308 V12 conversion begins

You're right that 60 is a tad big. I'm not sure how the engine will do with fuel but .45-.5 bsfc I guess which yields 46-51lb at 65% or 50-56lb at 60% for 800 hp by my math. Not knowing exactly I would rather set up to end with the duty cyle low rather than high I think. 48 and 52 I think are standard sizes on the low ens or 60 on the high end.

I guess the point is that with staged injectors I don't really have to guess right and it will still drive the best it possibly can around town becasue it will be on 19ish lb injectors and still make all the power it can. I'll probably aim for a total or about 55lb/hr so maybe a 19 and a 36 which are both very standard sizes I think.

 

VEMS Jason got back to me and while the unit will do staged injection it will not currently control more than 8 injectors….but that is on to do list. He contacted the firmware guys to see what it would take to either steal the 4 stepper motor outputs or 4 of the 8 ignition outputs for fuel and find out how long to make it happen.

This would be a really good option if it turns out they can make the upgrade because the worst case is I still have 4 ignition outputs from each ecu and possibly all 8. That means waste spark ignition would be no problem and possibly true direct fire would be availably, either way I wouldn’t need distributors . The ignition module is built in so I won’t need that and they cost about ½ what a haltech E11 costs.

Jason also recommended a reliable, inexpensive hall effect sense to use for the crank trigger. I’ll get a couple of those and mount them in the bell housing. If the new firmware plan doesn’t work out with the VEMS I can fall back to the haltech and the same sensors will work fine and I’m machining the cams to accept a distributor drive just in case. One change I’m making is the spec sheet for the sensor specifies a larger tooth as optimal than I had in my design, so changed from the 60-2 pattern to a 36-1 pattern which is also very standard and allows a larger tooth. Technically less teeth means it takes longer for the ECU to sense and rpm change but even at idle and with only 36 teeth it sees 1000 teeth per second or 1 every ms…that doesn’t seem like a problem. For comparison my old set-up only had 4 teeth and it ran just fine.

The steel for the flywheel arrived yesterday so as soon as I finalize a couple more little things the cutting can begin. I realized the other day that my crank has an adapter for the auto trans stuff the 400i had pressed in where the pilot bearing should be so I need to get that out and measure to figure out what the center bore of the flywheel needs to be. I also need to decide exactly where in the bellhousing I want to mount the crank sensors so I can time the trigger ring on the flywheel properly. I’ll probably look at these things tonight instead of working on the cams so I can wrap up the flywheel design and get it to they guys in the shop to get rolling on.
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Splitting the maps to run 1 set of injectors with 1 ecu and the others with the other would be a HUGE problem. The cross over point is load dependant and the 2 eucs would just never stay sync'd on where that point is. Also the tuning mpas in the 2 ECUs would be different making tuning that much harder.

What I'm going to do is a 6 cylinder engines. The maps in both ECUs will be identical and the if the ecus are slgithly out of sync on load sensing it makes no difference. Thsi is the only way to do it that makes sense.

 

Yup.

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It'll be fine......

The low end drivablitly with be very good, much better than stock for sure with the engine anf EFI configured the way I'm planning.

 

They are simple and I like that about them.....they just don't work very well and certainly are not capable of running this engine for street use.

 

The problem is you can't start the second set of injectors at 0 to go up becasue you can't really control anything beloe about 1.4ms so the second set has to come on at 1.4ms or there about. That measns the primary set need to step down at exactly the same time the seconaries come on or you'll have way too much fuel and the only way to know it's happening at exactly the same time is if 1 ecu is controlling both sets.

There are 2 common set-ups. one is the primarys step dow a programed amount at the trigger point for the secondaries and then stay at that setting with all the tuning from there up done withthe secondaries. this is the method I personally like the best. The second method is that at the trigger point both injectors fire for 1/2 the programed time....it's harder to tune the transition if the 2 injectors are not both the same size with this method.

 

Both ECUs must contain the same maps with each ecu controling everything on the 1/2 the engine or they will get all out of sync and there will be problems at the secondary injector trigger point.

Ideally the primary injectors will be small enough to only handle only idle and cruise giving the most control where it's most needed. Then the bigger injectors feed the engine from about 1/3 throttle and up where slight variations mean much less relative to the total flow. This is IMO the best way to make what is really a race engine behave on the street like a street engine. It’s also the best way to make hp because at power most of the fuel is injected near the top of the intake runner giving the most time possible to fully atomize.

I think 2 maps are allowed in both the ECUs I'm considering.

I am fitting the flywheel with a 36-1 trigger which means that I could run waste spark and semi-sequential injection from 1 ecu with no cam senor or second ecu needed. This is another fall back position if I find problems with the complicated system and I’m sure it will work…just not as well as the more sophisticated system.

 

Ahhh...they change the exhaust, air intake, new chip and a single injector mod...3 or which probably help

 

I popped the adapter out of the crank and the hole in the crank is 35mm just like all the other ferrari cranks. I also took a look at the crank timing and the #1 throw is directly in like with the bolt hole right next to the pin....that makes it easy.

The sensor really wants to be mounted to the engine it looks like instead of the bell housing so I'll need to think about that a little bit.

I fininished the second cam and most of the 3rd. 1 more night on the holes then I need to make some clearance on the intakes for the oversize buckets by shortening the bearing journal area 2mm....then they are finally real to ship.
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ECU Jason says if I use hall effect pickups the 2 ECUs will share the signal with no problem so all I need is 1 crank sensor and 1 cam sensor and so things just keep getting easier. He’s showing my flywheel trigger wheel design to his hardware guy to make sure he’s happy with everything before I start cutting metal.

After some time to process the crank sensor position I realized I hadn’t been thinking very well at all. The bell housing is basically round and will bolt on to the back of the block. The block however is a ½ circle and I’ll need to make a bolt on filler piece to cover the bottom ½ of the flywheel….the same flywheel with the trigger ring cut on it. Clearly the sensor or sensors go on that filler piece. Enough thinking about that.