edis 4 rev limiter?

A general forum and a place for initial or prospective users. See Manuals/Documentation
Click here to enter
Contact a Forum Administrator
If unsure where to post, post in this sub-forum.

Moderators: jsmcortina, muythaibxr

edis 4 rev limiter?

Postby slimeball6969 » Sat Dec 02, 2006 6:50 pm

i read about how we cannot use a rev limiter on edis 4

is there a way to fix this?

i want to get a full spark cut rev limiter (i think its the safest)

i have MS v2.2 with MSnSE

thanks
slimeball6969
Helpful MS/Extra'er
 
Posts: 82
Joined: Wed Nov 22, 2006 6:45 pm

thought of something

Postby slimeball6969 » Sat Dec 02, 2006 8:59 pm

i thought of wiring up a normally closed relay, and have it activate with rpm

so when it reaches a preset rpm, it opens the circut, and cuts power, this would control the power going into the coil

:RTFM:
slimeball6969
Helpful MS/Extra'er
 
Posts: 82
Joined: Wed Nov 22, 2006 6:45 pm

Postby jsmcortina » Mon Dec 04, 2006 7:11 am

That would do something, but would be even rougher than fuel cut.

James
I can supply, repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: viewtopic.php?f=104&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
jsmcortina
Site Admin
 
Posts: 33984
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK

Postby slimeball6969 » Mon Dec 04, 2006 11:46 pm

it would also throw some insane fireballs along with ear ringing backfiring 8)
slimeball6969
Helpful MS/Extra'er
 
Posts: 82
Joined: Wed Nov 22, 2006 6:45 pm

Re: edis 4 rev limiter?

Postby patsmx5 » Tue Oct 27, 2009 8:12 pm

Back from the dead...

I could swear I remember somoene posting a setup to mod the EDIS4 ignition system so that spark cut could done. But I've searched, and searched, and searched and.... And I just can't find it. I believe it was just a transistor that was wired between the +12V side of the coil so you could shut off spark. If anybody knows where the info is, a link would sure be nice. :D Pretty sure I found it on msextra or msefi a couple years ago, but I can't seem to find it now. Sure would like some launch control with this turbo. :mrgreen:
99' Mazda Miata, MS2E V3.0, GT3271 at 11 PSI,
patsmx5
Helpful MS/Extra'er
 
Posts: 36
Joined: Sun Feb 22, 2009 1:51 pm

Re: edis 4 rev limiter?

Postby racingmini_mtl » Tue Oct 27, 2009 9:22 pm

I don't remember seeing this but the main issue with doing spark cut by switching off the power supply to the coil is that if this is done while the coil is partially charged, you will get a spark at the wrong time and that could spell disaster for your engine.

The correct way would be to do direct coil control and ditch the EDIS module.

Jean
jbperf.com Main site . . . . . . . . . . . . . . . . . . . . . . jbperf.com Forum
Image
racingmini_mtl
Super MS/Extra'er
 
Posts: 8012
Joined: Sun May 02, 2004 6:51 am
Location: Quebec, Canada

Re: edis 4 rev limiter?

Postby sub » Wed Oct 28, 2009 5:07 am

if the limiter is, lets say, at 6000rpm and you are cutting the spark 1ms before the coil would normally be discharged the engine is 36° before planned ignition point! just remember that. at idle speed its not that risky.

second, using a relais for doing this means more delay because this mechanical system has inertia masses.

the only usable way is cutting the power supply to the coil AND synchronously shorting the charged windings! then the energy will be destroyed in the shortcut and no spark will ignite. i've seen such a construction somewhere, but cant remember.
sub
MS/Extra Newbie
 
Posts: 7
Joined: Tue Oct 27, 2009 11:44 pm

Re: edis 4 rev limiter?

Postby jsmcortina » Wed Oct 28, 2009 5:17 am

That sounds more effort than going to direct coil control!

James
I can supply, repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: viewtopic.php?f=104&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
jsmcortina
Site Admin
 
Posts: 33984
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK

Re: edis 4 rev limiter?

Postby chips60bug » Sat Oct 31, 2009 10:26 pm

Just do it right the first time, lose the EDIS module, keep the coil, sensor, and trigger wheel. Then convert the ECU to control the coils directly. Its really not hard and will cost you just over $20. I wanted spark cut and decided to ditch the module. It works just great!
chips60bug
Experienced MS/Extra'er
 
Posts: 368
Joined: Sun Aug 31, 2008 10:20 am
Location: Utah, USA

Re: edis 4 rev limiter?

