Nitrous activation problems

[Ricky Trussell]

Guys I went to the track tonight to run nitrous for the first time. FAST says it is armed when I flip the toggle on. I have my activation set for 75 tps and 3500 rpm. But it never came on. What could I have done wrong?? How can I check the soleniod to see if it comes on without activation the nitrous?

B to B system, timing control, electric fan control. I had read here before something about ecu limitations on what or how many options it can control but I used the fast plug in so I think my ecu is okay with everything I have.

Before all of you give me grief for not checking the selonoid for power at home, I have already bloodied my nose and gave myself two black eyes.

 

[Greg Kelley]

Turn bottle off. Unplug the white wire out of the FAST harness to your relay and ground the end leading to the relay. This should triger
the N2O sol.

If that doesn't work you have a wiring prob with the N2O sol or relay.

If it does work, hook the white back up and put a test light on the power to the sol wire (disconnect) and reduce your fast parameters to get the N2O to activate a fairly low rpm & TPS.

Observe your dashboard and the test light, and you should be able to determine if your setup is ok and/or if the FAST is ok.

 

[Ricky Trussell]

Just to give an update. I could not find why my nitrous was not activating. The answer was in my first post but I did not know it.

With the FAST controller bank to bank system you have no nitrous control if you control fans and fuel pump. This was the info I was given at tech from FAST.

I can control timing and nitrous. So my options are
1) nitrous with a micro switch and wet system.

2) send ecu back for update and not control fans and fuel pump but control nitrous and timing.

3) run dry system with a dedicated VE and timing tables with a micro.

Questions:

How will I tune a VE table from 12.5 to 11.5. I know I can't use the 02 to correct?

Can I use my map I have now set at 12.5 with VE's set at 88-92 wot. and change to 11.5 with ??? numbers? I know I can make a nitrous run and log to get close but I am worried about that first run. Is there a way to get close by changing VE %?? And how would I do this?

The new ecu needs to correct this limitation!!!!!!!!

 

[Lance]

Originally posted by Ricky Trussell
With the FAST controller bank to bank system you have no nitrous control if you control fans and fuel pump. This was the info I was given at tech from FAST.

That's not exactly correct. If you have an HEI bank to bank system, The I/O port normally used to control a stage of nitrous is used to operate the ignition bypass control signal. Otherwise, one stage of nitrous should be implemented and working. An HEI ECU can be reconfigured in the field to trade out fan operation for nitrous operation. If you contact Craig or I, we can send you an option file to change the configuration. Another option would be to upgrade the HEI ignition to an MSD distributer setup. This would require a factory reconfiguration of the ECU however.

The new ECU design will address the I/O shortage and then some.

 

[Ricky Trussell]

Lance, thanks for the reply. I talked to Mike (Taylor) I think, yesterday that was the info he told me. He told me that fans and fuel pump run off he same chip so I would lose both to run nitrous.

You are saying I can run my fuel pump and fans and my timing control then when I want to run nitrous I can turn fan control off and use an option file change to control the nitrous??

If I change to msd distributor what is the difference from the small cap hei that I have now? I have timing control thru the ecu now would I still have that with the msd?

contact me at 256-682-1951

 

[bobc455]

One more question.

Can we still provide a signal to the system when it is armed, so that even though it doesn't actually activate the nitrous, it still "thinks" that it does (i.e. retards the timing when conditions are met)?

That would be really handy.

-Bob Cunningham

 

[Lance]

The processor inside the ECU only has so many I/O ports. The interface components are not the problem. What we do is reassign the I/O port normally used for the fan, to operate a nitrous solenoid. This can be done with an option file but doing it does render the fan control inoperable. It can be changed back with another option file but all this will be a little cumbersome.

I cannot imagine any downside to adding a MSD inductive pickup distributor ignition. You would gain all the additional features of a real performance ignition system. And yes, the ECU would still control the ignition timing.

If an HEI ECU is configured for fan operation, the nitrous control routines are completely disabled and vice versa.

 

[Ricky Trussell]

It looks like the MSD inductive pickup is the way to go.
I know nothing about ignition types so stupidity will be all over this post.
I have an accel 300+ box that I am running with my ignition now. Would I still be using this with an inductive pick up distributor?? If so I assume accel sells an inductive pick up distributor?

I also assume the inductive pick up does not need the ecu to tell it "something" so that is why I could use the inductive with a fan and fuel pump control and still have timing control.

 

[Lance]

I'm not sure if Accel sells an inductive pickup distributor or not. You should still be able to use the Accel ignition with an MSD distributor.

The bypass control signal is a command from the ECU that tells the distributor to refer timing control (or not) to the ECU. In bypass mode, the HEI distributor uses it's own pickup to trigger the coil at the point where the reltor and pickup line up (usually 6 degrees). An MSD distributor does not implement any bypass scheme and would normally be set up so the trigger angle is ~50 degrees. The ECU would then delay the spark the amount of time necessary to fire at the programmed angle. The beauty is that the spark is fired much closer to the reference angle resulting in more accurate timing.

 

[Syclone Dude]

Guys I had this same problem and I received the option files from Lance (thanks Lance!). the simple solution here is to run a thermostatic swith to control the fans. I bought one for like $14 at autozone then use the option file to enable the N2o output.

hth
BigAl...

 

[Ricky Trussell]

Lance, You have mail.

Syclone dude you are right the fans control is the cheapest way. I know it will also be the quickest way to get me running. Maybe over the winter I can look at the MSD distributor. I am running the computer controlled small cap hei. I don't have room for a bigger distributor.