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Microsquirt for n/a 16v?

oldschoolvolvo

Well-known member
Joined
Mar 27, 2004
Location
Lancaster, PA
Looking for some feedback?considering doing a standalone conversion on my n/a 16v setup.

Is it reasonable to expect a noticeable change/improvement in the performance of the engine by changing to standalone vs. existing LH management? No other variables changed.

Car runs well as-is IMO, but if there is a tangible benefit to converting to standalone I?d like to pursue it.

In other words, how much can you improve the performance of the engine by only optimizing the tune? Is it a pursuit of diminishing returns on a n/a setup?

Current engine management is LH2.4 (B234) + EZ-117K (sbabbs B234 clone EZK box).

Standalone hardware would likely be microsquirt.
 
I don't have that much hands on experience with this, but I would guess that neglecting emissions may improve performance a bit. To allow run engine with richer mixture and more advance might give little more ummph.
Ignition timing is very effective way control exhaust gas temperature, which is needed to keep catalysator "ON".

But if you make some changes to your engine, then definitely tuning is needed.
 
Main benefits to uS over LH: You can adjust accel enrichment, lean it out a bit, and adjust the timing table.

That being said, you're not going to see a lot of HP/Torque change unless you start modifying the engine. You might be able to pick up 5-10hp, but that's about it honestly.
 
The other benefits are,
adjustable rev limiter,
Launch control,
Flat shifting,
adjustable idle speed control,
electric fan control,
table switching,
nitrous control,
Idle advance control,
AC idle up,
Knock sensor?,
Flex fuel,
Baro correction,
Logging with an attached computer,
You can switch tunes or make any changes in a minute.
 
The other benefits are,
adjustable rev limiter,
Launch control,
Flat shifting,
adjustable idle speed control,
electric fan control,
table switching,
nitrous control,
Idle advance control,
AC idle up,
Knock sensor?,
Flex fuel,
Baro correction,
Logging with an attached computer,
You can switch tunes or make any changes in a minute.

Microsquirt has only about half of those features you mentioned.
 
many brands of the standalone box around here.

The major advantage that effect to power and LH can't do are
-Injection angle
-Direct coil on plug
-Accelerate enrichment

thses are main point that you will gain power because

LH - inject every rev of crank, means 2 times per one spark, so it doesn't care about Injection angle. you will lose some Volumetric Eff. and not so precise AF control from the vapor of fuel that injected in not proper time and stuck around port and back of intake valve. Better VE and AF control are the most advantage point of stanalone.

LH - use distributor. direct coil more stable in high rev. less misfire , more power.

LH - Don't have TPS, it have only Idel and Full throttle switch mount on the throttle. so you cant do the function of fuel enrichment.

but.

LH - have a very forgivable system that we call "Adaptive" you can run it with nearly 30 yaers old system, how do you think its true? :oogle:
 
Injection timing has "nothing" to do with performance. With right sized injectors duty cycle is around 70-90%, so basically it is open most of the time.

On lower engine speed it got positive effect on HC-emissions when fuel is injected on hot closed intake valve. Fuel evaporates better and combustion is more complete.
 
Injection timing has "nothing" to do with performance. With right sized injectors duty cycle is around 70-90%, so basically it is open most of the time.

On lower engine speed it got positive effect on HC-emissions when fuel is injected on hot closed intake valve. Fuel evaporates better and combustion is more complete.

The Injection angle is not the injection timing.

injection angle means angle of crank that injector starts or stop to inject.
Concept is you should inject only when intake valve open. because fuel mist have alot less volume than fuel vapor, air+mist(that was kicked with 3 bar pressure!!!) can induce to cylinder more than air+ fuel vapor, you will get better VE on part load.
You will get better control of AF in every cylinder too, because you have no idea how much fuel vaperized in each cylinder,
let say cylinder #1 with #2 if you inject as the same angle and same timing
if correct angle for a cylinder #1, so that means it wrong for #2 so you got alot of vapor, that mean air in #2 is push back and get in less than #1,
So, you got uneven AF and, then fuel trim read average value show you got rich so it reduce timming, then you will get knock on #1.

