Mini supercharger on 1zz

[shnazzle]

I reckon this is a proof of concept and we know it will be better with ECU, but that's for later and bigger budgets. If this can be done mechanically, it means it's flexible as well for budgets...to a certain degree.
Smaller/stock pulley and piggyback could just be Stg2 of the CarolynCharger  s:) s:)

[lamcote]

Yep, that's how I see it too.

[lamcote]

How does the standard ECU control the injectors? Does it apply a specific duty cycle or does it just open them for a certain period of time?

If it is by duty cycle, is it possible to find out what duty cycle the standard ECU map drives the standard injectors in open loop?

If it is a period of time, is it possible to find out what that time is, in open loop, and then convert this to a duty cycle percentage?

Presumably if the standard injector is driven at 80% duty cycle at a given load site, the ECU would then drive a bigger injector at the same 80% figure, in open loop?

EDIT: Yes you can convert injector opening times to duty cycle %.

SO, can anyone tell me how long (in Milliseconds) the standard ECU opens the injectors at various load points in open loop, or even just at max power (6,400rpm) with wide open throttle?

[shnazzle]

How does the standard ECU control the injectors? Does it apply a specific duty cycle or does it just open them for a certain period of time?

If it is by duty cycle, is it possible to find out what duty cycle the standard ECU map drives the standard injectors in open loop?

If it is a period of time, is it possible to find out what that time is, in open loop, and then convert this to a duty cycle percentage?

Presumably if the standard injector is driven at 80% duty cycle at a given load site, the ECU would then drive a bigger injector at the same 80% figure, in open loop?

EDIT: Yes you can convert injector opening times to duty cycle %.

SO, can anyone tell me how long (in Milliseconds) the standard ECU opens the injectors at various load points in open loop, or even just at max power (6,400rpm) with wide open throttle?

Wouldn't that be reverse engineering the stock ECU mapping? Which hasn't been possible. We don't know what kind of calculations the ECU applies to calculate injector pulses. I'm not even sure we know all of the parameters it takes into consideration or how many tables it has.

[lamcote]

That's a shame.

Yes it would be, but that would help us to predict what the new fuel level delivered with the new injectors will be, and we could therefore estimate how closely that might match the new airflow.

eg if we knew the standard ECU opens the injectors at 85% duty cycle at 6,400 and wide open throttle, we could calculate how much more fuel we will have with the yellow injectors installed and then estimate whether the predicted airflow we will have would be about right/wrong. However, for all we know, the standard ECU might open the injectors at 80% or 77% or 83% etc etc at that load site, so we can't know how much fuel we will be getting at that load site when the new injectors go in.

EDIT: Unless we can just assume that the injectors will deliver the same percentage more fuel as the percentage increase in max flow. ie 310/280=1.107 ie 11% more. Is it as simple as that? Probably is thinking about? It would be nice to check the map though.

Presumably we will be able to measure the AFR once it is all up and running and try to work it all out from there.

Are the standard injectors really 280cc? I am sure I have seen 240cc/250cc elsewhere but it is hard to find a definitive answer.

EDIT2: Just checked MWR website and they reckon standard 1zz injectors are rated at 255cc/min. (Yesterday's assumptions were based on 240cc standard size so I'll need to redo the numbers below.) That would mean 310cc yellows give 21.5% more fuel at any given point in the map, so:

standard 140bhp * 1.215 = 170bhp. So we should have fuel for 170bhp and would therefore need airflow for 170bhp. Current predictions based on airflow available are 190-200bhp on 120mm-96mm pulleys....OK or risking going lean?? Should we be looking for brown injectors~:
330/255=1.295
140*1.295 = 182bhp

Yes I know I'm rambling.

To clarify:
Based on the above assumptions, 330cc injectors should provide fuel for 182bhp on the standard ECU map (assuming peak power AFR stays the same)
120mm pulley would give air for c.190bhp
Is this the best way to go initially?? Unless someone can improve on the assumptions/predictions/calculations?

[shnazzle]

It's a lot of pressure to put the stock ECU under.
Do we even know if the injector lag times are the same/similar between the 1zz and brown injectors? Are we asking the ECU to compensate for too much?

I suspect the 2zz 310s won't be that different but once you go to an entirely different injector...

Or does it not make a difference because of the actual cam profile of the 1zz?

So many variables. That's my point; is it fair to assume the stock ECU can sort it all out just by adjusting timing, cycles, pulses, etc?

EDIT: Think I can answer my own question;....won't know until we try  s:) s:)  haha

[lamcote]

I think the point is that I expect the ECU won't make ANY compensations in open loop (ignoring LTFTs for the moment!). To do any prediction we need to assume the injector performance is comparable. What impact does lag time have and can we find specs for these?

Done a search. Yes it makes a difference, no specs available. Agreed, only way forward is to test.

Need to agree on the spec: 96mm or 120mm pulley and 310cc or 330cc injectors?

I favour 120mm and 330cc as safest option but I am notoriously risk averse and very easily persuaded.

[jvanzyl]

Well look, this project is welcome to the use of my Yellow injectors... maybe we should ask someone on the Celica forum if they have some browns we can test with as well?

