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Programmable Ignition
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ideola  



Joined: 01 Oct 2004
Posts: 15451
Location: Woodstock IL

PostPosted: Wed Jul 27, 2011 12:49 am    Post subject: Reply with quote

Honestly, I don't know that controlling the ignition electronically will give you that much benefit on the S1 without also going to EFI. The S1 fuel dizzy and WUR seem to be setup to over-fuel as a safety margin. I'm no EFI / DIS expert, but it seems to me that with regard to engine management, the overfueling issue is the thing to go after.

That said, you might really like having the MSD6AL (turbo version) on the S1, as it has multiple sparks below 3500 RPM, and hotter bigger single spark above. Don't know that it will translate to power necessarily, but for a fairly modest investment and relatively easy installation, you might see some more responsiveness.
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88 924S SE | 82 931 Holbert | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition
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WEASEL149  



Joined: 19 Aug 2005
Posts: 595
Location: UK, Sheffield

PostPosted: Wed Jul 27, 2011 1:12 am    Post subject: Reply with quote

ideola wrote:
Honestly, I don't know that controlling the ignition electronically will give you that much benefit on the S1 without also going to EFI. The S1 fuel dizzy and WUR seem to be setup to over-fuel as a safety margin. I'm no EFI / DIS expert, but it seems to me that with regard to engine management, the overfueling issue is the thing to go after.

That said, you might really like having the MSD6AL (turbo version) on the S1, as it has multiple sparks below 3500 RPM, and hotter bigger single spark above. Don't know that it will translate to power necessarily, but for a fairly modest investment and relatively easy installation, you might see some more responsiveness.


Yeah I totally agree with you about the over-fuelling CIS, and indeed the rewards of going full EFI (which I probably will eventually with all the ever-tightening european emission laws, not to mention fuel cost).

The thing that put me back on the programmable ignition trail was an engine management book by Dave Walker.
He's regarded as a heavyweight tuning guru in the UK and has been tuning cars for decades.
He basically said that most of the gains of going full management were to be had from accurate spark timing, particularly on turbocharged cars.
From what I remember he also said that having a distributor control timing from vacuum/boost was basically as good as not having anything at all lol!

If I remember correctly he did own a 931 for a while and converted it to full management. He also had differing maps in his ECU so he could run E85.
I think I remember him gaining 30hp purely from the advance he gained by running E85, before his injectors basically ran out of headroom.
I never found out what happened after or if he did fit larger injectors but it just goes to show what can be done running E85.

I've not looked into the MSD6AL - will have to have a look into that, thanks!
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Wed Jul 27, 2011 1:42 am    Post subject: Reply with quote

MSD6AL. . .interesting. Looks like it will run right off the S1 dizzy, but is it programmable? Anyone here used it?
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ideola  



Joined: 01 Oct 2004
Posts: 15451
Location: Woodstock IL

PostPosted: Wed Jul 27, 2011 1:57 am    Post subject: Reply with quote

Yes, the MSD6AL should be a perfect setup for the S1. I know Vaughan and Chris both use the non-turbo version on their NA race cars, which I believe both have the same basic CD-based ignition as the S1.

I have one on the shelf that I have been sitting on for years, and planning to put on the 941, but never got around to it due to the fueling issues, which turned out to be exacerbated by that floating valve guide. I have a new engine that is 90% built, should be completing the build this week, and hoping to start the swap in early August. As soon as the new motor is installed and broken in, the MSD is the first thing I want to add.
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88 924S SE | 82 931 Holbert | 81 Euro 931 | 81 Weissach | 80 US 928 | 80 US 931 '941' | 78 D-Prod Replica | 78 w/D-Prod kit | 78 Poli-Form | 78 Limited Edition
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ideola  



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PostPosted: Wed Jul 27, 2011 1:59 am    Post subject: Reply with quote

RE: Programmable, not sure what you mean by that, but if memory serves, there is a way to configure different rev limits.
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Rasta Monsta  



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PostPosted: Wed Jul 27, 2011 3:09 am    Post subject: Reply with quote

I mean, can you set up the advance curve, or are you stuck with what comes out of the box?