but with this concept, you will get fuel vaporize issue instead. HC will get high.
So manufacture solve by design 8/9/12/14 hole disc type injector that gives you very very small mist. that why modern port injection engine change to use the multi-hole injector.

but intake valve open very soon, that means you have only 220-260 degree of crank as your camshaft duty. that means if your cam and head have flow as 240 crank degree (maybe advertise @260) you have only 240/720= 33% of injector duty.

when you need more injection timing than 33% you need to sacrifice this phenomenal,
But with the correct angle, you still get a better result from mist pressure push intake in valve open period.
So some ECU can set start point some can set stop point.

for full load
Injection angle has less effect.
if you set drag car, you can neglect it.
have fun
 
please do not confuse
part load doesn't really mean only part throttle.
and also
Injection angle is not Injection Timing.

you can search for " Intake Port Phenomena in a Spark-Ignition Engine "
many theories and experiments. include CFD

the important thing is standalone CAN CONTROL A/F better from VE was improved and equal.
so you got higher COV, less missfire so you gain more power.

I just share my point of view,
sorry if it not the same as your experience,
I don't want to fight, Covid19 is enough.

World change every day, new things comes around us.
but Fact is Fact.
 
please do not confuse
part load doesn't really mean only part throttle.
How are you defining load? MAP over atmospheric pressure (baro)?
I think you're getting pedantic here though.

Injection angle is not Injection Timing.

you can search for " Intake Port Phenomena in a Spark-Ignition Engine "
many theories and experiments. include CFD

I 100% do not trust anyone's CFD if it is not backed up by physical testing.
I trust it even less if it's using Solidworks. SW CFD package is basically MS Painting in flow lines, and with the accuracy of a toddler and an etch-a-sketch

the important thing is standalone CAN CONTROL A/F better from VE was improved and equal.
so you got higher COV, less missfire so you gain more power.

There are a lot of things that play into COV (coefficient of variation with respect to IMEP).
Tuning is only a small part of that.

I just share my point of view,

Thanks :)

World change every day, new things comes around us.
but Fact is Fact.

Facts are not facts, especially with respect to science. Science changes as we learn more. Engine theories from the 1960s were disproved and changed in the 1970s, and so one and so one.
The research I did 10 years ago is already old news and archived in a basement somewhere, with my papers gathering dust.

Math is pretty stable throughout time though.
Time for some work from home beers :cheers:
 
thing that explained was the thing I learned 20 years ago,:lol::lol::lol:
on my age,
Homogeneous charge is not so mentioned, just a little in emission and knock limit.
BUT the satisfied charge or nickname is lern-burn technic was major topic.
because 80% of ICE. runing on part load, the intake phenomenal totally difference from full load. it so complicate to understand it behavior. many conflicts in research found all the time because we still don't know about it,
GDI is my topic on that time, so i lern and test a lot about intake phenomenal and fuel atomization and vaporized that effect to IMEP and COV.


now a day, I'm older.:-P:-P:-P
many things change.
ICE nearly replace with EV.
you don't need to trust CFD, it proved themself without your trust.
You saw very complicate plastic intake, with multihole injectors with powerful ECU,
that can control Stoic AF exact only at sparkplug tip on part load with 0.98-0.99 COV with very low fuel consumption, also give you the best performance on full load too...
How can you do it without simulation research with good verification?

For full load, things still not go that fast.
Homogeneous charge play on this time and seem we already well known about it since 90th.
So the 30-year engine with good head and block design still can beat with a modern engine.
Just Knock limit and abit of heat transfer(also from FEA.) that modern engine has an advantage.

on my opinion.
RED Block is a good one. 8V is simple and good head to play with, 16V is more serious head and much more fun.
if you want to daily use it standalone with multihole injector are recommended
but for drag or race,
you can stand alone or re-chipped LH with big pin type injector.
the result is not that much, if you don't need the trick, lanch control..ect,

have fun.
 
