MPi injector information: Response Time
Turbo Mini Forums

So, I've been doing a lot of work on fuel injectors this weekend.

I've tested many, many different injectors and have some great information. Sadly (for you) almost all of it is going to stay with me. If you have a problem with that, bear in mind I've given a whole load to this site, and shared many tweaks and tricks. I'm now pulling my cards a little closer to my chest...

But - here is what I have found that is great information for the majority.

Injector response of the Rover MJY100460 injector (as found on MPi mini / Dizzyless [DIS] Rover 2000cc 16v turbo).
This is a very VERY good injector. It has a fantastic spray pattern, and is a high-impedance unit.

35psi Rail Pressure.
0.5ms: Nothing
0.6ms: Extremely unstable / barely opening
0.7ms: Erratic
0.8ms: Good
0.9ms: Perfect


70psi Rail Pressure
0.6ms: Nothing
0.7ms: Nothing
0.8ms: Erratic
0.9ms: Good
1.0ms: Perfect




Now - here is something VERY interesting... A cosworth 'yellow' injector response was tested aswell. These are 'low impedance' units; supposedly superior response time to high-imedance units.

35psi Rail Pressure.
0.8ms: Nothing - injector not even opening
0.9ms: injector making a noise, but no fluid
1.0ms: Erratic
1.1ms: Perfect


70psi Rail Pressure
0.9ms: Nothing - injector not even opening
1.0ms: injector making a noise, but no fluid
1.1ms: Erratic
1.2ms: Perfect





Conclusion: The MPi injector is a BLOOMIN GOOD piece of kit....

Edited by TurboDave16V on 8th May, 2006.

Good info Dave :)

Its a shame you don't want to share, if only for the reason it starts a trend and others will follow.

Alex

AlexF

"Sadly (for you) almost all of it is going to stay with me. If you have a problem with that, bear in mind I've given a whole load to this site, and shared many tweaks and tricks. I'm now pulling my cards a little closer to my chest... "

You've been in the States for too long!

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On 08/05/2006 05:31:27 TurboDave said:

Conclusion: The MPi injector is a BLOOMIN GOOD piece of kit....

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

If anyone else built an injector test rig - and spend 10 hours playing with different variables; they'll arrive at the same findings as myself.

There is nothing clever at all in what i found - just my own time invested in testing, and researching different injectors, and gettting hold of some to a spec i thought would work (and they do)...
Why I should graft and then hand out every detail is beyond me; I certainly wouldn 't ask it of anyone else - let alone EXPECT it...

When Paul Wigginton revealled that he'd sorted the geometry on his mini and knocked 0.2/3seconds off his 60ft time (but wasn't about to reveal what it was); no-one gave him any of this nonsense. So why do I get it?


There is actually a key piece of information in my first post; which you may or may not pick up on... THAT is a clue to making the whole thing work.

Edited by TurboDave16V on 8th May, 2006.

yes dave... responce time v rail pressure and the important flow v pressure :)

Alex

AlexF

AND the fact that the MPi injector is happy at 70psi rail pressure.... Some of the injectors i tested weren't....

Team www.sheepspeed.com Racing

I will gladly help where I can, but I have limited resources and time like most people.

I was just a bit miffed when I read Dave's post this morning after last weeks discussions about the T2 and his reluctance to give up his copy of the map.

Dave, I fully understand if you are intent on winning races. However, for a lot of us, this is just a way of having fun and an interesting diversion.

We all wish to advance the use of EFI on a turbo'ed mini and it will be done. Dave has done more than any of us and we are indebted to him. However, it's a shame that we might get to a point where the last part of the jigsaw will be missing.

Personally, i have to decide whether to follow the TD/Jean/Megasquirt route or go it alone.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Axel - I was about to post the T2 map for all. Then I read something interesting, and enquire about it - and i'm greeted with someone who DOESN'T want to share any info with me - but will happily take what i've got, AND then throw their toys out of the pram (moan) when i hold back on posting the compressor map... So I would have been helping them out, but get absolutely jack-nothing in return??????

Look at it another way - If One-way-traffic has never been of concern or even apparent to oneself; chances are that it's been going in your favour all the time... Not a dig at you in any way, but I've noticed this a lot more over the last 12months.

Ultimately - I will post the T2 map up when I feel less agrivated. For the time-being, it's staying right where it is.

And as regards not providing or missing out the last piece of the puzzle - four MPi injectors at 70psi rail will be enough (going off basic BSFC calcs) for a 180hp A-series. That's more than anyone else has ever researched or posted before???

I mean - What more do you want? If you've got to 180hp off other peeps knowledge alone, then the next step should at least be your own.

And don't talk to me about not having time... I was still up at 12:30 in the morning finishing off the testing - then posted the results, then up at 6 for work. And I've got it easy compared to some peeps who put in silly hours like Iain, Tom and Peter. They still manage to do stuff off their own backs though....

If that sounds nowty - then apologies. We'll crack a tin of beer sometime in the future and I'll discuss lots of stuff with you - and provide many keys to doors. It's up to decide which key to use in which door and walk through them though...

ps - Thanks for all those who've PM'd, backing me up on this 'sharing' shenanigans

Edited by TurboDave16V on 16th May, 2006.

