L8 APEKS

Hey guys,

I am looking into the possibility of ditching the K-Jet setup in favor of Megasquirt on a '79.

I understand I'll need some sensors off later model cars for computer input (coolant temp, TPS), as well as intake runners with standard injector holes, and fuel rails.

Can anyone help me out with which years/models I'd be best to pull these parts from? Any info appreciated! Thanks in advance!

wildwestsydney

I would not hesitate to go the Megasquirt route. I sucessfully installed a MSI on my 1998 suzuki DR 350 dual sport motorcycle. I did not go for ignition control just fuel. I was very happy with the project. I saved a ton of gas money using the bike to back and forth to work. That was one of the deciding factors in taking the plunge into a 928, I figured that I could always Megasquirt it if I had an ECU failure. I would look into getting a set of injectors from summit. There are tons of fuel rail kits that could be adapted. Summit also have a generic inline high PSI electric fuel pump for EFI apps for around a $100. If you go for it you will have a super reliable very tunable ECU. I went with a MSI for the cost. I bought a kit and soldered it together my self, it was not a big deal.

L8 APEKS

Yeah...many friends have used it with amazing results, normally finding ~20hp in the process too. A guy did this in a '76 MBZ 450SL, the engine is very similar to the early 928 lump.

If I do race this in NASA, Megasquirt is currently a 7-point hit. That only leaves me room for tires and a partial exhaust. We'll see!

heinrich

lizard931 here has excellent experience with this stuff.

BC

7 points? Well, that answers my question then.

BC

If its 7 points then I would do spark as well, and make sure you get the best out of the MS system. Maybe even run ethanol for an extra 5% power (if you up the compression)

Lizard928

I have a 928 running on MSII V3.0 right now, and I am sure that there will be some lads in the seattle area who will be running MS soon as well.

I have 36-1 timing rings which replace the AC pulley (or could be run with the AC pulley, but would cause alittle missalignment of the other belts). This timing ring would enable you to run EDIS which is THE way to go for ign systems imo.

As well I would NOT bother trying to get/find Porsche sensors for the IAT and CLT. Just go with Gm sensors.

You can purchase them very cheap with a pigtail from www.diyautotune.com

And you can definetly find a few more ponies out of the engine.

BC

Has your friend installed that flywheel I had the timing ring put on? Did it work? I was going to do it again.

Lizard928

Brendan, the timing ring you had on that flywheel would never have worked. It interfered with parts on the engine. We ended up pressing it off, and putting on a factory 100-1 ring

L8 APEKS

Colin,

Thanks so much for chiming in!

At this point, I was not going to use MS for ignition; I was only going to use MS for fuel. It all depends on what happens as I start tearing this thing down to see what kind of shape it's in. I'm already inclined to do a quick driveway hone and re-ring w/ mains and rods just for gits and shiggles. No better way to get to know an engine, right!?

The chap I saw who converted the 450SL left the air metering assembly atop the engine; but he removed the flap door. Did you do something similar? I would appreciate any pictures or write-ups if you published any. Let me know! Thanks again!

BC

Do you still have it? It just needed to be cut down a bit probably. Its a good idea, and makes for a solid signal - it just needed work. What you are saying is that the teeth would need to be shorter, right?

I have another 84 flywheel with no teeth (a bit larger) and will do the same thing, probably, for the 82. Putting the wheel on the front of the engine interferes with using an SC crank pulley.

Have you gotten your VEMS yet?

L8 APEKS

PS...after reviewing the rules, MS for fuel only may only be a +2 point mod.

hacker-pschorr

Almost any EFI will require a crank sensor - something these motors do not have a provision for. You could use the green wire, not the best solution since it's driven off the timing belt and not always 100% accurate versus a block mounted sensor.

I'm having Todd add an OEM 928 crank sensor to the lower bellhousing of my 79, and I'm having an 85/86 timing wheel installed on my flywheel in the proper orientation for where the sensor will be. This will allow me to use any year block with this flywheel / lower bellhousing.

I'm converting my 79 to LH/EZF from a EuroS using the twin dizzy. With any luck I'll actually start this project this winter. I already have all the parts.

wildwestsydney

I hope you take the plunge to MS EFI. It sounds like you allready have some support. Great advice on the GM sensors thats what I used on my bike. The MS is a MAP based system so I don't think it should be a big deal to get a good signal for that from the 928 spider manifold.

L8 APEKS

I thought the crank sensor was NOT required for MS fuel? Just a MAP or MAF, CTS, TPS?