100% not worth it on a stock n/a setup. If it runs and drives well and doesn't get terrible mileage. Microsquirt is not worth the hassle imo
 
I don't know what anyone else said / I didn't read above at all, but:

I have two bone stock B234F engined cars:

90 740 GLE AW72L 4.1 rear
88 240 GL AW72L 3.73 rear

They both could probably do with new plugs, but:

240 has FreeEMS, no airbox/airfilter so is noisy, pseudo wasted spark with toyota COPs and an untuned flat 75 or 80% VE table that's a bit lean around peak torque but I just run 98 RON fuel in it and it doesn't ping like that. Algorithms are good enough to daily like this.

Comparing the two:

240 is more responsive / strong down low and feels strong through mid range despite tall diff
740 can be hesitant when cold and at lower RPMs but sings well through to 6k hard cut
240 can rev a bit higher, but the valve springs are border line at 6000 anyway, so not much and you have to hold the box from shifting to achieve it
240 starts immediately with my code, but YMMV on megasquirt...
740 starts fine, but not as quickly because OEM was primitive/crap
240 has no idle valve or control so must be warmed up manually with the gas pedal and/or while driving
740 idles a little low cold, initially, but settles fairly quickly, idle valve probably dirty/sticky/etc

240 is running some crusty old firmware from ages ago without:

1) any accel enrichment - so lean pops audible if you stab it suddenly at the wrong time but hesitation minimal due to base algorithms and design

2) new precision smooth RPM code I intricately designed and developed but never widely rolled out - in practice this doesn't matter much, but knowing it's accurate to 0.5 RPM to 4000 RPM and < 1RPM to redline is nice compared to eg MS1 that is at best accurate to 100RPM :-D

various other enhancements that I can't recall right now. Basically I'm dog fooding and I've been dailying the car with no wideband and no tune for a little over 2 years now without major complaints (gas mileage is okay, 350km/tank vs 400/tank in the OEM car). No fouled plugs or any other issues. Had it to about 100mph when I didn't have a 4th gear with OD wire cut. Probably haven't had the 740 higher but have taken the 740 to a drag event and drift event. YT clip of B234F donuts on tail of drag strip at drift day here: https://www.youtube.com/watch?v=Ds3wSdXyf9Q

My plans are to develop an NA tune in the car for my lighter 360 hatchback including cams and ITBs and then swap that gear into the smaller car and develop a mild turbo setup for my 240 wagon in this, then swap that out and not sure after that, maybe the BMW V12 I intended to put in it. A standalone gives you options to expand, but the differences are NOT worth it unless you're swapping chassis like I was. No room for that dizzy, no factory EFI loom or pump etc, custom loom by me.

To get OEM like driveability and economy and power will take you quite a bit of work and any gains will be minimal, eg less than 10% or so. IE, not worth it unless you have plans like I do to make more power and or aspirate differently. If you had a manual being able to get valve springs into it and raise the rev limit with some mild cams would be totally worth it.

My 2c.
 
I see someone complaining about distributor ignition above.

I *hate* dizzies, for a LOT of reasons, but:

If:

  • NA (not turbo/super)
  • 4 cylinder
  • 8000-9000 RPM or less
  • appropriate coil with fast dwell characteristics, AKA a modern coil, not oil filled can
  • good condition leads
  • good condition rotor/cap

Then:

It's totally fine. Until some moisture gets inside the cap ;-)

Dizzies are often hard to package in RWD setups so often they get ditched for that reason alone - that's mostly why I changed to Toyota cops firing twice per cycle.

Those COP units are pretty sensitive though, I had wrong dwell settings on first start and it lost a coil within about 2 minutes. Fixed it and replaced the coil and more than 2 years later no faults despite double fire, with once being into highly ionized exhaust gas AKA a near dead short. In fact, I still haven't bolted them in, so they're rattling around in there trying to vibrate to death :-D
 
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