DIY Fuel injection thread.

[BlownCorona]

you should definitely not mount the ECU on the engine. it will fucking hate the vibrations

[nzstato]

Just now, BlownCorona said:

you should definitely not mount the ECU on the engine. it will fucking hate the vibrations

Think it’s been there for a long time... doubt it likes the heat either.  Going to move it....

[yoeddynz]

Just now, BlownCorona said:

you should definitely not mount the ECU on the engine. it will fucking hate the vibrations

What @nzstato needs is some Barry mounts!

[nzstato]

Just now, BlownCorona said:

you should definitely not mount the ECU on the engine. it will fucking hate the vibrations

Think it’s been there for a long time... doubt it likes the heat either.  Going to move it....

[NickJ]

Can you rig up a dummy exhaust that vents skywards for the O2 sensor to live in?

Yeah it will change the tune slightly to the actual exhaust, but will save flooding it with water

[kws]

I can't see a sensor being happy so close to the exhaust port if you were to put it in a single runner

[chris r]

Or is it possible to just run the coolant hose off the side of the boat instead of through the wet exhaust while you tube it? 

[nzstato]

Just now, chris r said:

Or is it possible to just run the coolant hose off the side of the boat instead of through the wet exhaust while you tube it? 

That might be the better option... going to think about it some more.... I really would prefer not to drill into the alloy and go through the flexi, issue is backflush water entering that area.

Cheers

Was looking to get a serial/bluetooth/Wifi adapter for logging, but might just be alot easier to run an extra long cable and sit an old laptop on the back seat

 

[Yowzer]

Chuck a factory log Mani back on and run a stack out the back, chuck the sensor in there for tuning.

[shrike]

Just realized what I pulled out of the fake evo and I thought was a link knock block light is actually a knocklink, will see what the wiring is like and wire it back in, will help with my speeduino tune so score will be good to have some indication of knock and will make the tune less knock prone due to not having knock control. Just need to raid a factory 4g63 knock sensor plug off one of my looms and work out what the wiring is

https://dealers.linkecu.com/G4KNL

[BlownCorona]

thats pretty cool! 

are they reliable and can you still buy them? super interested in acquiring one, over the planned diy knock ears. 

[Roman]

On 22/05/2020 at 20:39, chris r said:

Not quite diy level because (not my racecar) 

Set up is link g4+ storm. Vss wired up and Canbus to a dash (dash to be purchased). We want to know fuel used over x distance so can calculate fuelling levels prior to stage so its not over full and sloshing around and stinking 

We are wondering if there is any option of a fuel used over x distance or even a average fuel usage over a trip time function that the link can do? Or would that all be on the dash side of things. 

Would prefer not to fill tank then do 100km of touring, then 100km of rally pace to get data 

 

Hey, 

If the engine has been tuned using Modelled Fuel equation then it can output instant fuel consumption in CC/min. 
But your injector data needs to be accurate for it to work good.

If the engine has been tuned in traditional mode, then its trickier.

So here are some options
If you dont mind using a laptop and you just want to review the data at the end of a run:

Log instant fuel consumption and vehicle speed at say 10hz, or whatever will give enough length of time for entire stage.
Open PClink and look at the log file. 
Make a new feature thing on the page called "Statistics" and add fuel and speed to it.
You can look at the average instant fuel value over the whole run, and then look at the length of time car was running to work out the total litres used.
Average cc/min * how many minutes = total CC of fuel used so divide by 1000 for litres

Alternative option using canbus and an arduino:

Setup a canbus frame outputting instant fuel consumption and vehicle speed. 
Setup arduino to receive these, and then it could just incrementally count how many km you've travelled and how much fuel you've used.
Could output to a small LCD screen or just a simple LED bar or something. 
While you're at it, may as well add some switches or potentiometers to this box, so you get some free inputs back to the ECU that you can send over CAN.
I could probably bodge something together for this if you were keen. 

 

[chris r]

Just now, Roman said:

Hey, 

If the engine has been tuned using Modelled Fuel equation then it can output instant fuel consumption in CC/min. 
But your injector data needs to be accurate for it to work good.

If the engine has been tuned in traditional mode, then its trickier.

So here are some options
If you dont mind using a laptop and you just want to review the data at the end of a run:
 

  Hide contents

Log instant fuel consumption and vehicle speed at say 10hz, or whatever will give enough length of time for entire stage.
Open PClink and look at the log file. 
Make a new feature thing on the page called "Statistics" and add fuel and speed to it.
You can look at the average instant fuel value over the whole run, and then look at the length of time car was running to work out the total litres used.
Average cc/min * how many minutes = total CC of fuel used so divide by 1000 for litres

 

 

Alternative option using canbus and an arduino
 

 

Thanks. I'll be going back this weekend so will have a sharn and see what we can work out. 

