FAST XFI 2.0 VSS & Electromotive Ignition

hemi8

Goin Sideways
Joined
Jun 6, 2001
Does the FAST system need/use the VSS signal? Reason I ask is I'd like to remove the speedo cable and signal generator and use a GPS speedo.
Also, can I ditch the factory cam sensor/crank sensor/ignition module and coil and use the Electromotive Ignition system with the FAST system?

Mike
 
Does the FAST system need/use the VSS signal? Reason I ask is I'd like to remove the speedo cable and signal generator and use a GPS speedo.
Also, can I ditch the factory cam sensor/crank sensor/ignition module and coil and use the Electromotive Ignition system with the FAST system?

Mike
It doesn't need the VSS unless you wan't the XFI to control or monitor speed based parameters (like TCC lock-up MPG and traction control). If you want to disable the speedo cable you could install a driveshaft sensor and pin it directly to the harness plug on the XFI box. Then you could do whatever you want behind the dash.

But, why go with an Electromotive? What can it do that can't be done with XFI? Cam and crank sensors need to remain "in the loop".

So, I figure you want to control fueling with one system and ignition with another? Way to complicated for me. One system can do it all.
 
I am looking at the Electromotive XDI stand alone ignition system, the ignition system is robust, extremely accurate and eliminates the cam sensor. But since the FAST system is tied to the factory harness is it going to fail if it does not get signals from the ignition module harness?

Mike
 
I am looking at the Electromotive XDI stand alone ignition system, the ignition system is robust, extremely accurate and eliminates the cam sensor. But since the FAST system is tied to the factory harness is it going to fail if it does not get signals from the ignition module harness?

Mike
I think the XFI only sends info to the ignition module, not receives it. I could be wrong.

However, I know it needs a cam sensor signal to control the injectors in sequential mode. Without it, it can be used in batch fire (bank to bank). It uses the crank sensor for ignition.

Still, I'm wondering why the complexity? So many people with very streetable high powered cars are using factory coil packs or "easy upgrades" with one system. I myself have never had a problem. I like the idea of upgrading especially when a system fails.

So far, I still have a factory coilpack with no upgrades. But when it fails, I'll still try to maintain control with a single all inclusive system.
 
Technically, the C3I module conditions the crank and cam sensor signals and then sends them to the the ECU. The ECU provides the C3I module with the electronic spark timing signal (EST) and the bypass signal . The bypass signal (ECU asserts when cranking) tells the C3I to use the crank sensor signal directly (10* BTDC) for spark timing.

The XFI can still run sequential fuel and individual cylinder fuel trim without a cam sensor signal since each injector is hardwired to the XFI.. However, the actual injector timing will be randomly synchronized and idle quality may suffer. Since both the crank sensor signal (REF) and the spark timing signal (EST) is multiplexed, the C3I module requires a cam signal to figure out which cylinder is which. The XFI also needs the cam sync to figure out which cylinder is which for individual cylinder spark timing offset.
 
So would you say that when using the FAST XFI system one should use either the FAST COP, Bailey's COP, distributor or the stock system in order to avoid compatibility issues?

Mike
 
So would you say that when using the FAST XFI system one should use either the FAST COP, Bailey's COP, distributor or the stock system in order to avoid compatibility issues?

Mike

No, not necessarily. I think compatibility can always be found if need be. But if not needed, then you may want to avoid complexity.

I for one, love cool new stuff. And I think everything is too complicated until you know it. Then you know it....... and then it's easy!

Sometimes it's the COOL factor that makes it worth it. God knows, I'm all about cool. But is it worth it? How much is there to be gained.
 
Most people will stick with know ignition combos that have plug and play harnesses since there are a lot of possibilities with noise issues and also the need to add pull up or pull down resisters on the crank and cam sensors when venturing outside the normal box.
AG.
 
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