Mini supercharger on 1zz

[shnazzle]

We will need a range of custom SC pulley sizes available though, unless we are happy having a mandatory 4,500 rpm redline.

That would knock the entire solution out of the running as the engine itself doesn't really come to life until around 4k. You'd turn it into a diesel.

The stock ECU will fire errors and the like if the fuel trims are +/- 25 for extended periods of time. Would 310cc injectors be within that limit on low boost?

[lamcote]

If yellow 2zz injectors are 310cc that suggests a max power of around 195bhp.
Based on previous assumptions this suggests a pulley of c.120mm.
Brown injectors (330cc) would then need to be c.95mm

[lamcote]

Does the standard ECU throw a wobbly if just the LTFT is at -25, or only if both the LTFT AND the STFT are at -25?

[shnazzle]

Does the standard ECU throw a wobbly if just the LTFT is at -25, or only if both the LTFT AND the STFT are at -25?

It's both. which I suspect would be the case in this ..err..case.

However;
"If the total of the short–term fuel trim value and long–term fuel trim value is within ±38 %, the system functioning normally."

I was fairly sure the max calibration was set to 25... hmm..

[lamcote]

Can anyone suggest if the MAF riser mod is going to help or hinder with this, to save me having to get my head around it.....?

[lamcote]

Wow that's extremely helpful. So we have 38% tolerance to play with. ie -25% LTFT plus -13% STFT before we hit probs.

I wonder if that means that if the 1zz injectors are 240cc we have tolerance for up to 138% of that capacity ie up to 330cc injectors? That would be nice!!!

That could make Carolyn's suggestion of 310cc a great option. Great intuition, oh what it must be like to be an engineer.

[shnazzle]

Can anyone suggest if the MAF riser mod is going to help or hinder with this, to save me having to get my head around it.....?

It's such an unknown with the SC. It provides boost pretty much instantly doesn't it?
Your starting position from idle is already flowing more than stock.
So, the airflow with the MAF at stock height might be a perfect match for the 310cc at the same duty cycle as the stock injectors.

If there is a gap at idle, a slight rise of MAF might make the car go towards overfueling at load but be better at idle.

So the question is, what pulley do you use to get that fine balance that balances the 310cc injectors with the additional airflow from the SC across the range? And, how far do you raise the MAF to make the ECU think

[lamcote]

Maybe it's another tinkering parameter? How exciting....

[shnazzle]

This is typical for me, always over-complicating things but...
Cap tried a MAF construction whereby he had variable vanes to adjust airflow...

If we wanted the car to read the lowest flow possible at idle, perhaps we could DIY a variable vane with an actuator, triggered by the idle air control valve signal, with a bit of clever use of a resistor and relay?

[lamcote]

I like it, and not beyond Carolyn's abilities to create no doubt.

[Carolyn]

Now you guys are thinking creatively.  A controllable maf... sounds like a plan to me.

[shnazzle]

 m http://www.spyderchat.com/forums/showth ... orta/page4 m

[lamcote]

Oh yes, this could be all the control we need? Well done..

[Carolyn]

Spring loaded vane with adjustable tension.  The more it sucks -the less vane...

[shnazzle]

Spring loaded vane with adjustable tension.  The more it sucks -the less vane...

ooohh...getting fancy now  s:) s:)   I like it

[Carolyn]

Got to make the inlet anyway.  Will not be too hard to make and very adjustable.  Can also experiment with vane size, if I make the vane easy to swap out.

[lamcote]

It's an SU carburettor for the MAF isn't it?

[Carolyn]

kind of   Are you suggesting damping?  Could be done.  I do like the idea of making it purely mechanical.

[Carolyn]

Got to make the inlet anyway.  Will not be too hard to make and very adjustable.  Can also experiment with vane size, if I make the vane easy to swap out.

Better still, an adjustable stop.  That way you can set the start point.  This is very do-able.

[lamcote]

I guess damping would only be required if it turned out to react too quickly. If the Spyderchat guy didn't need damping, hopefully we won't? Unless you think it would improve it? Probably have to build it and test it to know?

Very glad to hear you think it is do-able if we need it, we possibly may not.

Would you want to test out a basic system first to see how we go and then try this, or do you think it is wise to have this ready ASAP?

[Carolyn]

Agreed.  It's build and test time.  Pick yer pulley, yellow injectors, go for it.

[lamcote]

Well I would suggest 120mm SC pulley as a starting point with Yellows, and see how we go.

What needs to happen now before we can do a test run?

[Carolyn]

Build the subframe.  Weld up the input plate.  Mount the throttle body. Sort out the exhaust manifold.  (Had an offer of one, sent a PM but no response as yet) Make the MAF tube. Get all the parts together for the out side to get the air through the intercooler and to the plenum.  Figure out how to make the bypass work. Install in the blue car.  Includes throttle cable and wiring extensions as the throttle body will be in a different place.
gonna take while...
No small project.  Will be a lot easier to re-produce one one is built.

[lamcote]

What help can I or others provide towards that, (if any, he says, looking at it rather bewildered!). Just ask if you need anything.

I'll keep thinking about the pulley size to try to be sure.

[Carolyn]

I'm going to drop the exhaust out of the blue car and start trial fitting the supercharger to figure out the subframe.  We'll go from there. Step-by-step. Once we can get the thing in, we will sequentially work through it.  Input...then output.  Don't get daunted, it's amazing how things happen when you work through it sequentially.