Postby robocog » Fri Nov 06, 2009 12:34 pm

Just heading down the adding a hard rev limiter path and a little research has revealed an interesting idea of starving the coilpack of current instead of just cutting power to it...which sounds like it would do the job safely and the vids I have seen of them in action show them to do the job

I have just ordered a hard limit board from the Autosport Labs site (Megajolt website) and will be trying that out myself as its as cheap as it gets, and a lot cheaper than completely ditching EDIS for now
Looks like theres a few users out there gone this route with great sucess

The board appears to accept a negative input to trigger the starvation so just need to use an RPM based output to trigger it from megasquirt

I know I will eventually want to play with flat shift and launch control which I think I'm right in saying will involve ditching EDIS unless theres a way of fudging the megasquirts rpm based outputs, clutch switch and maybe some logic to play nicely with the hard limit board?

I know I'm probably just delaying the innevitable...but EDIS has been rock solid and bombproof for me and makes the ignition side a no brainer and I have to admit I am a bit daunted about ditching it

Regards
Rob
robocog
MS/Extra Newbie
 
Posts: 12
Joined: Tue Nov 20, 2007 3:06 pm

Re: edis 4 rev limiter?

Postby W113 » Fri Nov 06, 2009 12:58 pm

Rob,

I agree , EDIS is great stuff. Hard to beat.
Have you thought about rev limiting by somehow cutting pwr to the fuel pump relay?
With a decent hysteresis , say off at 6300 rpm and on at 6200 rpm.

If you have access to MBs , W124 junked cars ( 200 E and 230 E, the pathology is RUST) you will even find a ready made
fuel pump relay that has this built in, Runs off of the pin 1 PIP EDIS rpm signal. Sits in the aquarium in front of the windscreen
Even marked with rev limit!

Quite a few European BOSCH KE Jetronic cars used this , it works OK as long as you
take reasonable care and do not stomp on it for minutes at a time .

W113
If not understood , it will not work
W113
Master MS/Extra'er
 
Posts: 472
Joined: Tue Dec 05, 2006 3:35 am
Location: Sweden

Re: edis 4 rev limiter?

Postby robocog » Fri Nov 06, 2009 4:16 pm

would be worried about cutting fuel (via pressure or injector) incase I get settings wrong
though thinking about it as long as it fully cuts fuel rather than went 'lean enough to do bad things' the end result /should/ be the same?
but what about it holding RPM to a limit?
I guess it must be seen as a lean mixture if its cutting fuel intermittently to keep it 'pinned' at max desired RPM required unless I am not grasping it properly?

The more I try and get my head round it the less I like the idea

Prefer to do the spark side of things-it sounds like the safest way to limit foot related RPM.. though not sure if the lambda sensor or exhaust wadding will feel the same way?..more easily replaced than molten pistons though

Not sure fuel cut would have the same 'urgency and authority' that the rev ceiling had been found and may lead to "mash pedal harder into the bulkhead to see if it does more" if its a silent/invisible barrier (had the fuel pump blow a fuse a few times whilst out playing and I know my gut reaction was to stab the loud pedal a fair few times into the bulkhead before realising it wasn't having the desired effect)

Looking forward to the hard limiter kit to arrive and give it a try, not that I intend to be leaning on it on a regular basis
also half fancy using it as an anti theft measure via a switch from rpm output set to 1000 rpm so car will start/run if hotwired, but not really useful apart from attracting major attention at walking pace gettaway speed
Just got a non-contact RFID immobiliser switch thingy that would fit into my plan quite nicely


Regards
Rob
robocog
MS/Extra Newbie
 
Posts: 12
Joined: Tue Nov 20, 2007 3:06 pm

Re: edis 4 rev limiter?

Postby W113 » Sat Nov 07, 2009 3:31 am

The fuel cut was used on production vehicles . It works by stopping the fuel pump. The pressure will be maintained for a
few 1/10 of a sec, then it will drop and rpm will start dropping, rapidly, due to fuel starvation, ie lean burn :oops:
Pump will kick in , engine starts revup ..... and so it goes.

This was signal to the driver to shift up. It was used on manual as well as auto gbox cars.
Most drivers would lift off and shift up. It was good enough for MB, they probably made quite extensive tests
what happened if you just stayed in gear and stomped. My next life will be as production test driver, as is now I have
to pay for all of my excesses :shock:

I had a 300E ( W124) and tested it a few times . This was an autobox jalopy, and it did not shudder, jerk or bang,
it just levelled out at 6350 rpm as long ( 1-2 s?) as I stepped on it.

