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Meeting 90dB Noise with GT350/R

FYI guys, with the grimspeed plug you can have the valves stay open.

Simply have the car run, open the valves and then unplug the two harnesses.

Turn the car off and install the plugs and now they will stay open.
 
I discovered this by accident but didn’t test it in a long term basis. Will they stay open permanently?
 
Has anyone tested the grimspeed plug on the track and was there any adverse effect on car performance, I have an opportunity to go to mt tremblanc but they have a 92dbA limit at 50 ft and if there is no issue at full throttle I can confirm, my attendance.
 
Yes they work on track. That’s the whole point of this thread. :)
Sorry I think I asked the question incorrectly, I would like to know if the car with the baffles closed performs OK with the extra back pressure, is the computer adjusting OK or does the car run a little choked or any other symptoms with baffles closed and in track mode with wide open throttle.
 
I posted in the other thread but figured it would make sense here too. I like the AWE SwitchPath method better than the Grimmspeed modules because you don't have to keep plugging/unplugging anything. Just open and close at the press of a button. No CEL here either. It's more expensive but MUCH more convenient. This way you only need to keep them closed for a short amount of time every lap while you pass the sound booth. I didn't want anything that will keep them shut the entire session just in case there's a durability/tuning reason Ford forces the exhaust open at WOT. If there was a durability reason for it, it shouldn't hurt if you force them shut for a couple seconds every lap. Seems like a safer solution than forcing them shut the entire time.

 
I’ve got my Grimm modules in now, since I busted sound a couple times recently.

At first, I thought the valves weren’t closed enough when I shut off the car. They stay in about a 30% open position when in resting mode. Then once the modules are plugged in, they don’t move anymore. As others have noted, you can get the car to turn off in wide open mode, too. At first start up, I thought the partial opening was going to be too loud. But that’s only the case at idle, where it’s louder than normal. From 3000 RPM on up, it’s a perfectly mid-level sound. Less aggressive than full open exhaust, but with a good sound and I think 90bd compliant. I’ll know on Oct 25 at Laguna.

Btw, I like the Awe solution. Thanks, I may still go that way at some point.
 
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Not sure of what's going on there but I'd take it to your dealer and have them look at it. Make sure the Grimm modules are not on the car. ;)

I’m not sure if you’re responding to me?

There is nothing wrong.... (maybe I stated things incorrectly. I meant that I had previously busted sound. So now I am putting the modules back in... I wasn’t saying that I busted sound after the modules).

I just re-installed the modules, as I have before, and I know how they go in... so I don’t need the dealer to check anything. If you’re saying that the valves shouldn’t sit half open, I think that’s normal off position. Before I put the modules back in, the valves were opening and closing exactly as they should in all modes. But they always have settled half open. I think it is why we get the loud “braaap “ on initial cold start. Then the valves close until mode is changed.

Am I making sense? Thanks!
 
Beware of running the engine for prolonged periods in track mode at high rpm with the exhaust valves closed. That’s a lot of extra back pressure that the valvetrain isn’t expecting.

There must be a reason the valves open in normal mode at high rpm/load
 
I was referring to the 30% open. I think they should be fully closed. I ran LS with resonator delete and the Grimm modules and passed 90 db.

Ah, thanks. The valves close fully when running in normal mode. They just don’t when turning the car off. I wonder if it is unique to 2018. I’m going to call Darrell Anderson at AV8 Supercars, since he initially installed them the first time and I know he had the valve fully closed. Also, if I go the Awe route, this may be irrelevant.

Thanks again!!
 
Doubtful you will pass sound at Laguna with the valves partially opened. I failed sound there once with them fully closed. It was one of those days with low clouds that amplifies sound. Been there about six other times on clear days and I have had no problem passing sound with them shut. Will be ar Laguna again on Oct 21.

What we really need is a GPS based system that knows when to open and close the valves. Used very successfully by some 911 owners. People smarter than me: get on it!
 
Doubtful you will pass sound at Laguna with the valves partially opened. I failed sound there once with them fully closed. It was one of those days with low clouds that amplifies sound. Been there about six other times on clear days and I have had no problem passing sound with them shut. Will be ar Laguna again on Oct 21.

Thanks Nordique, I believe you are right. My friend runs his partially open at Sonoma and reads more like 94. I will either get them shut completely and then re-install the Grimms, or I will buy the Awe product.

EDIT: I figured out the trick to getting the valves to close completely before putting the Grimm modules in... what you do is turn on the ignition button (without actually starting the car) so you are in accessory mode. That closes the valves and then you install the small plastic modules to keep the valves closed. Done deal.
 
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