Initial tune woes with new manifold and TB on my 355

[antus]

19/14=0.422
new values = current values *0.422 so your values will be just under half as much injection time in milliseconds for the injectors that are just over twice the size.

I thought it was first stage is milliseconds opening time up to... 200rpm?, second stage is 200-400rpm. But I am not completely sure and its not clear from the code. Temperature correction is also applied. Since its only cracking it just needs to get the engine rotating so its not critical to be absolutely perfect, you just want it to fire and not flood when you start it whether its hot or cold. There is a fair bit of leeway in the values you use, the ballpark changes are generally enough. But vlad is right, you'd need to reduce the minimum ms else the other tables might not be used if you lower the values.

I think I hit this once helping a guy out with a sprint car, got it running well, but it was still hard to start. In hind sight I bet it was the minimum crank ms that we hadnt lowered for the huge methanol injectors and didnt find at the time. always something to learn!

[Mr DOHC]

Those BPW for cranking are assuming a stock 5L now running 440cc injectors.
This is a 355, big cam, dual plane and a 1000c TB. So what do you reckon, 20% more than 0.422?

[vlad01]

Maybe? I would just try the 0.4 - 0.45. Too much can flood and be a pain in the ass, too lean is not bad as long as it reliably starts it's a non issue unlike flooding.

[Mr DOHC]

Bit odd, ive been chasing a cranking issue this weekend.
Ive tried various Msec values in both the First stage and Second stage cranking maps.
i watched the gauges this time and for some reason, JUST as it kicks, my BPW goes off the charts to 921.88 BPW (log attached)

I've done a difference check between my map and the stock one, apart from the basic stuff like injector size, idle speed and the AFR voltage. the maps are much the same.

Any ideas on that?

[vlad01]

I would just ignore that, probably just some random data as it's only for a split sec on the initial turn over of the engine.

[Mr DOHC]

Kk
Turns out the plugs were fouled. Cleaned up and it started.

I have my VE values up around 90 at 2200/75. But the duty cycle is only 10%.
I thought 105 was the theoretical limit of the value you can put in the VE table?

[vlad01]

100% is the max you can put in or what ever that is in 8bit value. I try to not exceed 90% at the peak VE. So in this case it sounds like you need to increase your injector rate in the tune by a % and then reduce your VE values by the same % so you are tuning from the same point but with more headroom in the VE table. This is pretty normal as Kinjflow and all theory can only tell you so much and the engine might be wanting different in real life.

[Mr DOHC]

“ increase your injector rate in the tune by a %”

You mean in the Kinjflow?

[vlad01]

This setting. That's my value for the 440cc injectors but mind you this a hot V6 race engine and the engine doesn't exist yet but I converted the tune from a factory based one to 12P for this combo but with 440cc injectors instead of the the unknown falcon? ones used in the late 80s. When the engine gets built and tuned on an engine dyno this value will likely change just like I suggested.

Injec-Flow.PNG (34.29 KiB) Viewed 1624 times

[Mr DOHC]

I have 0.064 in there for mine. Just to test I changed it to your value and it obviously didn’t make a difference.

It’s like I’m missing some multiplier somewhere?


ok, lets make sure i have the right shit going forward
i opened the OSE $12P V112 BLCF V8.BIN
modified it with the injector sizing to 0.064,
changed the WB setting to have a lower limit of 10.0 for 0V and upper of 20.0 for 5V in the VE Learn Param
changed injector bias vs voltage and bias add-on
First and second stage crank pulses

Have i even got the , bin, ADX and XDF of the right type (VP Auto BTW) that all talk correctly?
OSE $12P V112 BLCF V8.BIN
OSE12P V112 - 1,2 and 3 bar.xdf
OSE_$12PV112_1BAR - Petrol with calcVE.adx