[nzstato]

Yet to start logging with the boat but looking at the current tune, and noting some potential problems....

Firstly, REQ_Fuel (base injector pulse width) is set ~11% too low (6.0 vs 6.7ms) for what the calculator shows, they've used some funny parameters in the calc to get 6.0ms so likely whoever was originally doing it found that 6.0 was (close to right)

Looking at the fuel table there are two 'ridges', the low MAP/low RPM one was probably set in an attempt to help idling (the idle control valve has been removed) and the higher one probably because thats where the engine is mostly in the table - my reading shows that since the load on the engine is relatively constant (i.e. you're pushing water through a jet pump) you only use a small portion of the map.

 

Also, it starts pretty quick, the cranking table for MS1 is set by pulse width direct rather than % off the VE table, works out to be ~80% fuel so I think that may be roughly on the money.  However takes a number of jabs on the throttle to stay going on the early stage of warmup. My feel from this is that the After Start Enrichment is too lean (and compensated by high values in the VE table) but warmup curve is probably ok.  Or, is the fact there is no idle valve going to play into this?  Being a direct drive boat I ideally dont want >1000rpm at any point during startup/idle and so wonder I can get away with no idle valve.  Appreciate startup will never be spot on but perhaps a bit better than this currently if I can sort out these tables.

Advice?

 

[Roman]

No IACV sucks a bit, but you can work around it by pulling ignition timing out of your hot idle so the rpm drops. Then adjusting the throttle stop so you reach your hot idle rpm goal with more air. So now you can have the extra air you need for cold start with more ign timing.

That 6ms value is incredibly arbitrary it just rescales your whole map up or down. So it doesnt have to be an exact value, its just so you get good resolution of the numbers in the table.

6 or 6.7 isnt going to be a big deal

 

[nzstato]

Just now, Roman said:

No IACV sucks a bit, but you can work around it by pulling ignition timing out of your hot idle so the rpm drops. Then adjusting the throttle stop so you reach your hot idle rpm goal with more air. So now you can have the extra air you need for cold start with more ign timing.

That 6ms value is incredibly arbitrary it just rescales your whole map up or down. So it doesnt have to be an exact value, its just so you get good resolution of the numbers in the table.

6 or 6.7 isnt going to be a big deal

 

Thats an awesome idea... if my hot timing is ~12deg, knock this back to 8-10 might be enough?  Asuming I keep the relevent cells out of this a bit higher shouldnt cause any off idle accel issues?

Yes, know REQ_Fuel is just a scaler, just cautious since this early megasquirt version swaps between raw and % tables (compared to later models) that I dont mess certain parts up. 

[Roman]

Yeah something like that, youll just need to see how far you can drop it with just timing. 

Might be sensitive to it or might not. Can maybe rich or lean it out to drop the idle a bit too. A lean mix needs more ign advance as it burns slower. So you might be able to exaggerate the effect by running a little lean too.

[nzstato]

Don't have the functionality here but this fills in the blanks where I need to go...

https://www.msextra.com/forums/viewtopic.php?f=134&t=66937

 

[kpr]

Map looks horrible.  I would suggest disconnecting  the shaft between the engine and jet unit if possible.  So you can run the engine while out of water. Tune as much of map as possible  free revving it and getting all the idle stuff right  .  Then yeah from that guess the rest of the tune. A stock engine without cams will have a fairly smooth map with highest numbers being at max torque.    Once in the water, as you say will only be able to tune certain part of the map, the way the jet unit loads the motor.  I would  do   part throttle runs. Once get that right . Repeat at higher throttle.  Right up to full throttle.   Then  use trend from the points you tuned to guess rest of map.  Need to sort the main tune before bothering with any of the compensation 

[mjrstar]

Buy differential, make super long driveshaft, strap down, dyno tune, profit? 

EDIT BELOW... to add something possibly useful or not. 

You will have to make a bit of a compromise on the idle I reckon, probably to the point where it'll need maybe 30 seconds or more of no load idle / warmup before being able to be happy.  I reckon the cold start fuel decay is more about air density change with manifold heat soak and wetting of the head / manifold on start than genuine running of the engine vs coolant and block temp. 

My 1ggte KP runs nothing in the way of an iacv, (or tps for that matter) and for a track machine built nearly 20 years ago it is a reasonable setup, with decent idle stability once its been running for a minute. Sure this you wouldn't put up with for a road car though.