DIYEFI.org Forum

I’m a new member here and I figured this is as good a place to introduce myself as anywhere. My name is Mark and I’m a mechanical engineer. I’ve been playing at racing in various forms for almost 30 years now. I work in new product development and I have some decent experience in specifying system input/output requirements…so I know a lot more about what the engine needs and wants than most and probably a lot less about what the electronics are actually doing than most on this forum.

My current project is an 84 Ferrari 308. I’ve had the car 9 years now. The first thing I did when I got it was spend a year to rebuild the engine and design and install a supercharger system using a custom intake and an eaton MP90 blower. I installed a haltech E6k running multipoint injection with waste spark and it was good. It make 300 rwhp from the little 3.0 liter V8 and I drove it that way for a couple years.

After a couple years I decided if a small supercharger was good a bigger supercharger would be better so off with the MP90 and on with a whipple Ax2300 screw type blower with a new custom intake designed to hold a water/air intercooler. Off with the E6k and on with an E11V1. This setup made 420 rwhp at 22 psi on pump gas. The haltech just never quite delivered the control I was looking for so I upgraded to a motec M800 and things were good.

Fast forward a couple more years to the current project. I pulled the V8 out and bought myself a very tired 4.8L V12 from a Ferrari 400i. Then I got a set of 4 valve heads from a Testarossa saying “I’ll bet they fit” on the 400 block (which is a 2V engine). I’ve spent the past year and a half force fitting the 400 block onto the 308 transaxle and the TR heads onto the 400 block….it turned out this was a very bad idea and a just plain stupid amount of work but I’m getting there. If you are interesting in all the gory details I’ve got losts of pictures in a VERY long thread on the Ferrari forum, (they make you register to see the pics but its free and they don’t send spam). It should make about 750-800 crank hp at about 9000 rpm when complete

http://www.ferrarichat.com/forum/showth ... p?t=170171

I’m getting to the point where I need to be planning for how to control this thing. The engine will have 12 throttle bodies and 24 fuel injectors (12 show injectors, 12 port injectors). It will need to be sequential injection. I know, I know, many if not most of you probably believe that sequential injection is a only a nice to have and Hi/Low injectors are just plain silly but I that is an incorrect assertion that is not supported by any data I’ve ever seen.

The options at this point appear limited to a pair of Motec M800s linked over the canbus to share sensor info and tuning maps or wait (this will be about when the engine is done anyway)for the new Motec M190 that is due out in 6-12 months that will have 24 injector channels and 12 ignitions channels all in 1 ecu. Both of these options are really frikin expensive but I haven’t found any decent alternative….a pair of haltech plat 2000 maybe but then I’m locked into twin distributor ignition (which I may use anyway) and I’ll have to live without traction control or add a pair of firkin expensive stand alone TC units and won’t have saved any money. When I first stumbled on the DIYEFI project I was hoping there would be some way to make it work for me, but with only 6 fuel channels I would need 4 of them and that seems a bit silly and would be horrible to try and tune.

Great looking piece of machinery.

Have you tried group firing the staged injectors? I understand this isn't the best way but at higher rpm where the injectors will be opening having full sequential is less of an advantage (quite happy for you to correct me if I'm wrong on this).

What phasing with reference to TDC/BDC or valve opening do you fire the injectors at?

The microcontroller in the FreeEMS has quite a few outputs that could control your injectors. I think the main reason it is currently aiming for 6inj, 6ignition is that that is the maximum that can be designed for in the software while still allowing seperate mapping/trimming of each injector channel. Best to ask on the FreeEMS General board.

longracing wrote:Great looking piece of machinery.

Have you tried group firing the staged injectors? I understand this isn't the best way but at higher rpm where the injectors will be opening having full sequential is less of an advantage (quite happy for you to correct me if I'm wrong on this).

What phasing with reference to TDC/BDC or valve opening do you fire the injectors at?

Grouping the injectors isn’t a good idea. The injector duty cycle doesn’t want to be more than about 60% if making the most hp possible is the goal… and it is so in my case the main injectors will be at about a 50%-55% duty cycle I think.

Injection should end at about BDC on the intake stroke. There is some benefit to playing with the exact injection end point and the high end ecus let you mess with it, but BTC is normally close enough.

mk e wrote:There is some benefit to playing with the exact injection end point and the high end ecus let you mess with it, but BTC is normally close enough.

High end ones, and of course, MS2 ;-)

I think you under rate it a lot. A friend of mine just took his BMW turbo project for certification to become road legal in NZ and the certifier who is a VERY well respected man and has driven more modified cars and scratch built cars than probably anyone else in the country said that it was one of the best tuned cars he's been in. This compared to all those commercial ECU's from ozzy, nz, america, etc. Nothing like an owner that REALLY cares to get the most out of a device. MS(all variants) have many issues, but don't be too quick to discount the benefits and strengths.

Fred.

Fred wrote:

mk e wrote:There is some benefit to playing with the exact injection end point and the high end ecus let you mess with it, but BTC is normally close enough.

High end ones, and of course, MS2

I think you under rate it a lot. A friend of mine just took his BMW turbo project for certification to become road legal in NZ and the certifier who is a VERY well respected man and has driven more modified cars and scratch built cars than probably anyone else in the country said that it was one of the best tuned cars he's been in. This compared to all those commercial ECU's from ozzy, nz, america, etc. Nothing like an owner that REALLY cares to get the most out of a device. MS(all variants) have many issues, but don't be too quick to discount the benefits and strengths.

Fred.

There is no question in my mind that a talented electronics person can make a MS work fine in many applications.....but most people can't. In theory the MS2 is now sequential and has 16x32 maps...I believe you but if I bought one and trusted their web site like I would do, I would had multipoint and 12x12 maps. the 2 cars I pulled them off of had issues with rapid acceleration rates that nothing seemed to fix and also waves in the torque curve that could not be corrected without pulling rpm points from around the idle set point which then cause idle and cold start issues....and of course plugs that were loading up at low power/idle with the multipoint injection.

See, now you are getting into the actual issues with MS. Which website? Which firmware? You are right that it takes quite a bit of inside info to make a (any) MS setup work sweetly, but that doesn't mean that the ECU is not a capable one which was your present in your initial implications. As it happens I've been blatting around in another MS2 vehicle today and yesterday in San Diego and it's lovely. It could be setup and tuned better, but the owner (Abe) is a tinkerer (so it's often changing...) and it's good enough as is. Pretty fast along the "freeway" teaching various cars lessons here and there :-)

The issues with MS are mainly documentation, political, transparency, grounding, pin-count and code bugs. I may have forgotten some though :-) If you understand the device well (without being a guru with code or electronics) then you can get excellent results from it without a worry.

Fred.