Individual injector trim?
 

It looks like if you run full sequential injection you can manage each injector's fuel trim. Anyone doing this with great success? Just kinda curious.

To do it accurately and see gains, you need four widebands.

So you think that taking the flow info from Witch Hunter and putting REQFUEL for the average and then trimming each from that would not be worth the time? Too many other variables?

Also, here is another approach... multiple EGT rather than multiple AFR:
Megasquirt-3 MS3 AFR Safety System

Really? How would that even work? I mean logistically where would you put four widebands?

...and sequential injection.

Plenty of room on Savington's headers.

https://www.miataturbo.net/attachmen...et-j2wqrrl-jpg

Easy peasy. Reverent actually has exactly that on his miata right now.

I tried to find a pic, but can't find it. I'm sure he can re-post it

I get the idea from the nuge's pic, so basically you end up with individual runners on each exhaust cylinder and each one gets a wideband.

Strangely enough, I can't find the pic with the widebands on the headers.

https://www.miataturbo.net/attachmen...1&d=1380352144

https://www.miataturbo.net/attachmen...1&d=1380352046

Did you see much deviation cylinder to cylinder Rev?

0.1-0.2. And guess what, cyl #4 is not the "hottest" (old m.net myth), and there's no direct correlation between EGT temps and AFR, ie the hottest cylinder is not the one that runs the leanest.

So where is the data on individual cylinder temp?

And you are talking EGT not coolant right?

Dann

What data do you want? Yes, EGT, not coolant temps.

I thought cyl 4 was only hot on the earlier cars, with the MK2.5, the adjusted headgasket fixed the issue?

Me too, and coolant only not EGT, Id have thought egt would have to do with flow in the IM and fuel rail.

Dann

I just said what the m.net myth was. :)

No turbo for you Reverant? Or is it somewhere down the line?

lol @ individal widebands

4 channel EGT

http://imageshack.us/scaled/landing/13/egtsnavsn2o.png

okay, Tom.

Yep, basically all the dual feed fuel rail fanbois were saying #4 was starving, etc.

Just clicked in my head once you mentioned that, thanks Vlad.

Yep. The sensors don't last long, obviously, so you install them for tuning and then remove them for regular use (like Dimitris has done). I have an AEM 4-channel controller but haven't had time to put it to use.

I also have 4 HBX-1 heatsinks in there now (I used to have the DIY copper heatsinks as recommended by Innovate, however they would crack on a regular basis due to vibrations), so the sensors last a little longer than expected.

Btw I do have the sensors installed on a permanent basis as I am always testing ECUs on my car.

EGT would be much more reliable, not to mention cheaper.

Ive been thinking of building a multiple channel EGT setup using some AD595 thermocouple amplifiers. Theyre kinda of expensive pieces of silicon (~$15 each), but not much else is required to build it, and thats still nothing compared to widebands.

EDIT:
Another cool thing about EGT is that you can see detonation.

You can see exactly zero det from EGTs. Ask me how I know.

User error I think.
Its probably useless for catching detonation while driving the car, but if youre logging it on the dyno you should see a sudden drop in EGT when detonation occurs. Unfortunately this is so counter-intuitive that people have frequently made the mistake of not interpreting the drop in EGT as a bad thing.

Dimitris, how much effort did you go to ensuring the EGT and WB bungs and the parts which block them when not in use do not impede flow?

I wonder if simply not protruding into the cylinder is enough.

Dann

Zero effort. This is my DD/mobile lab/track toy, so even if I lose 5hp because of the reduced flow, I don't care. :)

We saw nothing at 25psi on the dyno, AFRs were stable, EGT was stable, then poof, white smoke (ouch - hello, can I haz open window, stuffy in here blah blah blah.