Fuel Injector Recommendations (GENERAL EFI INFO)!!!
Turbo Mini Forums

misunderstanding methinks, im refferign to weldign abolt to the big sprocket thats bolted to the cam and modifying the timing chain cover to house a sensor.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

d'oh!!! Sorry Evo!
Some manc tw4t can't read! That'd work for sure!


Gav, I had Alpha on my mini years ago.


You can see the setup in the picture above. Note the Weber idle-valve behind the servo... that picture was at Mini40 @ silverstone.(september '99???). I'd already had it for 7/8 months at that point.

Here is the power I got with the weber:


Note the boost. And the power. This was with a T2 - but with the small turbine trim of the non-water cooled R5GT turbo. It actually felt like more power I recall. Beautiful power delivery - and it ran a 14.9 at Avon park a few days after (lost out on the trophies by miliseconds - everyone else was on slicks i recall).
Problems. Well - it was running cossie grey injectors. They couldn't get any more fuel in there at higher boost, so i was limited on the boost or I could drop the rpm to red-line at 5600 which allowed 14psi. I chose rpm - and to keep the boost lower.
A real indication of the limits of even single (per inlet tract) 550cc injectors...

Emmisions at idle was not overly great. The greys are sluggish low-impedance units; basically a twenty year-old design.
The Weber was good when it was good - but Aldons (the nearest weber tuner) was 100 miles away. I had a problem with the Weber aswell - it completely lost its map once - the ecu was completely empty so the guys at Aldons said. It then started to mis-behave generally.
I found DTA and this said it'd work on the a-series. I purchased it - as did my mate graeme for his mini turbo. This is where the problems started.
I got serious HC's from my engine on the Rollers. It made around 90hp with almost neat fuel coming out the tailpie, HC's off the scale and 15psi of boost. As did Graemes mini tuned at the same place a week later.
The RR tuner (a twat) and Allan at DTA said my engine was bad - asked me if i knew how to time a camshaft (really arsey). I knew it wasn't the cam - and everythign else was exactly as it had worked with the Weber Alpha. Then there was this other mini with the same symptoms - but worse - because Graeme had dual injectors - the first set mounted pointing at the valve, the second set 8/9 inches back from the manifold face.

Best mine could do was a 16.2 second 1/4. I still had the nitrous fitted (which had never been used since the Alpha started playing up) with a monojet. So, I turned the bottle off, connected the solenoids, and (with a basically continuous fuel supply like a carburettor) pulled a 15.5. At that point i knew it was fuelling badly.
So I put an SU on it, and with a hand-filed needle, it ran a 14.7 two weeks later at york on 14psi.
DTA still weren't interested. At that point, I heard about Marcel Chichak about to run his DTA A-series all the way over in Canada. I contacted Marcel, and we began discussions. Biggest thing was realising the injection event WASN'T at TDC like you'd think but linked to the ignition pulse. Allan at DTA denied this initially; he changed his mind when i showed him the traces from a very expensive digital trace recorder. The crank sensor, ignition pulse, and injector pulse were measured which proved as i changed from 15degrees to 55 degrees at 1500rpm (the absolute limits the engine would run - LOL!). The injection point moved as i swung the ignition in the Map...
Graeme gave up and installed an XE at this point!

Later, Marcel got a 'one off' update from DTA to try swinging the injection point. That was the last help we had off DTA...
I'd had my mini tuned at emerald soon after, and enjoyed taking time chatting with DW about the A-series problem. He said he'd be keen to work with Marcel to get an ECU that worked - Marcel then sent loads of info to Dave and Karl, but nothign more ever came of it. Last i saw, they're using an 'electronic SU'... Not ideal...
The rest - is pretty much history that you can read by enetering 'injection' into the search box on this site

Edited by TurboDave16V on 29th Nov, 2005.

Hi Dave,
Thanks this is all starting to make a lot more sense to me now. I can see your drive to sort this having had your fingers burnt with the DTA. I've got to be honest and say at this point the old su still looks a good option for the A-series. I've thought about changing firing order, crank design won't let you. If the Omex is mappable inj. timing like they say, I think that's the best bet, but don't fancy gambling near 1k on it. I'm sure the spec you're running is going to want two sets of injectors second set in the ram pipes on N/A, not sure on best positioning on a turbo though...
From what the guy at Omex said Rover had a real struggle with the injection and used a short duration cam to get more time between valve openings to switch injectors on and off. How about standard MPI setup with bigger injectors and/or rising rate reg. Then another ecu running outer injectors on higher boost where timing may not be as critical?
I've just read that each inlet valve opens 4 times in less than a second @1000 rpm to 21 times per sec @ 5K, at this point injection becomes almost continous, so maybe this could be the way forward using say Msquirt with no numbers in the map below 2K then build up as the MPI fades out? I think you've proven at high speed/boost you can literally poor the fuel in with your use of the nitrous monojet to good effect!
I'm not going to run the sort of boost you've got, so the money I don't spend on injection should get me a T2 manifold and a few other bits to get me started. But don't get me wrong I'm still thinking about this...... probably way too much to be honest!!
Cheers,
Gavin. :)

Edited by Bat on 30th Nov, 2005.

