MSefi.com read only forum (Jan.15,2018)

I have built a MSII about a year ago to run my Vette LT1 motor swap into my '87 Porsche944S. I have since been layed off of work and now going to school full time for mechanical engineering. Since time and money is low now I am thinking of going a different route with the 944S project.

I am thinking of using the stock Porsche S 16 valve motor but using a set of Suzuki Hayabusa throttle bodies for my fuel injection.

My question is if the MSII would run the Hayabusa fuel injectors, throttle position switch and temp sensors. What about a fast idle stepper motor?

I was also planing on controling all 4 ITB by using all the sensors on only 1 cylinder and "trusting" the other 3 are working just the same. I do have a 4 channel pyrometer to measure all 4 exhaust temps (one for each runner) to notify me if things are way off (A/F ratio wise).

Ignition would be handled by the Ford EDIS4 ignition system and a trigger wheel.

What faults do you guys see in my project?

Best Regards,
Speedy:)

The only issue I could think of is if your A/F is way off on the other 3 cylinders, something bad may happen. But not positive, I'd definite check that out though. I'm still figuring out the ITB setup myself; I have all 4 going into one to the MAP sensor. Sorry I can't be of more help.

Which busa TBs do you have?
Hi or Lo impedance? Flow rate?
MS2 should run them all.

Use GM sensors, they're cheap enough and you don't have to recalibrate your inputs. Mount the MAT in one of the air cleaners.
The Suzi TPS should calibrate fine. I'm using one.
Tee all TB pressures together and run one line to the MAP sensor with a restrictor in it. Refer megamanual.

I would use a WB O2. Much easier to tune a ITB setup with one IMO.
Can you put it in a collector somewhere? Where at least 2 cylinder outlets meet.

Do you really need the stepper? I just use a soleniod to open the throttle a little and it works great.

EDIS is great too.

Thanks for all the responses. As of yet I don't have the Busa throttle bodies. I was looking at running the busa fuel injectors and fuel rail since the 944 stock intake manifold, fuel rail and injectors were damaged in the engine fire. If I use the busa stuff I can cut the mounting flange from the stock intake and weld on brakets to mount the busa ITBs.

I was planning on using a WB O2 sensor like the Inovative setup. There is a single bung already in the 4-2-1 header which i can use to get the A/F ratios.

I like your idea of T-ing all the vacuum lines together for the MAP sensor instead of monitoring only 1 cylinder.

For the fast idle stepper/ solenoid should I weld in air fittings between the ITB and the head and attach the stepper/ soleniod to these fittings by a T?

Thanks again for all your help. I so badley want to get this car out of the garage to see the light of day once again.

Regards,
Speedy:)

speedracing944 wrote:For the fast idle stepper/ solenoid should I weld in air fittings between the ITB and the head and attach the stepper/ soleniod to these fittings by a T?

Thanks again for all your help. I so badley want to get this car out of the garage to see the light of day once again.

Regards,
Speedy:)

Install the air fittings anywhere after the throttle plates. Whatever works best for your installation. My TR8's idle solenoid is probably 18 inches of hose and tubing from the intake entry point. It's not ITB's so it was easier. My TR3 will eventually have a Honda 600 4Fi intake, so I know what you are looking at.

My TR8 was down for quite some time while I did lots of mechanical and sheet metal work, concurrent with the MS conversion. I know how you feel. I'm still tuning, but it's so nice to get it out and drive around again.

Search for ITB setups. Many folks run the ITB vacuum lines into a common plenum before the MS.

Jack