One advantage is that the horrible mech transients that comes from a hard spark cut are avoided. Also the exhaust bangs,
which certainly is a prime concern on catalyst cars. The cat structure collapses at a cat explosion if it is the ceramic haney-
comb stuff.

The soft spark cut you describe is interesting, but you have to control dwell as well, reducing the current is only a partial solution.
And dwell is an internal function in EDIS, not accessible afaIk.

Stored energy in the coil = 0,5*the coil current squared*charging time Ws.

But testing the current limiter seems a good solution. A simple test would be to supply the whole EDIS with a variable power supply at
6-12 VDC good for 3-5 Amps , and see how it reacts at say 6100 rpm when you reduce the drive voltage.

Good luck and please let us know how it goes. Very interesting.
I am presently helping a friend with a very hot Ford 351W, MS2 Extra 2.1.0 and EDIS. And we have decided to rely on the inherent EDIS 8
rpm limiter which is around 6700 rpm, but your idea seems interesting. The 350W is extremely well balanced and in top condition mechanically,
but a rev limit at 6100 would be MUCH better. It sits in a GT40 replica , very light and up to 3rd gear the rpm shoots off of the scale very fast!
We also managed to pulverize the Renault 5 speed box :yeah!: . So now the car is down for mods, a competition modded AUDI box is on its way in .
Good for 1500kg and 750 hp. Should be enough 8)

Best regards

W113
If not understood , it will not work
W113
Master MS/Extra'er
 
Posts: 472
Joined: Tue Dec 05, 2006 3:35 am
Location: Sweden

Re: edis 4 rev limiter?

Postby robocog » Tue Jan 22, 2013 12:06 pm

Necro post
Just got a PM asking how I got on with it

Is it really that long ago that I bought the hard rev limiter??...crikey where do the years go?

I still have it (and not even opened the packet yet !!!)

Had our first child a year and a half ago...so the toy car has not moved much since then

I have bought a new alloy sump (hoping it will cure the weep that stains the driveway) and a few new bits and bobs that need bolting to her
Assuming we get a summer this year I will get round to building and trying the rev limiter eventually

I will update here when something happens :-)

Regards
Rob
robocog
MS/Extra Newbie
 
Posts: 12
Joined: Tue Nov 20, 2007 3:06 pm

Re: edis 4 rev limiter?

Postby robocog » Sat Dec 09, 2017 2:59 pm

ROFL, car is only just about to be put back on the road - I'd completely forgotten about this thread
Tonight has been spent ripping through the toy cupboard and most of the house in search of the hard rev limiter circuit board - it seems to have vanished :(

(though I found the parts I also bought to try and bet bluetooth serial working)

Engine went back in the car last weekend and today has been very frustrating putting the last mechanical and electrical bits back on the car
Got as far as getting the oil pump primed and oil pressure built up enough to turn off the warning light

Finding the megasquirt ecu and dusting if off ( it lived indoors all this time)

Hooking up a new battery to the car and finding that
the lift pump to swirl pot has siezed
the high pressure fuel pipes have leaks
and worst of all the loom feeding the megasquirt has gone bad somewhere
(ecu still works as I hooked it up to the jimstim and connected via the PC and twiddled the knobs to verify it was still alive , just no lights on the ecu and fuel pump constantly running when hooked up to the cars own loom)

Edis was giving sparks (but seemingly quite weak)
When I put the megasquirt in I didn't place the fusebox and relays wisely and they are an absolute swine to get to to test and check and have possibly has water ingress

Hoping its just a simple dirty connection or earth or a relay that has gone bad
(did I mention the relays and fuses are in the stupidest most inaccessible place possible?)

Going to start at the ecu connector as I have a nasty feeling that water may have ingressed into the shell over the years and its the only bit I can get to without a LOT of effort (dash off job)
(I did put plenty of dilectric grease into the pin side, but internally will have been left raw solder connection...and of course I left it dangling so any moisture could work its way down the wires and into the shell...doh!)

I should be thankful - the car is going to be back on the road and I didn't cave in and sell it on after all these years
Looking forward to taking my new co-pilot out in it
Was rather hoping I could pick up the Christmas tree in it - but its not looking likely for this year, left it too late, unless I strike it lucky tomorrow - back out with the plastic one again

Regards
Rob
robocog
MS/Extra Newbie
 
Posts: 12
Joined: Tue Nov 20, 2007 3:06 pm


Return to General, New users, Purchasing

Who is online

Users browsing this forum: Bing [Bot] and 2 guests