Mini 3 Port Injection
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Mini 3 Port Injection
"Dyagciog" wrote:
> Cng1 - You stated that the first set of injectors where Rover injectors, which car are they from?
Rover Mini
By my estimation the factory injectors are 440cc/min monsters!
Posted by email.
> Cng1 - You stated that the first set of injectors where Rover injectors, which car are they from?
Rover Mini
By my estimation the factory injectors are 440cc/min monsters!Posted by email.
Mini 3 Port Injection
"mini1071s" wrote:
> No power above 4000 rpm is a classic symptom of charge robbing, any EGT data or
>lamda data? A stock mini cam will run to 7k on the A+.
Why would that be a classic symptom? At that point we're running 80% duration with
4 squirts per cycle so there should be a pretty even mixture throughout the port
opening.
Lambda is being measured on the outer two (lean) cylinders and is currently set up
at 14:1 at WOT. I've got another wideband I could hook in but no time to do that
right now.
Posted by email.
> No power above 4000 rpm is a classic symptom of charge robbing, any EGT data or
>lamda data? A stock mini cam will run to 7k on the A+.
Why would that be a classic symptom? At that point we're running 80% duration with
4 squirts per cycle so there should be a pretty even mixture throughout the port
opening.
Lambda is being measured on the outer two (lean) cylinders and is currently set up
at 14:1 at WOT. I've got another wideband I could hook in but no time to do that
right now.
Posted by email.
Mini 3 Port Injection
"racingmini_mtl" wrote:
> I'm just wondering because from what you reported in this thread you haven't had a very well running engine up to now or am I not reading you correctly? I'm still under the impression that you would have a better performing engine if you were using TBI instead but it would be great if it wasn't the case. So give us a few additional details.
With the huge factory injectors it was impossible to map, at 5000rpm WOT I saw a
peak of 40% duration and at idle it was either dead or hugely rich due to
the lack of resolution.
Now that I have smaller injectors I've got it mapped enough to be perfectly
driveable. The only issues now being lack of power at the top end and a lack
of resolution at idle. The resolution issue is easily fixable with ms2. The
top end is more of an annoyance.
Posted by email.
> I'm just wondering because from what you reported in this thread you haven't had a very well running engine up to now or am I not reading you correctly? I'm still under the impression that you would have a better performing engine if you were using TBI instead but it would be great if it wasn't the case. So give us a few additional details.
With the huge factory injectors it was impossible to map, at 5000rpm WOT I saw a
peak of 40% duration and at idle it was either dead or hugely rich due to
the lack of resolution.
Now that I have smaller injectors I've got it mapped enough to be perfectly
driveable. The only issues now being lack of power at the top end and a lack
of resolution at idle. The resolution issue is easily fixable with ms2. The
top end is more of an annoyance.
Posted by email.
It is indicative of running out of time to inject discrete pulses directly into the port and charge robbing. This is why the wet manifold approach works and the port injection does not.
Just like the stock VW flat 4 air cooled engine, restricted by the tiny carb - this staggers up to about 4k as well. This is in effect what you have done with the port injection unless you can either adjust the phasing of the timing to cope with the siamese ports, for which you need sequential injection and a further mapping dimension, or you revert to more squirts and this is basically then a wet manifold, which really is just about as good. You could run 4 staged injectors with the second set coming in for boost, (I am refering to my A series as this is a turbo engine).
http://www.planet.eon.net/~chichm/efi/siamese.htm
I have tried and tried to do what you are doing in the past and it has not worked, I had the same problems. Admittedly, the MS 2 will tidy up the bottom end, (as long as the injector response time will allow this).
Obviously I really hope I am wrong and good luck to you but many of us have been there before and hit the same 4k wall. The O2 readings should prove if all is ok. In my case, the centre cylinders were running very lean and nothing we could do would solve it. We also ran out of injector capacity to fuel the engine. As did rover, as they would fuel to 70bhp, just look at the dyno figures for the so called 90 bhp kits, around 70bhp. That said, i have run the stock rover spi system on a highly tuned 998 which made 70bhp and had lovely drivability. But with a flowed 1.5 inch SU it made 80bhp.
I have gone for the BMW 16v head conversion instead now, 8 ports....
Good luck to you and I hope I am utterly wrong, after all you already have got further than 99% of us who have tried this.
Just like the stock VW flat 4 air cooled engine, restricted by the tiny carb - this staggers up to about 4k as well. This is in effect what you have done with the port injection unless you can either adjust the phasing of the timing to cope with the siamese ports, for which you need sequential injection and a further mapping dimension, or you revert to more squirts and this is basically then a wet manifold, which really is just about as good. You could run 4 staged injectors with the second set coming in for boost, (I am refering to my A series as this is a turbo engine).
http://www.planet.eon.net/~chichm/efi/siamese.htm
I have tried and tried to do what you are doing in the past and it has not worked, I had the same problems. Admittedly, the MS 2 will tidy up the bottom end, (as long as the injector response time will allow this).
