whojoemama

Hi Goldilocks. I’d be really interested to hear (pun) how things turn out with stock OAP and JCRs. Right now i’m running Flat6 OAPs with Valved JCRs with Valve Controllers. its probably a little much and there is a funky dead spot of some sort LMK how your turns out.

gridlock61

'Gridlock' that is .

Of all the combinations I've tried, the best compromise has been the stock OAP's with the JCR rear section. I do wish it had a little more volume and intensity at high RPM, but it is much better than with the stock rear section, and keeps the drone under control. The JCR with the Fabspeed OAP was the most exotic sounding, but just was too much, especially in the drone area between 2 and 4k RPM. The Soul resonated OAP's did reduce drone a bit, but not nearly enough for me, and added an odd hollow-ish sound that I don't like. I would try the JCR silenced OAP's, but getting tired of trying so many combinations, and don't really want to spend another 4k just to try it. So it looks like I'm going back to the stock OAP's, which with the JCR rear section is a good compromise. Of course YMMV.

mprog

terry, you have that paired to a JCR rear section?

Westcoast

I too ran this setup on my Spyder until the Akra Link-pipes were delivered, in that configuration it sounded awesome, really no more drone than the stock system, but a beautiful exotic sounding exhaust. The only thing I wanted more of was the intensity and volume, the Akra Link-pipes gave this but also brought in the drone. So its not for everybody.

It has been nearly 3 years now with this configuration and I have no desire to tame the 4.0l beast!

gridlock61

Well that's a bit odd. As I mentioned there is a significant reduction in drone with the stock OAP's as compared to the Soul resonated OAP's. It doesn't make much sense to me how that isn't the case when you consider the differences in design, with the stock OAP having a fairly dense filter as compared to the Soul, which is a very open design.

tigerhonaker

Terry

I have not tried the JCR rear section.

I do have the SOUL ceramic coated OAP, SOUL rear-valved-muffler, SOUL sound symposer delete & Cargraphics valve controller.

Terry

IL_Pete

The OP here. I tried 4 different combinations of OAPs with the JCR Silenced Exhaust.

(1) JCR Silenced Exhaust with Stock OAPs (with a Cayman GTS 4.0 in 2021). Too quiet. Also, lacks the extra "Pull" (HP/Torque) you get with the JCR plus some freer flowing OAPs. Once you experience it, you can't go back to stock OAPs and lose it. It is a very noticeable difference.

(2) JCR Silenced with the Soul regular straight through OAPs (with the same Cayman GTS 4.0). Sounded great, louder and more rowdy, great additional Pull, but the Drone/Boominess was completely unbearable, for me. In the usual troubled RPMs, I think 1800 to 2400 and again in the high two thousands and again in the three thousands somewhere, I can't recall the exact ranges, go back and look here if you want to know exactly. The Drone/Boominess was bad enough that I went back to stock OAPs within a couple of weeks. But then I was really upset that I lost that awesome extra power/pull. Most noticeable above 6K rpm in 2nd and 3rd. So then I went looking for another solution.

(3) JCR Silenced with the Cargraphic High Flow Filter OAPs (with the same Cayman GTS 4.0). This was the goldilocks solution! Had that extra pull, the exhaust was loud enough and sounded great, and the Drone/Boominess was a lot less than with the wide open OAPs! I recommend this solution with the JCR Exhaust with a hardtop, Cayman GTS 4.0 or GT4.

(I happen to still have that set of CG HFF OAPs for sale in the marketplace. In my Boxster 25 part-out listing.)

I then went from the Cayman GTS 4.0 to the Boxster 25, and started with the #3 setup above, and it was great again.

(4) Soul had come out with their Resonated OAPs, so I thought I would try those with the JCR Silenced Exhaust. That combination was good for a Boxster, but I don't know that it would be good for a Cayman or GT4, I think the CG HFF ones would be better. In the Boxster it did sound a little more aggressive, but it did create a little more Drone/Boominess - it was tolerable in a Boxster with the soft top, but I think it would be too much Drone/Boominess for a Cayman GTS 4.0 or GT4.

In my GT4, I did the Kline without Headers and later added Headers and a Tune. I had previously also tried the Kline in the Cayman GTS 4.0, both times in Inconel. The Kline has the least Drone/Boominess, but the JCR does sound more Motorsport, more ballistic, when paired with an aftermarket OAP.

Reedy

Sounds like a very expensive and time consuming project, really appreciate your efforts! As a JCR silenced customer I am on the fence on OAP's and this helps a lot. Once the local race track has sorted out its noise complaint issues with the neighbours I might take this a step further.

Alpha Ice

I was just catching up on all the new responses on this thread. I'm glad Pete came back to post, but I was also going to say the same thing. The Cargraphics will be what you want, as it is the closest combination to the factory given it has the material, and doesn't have the wide open pass through that the Soul/Akra have. I know you were looking at the Flat-6 ones as well mprog, I'm sure they will sound not far off of the Soul's in that respect. I was going to go the CG Hi Flow route until I just went full send

dub

I also went full send....we shall see!

@IL_Pete I might be your CG HFF OAP's huckleberry if the Flat6 are too much....stay tuned!