And, another benefit just occured to me. . .if you use the rev limter in this unit, you can crank up the ridiculous fuel cutting limiter in the pump relay and take it off the table. I'd like that.
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Last edited by Rasta Monsta on Wed Jul 27, 2011 3:29 am; edited 1 time in total
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WEASEL149  



Joined: 19 Aug 2005
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Location: UK, Sheffield

PostPosted: Wed Jul 27, 2011 3:21 am    Post subject: Reply with quote

Rasta Monsta wrote:
I mean, can you set up the advance curve, or are you stuck with what comes out of the box?


I've had a look on http://www.msdignition.com/Products/Ignitions/6530_-_MSD_Digital_Programmable_6AL-2.aspx and it looks as though the programmable version is the Digital Programmable 6AL-2.

This apparently hooks up to a laptop and uses their software to map. According to the sales blurb it can also map based on boost pressure.
This looks to be one of the better solutions I've seen, especially if you want your car to look almost stock and retain the distributor.

I must admit, I'm always fighting myself these days with the upgrades, "should I or should I not". That's the real reason I've not yet had the balls to do EFI.
I checked recently and there are 221 924 Turbos left in the UK with only 71 currently on the road. Do I really want to mess with a relatively original example?
Then the evil voice comes back "...well you're never gonna sell it, go on do it, you know you want to..."
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Min  



Joined: 04 Nov 2002
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Location: Vernon, British Columbia, Canada

PostPosted: Wed Jul 27, 2011 8:46 am    Post subject: Reply with quote

http://www.summitracing.com/parts/MSD-6530/

359.95 for programmable ignition.

http://www.diyautotune.com/catalog/megasquirtii-ems-system-smd-pcb357-assembled-unit-p-165.html

426.00 for a MSII fully assembled, which will allow full EFI later. Will allow for coil on plug ignition for a 4 cylinder.

http://www.diyautotune.com/catalog/megasquirtii-engine-management-system-wpcb3-unassembled-kit-p-59.html

260.00 if you want to assemble it yourself.

Will also need a stim to test it once assembled.

http://www.diyautotune.com/catalog/jimstim-v15-megasquirt-stimulator-wheel-simulator-unassembl-p-174.html

59.00

After you get your ignition setup (EDIS will do multispark btw) you can eventually invest in wideband sensors, etc to do full EFI. Food for thought anyways.

Min
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WEASEL149  



Joined: 19 Aug 2005
Posts: 595
Location: UK, Sheffield

PostPosted: Thu Aug 04, 2011 2:58 am    Post subject: Reply with quote

I've just found this thread http://www.924board.org/viewtopic.php?t=34172&highlight=trigger and it has some interesting info :-

ManicCycle wrote:
It's possible to use the S2 flywheel sensor with megasquirt or another ignition control but I don't know if you would have to write new programming for it or not. The S2 sensor reads 100 teeth. For each tooth, two voltage pulses are created. There is one tooth with a soft iron insert that creates two voltage pulses that are stronger which indicates TDC. I'm not sure if that tooth makes it 101 teeth or it's already counted in the 100. This info is coming from a copy of a porsche tech paper.


Would it be possible to get MS to read from the S2 flywheel?
I've heard of wheel decoders but don't know much about them. I wonder if any of the other aftermarket ECUs could be configured to read from the flywheel?
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Min  



Joined: 04 Nov 2002
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Location: Vernon, British Columbia, Canada

PostPosted: Thu Aug 04, 2011 3:43 am    Post subject: Reply with quote

WEASEL149 wrote:
Would it be possible to get MS to read from the S2 flywheel?
I've heard of wheel decoders but don't know much about them. I wonder if any of the other aftermarket ECUs could be configured to read from the flywheel?


I figured we already covered this in another thread. Megasquirt could theoretically read from the s2 flywheel, but you will probably have to do all the coding for it yourself. I have no knowledge of other aftermarket ecu's so, no idea on any of them either. Chances of a aftermarket ecu being able to read the S2's weird trigger? pretty low. Your on your own if this is the path you want to take.