Obviously I really hope I am wrong and good luck to you but many of us have been there before and hit the same 4k wall. The O2 readings should prove if all is ok. In my case, the centre cylinders were running very lean and nothing we could do would solve it. We also ran out of injector capacity to fuel the engine. As did rover, as they would fuel to 70bhp, just look at the dyno figures for the so called 90 bhp kits, around 70bhp. That said, i have run the stock rover spi system on a highly tuned 998 which made 70bhp and had lovely drivability. But with a flowed 1.5 inch SU it made 80bhp.
I have gone for the BMW 16v head conversion instead now, 8 ports....
Good luck to you and I hope I am utterly wrong, after all you already have got further than 99% of us who have tried this.
-
tobyanscombe
- MegaSquirt Newbie
- Posts: 9
- Joined: Thu May 05, 2005 3:09 pm
Mini 3 Port Injection
"mini1071s" wrote:
> It is indicative of running out of time to inject discrete pulses directly into the port and charge robbing. This is why the wet manifold approach works and the port injection does not.
We're not trying to time the pulses relative to valve opening. What you're
saying would be spot on if it was sequential.
I've solved the mystery of the lack of power above 4000rpm. Nothing to
do with charge robbing at all, I'd got the the lambda sensor plugged into
the wrong port so I was mapping to 14.5:1 on the rich cylinders rather than
on the lean ones. Problem solved. Plenty of power past 4000rpm now.
> http://www.planet.eon.net/~chichm/efi/siamese.htm
Oh that old gem. Nowt wrong with theory but as long as you don't mind
the inner cylinders running richer than the outers then there's nothing
stopping you. As both Dave Walker and I have now shown. Keep the injectors
smallish so that you can run a decent duration at WOT and it'll work.
> I have gone for the BMW 16v head conversion instead now, 8 ports....
How the hell have you got the 16v head on the a-series block? Why have
you done that rather than going to a 7 or 8-port conversion or for that
matter to drop a K-series or honda engine in.
Posted by email.
> It is indicative of running out of time to inject discrete pulses directly into the port and charge robbing. This is why the wet manifold approach works and the port injection does not.
We're not trying to time the pulses relative to valve opening. What you're
saying would be spot on if it was sequential.
I've solved the mystery of the lack of power above 4000rpm. Nothing to
do with charge robbing at all, I'd got the the lambda sensor plugged into
the wrong port so I was mapping to 14.5:1 on the rich cylinders rather than
on the lean ones. Problem solved. Plenty of power past 4000rpm now.
> http://www.planet.eon.net/~chichm/efi/siamese.htm
Oh that old gem. Nowt wrong with theory but as long as you don't mind
the inner cylinders running richer than the outers then there's nothing
stopping you. As both Dave Walker and I have now shown. Keep the injectors
smallish so that you can run a decent duration at WOT and it'll work.
> I have gone for the BMW 16v head conversion instead now, 8 ports....
How the hell have you got the 16v head on the a-series block? Why have
you done that rather than going to a 7 or 8-port conversion or for that
matter to drop a K-series or honda engine in.
Posted by email.
-
Bill Shurvinton
- MegaSquirt Newbie
- Posts: 23
- Joined: Fri May 07, 2004 1:20 pm
- Location: My Hampshire Hill
Silly one, but it could be you need hybrid alpha-n if the TB is big. You lose all vac signal just off idle.cng1 wrote: The smaller injectors seem to be ideally sized but running 4-squirts per cycle it's very lumpy pulling away from idle, MS2 will fix that though as it's just down to resolution. The TB is also a bit on the large size which means that a gentle cruise is at 90kpa which isn't helping but I think we can cope with that.
email me if you want to borrow my MS2 for a play.
Mini 3 Port Injection
"Bill Shurvinton" wrote:
> Silly one, but it could be you need hybrid alpha-n if the TB is big. You lose all vac signal just off idle.
You're right in that the TB is an issue, going from 0-3% throttle causes
MAP to jump from 30 to 50 and 10% throttle is good for 80KPA, all at idle
but I think resolution is the next thing to address.
> email me if you want to borrow my MS2 for a play.
One way or another I'm going to want an MS2, will talk to you offline about
that
Posted by email.
> Silly one, but it could be you need hybrid alpha-n if the TB is big. You lose all vac signal just off idle.
You're right in that the TB is an issue, going from 0-3% throttle causes
MAP to jump from 30 to 50 and 10% throttle is good for 80KPA, all at idle
but I think resolution is the next thing to address.
> email me if you want to borrow my MS2 for a play.
One way or another I'm going to want an MS2, will talk to you offline about
that
Posted by email.