[lamcote]

That's the spirit, thanks very much indeed.

[shnazzle]

Brilliant!

Ok, I'll man up....
I'll offer up my eManage Blue with harness temporarily, if need be. But only if the maps on there can be stored SAFELY! I don't want to lose them.
Rather not of course  s:) s:)  I'd get pretty fed up with my car without the extra pull.

Problem is of course that it is a Blue. So might not do what we need.

[lamcote]

Wow that's excellent. As you say, not sure what the difference between the Blue and Ultimate is. Have you any documentation that might explain it? I'll have a look at their website.
Hopefully we won't need a piggyback of course so your maps would be safe.
We are getting some more momentum going now. Brill!

[shnazzle]

If you look it up the Ultimate had about an A4 sheet full of features over the Blue. Question is whether we need them.
One thing I know for sure is that the ultimate has plugs in the front for a extra sensors (such as a map sensor) and the blue doesn't. And the table sizes are 16x16 vs 20x20 on the ultimate. Just means the map is less smooth. But it does interpolate so probably won't feel it.

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[Essex2Visuvesi]

Ok
Just to be sure were singing from the same hymn sheet

You need one of these in 120mm?
 m http://www.ebay.co.uk/itm/331888292552 m

Also where is the 120mm diameter referenced to? by that i mean in the peak or trough of the grooves?

[Carolyn]

That's it.  Biggest I can find is from the States (96 mm).  Peak of the grooves.  In fact I think they go by the overall diameter, which is a bit imprecise.  ID is for interference fit on 19.182 mm shaft.

[Essex2Visuvesi]

OK thanks for the claiification
So I'll source a standard pulley and machine a new one to the same dimensions other than the diameter.

I was going to go for a turbo kit on mine, but this looks interesting.
I have an Apexi FC on the way from Japan if its any use?

[Carolyn]

That's a real help.  I've got the machine-shop pretty busy right now. Each mini-groove is tapered - not a simple thing to turn.  Please understand, we may not succeed.... I expect we will but it will take time.
You're on the list for a subframe at cost.

[Carolyn]

I'll pull the one off the SC and send it to you.  Please PM your address,

[shnazzle]

OK thanks for the claiification
So I'll source a standard pulley and machine a new one to the same dimensions other than the diameter.

I was going to go for a turbo kit on mine, but this looks interesting.
I have an Apexi FC on the way from Japan if its any use?

Apexi FC would be miles ahead of the  emanage blue. Harder to tune, but faaaaar more suitable

[lamcote]

Brilliant, this must be the best forum on the Web. Thanks to everyone for their input and help. I really hope we can pull this off.

[Essex2Visuvesi]

OK thanks for the claiification
So I'll source a standard pulley and machine a new one to the same dimensions other than the diameter.

I was going to go for a turbo kit on mine, but this looks interesting.
I have an Apexi FC on the way from Japan if its any use?

Apexi FC would be miles ahead of the  emanage blue. Harder to tune, but faaaaar more suitable

A big but wit the Apexi tho is the Price, as this is supposed to be a Low-Cost conversion and the Apexi is around 800quid, add to that another the 200 for the programmer its gonna make a big dent in the budget.
I'm happy to loan mine out as I was going to go down the turbo route, but I'm now having second thoughts as this looks to be a more fun way to go.

[shnazzle]

It's a fine point. But I guess we'd just be proving that with a map, regardless on what, this works well.

I'm still for the idea of trying mechanical first,and have the blue or fc as a backup

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[Essex2Visuvesi]

Just gone back and read through the entire thread and I have some more thoughts

With regards to charge cooling a couple of thoughts to add to the mix:-
Water injection?
I used an aquamist with great success on a highly modified Renault 5 GT Turbo many years ago and also the AEM on my Wife's old Startlet rally car

As the boost pressures are quite low and space is limited then the  GT Turbo intercooler could be a posibility (these were used as an upgrade to the Smart Roadster stock item)

[shnazzle]

Would cooling even be necessary at these boost levels? I know it's better...but is it necessary?

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[lamcote]

Me too.

If it finishes up needing a piggyback /standalone to work, people will inevitably chose their own solution anyway. We could still develop a standard map on one of the (cheaper) options to keep costs down, but if we've proved it works (on one of the ECUs currently on offer), one of us would be ordering one of these anyway so at that point we could use that one.

[lamcote]

It's on the cusp for cooling. Less than c.4psi means intercooling can actually lose power because the pressure drop across the intercooler (assuming typical flow efficiency) more than offsets the gain from lower air temps. However if we get the predicted 5ish psi, added to the fact that the supercharger is tucked under the exhaust manifold (so likely to get hot), I feel intercooling would be preferable. Also the space limitation is around the siting of the supercharger itself, there should be relatively more room available for the plumbing.

If we finish up using the standard Mini supercharger outlet pipe we probably need to use the Mini intercooler because of the odd shapes involved. If not the Renault option sounds worth looking at.

Water cooling again is an option although I worry about putting water through the engine, not sure if that's fair, but I do (rust, leaks etc) and a normal intercooler is probably a lot more straightforward (and reliable?) if there is the space.