Speedmaster 8-Stack Injection

#1
Hey guys,

Just wondering if anyone has installed an Speedmaster 8-Stack injection system into their car yet? i don't really have a wiring diagram so that would help but pretty sure ive got them all sorted out anyway.

My main issue though is the cable that i believe to be for the IAC. Ive read that it can be quite a problem to get one to work on the 8 stack and thats if its even possible? Does the car need to actually run the IAC and will the computer still be able to learn what it needs to (speedmaster self learning ecu) without it being connected?

Thanks for your time!

Mitch
 
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#3
Mitchell,

Yes, I have.

Just to be precise, the mechanicals (inlet manifold, TB's, linkage, etc.) is a speedmaster product. The EFI control system you're working with is made and sold by FAST (Electronic Fuel Injection Leader - FAST(R) - Fuel Air Spark Technology Fuelairspark.com), and it's FAST that provides the post-sale support.

The IAC (Idle Air Control valve) does not have to be used with the FAST EZ EFI 2.0 system. You can use a plain old mechanical adjustment at the TB's if you prefer. The IAC connector will be sending a signal through the cable to modulate idle rpm, but not being hooked up to anything....well, it won't actually do anything. Yes, the ECU will learn just fine without it hooked up.

The IAC can be quite easily used on the speedmaster inlet manifold. There are a number of ports in the plenum downstream of the butterflys in the TB. Use one of those ports to connect the IAC with a good quality (non-collapsable) vacuum tube. The ports are NPT. You'll have to fabricate a bracket to mount the IAC on the manifold. Hook up the connector and you're in business. There is a calibration routine for the IAC and idle speed in the set up routine. Works very well keeping a nice steady idle once set up.

You should have received the instructions and wiring diagram in the box the FAST EZ EFI 2.0 came in.
 

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#4
Hey terry, im not sure yet. Will have to see if i can find that option on tge software. I dont want to install it all to find out it cant be done and have to remove the manifold again.

Cliff, this is an older version and supposedly either made by fast or has copied fast components or something like that. I will try to post a pic of it. Its speedmaster turnkey efi.

Im still new to the whole iac concept as this is the first efi ive mucked around with. So the idea would be to mount the iac in the plenum underneath and use an existing hole in the top to let the air inside?


Additionally ive come across another hurdle... the carbon canister. It has electrics hooked up from the old motec system but this new setup does not have any wiring for it. Does it need to be connected or will it operate fine without it?
 
#5
Hey terry, im not sure yet. Will have to see if i can find that option on tge software. I dont want to install it all to find out it cant be done and have to remove the manifold again.

Cliff, this is an older version and supposedly either made by fast or has copied fast components or something like that. I will try to post a pic of it. Its speedmaster turnkey efi.

Im still new to the whole iac concept as this is the first efi ive mucked around with. So the idea would be to mount the iac in the plenum underneath and use an existing hole in the top to let the air inside?


Additionally ive come across another hurdle... the carbon canister. It has electrics hooked up from the old motec system but this new setup does not have any wiring for it. Does it need to be connected or will it operate fine without it?
Mitch,

Yes, that's the basic idea. You can actually mount the IAC is a variety of locations - it's essentially just a breathing tube for add'l air into the plenum downstream of the throttle plates. I made a holder out of aluminium for it which is actually above the plenum, with a tube connected to an existing port on the top of the plenum. Different ways to skin a cat but that's the basic idea.
 

Randy V

Administrator
#6
Mitch,

Yes, that's the basic idea. You can actually mount the IAC is a variety of locations - it's essentially just a breathing tube for add'l air into the plenum downstream of the throttle plates. I made a holder out of aluminium for it which is actually above the plenum, with a tube connected to an existing port on the top of the plenum. Different ways to skin a cat but that's the basic idea.
Then your intake manifold must have a shared plenum if you are running a single IAC (actually, I’ve never seen more than one IAC used)...
Also, if a shared plenum, you would have a reliable vacuum source for your MAP sensor...
 
#7
Then your intake manifold must have a shared plenum if you are running a single IAC (actually, I’ve never seen more than one IAC used)...
Also, if a shared plenum, you would have a reliable vacuum source for your MAP sensor...
What I used on mine was a common plenum (the hollow portion of the mounting platform for the throttle pivot) from each ITB vacuum port, connecting all 8 vacuum tubes. The IAC was then valved to that common plenum. The MAP is also connected to this.

Early on in the build. Not pretty, but nothing I make is.



 
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#9
Then your intake manifold must have a shared plenum if you are running a single IAC (actually, I’ve never seen more than one IAC used)...
Also, if a shared plenum, you would have a reliable vacuum source for your MAP sensor...
Randy,

Yes, that's correct. I believe the manifold the OP has does have the shared/common plenum. This is the same with the Inglese 8 stack and other manifolds made for this type of multi-port/multi-throat system. The common plenum usually sits on the bottom between the runners with about a 1/4 inch hole "port" from the runner to the plenum.

The common plenum is also helpful for other stuff (other than the IAC) too - brake booster, MAP sensor, etc.
 
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