Great info as always dave, i dont have a clue how to use it or go forward from it, but its still great. Im sure it'll be fun finding out :cool:

What do u share is appriciated by most, but at the end of the day its your ballache which has gone into it and its your info at the end of the day!

Edited by andeh on 8th May, 2006.

I've seen the future and tbh its Pie

More testing happening tonight folks!
This WILL be even more interesting I guarantee...

OK - update.
Peter the Slavedriver has been hassling my input to Maga7ine for too long. So I've spent my evening working for him.

I'm going to go home and take some dimensions off a K1100 head so Jimster isn't being held up too much (I'm doing a CAD file for the front cover) on his turbo twink project.



Sorry, but you'll have to wait till tomorrow for the exciting testing. I'll tell you what it is though - and one that'll be usefull to us ALL...

I'm going to measure the difference in flowrate through the MPi injector at a fixed fuel pressure of 5-bar (the pressure that i assume everyone would be running them at) with 13.5, 12.0 and 10.5volts at the pump.
It shouldn't make a difference to flowrate of course - but let me assure you - It does... We can then have a debate about why it makes a difference LOL! At the least - it'll make it easier to build an injector map if you know what the change will be when you're by-passing the resistor.

I'll also be testing an older-generation hi-impedance bosch injector - AND running another cossie yellow in series with the tested one (needed for low-impedance stuff) so we can see how much MORE that slows the response time down by - of an already crap response time! This is how I had my DTA wired originally - when it made a whopping 78hp at the wheels with 15psi of boost and HC's off the scale... Hoping it'll explain a lot!



All interesting stuff huh. And Remember Folks, this is only available here - on www.Turbominis.co.uk (and Maga7ine as/when i pull my finger out)...

Put that in your pipe and smoke it.

Edited by TurboDave16V on 10th May, 2006.

i dont get that. asumign at those voltages the pump is still capable of over 5 bar then surelythe regulator will provide the injectors with 5 bar? .. unless the regulaotrs response time i sso low it gets "beet" by the injector and the fuel pressure has an effect of regulator response.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Team www.sheepspeed.com Racing

I'm just loooking forward to seeing a heavily modified Cossie with Mini injectors :)

Right then - MORE results.

First off - the Cossie yellows wired in series, as is common for when trying to run low-impedance stuff on aftermarket ECU's... I'd love to have been able to report back on this, but i've just realised after putting the three fullstops at the end of the last sentence, that i wired them in parralel. That's what testing at stupid hours does for you.



Next - the 'high impedance' vauxhall injectors (from an XE) circa 1988.
The reason i wanted to test these, was becuase EVERYONE says that low-impedance injectors have a faster opening than High impedance. It's written in enough textbooks and websites, so it must be right huh?
Well - as i reported in the first post - the low impedance 'cossie yellow' unit was some 0.2 to 0.3 seconds slower response than the Rover MJY100460 unit. This was throwing the 'oft stated facts' into the air. So where did these 'facts' originate from? Easy test - try some injectors of the same generation as the 'cossie' units.
These injectors are the ones used in the Vauxhall XE engine, right until it went dizzyless (whenever that was).
And what a load of crap they are!

35psi Rail Pressure.
1.2ms: Nothing
1.3ms: Faintest clicking- nothing coming out
1.4ms: Faintest clicking- nothing coming out
1.5ms: quiet clicking- nothing coming out
1.6ms: Loud clicking- nothing coming out
1.7ms: Erratic
1.8ms: Good
1.9ms: Perfect


70psi Rail Pressure.

1.3ms: Faintest clicking- nothing coming out
1.4ms: Faintest clicking- nothing coming out
1.5ms: quiet clicking- nothing coming out
1.6ms: quiet clicking- nothing coming out
1.7ms: Loud clicking- nothing coming out
1.8ms: Loud clicking- nothing coming out
1.9ms: Erratic
2.0ms: Perfect



So to summarise:
Twenty years ago - Low impedance (peak and hold) injectors were indeed faster responding than high-impedance injectors.
Times change however - as proven by an injector from nearly a decade ago having a response time superior to that of a low-impedance unit of times (thankfully) long gone.
I don't feel it's unreasonable to assume that modern high-impedance injectors are probably down as low as 0.6ms stable response. I don't believe they'll get much faster than that however...
You cannot assume anything of course - if you are unsure, get your injectors tested.

Edited by TurboDave16V on 10th May, 2006.

So Dave, who took that picture?

Team www.sheepspeed.com Racing

Neighbours lad who's been popping in from time to time, seeing what i'm up to...


WHY??????

Edited by TurboDave16V on 10th May, 2006.

What, that the neighbour boy took the pictures?
I'm quite certain that this was not the answer that me and Jim hoped for, but nevertheless...

I guess it really is valuable information, because now we know for certain that Dave isn't hooked up with some Yankee bimbo with hoops

Aye - he's been my apprentice!

Nothing happenig on the female aspect - I'd have thought the references to many late nights in the workshop would have made that obvious! LOL!

then again it might be different in the USA they might like that kind of thing!!

Alan Sugar eat your heart out!