Running dual AFMs, how was it done again..

[brother_david]

Im going to run 2xQ45 AFMs to my R33 Gtst since im running quite big twins.
I just want to doublecheck how to go about it;

Im going to run the 2 AFMs through an Apexi SAFC II but then i can ADD or AVG (average) the single output value going to the ECU.

So the way i was thinking of going about it is to AVG it but then i need to do something about the fuel side since otherwise it will get twice the amount of air it thinks its getting.

Would the correct way to go be to change the K-value?

Im running 6x Bosch 1600cc injectors, did a quick change to the inj. and changed the AFM to Q45. Got a K-value of about 16600.
Putting this into the Apexi dual go-about would mean i would double it up and get a K-value of about 33200.

Information taken from:
http://ecu2.forumwise.com/ecu2-thread1821.html

Cheers

[Eric]

yes, that's the correct way if the AFC is in AVG mode.

although I have just checked it using the latest Nistune version and I get a K-value of approx. 9850 for your setup.
I noticed in earlier versions of Nistune if you did a injector resize and AFM change, you would end up with 2 totally different K-values, depending in which order you had the software calculate the K-value. (AFM change first or injector resize first)
This problem seems to have been fixed though..

[brother_david]

I think im running the latest release, 0.9.14.2

Would you mind telling me in what order you did this, i cant change AFM first, its says the inj multiplier (K constant) gets to large and that i should change inj first.

(Running Z32 ECU with correct adr-file)
1. I start with loading a ECR33 RB25DET-bin file.

2. Changing injector size, both fields says '0' so i change the Current to 370cc and New to 1600cc.
-K constant changes from 44602 to 10314

3. Changing the AFM to Q45 with 'Adjust TP scales' ticked but without 'Halve values during translation' gives:
-K constant changes to 16502

Nowhere near your 9850 though so thats what alerted me!

[Matt]

do the injector size first

Previously K constant going out of range doing AFM change would go unnoticed and resulted in a bad K value

[brother_david]

Thanks Matt, I guess the figures arent that weird then but itll show when i turn the key!

By the way, the second board arrived acouple of days ago (David from Sweden)

[Eric]

>> Nowhere near your 9850 though so thats what alerted me!

I used the ECR33 addresss file to calculate, so that's why the K is different.
But if you are using a Z32 ECU and addressfile you can't just load up a ECR33 binary, so the K-value you found is nowhere near the correct value either..

You will need to use a Z32 binary that has been adapted to run a RB25 and work from there

[brother_david]

Ye, sorry mate kind off left that out of the equation
Was a bit to keen on testing the different settings so that i instead of using the old bin file from the old ECU took the wrong one i had laying around on my stationary comp, explains a thing or two! Good thing i aint using that to tune the engine and a good thing you pointed that out!

Getting closer and closer to start up, hopefully if i recieve the thermostat i can do it by the end of the week.

[brother_david]

Been up to no good again..;

Checked the last bin i ran the car on.
With the old AFM and stock 370cc injectors it had an injector multiplier value of 202.

Changed injectors to 1600cc and AFM to Q45 and that gave a value of 73, using dual AFMs through SAFC-II in average mode i doubled the value to 146.

Havent had success starting it yet but thats because of having the wrong igniter pack; R32 GTR igniter fits on backwards on the R33 GTST Series 1 harness but probably wont give a whole lot of reaction .

[brother_david]

Started a while ago, all fine with AFMs and tps after i dialed it in on 0.45 volts, revs freely up to about 3500 rpms, but i havent got the wideband connected so i dont know if it cuts out above that due to fuel issues.
Problem was the faulty igniter pack, started straight up when it was changed

Sounds mad but you cant hear it in the vid since the mic on my phone breaks completely when i rev it Doesnt help that it has got a 4" exhaust system ither..

http://www.youtube.com/watch?v=qgZ6LR7ySmA