DIY Fuel injection thread.

[Yowzer]

Did you also change the enrichment pulse width? I found that made the most difference on my V5.

 

One thing I can't fathom is how the cold start values all work. I'll get there one day.

I think I left that the same

 

Yeah the cold start is a bit weird. Still haven't got that right.

[Rookie]

Any of you dudes know how to make the rev limiter really noisy and shoot flames? I have it spark cutting at the moment, but I think I am cutting too many spark events or something. Tips?

[stillway]

more spark cut, less fuel cut.. more unburnt fuel = more bang ..hows your limiter setup atm?

 

http://www.learntotune.com/discussions/topic/rev-limiters/

 

[kpr]

don't know if you can do it on ms.  but link you can retard the timing when rev limiting.  so it starts to spit more fuel out the exhaust and make poser bangs and flames

[Yowzer]

Just tweak the timing down on the ign table once it reaches redline

[Yowzer]

Pretty sure the MSExtra allows quite a few variations of rev limiter, such as combining ign retarding and cutting every second spark for max fireballs

[Yowzer]

Ok it doesn't do the spark thing I said, but here's this

 

8.3. Rev Limiter
Clicking Basic/Load Settings > Rev Limiter will display the following screen:

From this screen you are able to control settings such as hard rev limit, coolant temperature limit, spark retard,
spark cut and fuel cut.
8.3.1. Hard Rev Limit
Hard Rev Limit (RPM)
Specifies the rev limiter max RPM (you must also select a rev-limiter type below.)
Soft Limit Zone / Hysteresis (RPM)
Sets an RPM deadband, soft limiters start this many RPM below the hard limit. If fuel cut is enabled, then the
RPMs must fall by this much before fuel is re-enabled. A number of hundred RPM is suggested.
8.3.2. Coolant Temp Limiter
Rev Limiter CLT based
Enables optional coolant based rev limiter, so that the rev limit can be lowered when the engine is cold. The
© 2014 James Murray 2014-09-08 Page 73/195Megasquirt-2: TunerStudio MS Lite Reference Guide
curve on the right hand of the screen (or the values for Coolant Temperature and Rev Limits) can be customized
either by dragging the points on the curve or entering values into the table. This sets the lower 'retard above'
limit at your chosen temperatures.
Rev Limit TPS Bypass (TPS %)
Above this TPS% the coolant curve is ignored. This should be set to a high percentage, so that only in an
emergency when you really need full throttle on a cold engine can you override the cold limit. Or set to over
100% so that the limit in the curve is always used whatever the throttle position.
RPM When In TPS Bypass (RPM)
Rev limit when the TPS bypass limit has been passed.
8.3.3. Spark Retard
Spark Retard Mode
There are four options for spark retardation to limit revs:
• Off – no spark retard used;
• Progressive retard – timing is progressively retarded above the set RPM;
• Fixed angle – above the set RPM the timing is immediately changed to this angle.
Maximum Retard (deg)
Maximum timing retard.
Retard To (deg)
Timing value used in fixed angle.
8.3.4. Spark Cut and Fuel Cut
Enable Spark Cut Limiting
Enables spark-cut limiting (will not work with EDIS, TFI or GMDIS.)
If enabled this option can cause catalyst damage and is noisy in operation.
Enable Fuel Cut Limiting
Whether fuel-cut rev limiting is enabled.
Progressive Fuel Cut
Enables a progressive non-rotational fuel cut that drops cylinders as revs rise between the lower and hard fuel
cut limits. Requires Sequential/Semi-Sequential.
This option must not be used with staged or throttle-body injection.

[UTERUS]

Would it be ghetto to change the cells at/around rev limit to a fairly retarded timing number and adjust to suit desired fire level?

[Rookie]

Ok, this is what I have at the moment/to play with.

 

So if I change the spark retard mode to "Fixed" and say "-10" will that give me poser flames?

[Rookie]

Next question, how much extra fuel do I have to add to the high rpm/low load cells for epic flames on over run? 20%

[Yowzer]

Most probably. Tweak the fuel cells to dump in heaps of extra fuel too, and report back.

[yoeddynz]

Such fun !

My question today. I realise each engine is different but what sort of cruise afrs do you fellas aim for. Let's say 4 or 5th gear at 50 kph on the flat. I notice when I go too lean it starts hunting so I'm around low 15s.

I wonder what factory ecus aim for.

[Rookie]

If you are at low 15s you are doing pretty well in my book, that should keep the Scotsman in you happy...

[Testament]

10:1 everywhere

[eke_zetec_RWD]

Such fun !

My question today. I realise each engine is different but what sort of cruise afrs do you fellas aim for. Let's say 4 or 5th gear at 50 kph on the flat. I notice when I go too lean it starts hunting so I'm around low 15s.

I wonder what factory ecus aim for.

Just go as lean as you can before you notice it.

My escort (turbo pinto) does about 15.5 at 100kph in top and about 16.5 at about 50kph in 4th.

Never go that lean under load obvisously and you need the accel enrich to be pretty good to make it wake up nicely

[Spencer]

Old bore wash Tommy at it again.

I was PMing JasonK about tuning his Q-jet last night. Apparently it is running 9:1 on the secondaries, sweet economy.

I aim for as low as possible Alex, usually ends up around the low 15's. Its very motor specific though stuff with way better heads/combustion/fuel mixing can usually go leaner.

[yoeddynz]

Yeah I figure that until I activate the AE I can't go lower. I'm hoping with AE on and tuned I can go that bit lower and still have a nice cruise with out it bogging when I apply gentle throttle.

Someone on here ages back mentioned I shouldn't ever have it sitting exactly on 14.7 ? Don't know why? Something about it being a dangerous place?!!!

[Spencer]

Lies.

[Rookie]

It is a dangerous place if you have something against making NOx though hahaha

[Rookie]

Also why don't you have AE turned on? I can't even get my car to come off idle without it (it might be something to do with the slides though)