Min
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fiat22turbo  



Joined: 18 Jan 2006
Posts: 4040
Location: Portland, OR

PostPosted: Thu Aug 04, 2011 4:07 am    Post subject: Reply with quote

Seems like the S2 sensor is a Hall Effect sensor, so you'd just have to set it up for Hall Effect with MSExtra.

I don't have a way to test this though, so its just a theory at this point.
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1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)
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WEASEL149  



Joined: 19 Aug 2005
Posts: 595
Location: UK, Sheffield

PostPosted: Tue Aug 23, 2011 9:06 am    Post subject: Reply with quote

Well after some consideration and everyones input I think it's looking more and more like Megasquirt being the sensible option triggering from a front-mounted triggerwheel.

I actually plan to do the fuel first now, hopefully purchasing a fuel rail from Mr .Ideola
I have injector bungs and should shortly receive injectors.
I may consider other ECUs if one comes up second-hand for a reasonable price but it will probably be early next year now as I have the headgasket to deal with.
VEMS does look tempting and is reasonably priced with built-in wideband control. I would also consider a used Emerald.

I would like to get hold of a k26/8 from a 951 but as yet haven't found a used one but found loads of 220hp k26/6's.

I think at the same time I will delete the primary silencer and possibly vent the wastegate to atmosphere to get rid of a little back pressure.

A big thankyou to all the contributors to this thread; your help has been invaluable and is much appreciated
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WEASEL149  



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PostPosted: Thu Sep 08, 2011 9:28 am    Post subject: Reply with quote

Well I was all set to go Megasquirt 3 but then a second-hand VEMS ECU came up with a factory loom and wideband sensor. The guy had bought it for a race car and never fitted it, so it was too good to let it pass by.

I think I'll be going wasted spark and sequential injection.

Need to sort a fuel rail and fit a triggerwheel to the crank pulley.

I have injectors from a 944 Turbo but impedance is quite low so may go for a set of siemens deka high impedance to keep it simple. Will probably go for a Sard regulator.

If I can get the cash together and the right parts come up I'll upgrade the turbo. Either a 944 compressor or go for a k26/k27 hybrid.
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WEASEL149  



Joined: 19 Aug 2005
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Location: UK, Sheffield

PostPosted: Fri Apr 13, 2012 9:11 am    Post subject: Reply with quote

ideola wrote:
Well, for starters, the S2 "trigger wheel" is not a 60-2 setup...so triggering off of the sintered insert on the flywheel will require a system that can be set up for a completely custom arrangement.


Just to update this thread.
Today we were fitting a 915 alloy pressure plate to my car and lining up all the clutch assembly using a spare torque tube.
Anyway, I found myself noticing missing teeth on the triggerwheel/flywheel so decided to count the teeth. Result - 58 equally spaced teeth with a further 2 missing teeth = 60 - 2 trigger wheel.

This is something of a minor revelation to me as this is the first time I've had the engine out and bell housing off in 11 years of ownership.

So, the question is this - are all RoW/UK cars like this OR is this a custom-made wheel and part of the legacy left by Colin Belton (previous well-known owner).

EDIT: Carrera RSR has checked his S2 flywheel and his has 100 teeth so mine is a custom-machined flywheel/trigger wheel
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ideola  



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PostPosted: Sat Apr 21, 2012 1:59 pm    Post subject: Re: Programmable Ignition Reply with quote

ideola wrote:
WEASEL149 wrote:
the crank sensor from a BMW 2.8 apparently fits with minor work?


Can you be specific about which BMW 2.8 this? As in E## so I can chase it down? I would like to try to verify this little tidbit...


Found a couple of possible fits from BMWs:
12 14 1 730 027, from a '93-ish 320i
12 14 1 247 259, from a '94-ish 318i

These suckers aren't cheap, so I'm not going to be the guinea pig, but figured I'd put it out there since no one else has come up with specific model years...

...here's what the 318i unit looks like:

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