kitwetzler

Yup, that's the cylinder deactivation turning on

afisherunc

Ah, thank you! I have seen reference to this but prior to owning the car did not really understand its effect.

AZWCat

Has anyone tried the Kline exhaust with stock OAP? Seems like the result should be the same in terms of tone and pitch, just perhaps the volume may be a little lower.

afisherunc

I am pretty sure that's not possible because the Kline rear section only fits with the Kline OAP. I have read the Kline rear section is "flipped" in terms of the stock rear OAP connections.

TRZ06

THIS. You can not piece meal the Kline system, the OAP and rear section have to be done together.

TRZ06

I am just thinking out loud here, but that may be why Porsche added the Sound Symposer to begin with so they could get the added volume that they couldn't get from the exhaust side because of drone. For whatever reason, whether it is the platform or motor design or both, the 718 platform has a drone problem. I believe it is also why Porsche designed the valves to function the way that they do.

It is not super hard to work around it though, you just have to stay out of the 2K RPM range and use the closed valve mode when you want things in the cabin to be as quiet as possible.

I remember I had a Gintani system on my E90 M3 and that think was like living in a bass box at almost all RPMs, it was horrible, but in my early 30's I didn't care. That would not fly for me today.

The Kline system sounds so amazing everywhere else in the RPM range, so I think it is still worth it, but you just have to know what you are getting yourself into and be ok with it.

AZWCat

Yeah I saw from this guy's YT video that the valve is on the opposite side on the exhaust, however, he says that that means the OAP cannot be used with the OEM exhaust not that the Kline exhaust cannot be used with the OEM OAP. Did he get it backwards?
(14:55 starts talking about Kline)

afisherunc

I'm not certain here, just repeating what I have read, but the Kline OAP will not work with the stock rear, because the Kline OAP is designed for a rear that is "flipped" when compared to the stock rear. I have been thinking about it this way: the stock OAP is designed to work with stock rear. Kline OAP is designed to work with Kline rear. If you accept that the Kline rear is "flipped" from the stock rear, then attaching a non-flipped OAP (i.e. stock) to a flipped rear (i.e. Kline) probably would not work properly. I am not sure they would even line up right. That being said, I could be corrected here!

Edit: here is the post I was looking for with this info.

TRZ06

Here is another thinking out loud POV in my limited exposure to the Spyder and GT4 (pending riding with dnimi123 when I go to pick up my car) is in general I think any aftermarket system makes more sense in the Spyder over the GT4 because when I rode with Kit in his car, you could barely hear the intake and motor noises at all, while in every test drive I have done in the GT4, the intake and motor noises dominates the cabin and is quite loud.

Drone is also less of an issue in the Spyder as you are not in an enclosed space like the GT4. I do love the sound of the Kline and really love the higher pitched sound, but in the GT4 you have to overcome the intake sounds to get to the exhaust sound, and both together might be too loud from a DB level for anything over an hour and I definitely do not want that as I plan on having some all day driving adventures with mine.

Again, I am just thinking out loud and look forward to hearing dnimi123's car to really judge if an aftermarket system will be for me in the GT4 AND without me knowing how much of a difference deleting the sound Symposer really makes.

AZWCat

Thanks. It makes sense if the OAP openings are different sizes, and Kline switched them, then it wouldn't flow properly with a mix of parts.

electron mike

Thanks for the info. I don't expect zero drone in that low RPM zone, but the JCR system I had before with Akra OPF deletes was really bad and gave me a headache. I will probably just have to try the Kline system to see if it will work for me personally.

afisherunc

Went for a quick drive last week and took a phone video from my dash. Nothing special but the more Kline content the better, right?

My car is not broken in yet, but I am close, so I got to about 7k RPM when using the on ramp. Otherwise, what you hear is generally between 3.5-5.5k RPM. Windows are down until I go under the bridge.

K-Nut

I have manual , my valves are always open or always closed, auto start/ stop off (makes really weird noise) and do not hear any drone (Kline inconel exhaust with 200 cell cats) , I have Spyder and drive with roof down

afisherunc

Seems like there is a real difference between the Spyder and GT4 w/r/t drone, likely because you can put the top down. The GT4 absolutely has drone with valves forced open at low RPMs, with only the Kline OAP + rear section. It's not really a problem for me - the car is loud anyway - but it is there. For example, in the GT4 if you are going 75 MPH on the interstate in 7th, holding at that speed will leave you with a bit of drone. I'll see if my phone can pick it up next time I'm on the road.

K-Nut

well , no disrespect, but it’s a sport car and it makes noise, drone , and harsh , I guess we just have to deal with it. Porsche design exhaust with valves for a resin and any aftermarket modifications comes with cost ☹️ To me Kline is the best sounding exhaust on the market today , little drone is ok with me