Hey all,

I got my hands on a Cometic controller. I have an idea of how I want to use it, but I'm not sure if it can be done. I've never used a controller before.

What I would like to do is eliminate the WOT switch and the window switch. Let the controller do all the work. When I arm the system, the NO2 and fuel solenoids will fire based on the ramp I specify. Does that sound doable?

 

It might be possible to do but you have to realize how progressive controllers work. They work by opening and closing the solenoid really fast. Based on how much its open or shut is how much % of nitrous is being used. Opening and shutting the solenoids like this can be hard on them and cause them to burn up. Also window switches don't work on rpm, they generally work on time. So you could end up spraying at a bad rpm range and blowing up your engine. Window switches are cheap, get one.

 

Why do you want to eliminate the WOT switch?

What you are proposing could fire the nitrous when you aren't at WOT. That can have devastating effects. I once saw a guy put his car thru his trailer and into his truck. His nitrous activated while pulling into the trailer.

How would you account for staging?

You can count on the person in the other lane or the person activating the lights to work on your time frame.

 

You still need a WOT switch, and Window Switches work on RPM.
The WOT triggers the nitrous kit and will also activate the timer.

The window switch will use low RPM to provide or removes a ground, and High RPM does the opposite to deactivate the nitrous kit.

 

That is really not advisable. Use the Window Switch and do it right. You're asking for some big problems setting the system up like that.

 

If youre referring to the Modotek controller marketed by Cometic, you do not need a WOT switch nor a window switch.

The controller has features built in that can tap into the TPS sensor, and has a built in window switch.

Just find the TPS voltage at 0% throttle and 100% throttle and enter that into the PC Link software.

Your ramp can be programmed based on time or RPM in the edit PWN tab.

 

Do you have a link to the controller you were looking at? I may be able to be more helpful based on that info. You are going to have to have some means of activation wether it be WOT/TPS switch. Some of the controllers do have a built in TPS switch you can use as mentioned above, if it is a carb setup you can still wire a WOT switch in. With a progressor it is still activated by some variable such as WOT, RPM or boost, but it will still ramp the solenoids out like you are describing.

Thanks,
Garrett

 

Ok then, let me clarify a few things first.

I am currently on a road trip and very very tired (food, wine, you know how it is).

I currently have a standard setup that I installed myself. Holley kit, WOT micro switch and MSD window switch running at 3-6K, 100 shot. It all works very well.

What I want to do is stop the all or nothing way that this system works. I don't want 100% flow when the rpm hits 3k. I would rather see a slow ramp up starting at say 2K with 1% then 2% etc etc etc. Unless I'm missing something, this should be very safe. In fact, it seems safer than slamming 100% all at once. In any case, this is just a theory at this point that I wanted to run by the knowledgeable people on this site (shameless ***-kissing).

It's an 04 GTO LS1 that I have tuned myself. Only very minor mods.

This looks like the one I got, but it's labeled Cometic.

 

Yes.

You can eliminate your WOT and window switches as these features are built into the controller. You will need to tap into the appropriate RPM signal and TPS wires.

As for your percentages... A lot of variables, solenoid size, brand etc....the controller can pulse the solenoids at a defined frequency (in tuning software) typically smaller solenoids will like something around 25hertz. That means you can define the percentage every 0.04 seconds. Also solenoids may not open at all below 10%... And may not close at all once above 80%. Again lots of variables.

But in general it will allow you to ramp nitrous in versus 100% all at once.

 

That's exactly what the progressor does, in a nut shell. It will still be activated off of WOT and RPM like your current setup, but it will bring it in softer. You can adjust how soft.

-Garrett

 

Ok, that's what I thought. Except, when I say eliminate the WOT switch, I do mean I want to engage nitrous at part throttle, generating a relative power increase throughout the TPS range (more throttle, more ramp). Can the ramp up be tied to TPS?

I assumed there would be limits and restrictions in the ramp %, but right now I'm just trying get the basic setup in my head. As for how well the solenoids can handle this, I expected Mr. Nitrous would provide some info on parts when needed.

Oh, and Good Morning! I'm off to see the big pond!

 

that wouldn't be a good idea....

I do not think the controller has the ability to change the PWM on the fly based on TPS voltage.... Even if it could, the constant pulsing would quickly beat the **** out of the solenoid causing it to fail. Nitrous and Fuel solenoids are not fuel injectors, they can only withstand so much cycling.

 

You really only want to have the nitrous activated at WOT. Activating it at part throttle and really low RPM's could be detrimental to your bottom end parts.


-Garrett

 

And top end parts LOL....

Nitrous and fuel flooded intake = boom

 

Well yes, back fires are never good...

 

Holy crap it's good to be home!

FYI - The Portland freeway sucks.

So, a couple more things. I'm not talking about running this system active all the time. Just for 1/4 mile runs.

If the ramp starts very low, shouldn't this keep things safe at part throttle?

Mr. Nitrous Express, what kind of solenoids are available that can handle this kind of a setup?

 

All of our lightning series solenoids were designed to be progressed. We make them in 150hp, 300hp, and 500hp orifices. (Both fuel and nitrous solenoids.) As well as solenoids that will specifically handle alcohol setups.

Here's a link...

http://www.nitrousexpress.com/produc...ing%20solenoid

Also, to answer your other question, I would still only activate the nitrous at WOT. You can bring the ramp in softly, but if you try to spray it at part throttle, you could have a backfire.

Thanks,
Garrett

 

Ok, thanks for all the info.

Now I just have to figure out how to install it.

 

Garrett, any MTBF info for these?

 

This is correct. Please see attached screen shot. You can set a min/max RPM, IE built in window switch.

You an also set a min TPS % based on min/max voltage.

I have 0rpm set as I just installed it and needed to bench test things. I am using a time ramp just for testing, but will most likely ramp it in based on min RPM then PWM/Time.

So far it is working flawlessly on the bench.