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Yep - the SU sure has plenty of 'legs' left...

The MPi can isn't that bad - i suspect the numbers were changed for emmisions, not injection ability reasons tbh.
I'm not going to run MPi injectors, but some really special units that recently appeared - over 600cc/min, and have a response time similar to a low-impedance unit. They've also got a really good resolution at idle, and can work up to six bar - so that's two 850cc injectors per inlet tract: 1700cc total... If we assume even a 40% injection window, then that's equivalent to a having a set of 680cc injectors in a 4-port motor...

If we work on the principle that I achieved 130hp with cossie greys - on this cam - then I've got enough fuel capability for more than double the power. And that's more than i actually want!


I'll be verifying all this on an injector test rig before too long though!
I'm confident the injector numbers will allow this to happen - there will be complications, but I'm looking forwards to them!


ps - re what the guy at Omex said about Rover; I actually conversed with Mike Theaker (the Mini MPi 'designer') via email a few times, after taking a guess at his email addy - LOL!. He certainly didn't suggest to me that it was 'difficult' - afterall, all it's doing is adding fuel when the appropriate valve is open - exactly as any modern sequential system.

Edited by TurboDave16V on 30th Nov, 2005.

Hi Dave,
So what system have you got in mind to fire these monster injectors with?
Cheers,
Gavin.

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err - Page 3 - last message - think i've mentioned it a few other times aswell...

On 28/11/2005 01:51:29 TurboDave said:

Evo - like your thinking but i'm already ahead of you! As you know, i've recently found out the MPi injecotrs are a Whopping 480cc/min. We also know how hard it is to get more oomplah out of the MPi's than 90horses.

What i'm planning on doing is having this 'injector controller' configured such that is anyone follows my instructions, it'll work.

We'll be looking at two injectors per inlet tract - a set distance and angle from the manifold face. I'll reccomend some suitable injectors later. Fuel pressure will be a vacuum referenced 3bar. Or, if so needed, (turbo / high rpm / etc) is more important (than 2005 emissions spec's), 4-5bar vacuum referenced. The injector controller will control both injectors - but cleverly only run one (in each inlet tract) at lower rpm's, bringing the second injectors in at a pre-set point; at which point the fuel count is halved. A 'gain' will also be added to fine-tune the increased flow from runing two injectors at half duty, compared to one at full - resulting in a seamless 'stepover' (a problem, especially with higher-flow injectors).

We plan to have the setup such that you enter a code for the 'start' of injection and 'end' of injection. This code will be determined by your camshaft duration. You will simply select from a spread-sheet your inlet opening and closing points and then look up the code reference for this timing.
It'll also have a digital readout (based on the information calculated from the code) for the '% remaining' countdown on the current injector duty cycle, so you know when you're about to exceed the injection window and promote charge-stealling.

Basically, we want to make it as 'plug and play' as possible... ideally, without the need for buying and installing two wide-band lambda sensors...
I'm going to run it on my turbo for 12 months before releasing it - Suffice to say, if it can fuel a turbo at 20psi and 7000rpm, it'll fuel any a-series....

Edited by TurboDave16V on 30th Nov, 2005.

Good work Dave...

I should soon have the cam measurments from an MPi if you still need them :)

Alex

AlexF

what are the main differences when going forn a N/A injection setup to a Turbo setup?
I am just starting the fuel injection thing and will be running 2 680cc injectors to start with on a throttle body. The injectors will be running sequencialy.
Has anyone got a N/A systems running?

people have done...

the guy who runs pole star... but thats only really a wet manifold.

Alex

AlexF

Nigel,

The most simplest math:

A nat-asp works at 1-bar air presure.
If you're working at one bar boost this is 2-bar absolute. Hence, you need 100% (double) whatever injectors you were running in an equivalent nat-asp.

The BSFC is also higher however for a turbo, so you need a slightly larger injector again.

If you plan to run more than 1-bar boost - you'll need (again) a larger injector...

Guys I am running a polestar ecu not the mega crap OMEX??? the polestar is already running in N/A mode at 120bhp+, Neil the guy from polestar and me are now protoyping a Turbo systems, it seems most of the problems seem to be with getting something running hence why I have been the hack mini for polestar, half the cost of the Omex and it works??? I was not impressed by Omex at all?
I will let you know how we progress but at the mo we are dealing with turbo related problems and not general running probs..
hope to have a basic setup by march..?
Today I ran over 1 bar of boost and she flew16psi down the local dual carriage way (carb). so the injector system will be set for a power output of 160bhp
and since we already have a single injector runnnig 120bhp + we should be ok for 160bhp with 2 in sequential mode and maybe an extra high boost one?
Putting injectors in the inlet manifold is not the way to go, the fuel/air do not have time to mix.

