This is a forum member's GTS (I believe):

 

I have had my Kline Inconel for a couple weeks now in my GT4. Here are my opinions/thoughts... Imagine the sound volume of your car now at full throttle with the sport button pushed. That volume level of the piped in intake sound at full boil at high RPM is right about the volume level of the Kline with the valves locked open. There is no drone, but the exhaust sound does resonate into the cabin (as you would want if you are paying $6k + for an exhaust system).

Now that sound level isn't all the time, but at different RPM ranges and when on the throttle. Above 5K under heavy throttle, the volume level is a little higher still, but it is a nice higher pitched sound and it just screams.

You also get more burbles and pops on decel and more volume at high RPM decel.

By my ears it is perfect, loud enough to let you know it was money well spent, but not too loud that is becomes obnoxious as will some other systems out there.

 

Plus 1, it is the right amount of sound in any RPM range Valve force open or close, loud enough, but not too loud that it becomes obnoxious as other systems out there...more outer sound=drone inside.

 

Here's my 718 GT4 with KLINE inconel exhaust + CARGRAPHIC sport cats

Sounds perfect! And zero drone!

 

Sounds good. There are a ton of outside video clips of the Kline. I think what the OP wants to know is more about in cabin, windows closed details. That info. is harder to come by.

 

Here you go!

 

Now THAT is what I am talking about!! Where was that clip before, lol. That is the best/most accurate in cabin video I have heard. Although you have sport cats, it sounds very similar to my Kline Inconel with stock cats.

 

I'm assuming your windows are down? Do you mind doing one with windows up?

 

Windows were closed 😉

 

Does the Kline package come with nuts and bolts to connect to the cat?

 

No, you reuse OEM nuts and bolts

 

OK thanks. I’ve read that in a couple of places, and a couple places that say the supplied ones that are too short……

 

Correct

We reuse the factory studs and nuts off the cat to the OAP. From the OAP to the muffler we use Kline bolts w the factory nuts. You just slip on the hoses back on just don’t brake off the 1 time use clamps when you remove them….then you can slip them back on

 

Hi. You've more or less sold me. Would you say cruising at like 3k rpm with just maintenance throttle (like on freeways) the volume is about the same as the stock exhaust? I think that's the other concern that I want to make sure is ok.
I heard someone's Soul valved exhaust + OAP today and I thought it was a bit too loud in the lower RPMs too.

 

I have Kline's Inconel FBO, and cruising at 3K with Valves Closed is pretty much stock sounding. With Valves Open, it sounds very civilized and just slightly louder than stock with PSE activated, to my ears.