ismael_pt

iTrader: (1)

Car specs:
european 1.8 NB
T25 s13 turbo
adapted fuji-racing irtb's
rx8 injectors
adaptronic 420c v10 firmware

The car runs well when steady throttle is applied but tip-in is almost impossible to tune. No matter how much or less fuel the injectors sprays, the engine reacts the same way, it bogs down and shows a lean spike. Adding more than ~8ms to off-idle and the engine dies filled up with unburnt fuel after a huge lean situation.

I'm using MAP x TPS x RPM (dual tables) tuning method with TPS-based accel enrichment

List of things I've tried, unsuccessfully:

-Move the injectors from the irtb location to the stock location on the head.
-Relocate the injectors wires as described in this thread: https://www.miataturbo.net/adaptroni...sitions-65816/
-Switch from full sequential to batch firing in pairs with divided pulses

I think it can be related to injection timming but the 420c ecu uses a fixed injection angle, so I can't change it.

Faeflora

iTrader: (2)

Pics please.

ismael_pt

iTrader: (1)

Now the car has installed an external IAC valve and a few vaccum lines more

phillyb

iTrader: (8)

well isn't that some ****

18psi

iTrader: (76)

Holy crap....1st person I've seen yet (iirc) with IRTB'S+BOOST

You sir, are awesome

ismael_pt

iTrader: (1)

Thanks! It's a friend's car, i'm helping him to tune it.

Mine's a '01 with a much bigger turbo and a "simple" square-top intake manifold.

Faeflora

iTrader: (2)

Gawdam you are Man.

That shiz needs to be on the home page of this site. Reporting that post for going to 11 in awesomeness.

Regarding your problem, is overrun turned on? Or off.

ismael_pt

iTrader: (1)

Thanks for the compliments!

Overrun turns on at 60ºC but iirc it's only applied when rpm is greater than 1500-1600 or something

Oni

iTrader: (1)

Just a noob throwing out an idea. Does the adaptronic do anything equivalant to MS EAE? that might negate the need for so much normal AE perhaps?

Also how long is the lean spike? its hard to tell from the pic if its only 0.2 or 0.3 seconds it might just be a case of thats as good as it gets with an aftermarket, i know Brain ( i think ) has said before that u will never 100% get rid of lean tip in with MS since its reacting to changes after they happen.

Scott

hornetball

iTrader: (4)

Be careful. You may actually be too rich. When you kill the engine with fuel, you don't consume the oxygen and the WBO2 reports lean.

Have you tried reducing the acceleration enrichment?

ismael_pt

iTrader: (1)

I've tried from 0 to big numbers and it reacts the same way. Bigger pulses only makes the AFR richer after the lean spike. The only way to make the engine rev without hesitation is running 10'xx AFR at idle with nice black clouds coming out the exhaust.

ismael_pt

iTrader: (1)

The AE in adaptronic are not as complex as in MS. There is no fancy algorithms for fuel in walls, but is much more than capable to do the job.

The lean spike is almost 1 second and the car is undriveable.

18psi

iTrader: (76)

I'm almost positive we had these lean tip in issues when we were screwing around with the early adaptronics years ago. You already probably checked the adaptronic section, but I'd look through there again. Something about asynch pump settings and "predictive throttle" if I remember correctly.

In fact, I'm almost positive that by messing with those 2 settings I actually got mine to do EXTREMELY rich tip in, which ironically enough, was just as terrible as your lean tip in. I remember the car bogging like crazy then lurching forward.

Sorry I can't be of more help and post actual discussion threads, but I'd browse that section more if I were you.


*edit: then again, none of us had IRTB's so maybe that wouldn't help you.

ismael_pt

iTrader: (1)

Thanks Vlad. I think your talking about the "predicted MAP" option that was introduced in the firmware when a lot of users were having problems dialing the transient throttle.

This car is a pain in the *** to tune because you need to think in 4D instead of the traditional 3D fuel and spark tables. The theory says that acceleration enrichments are not very important when tuning using a TPS x RPM method. The ecu is configured to use a primary table to determine fuel and spark values based on TPS position, and a secondary table used as a multiply factor to attend for changes in manifold pressure, this indicates that the change in fuel values is going to happen faster based on a TPS table rather than using the traditional MAP x RPM method, so once the tables are correctly tuned, the transient throttle settings become less important.

This makes me think that there is some physical problem with fuel delivery or triggering.

richyvrlimited

iTrader: (1)

It's not anything to do with this is it?

https://www.miataturbo.net/adaptroni...sitions-65816/

Also tip in is effected by the VE table, look at the cells you hit when you stab the throttle and try playing with those.

Leafy

iTrader: (1)

With just your fueling scheme you should be to about 80% of the fuel you need on tip in with no stomp comp, at least for the rpms where you cant build boost, thats the nature of tps based fueling. I bet you need a **** of a lot less fuel at that RPM level of tip in, and its showing lean on the wideband because you're actually making it misfire with all that fuel.

Also, did you change your injection angle? The injectors are further from the head than stock so you need to have the injectors inject sooner.

richyvrlimited

iTrader: (1)

Guessing you didn't read the OP's posts.

He tried from zero fuel to lots.

You can't adjust the injection angle on his ECU.

Leafy

iTrader: (1)

I missed where he didnt try any comp. This sounds exactly like an injection angle problem. Putting the injectors back to the stock location would theoretically fix that.

ismael_pt

iTrader: (1)

The injectors are placed in the stock location.

Braineack

iTrader: (62)

no way, my tip-in enrichments go fat as what. and it shows up as so...you'd have to go 100%dc for something like you're saying to happen.





so the adaptronic might not be great at tps enrichments, but at least the adaptronic can do tip-in retard.