this your new single point throttle body injection system starts to claw back some advantage. With your restrictive and easily poisoned cats removed you are now free to tweak your simple to tune single point system so your RV8 idles where it wants to be at the far richer 13:1, you can also dial in a leaner than 14.7:1 AFR at cruise for a bit more economy and a richer than 14.7:1 to give a small power gain up to 3,000rpm where the 14CUX goes open loop anyway.
Add all this the even bigger advantage afforded by the dual plane Edelbrock Performer 2198 and I wouldn't mind betting this single point throttle body injection system will deliver outstanding drivability, ditching the 14CUX with is determined overly lean behaviour and the single plane manifold that goes with it has the making of an exceptionally smooth driving TVR. Don't underestimate the significance of switching a single plane manifold for a dual plane one, the drivability advantage it will give you is well proven and accepted fact.
So while you all thought I was being down on the single point idea all I was doing was pointing out in fundamental engineering terms it can never be as efficient as a semi-sequential port injection system. The real point is while the 14CUX is a semi-sequential port injection system it's one that does it's best to blindly stick to a very rigid and often less than ideal 14.7:1, it then does a great job of locking you out from tuning it and finally it must work with a single plane manifold that's far from ideal for drivability.
I'd like wish Geoff all the best with this FiTech single point project, while no one could ever persuade me it's the first thing in fuel injection technology, for the all the above reasons my money is on it producing a much much smoother drive than any 14CUX equipped RV8 could ever dream of delivering.
Run it 13:1 at idle, switch your vacuum advance from ported vacuum to manifold vacuum to safely run roughly 8 degrees more advance at idle only, then re-set your base idle to give a 1,050rpm idle.... she'll run cooler & purr like kitten
Replace the distributor with the Canems or Omex 200 ignition only system and it'll be better still, the only issue with this is your now separately mapping two systems (one for fuel & one for ignition), and it has to be said the final cost of your whole package of systems will likely be more expensive than if you'd just gone for a full integrated fuel and ignition system in the first place.
So in the end the biggest stand out advantage of the FiTech over other options really all boils down the fact you get to use it with the single plane Edelbrock Performer 2198 manifold.
These are 4 barrel equivalents so they've actually got 4 injectors.
Ideal for a retro hot rod as you get modern injection and ecu control with the looks of the sixties. Clever idea and looks easy to fit - the GEMS system is self tuning, but much more involved to install I believe. Be interesting to compare the two.
Ideal for a retro hot rod as you get modern injection and ecu control with the looks of the sixties. Clever idea and looks easy to fit - the GEMS system is self tuning, but much more involved to install I believe. Be interesting to compare the two.
Another point is that Ive ordered a 5.5 dominator from Rob. Also Clives equal length headers. The 14cux has no chance to fuel this monster and also the intake/plenum is a restricion.
I got the Edelbrock for 100 pounds, meaning I dont have to spend 600 on intake, plenumbase and plenum.
The Fitech 600 is 800 pounds. But I dont need MS at 600, injectors at 400, wiring loom at 200, wideband at 150.
I do need to sort out the ignition as a standalone. I have 2 vw coilpacks lying around. Was thinking of microsquirt..?
I got the Edelbrock for 100 pounds, meaning I dont have to spend 600 on intake, plenumbase and plenum.
The Fitech 600 is 800 pounds. But I dont need MS at 600, injectors at 400, wiring loom at 200, wideband at 150.
I do need to sort out the ignition as a standalone. I have 2 vw coilpacks lying around. Was thinking of microsquirt..?
ChilliWhizz said:
I'm with Dave on this one, his explanation makes it very clear... obviously..... it really is very simple as Dave has said....
LOl 
For the benefit of those who understandably can't be bothered to read my excessively verbose ramblings, here's a quick summary of my point.....
ChimpOnGas said:
So while you all thought I was being down on the single point idea all I was doing was pointing out in fundamental engineering terms and with all things being equal it can never be as efficient as a semi-sequential port injection system.
The important point here is while the 14CUX is a semi-sequential port injection system it's one that does it's best to blindly stick to a very rigid and in many cases less than ideal 14.7:1, it then does a great job of locking you out from changing this, and finally it's forced to work with a single plane manifold that's far from ideal for drivability.
I'd like to wish Geoff all the best with his FiTech single point project, while no one could ever persuade me it's the first thing in fuel injection technology, for the all the above reasons my money is on it producing a much much smoother drive than any 14CUX equipped RV8 could ever dream of delivering.
The important point here is while the 14CUX is a semi-sequential port injection system it's one that does it's best to blindly stick to a very rigid and in many cases less than ideal 14.7:1, it then does a great job of locking you out from changing this, and finally it's forced to work with a single plane manifold that's far from ideal for drivability.
I'd like to wish Geoff all the best with his FiTech single point project, while no one could ever persuade me it's the first thing in fuel injection technology, for the all the above reasons my money is on it producing a much much smoother drive than any 14CUX equipped RV8 could ever dream of delivering.
andy43 said:
These are 4 barrel equivalents so they've actually got 4 injectors.
But look where those injectors are mounted.andy43 said:
Ideal for a retro hot rod as you get modern injection and ecu control with the looks of the sixties. Clever idea and looks easy to fit -
Exactly andy43 said:
The GEMS system is self tuning, but much more involved to install I believe. Be interesting to compare the two.
The GEMS is a very powerful and sophisticated self tuning OEM quality fully sequential engine management system with knock sensing and 3D ignition control that is fully OBD-II compliant.It's a massive leap forward in technology when compared with the 14CUX but you will require a little help from Mark Adams to get it working correctly on a TVR. While the ECUs and the looms to go with them are plentiful and cheap to buy on from a Range Rover breaker this is really just the starting point, costs are likely to spiral from there.
