[yoeddynz]

Hiya all,

Hey can you use the 'ITB' mode from tunerstudio on speeduino yet?

Also- are there many speeduino users with 6 or more cylinders running with itbs, (with the only obvious choice currently being the batch injection) and if so - how do they get their airflow signal. Are they using a common vac chamber drawing off each itb and getting a map signal from that ? Or just using Alpha N. I would like to use the combination aproach found in the 'itb' mode available to Megasquirt users but seem to remember in not being something available in the speeduino code a few years back?

Just to note - the engine I am using is a Honda Goldwing flat six with (into my Hillman Imp) and I am thinking of fitting 6 itbs from a Bmw K M/C engine. Still a fair way to go with mods but I need to start thinking about which ecu route to follow, having previously built a MS2 for my Viva.

Cheers

Alex

[theonewithin]

No ITB mode.

[yoeddynz]

Still no itb mode you mean....

[theonewithin]

Eh. I run ITB's. Works better than what was already there before.

[yoeddynz]

Cool! So are you using alpha n or do you have some sort of vac lines/chamber arrangement you can get a decent map signal from? That is what I'm thinking of doing.

[jonbill]

fwiw, I have a 6 cylinder engine and ITBs. I use Alpha-N. it runs well.

[yoeddynz]

Cheers Jon- I had only just finished reading your thread you had started pretty much one year ago. I was actually thinking of sending you a PM to see how you had gotten on with it

I have never used alpha N before. My last injection setup (in fact first and only diy injection... so far) was a Mazda v6 and I ran that with a single TB, batch injection controlled by an MS2. I'm happy to setup up a small vac tank assembly to get a signal to use if it meant I can have more info for the ecu and improve the tune.

Also- batch vs sequential. I'd love full sequential but the budget I have (actual reality is more like what I want to spend..) cant stretch to an ECU that will give me that for a 6.

I have the same fears that seem to be common among many folk regarding injection staging - will batch injection work fine with ITBs? In my head it seems reasonable to think you can get away with batch injection on a single TB setup because the 'fuel' mist has some runners and a plenum to reside in before the valve opens. I fear that with itbs on batch there would be problems at idle where some fuel mist hangs when the injector is not squirting at the perfect time in relation to its inlet valve opening. Fuel mist hangs or maybe there is not enough depending?

However- what PSIG said in your thread makes sense too. The fuel mist from one itb cant ever get sucked into the wrong cylinder.

I realise that once we go beyond idle and cruise this all becomes irrelevant. However- its at idle and cruise where I can notice the difference between nicely setup injection and something thats wrong. I want my engine to idle well and be really smooth

Probably over thinking it some might say eh... but hey- that's why we tinker with these things- the chance to ponder, discuss and try to improve things (by ourselves without just lobbing loads of money at it )

Alex

[jonbill]

My Datsun is my first EFI project - I spent the previous 5 years getting triple Dellorto DHLAs working properly. Getting Speeduino working on it was way easier than getting the carbs right! It is a big engine in a small car, so it is a forgiving combination but getting a lot of resolution into the bottom of the Y axis of the VE table has been key - 'cruise' is anywhere between 2 and 12% TPS so I have nearly 1/2 of the Y axis in that range. It's not fantastically smooth at idle, but I've never seen a Nissan L-Gata that was and it's no worse than with the carbs when they were running right. And it does have a rather large cam and there are 6 cylinders to get balanced.

In terms of batch vs sequential - In both cases the full fuel dose has been delivered before the valve opens. the combustion in the cylinder doesn't care that one half of the dose was hanging around a little longer than the other.

It would be interesting to compare with an ITB setup where the ITB is only a tube with a throttle plate, and the injector was direct to the head - I imagine that might get better consistency of vaporisation and burn, but that's only imagination, I don't have enough motivation to try it

[theonewithin]

Batch fire will be fine.

It's what I run.

Note this is on a motorbike which is where you will find most ITB setups.

[Billzilla]

FWIW I've run TPS vs RPM (on a Motec though) for years with good success. I only use a MAP sensor for altitude compensation.