Edited by TurboDave16V on 4th Dec, 2005.

Dave,

Think I understand what you are saying, yes there will be fuel left lying around. when I say sequential I am talking about how the injectors are triggered not where they are placed.
I am going to try and have 2 injectors in a throttle body so I guess you could call that a 'wet manifold' or 'electronic carb'
Not sure what the end difference would be, ie drivability..over an injector per port set-up?

I think Dave's point of view is that if you only end up with something that is an electronic SU, what is the point of expending a lot of time effort and money if the end result is no superior to the SU?

I also personally agree, if I am going to spend £1000 (which is a realistic figure I believe to achieve injection), it needs to significantly improve on an SU.

Tom,

Yes it has to be better and in N/A mode the car already is far far smoother and with slightly more power at lower RPM, also the throttle responce is better.
The car is so much more drivable, it may not make any difference to the race guys but I use my turbo as much as possible on the road, so am always on off boost and anything that makes the transition to full boost quicker/smoother is a help.
Also I then have the ablity to play with it myself instead of needing a wizard in SU needle profiles.
It will also meen the traction control will be more affective as I can cut/change the injector timing and not the ignition (or both).
It does have to be said that the Standard SU I currently run with only a machined needle is the very good. I have no other mods to it, thats impressive.

It will be better for sure, especially as the needle profile on our engines is ultimately limted by the profile it needs for maximum boost; leading to a richer mixture at cruise than would be preffered for good economy.

Be wary of 'cutting' the fuelling under boost with the traction control; This needs exceptionally carefull consideration

Hi,
Traction control cutting the fuel won't be a problem on a 4 port head, but you could still get some fuel in the cut cylinder on an A series, which could cause a seriously weak mixture.
As Dave says.. if on boost could be catastophic! You would need to cut the spark as well, now you need to cut the spark on the same cylinder, that means a phase sensor at least......
Cheers,
Gavin. :)

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I am surprised that retard alone isn't enough... I had my engie set on tons of retard over 20% throttle at 2000 through to redline in my map (basically on the over-run). Flames and popping happened, and boy did it pull the revs and slow the car down! Great for racing, bad when driving along deansgate between the traffic lights every 100ft.

Edited by TurboDave16V on 6th Dec, 2005.

yeah I think we will leave cutting the injectors until we know more, will leave it as it is, cutting just the spark for now.
Flames out the back dave OK if you don't like the guy behind?

Now on to the rising rate FPR.
I have found a US company called Automotive Inc and they do a set 1.1 ratio fpr i.e for every psi of boost the fuel pressure rises by 1 psi or an adjustable one 1.1 to 10.1, nice bit of kit, was thinking using of one, trying to get them to send one to my other company in the states..check them out..
automotiveinc.com p/n 13109 1.1

I'm (now) going to avoid using one if possible, having done a little research into them.

Basically, nothing beats a nice reliable vacuum referenced 1:1 fuel pressure regulator.

What is wrong with the standard Pressure regulator on the Turbo ? it seems to work ok upto 16psi and my fuel pres gauge says it is rising at the same rate as boost pressure ?? Don't lets forget that the pump in question is used on about 70% of injection cars at the time of Met Tur manufacture !!!

Jaguar prototyped a system a few years ago with a X type 3.5L Supercharged car what they found was they could deliver less fuel to the injectors by lowering the pressure, then giving full flow at the calibrated pressure for the injectors and upto 10% overflow by "over" pressurising the system, unfortunately I don't know about the reliability issues that may have been incurred

Except that you won't see one of these on the road

Thanks
Kind Regards Martin

http://www.mra-minis.co.uk

Edited by TurboDave16V on 6th Dec, 2005.

Yes I have heard some adjustable fpr's can be unreliable, I think I will settle for the 1:1 ratio.

Good call that man!

So how's the timescale for all this looking Nigel? Is this the 'winter' project? - I assume your mini doesn't see a salty road if you can help it!

The time scale is roughly to have something working by april, I'm also pretty skint as the wife is now a uni student, also polestar have other things doing as well.
Yeah I do if I have to otherwise I just drive it on the dry days, didn't have the inlet manifold connected and the other morning it was -2 so I was pushing my luck and yes it did freeze the carb, bloody thing wouldn't start again right on the busy gatwick roundabout, had to push it around the roundabout, what a laugh!
Who are these people who say leave the manifold disconnected? (mini mags)...
Will keep you posted and post some pics when I get everything machined up.
Was also thinking of a stainless turbo elbow 50.8mm? and just sleeve it to the stainless downpipe?