Saying that what you'll end up with has to be head and shoulders above anything else on offer for our cars, don't forget a Megasquirt, Canems, Emerald ect are all likely to still be a semi-sequential injection system unless you specify them otherwise.
You most certainly can't compare one of these single point carburettor replacing throttle body injection systems with the self tuning fully sequential knock sensing and 3D ignition control GEMS engine management system.
The two exist as polar opposite ends of fuel injection/engine management sophistication and technology, where these single point carburettor replacing throttle body injection systems start to show some sort of advantage is when you compare them with the 14CUX.
Single point carburettor replacing throttle body injection systems are also designed to be simple to fit, simple to tune, and in the case of the RV8 will bolt straight onto the Edelbrock Performer 2198 dual plane inlet manifold. Being of a dual plane design this Edelbrock inlet manifold will deliver significant drivability improvements all on it's own, especially when compared with the single plane design manifold you got as standard with all Chims & Griffs.
SILICONEKID345HP said:
I still don't understand semi and full seqentuel 
Fully sequential injection is timed to the engine, more specifically the prescribed dose of fuel is introduced into each individual cylinder runner of the inlet manifold by each individual injector, but only when the inlet valve is open. So each cylinder only receives it's specific serving of fuel when it actually calls for it, because fully sequential injection is timed to the engine the best way to think of it is like the way your ignition system provides a timed spark to each cylinder.Your spark is timed to occur a varying number of degrees before the compression stroke is complete at top dead centre (depending on engine speed & load), while fully sequential injection introduces the piece of fuel at a varying number of degrees before the inlet valve snaps shut.
Because sequential injection is timed to the engine the ECU must know precisely where each piston is on it's journey through all four of it's cycles (induction, compression, power, & exhaust), to achieve this a cam position sensor is used.
The advantage of fully sequential injection over semi-sequential injection is the applied quantity of fuel can be precisely prescribed and delivered to each cylinder at the exact moment it's called for. By comparison semi-sequential injection effectively just lobs in fuel in batches, this fuel collects & accumulates in the inlet manifold runner until the inlet valve opens at which point it'll be drawn into the combustion chamber.
In truth the fully sequential and semi-sequential injection systems we're talking about here are both port injection, that is both systems squirt fuel not directly into the combustion chamber but into the inlet manifold. The key benefit fully sequential port injection can deliver is improved idle quality, idle emissions, and a very small improvement in fuel economy but only really during urban driving. This is because by the time the engine is turning at 2,000rpm or more the valves are opening and snapping shut so quickly the fuel delivery precision advantage of injecting fuel fully sequentially is completely lost.
A fully sequential injection system dictates additional complexity, you need 8 injector drivers inside your ECU rather than the 4 required for semi-sequential injection. fully sequential injection also needs that cam position sensor so the ECU knows precisely where the engine is as it passes through it's four cycles and ultimately it'll be more complex and time consuming to map.
While many in the world of engine management will try to convince you there are minimum improvements to be felt between semi & fully sequential injection Nigel (Hoofa) has done it and reports some real improvements. Based on the science (valve speed) I suspect the improvements Nigel is feeling are between idle and 2,000rpm but that's not to undermine the idea because it's my belief anything you can do to make a Chimaera run smoother between idle and 2,000rpmm will translate into a huge improvement in the way the car drives and feels on the road. This is because idle to 2,000rpm is a window in the rev range we all spend a lot more time in than we realise, or would like to admit.
As with my earlier comments regarding the drivability issues the single plane manifold design inflicts can be largely removed by using a dual plane manifold, so going fully sequential injection will help in this area too. When the engine management expert attempts to convince you there are minimal improvements to be felt between semi & fully sequential injection he's almost certainly thinking about a different engine type and set up to ours. While on the face of it he has science on his side, if you challenge him to think about the effects of going fully sequential on a V8 forced to run with single plane manifold he may just be forced to give you a different and more positive answer.
I get the 'keep things simple' argument, but lets face if we wanted to take that outlook to it's natural conclusion we would all be going back to carburettors. Fuel injection and engine management systems have progressed massively over the years, if I had my choice I'd always take the latest development because once its been properly developed and proven it will always be better than the technology it replaces.
Follow the history and evolution of Bosch engine management systems from the early days of mechanical injection and distributors to today's direct injection coil on plug systems making sure you studying everything in between, and you'll soon see every 3-4 years they make another significant leap forward. Fully sequential injection arrived in the mid to late nineties, so while we can hardly consider it new technology it was definitely one of those big leaps forward.
Personally I'd love to take my semi-sequential Canems system to the next level by going fully sequential, the problem is it's an expensive way to deliver those drivability improvements, improvements I can achieve much cheaper by adapting a Thor inlet manifold to fit my Chimaera.
Edited by ChimpOnGas on Friday 10th February 19:08
Geoff38 said:
Still gathering all the bits and pieces for this install , hopefully starting on monday.
Just collected the newly vapour blasted manifold
look at this: https://www.youtube.com/watch?v=i2DvnoHWagkJust collected the newly vapour blasted manifold
If you mill down the wall between the 2 planes, and possibly add a spacer, it will give you more torque and smoothness low down
Why on earth would you take off a multi injection EFI system and replace it with something less efficient?! This is simply an EFI carburettor emulator for yanks who want to have something that looks like a carb 'cos its cool, but can't be bothered to tune it - why don't you also change the brakes for drums while you're at it? 
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