GEN 7 DFI Questions

Can someone let me know what the differences are and the benefits of having a bank-to-bank as opposed to the sequential. What options are available?

I am interested in having DFI in the car and leaving the limitations of the stock PCM, but, do I still need the stock PCM for things like speedometer, cooling fans, etc? .. I have a TH400 in it now, so, no need for the tranny controls..

Thanks,

Sean

Originally posted by Sean94Z
Can someone let me know what the differences are and the benefits of having a bank-to-bank as opposed to the sequential. What options are available?

I am interested in having DFI in the car and leaving the limitations of the stock PCM, but, do I still need the stock PCM for things like speedometer, cooling fans, etc? .. I have a TH400 in it now, so, no need for the tranny controls..

Thanks,

Sean

Bank to bank works ok, but it may be a little easier to get a good idle and very good drivability at very low load/low rpm with sequential. No difference in max hp. I think they charge a bit more for sequential, right?

Rich Krause

Bank to Bank injection can sometimes cause pressure waves in your fuel rails when using larger injectors because you are opening 4 injectors at once. This can affect the actual fuel pressure in the rail, and sometimes leads to driveability problems.

Since sequential injection opens one injector at a time, you don't see much variance in fuel rail pressure as the injectors fire.

As far as the DFI stuff, the newer systems come with both sequential and bank to bank injection in the box. You just use the tuning software to select the configuration that you want to use. No extra cost, and no sending the box in for an upgrade when you want to go sequential.

It also handles things like dual fans, ac clutch control, shift light, mil light and stuff like that. you can piggyback it to the stock PCM if you want, but you don't have to. You'd just have to figure a way to run the speedo, as there are no vss inputs to the DFI box.

Does GEN7 control low-z injectors w/o a VIC like the Gen6 needed?

Sorry to ask all these questions, I e-mailed a few 'recommended' vendors, but no one has gotten back to me.

--Sean

You can use low impedance injectors -- 2 per driver if you need to.

Try contacting TurboPeople in New York, they are in your area, and are just about the best around when it comes to DFI stuff.

I'm looking into doing the same thing w/ the Gen VII, and I still have the 4L60E (a 1k rebuild too, actually) so I need the tranny controls.

In terms of piggybacking the stock PCM, I have a few questions. So far I know the MAP, TPS, and tach signal will be needed by both the DFI and PCM units, so those signals will have to be spliced to both. Will there be any voltage drops or resistance changes from both computers getting the signals? Will diodes be needed to prevent any sorts of feedback between the two computers?

Also, in hopes of not blowing up the stock PCM, will it harm anything that the PCM's outputs are no longer hooked up to anything (ie, the fuel injector output wires will no longer be hooked up, nor the IAC motor outputs, etc.) The only thing I'm considering leaving hooked up is the fuel pump relay for safety reasons (so if you're in an accident, the PCM will shut the ground to the relay off to avoid a car fire as well--assuming a 95 Formula has this impact sensor.)

If I forgot any questions that other people have, please chime in, and if anyone has any answers, PLEASE CHIME IN! :D

Rob

The DFI doesn't have trans controls, so you'd have to get an aftermarket controller like the one from TCI.

Shouldn't be any harm in sharing sensor connections between the pcm and the DFI. The DFI will come with some of it's own sensors also, like a Manifold Surface Temperature sensor.

You may want to contact someone that makes adapter harnesses like this place. (http://fasttrackperformance.com/) It could save you a lot of work. They are pretty good about answering questions too.