New mufflers, no valves - Disable active exhaust via tune?

[madlag]

So those of you familiar with me know that I have a custom fabricated exhaust system from Kooks (they're local to me) and they just built me a set of mufflers which were installed Friday. No exhaust valves because I'm tired of the switch and wanted some consistency.

The reason for custom build was I wanted it deeper and quieter than what I had since long tubes + catless = ear bleed.

As you know without the valves you can't select drive modes. My question is, can the active exhaust valves be disabled via Lund tune or am I better off using Grimmspeed defeat modules? I emailed Lund but haven't heard back yet. Anyone else in this situation?

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[alan0614]

The reason for custom build was I wanted it deeper and quieter than what I had since long tubes + catless = ear bleed.

I can personally attest to ear bleed. Something akin to being passed by a F-18.

Can’t wait to hear the new setup Ryan.

 

[Kobi Addiction]

Madlag, a bit off topic, but I'd like to hear your opinion on the new sound. Sound clips would be great, but it's always tough to gauge exactly how high pitched it is through clips. LTH, Catless, Corsa Double X, Res Delete through Stock Mufflers.....is borderline too much. With cats on, its damn near perfect.....but I want to be catless. I'd love to quiet it down just a hair with some new mufflers!

As far as disabling through a tune, give Lund a call and ask. Could be possible...

 

[nastang87xx]

The muffler valves are in a closed loop system with the drive modes and the kill switch. But the kill switch is only an override and doesn't decouple the exhaust mode from the drive modes. I personally have found this rather unusual since day 1 but there most likely is a functional purpose behind it in that something like 1/3 or 1/2 throttle will flip the exhaust valves open no matter the drive mode. C7 Vettes were killing actuators from heat build up if users closed their valves when running their cars hard. Guessing this has something to do with it...? The valves can't be "tuned out."

Anyway, get the Grimmspeed piece and just be done with it.

 

[Tribefan]

I can personally attest to ear bleed. Something akin to being passed by a F-18.

Can’t wait to hear the new setup Ryan.

Based on having attended about 2 dozen air shows over the years, I would say it's probably closer to an F-16 than an F-18. F-18's sound a little deeper in my opinion. I, too, can't wait to hear the clip and hear it in person.

 

[madlag]

Madlag, a bit off topic, but I'd like to hear your opinion on the new sound. Sound clips would be great, but it's always tough to gauge exactly how high pitched it is through clips. LTH, Catless, Corsa Double X, Res Delete through Stock Mufflers.....is borderline too much. With cats on, its damn near perfect.....but I want to be catless. I'd love to quiet it down just a hair with some new mufflers!

As far as disabling through a tune, give Lund a call and ask. Could be possible...

The muffler valves are in a closed loop system with the drive modes and the kill switch. But the kill switch is only an override and doesn't decouple the exhaust mode from the drive modes. I personally have found this rather unusual since day 1 but there most likely is a functional purpose behind it in that something like 1/3 or 1/2 throttle will flip the exhaust valves open no matter the drive mode. C7 Vettes were killing actuators from heat build up if users closed their valves when running their cars hard. Guessing this has something to do with it...? The valves can't be "tuned out."

Anyway, get the Grimmspeed piece and just be done with it.

I'm waiting to hear back from Lund. I have a set of grimmspeed defeat modules but kooks said they didn't fit. I'm going to roll under the car tonight and take a look for myself what the issue is. Accordinting to grimmspeed they only have one set of these.

As far as the exhaust goes, here's a desc and a few pics. Long tubes feed small custom made resonators, flex joint, custom X, custom long resonators, H pipe and into the custom mufflers. Only two pics I have right now are these. they did A LOT of R&D on this set up including vibration and false knock detection. As of the time of these pictures, this went into the factory mufflers. With the new mufflers its pretty amazing sounding.

 

[Kobi Addiction]

It's beautiful

 

[nastang87xx]

Interesting, I thought those were cats for a moment.

 

[madlag]

Interesting, I thought those were cats for a moment.

thats on purpose it would pass a visual inspection lol.

 

[nastang87xx]

Can one buy those resonators? If I go long tubes I want to get resonators into my double X pipe. There's not a lot of room to cut and clamp.

 

[honeybadger]

I run the Grimmspeed modules. I'd highly recommend them. Easy to use and once you plug in, you can forget about it and not affect anything else.

 

[madlag]

Can one buy those resonators? If I go long tubes I want to get resonators into my double X pipe. There's not a lot of room to cut and clamp.

You'd have to ask Kooks. I kind of doubt it though since this is one off made by the R&D team when they had the car.

I run the Grimmspeed modules. I'd highly recommend them. Easy to use and once you plug in, you can forget about it and not affect anything else.

Is there an intermediary harness on the valves? Like a harness plug on the car side the valve side? I just saw in another thread that was causing some confusion.

 

[madlag]

Lund just emailed me back with a tune revision that they say should fix the drive modes without using the grimmspeed connectors. I'll try it tonight and see. I'll prob still plug the grimmspeeds in lol

 

[honeybadger]

You'd have to ask Kooks. I kind of doubt it though since this is one off made by the R&D team when they had the car.

Is there an intermediary harness on the valves? Like a harness plug on the car side the valve side? I just saw in another thread that was causing some confusion.

There's an extension part of the harness that causes some confusion. The grimmspeed plugs into the very end of the harness (i.e. the same place as the valves) - the valves don't have any wires coming out of them. Just the plug.

 

[nordique14]

I'm waiting to hear back from Lund. I have a set of grimmspeed defeat modules but kooks said they didn't fit. I'm going to roll under the car tonight and take a look for myself what the issue is. Accordinting to grimmspeed they only have one set of these.

The units plug into the standard GT350 wiring harness that connect to the exhaust valves. They would not plug into anything Kooks produces.

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