Fugitive C7

Theta, and chance on me buying one of these from you. I seriously miss running around in Track/sport mode. But with long tubes and umm "cats" they way mine are configured it's LOUD

Theta

I'll roll some of these into production. I've had a lot of PMs asking for the same. Still going to work with small batches, and the charity aspect is obviously still there.

To be honest, I was worried that the valves would be changing and the design would need to be re-worked. That wasn't a pleasant thought, to say the least.

Let me re-visit the smaller boards and see what the best route to take for you guys is. I still have 80%+ of the requests coming from NPP-owners, which makes me glad that I found a way to quiet it down. It's extremely useful on days like today (speed traps lined up along the highway in my area - it's the 2nd day of the month, and we all know there's no quota. )

I'm going to build them by hand (as was always the intention) instead of sending DIY kits for the moment - the tolerances are just too tight to not have tested on a scope before I can make sure they're dead-on. Hope that's not a problem for anyone.

Fugitive C7

You're a life saver. Not sure if you remember in the past, but i used to complain about the volume problem over a year ago. Glad to finally have a solution for this!!!

Just let me know where and went to send the money!!

Mluzzy1

After getting the NPP exhaust installed today at my dealer ,I'll officially be interested in one too. Although , it IS really nice to be able to hear the car.

Fugitive C7

Try getting long-tube headers with.. umm a "cat modification" and a supercharger... Phew... That will peel the skin off your victims face as you pass them.

Theta

Alright - update time... I'm going to try to simplify the design and see if that makes it more foolproof. Don't kill me, yet.

I know there are a lot of you wanting this now, and I can handle getting them off to people. My worry is that we're starting to see NPP/AFM failures and oddities creep up in the strangest places.

This device is rather simple, and doesn't harm the valve. However, if a valve is already prone to heat issues, the circuitry isn't going to be able to overcome that. Thankfully, these valves just stay open when they overheat (safety precaution from the spring rate).

I'm going to make a pretty drastic change to the signal switching and the running of the physical switch, etc. It makes sense (and works well) the way it stands, but by simplifying the circuit to simply send a 'close' signal (80% duty) or de-activate the circuit, we can just use the spring rate to return without having to hit the actuators with a different duty cycle.

Bottom line, these actuators are going to be a problem for a lot of people sooner or later. I just want to make sure that what goes out there actually does what it's supposed to do. The design currently works perfectly, but the actual devices it's working with are flawed - something that was not originally factored in.

Regarding price, these aren't going to be expensive - let me get an accurate price and number for a small run, parts, etc. and add $50 (or as much as you'd like) for charity. After all, that's what this was and is still about.

Original boards were running me right around $50 for small runs (note that none were sold, three were used for testing, one is a master, one is in my car, and the last is on a shelf here... I've eaten all of that cost - not trying to pull one over on anyone), so figure on somewhere around $100 plus $10 shipping with the normal donation (a little more for the wiring and connectors for the NPP conversion, I'll figure that out as well). Not trying to make anything off of these - I just want you guys to have a working product. Until I overheated my valve a few days ago, I would have sworn this was an isolated issue... Now, the more I reach out, the more I find that it's far from it.

Hope that makes sense. I'm working on this as we speak, so hang tight.

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descartesfool

Well now! I'm not feeling so lonely....

Theta

Yep - I'll get with you on this. I have several irons in the fire to put this to bed once and for all (well, sort of). I'll pop back over to your thread to comment, because we're getting nowhere using the 'normal routes' as you now know.

FYREANT

This would be a good topic for "Ask Tadge". Though, that one might back him into a corner..

Theta

I don't think you'll get anything other than the corporate line, which is what I've run into at this point. I've gone up the ladder as far as I'm going to get - I now know some more interesting info, but it changes nothing.

I'm working with a manufacturer here to see if we can make spring-loaded 'dummy' loads for the valves. For those that either don't want to or can't tune out the AFM valves, that's the best option (and tuning the checks out is a LOT harder than tuning the actual AFM out). Hanging two valve assemblies from zip ties isn't exactly my idea of a good answer. At least the actuators on a small device could still neatly tuck into the frame area.

After speaking with a few parties at length about this, I have decided that I will not be looking into designing a simulator or bypass device for the AFM valves. Since they are bi-directionally communicating with the CCM, I don't want to take any chance of a spillover or mistake there. The CCM controls too many safety features of the vehicle to mess with this.

I won't put words out there, but suffice to say that this problem has existed for a long time on the C7, and is just now being brought to light after a few people made it known here. As I've maintained even before I knew this, there was absolutely a reason that GM left them off of the Z06, which is also equipped with the same DoD/AFM system.

.

FYREANT

I honestly think that GM's least expensive way out of this issue is to essentially replace all necessary components of MY14 Z06's with MY15 Z06 parts (AFM Delete + anything required for computers and tuning) for all 14' Z06 people that have pushed the car hard enough to manifest the issue. It would be a hell of a lot cheaper than a recall to do ALL the MY14's. But, what are the odds of them doing either.. LOL

Theta

Did you mean 2014 Z51? Wasn't a 2014 Z06.

There was a (supposed) batch of early-production 2015 Z06 cars with AFM, but I have yet to find an owner of one, so it may just be a myth...

Odds are slim across the board. However, it's times like this that the community steps up and figures out a way to fix the problem. It doesn't help that it's affecting such a small subset of people. They have more pressing issues (overheating, etc) to deal with. I think you'll find that very few C7s are tracked (in comparison, percentage-wise, to Z06s).

FYREANT

Oops I did mean 14' Z51's. Its late, I should be sleeping lol. Good point on the bigger fish to fry too. Overheating is affecting droves of C7's.

sxeC7

I've been following this thread with great interest since I, like many others, want to have direct control of my NPP. I had the Mild to Wild switch on my C6 and loved it, but was disappointed to find that it would not work on the C7.
The work Theta has done is very encouraging and I'm anxious to get one on his units, but the progress seems to have slowed because of various issues. Out of pocket costs seem to be one. For myself, I want a plug and play unit ready to install.

What is it that we can do to help? Would prepaying be of benefit, say $150-200. With a 2014 production run of over 37,000 C7's and probably as many for 2015 there has to be a viable market even if only 50% had NPP installed and conservatively only10% of those owners wanted separate control.

thegame

True I would definitly buy a true mild to wild switch if it was available.

Theta

Thanks, bud!

Originally, the idea was to start a Kickstarter (or some sort of crowdfunding project) but the forum rules and the sheer amount of hassle involved in making sure everything was fulfilled was going to be a nightmare for us.

The admins and owners of IB were gracious enough to let me work with these and sell them (once I reached that point) with the proceeds going to charity after build costs - that, after all, was my intention all along.

The start-up costs have been absorbed, and recurring costs aren't too terribly bad. I have a box of a dozen valves here that weren't cheap, and an NPP system and valves that another member split that cost with me. Once I sell that, we'll settle up on that.

I'm all for raising capital for this project for printing out large batches of these, but as it sat, I wasn't in a bind for doing that already.

You could see where it was moving along really quickly with regard to better and smaller builds, but then we started having reports from other users (like descartesfool) losing AFM valves. After testing, I was able to panic both my AFM and NPP valves due to heat and frequency variables (that are a valve-specific issue).

I'm thrilled to report that all testers of the original design are still running strong to this day. Again, only a single hiccup was encountered with a panicked valve that returned to normal after a cool-down.

Here's my worry - I like to think that I have a decent reputation here. If I release this product to work with faulty valves, and those valves panic/fail as a result of the inherent flaws, I think my product/design will be blamed unfairly for some of these issues.

Whether it's a matter of pride or of trying to make sure that you all get the absolute best device for doing this (closing/opening at will), I guess I'm a bit worried now.

However, if those that want this understand that the valves (AFM and NPP being the same valve) have inherent flaws, I'm happy to start mass producing these and sending them out. Any EE will tell you that the circuit design can (in no way) kill a valve, or damage it in any way. The panic states are what worry me, though, as the switch (and for that matter, the entire ESM system) can no longer control a fault NPP valve until it cools or is reset using GDS2.

Only I have had this issue, and I was purposely trying to kill the valves in the process for quality testing. So, you could call it an extreme outlier.

I would like to finish up a final design that has a few tweaks to the switching (eliminating the signal pathway to and from the switch) and allows for a smoother capacitor charge/discharge to keep the frequency even tighter than it has been (in the capacitor world, +/- 10% is about the norm, while we need +/- 0.5%... quite the challenge!).

I didn't intend for progress to slow on this, but I didn't want to see a lot of (potentially) unhappy people if we were able to quick-fix the actuator issues. As it stands, that's not going to be possible at the moment, so this is till the nest working shot there is for full manual control.

Hope that makes sense. I'm still a little medicated from some procedures today, so I'll have to correct for errors if I see any later.

thegame

Theta you are nicer and smarter than you should be !! I really had no idea the NPP thing was so complicated. I didn't know the afm and valves had any connection. I know in theory its hitting a button to open and close. What I started doing even thought it's a slight pain in the *** is simply pulling the fuse and putting it back when I want quiet. I know doing it on the fly is better and more convient but what you just wrote I had no idea it was so complicated

Theta

I appreciate the kind words. Every engineer that I've shown this to has shaken their head and/or facepalmed at the downright silly amount of complexity used for opening/closing a simple valve.

Here's the abridged version: The AFM and NPP valves are identical in part number, pins, etc. The AFM valves are constantly variable using pulse width and have bi-directional I/O communication. The NPP valves need only an input that essentially says "OPEN" or "CLOSE".

However, since they still rely on being controlled by a PWM signal (and not just any PWM signal mind you, but a positive-pulse signal with a +1.2V offset), the open/close is far more complex than it needs to be.

One would have hoped for a simple 12v on and off, but it's just not happening with the CCM controlling things, and the valves being designed like this. There are also inherent flaws in the valve electronics, which makes my (and others') work that much harder.

I've been trying to get this re-worked as quickly as possible by gathering new data and parts on the (supposedly-updated-but-not-really) valves in droves, but I can't fix the valve design. From a circuit perspective, this is one of the cleanest injection methods I've seen with this many obstacles in the way, and I've heard the same from many in the industry who I deeply admire. That's always a good boost to my morale.

thegame

ughh that sucks. I'll just pull the fuse leave it open and keep a few extra fuses handy for when I need it quiet for some reason.

Theta

Remember that I've also posted the switch mod that simply moves the fuse control into the cabin to create a simple ON/OFF switch.

This complex mod is more for those who want to be able to close the valves while racing in Track mode.

If you only want fuse control, that's easy, cheap, and quick. I can link that if you'd like.