jcmer22

Did you experience the drone with the valves closed?

IL_Pete

Yes, valves open and closed. Less with valves closed, but still very present. Maybe 30% less.

Also, I think the Sound Symposer Delete does help a bit, but just a little, not a huge difference. I didn't do that on its own, but that's the impression I get, it makes the sound a little less connected to the cabin, but still that resonance is very strong in the cabin when it occurs.

I did an extreme example of drone for my son today, something like 40 mph in 6th and punch it. It was LOUD! We both laughed.

jcmer22

Ive been chatting with Jonny at JCR and I think I’m going to try their silenced link pipes and silenced valved exhaust. Hopefully that’s a good combo. It’s not my DD

5Zigen

Great summary.

I got the JCR silenced valved rear section coming shortly and was contemplating the Soul or Akra OAP, but given your review and a few others I am going to stick with the stock OAP until JCR releases their silenced OAPs (come on Jonny get that released lol).

SBARacing

I would say that the best combination for me ended up being the DIY gutted stock OAP. It gives it more base, deeper note than the aftermarket one. I think that the gases in that open rounded tube makes that tone and it’s amazing. I was also thinking about the JCR OPF if I’m a few months I’ll want something louder.

IL_Pete

I think that might be a good setup! I am still thinking about that.

Thanks for clarifying that it is not your daily driver. In more spirited driving situations, it is really easy to keep it out of that more prominent drone range of 1800-2200 RPM. Gently tooling around town running errands, not as much, so the driving context makes a big difference. I am still a bit torn about whether to leave the OPF Delete OAPs in or not, at least for a while. Part of me says take them out asap before I fall in love with the more ballistic country road drives!

Congrats on the exhaust on the way! Either way, I am sure you will dig it.


That is an interesting thought as well. @Larry Cable still has me thinking about those Cargraphics ones, which can be had empty or with a high flow filter. (He has the latter and likes it, with the Akra exhaust.)

Lots of choices!

BrianShaw23

Great thread on exhaust modifications! Did you notice any performance improvements when you got the Soul OAPs as well? How would you compare the performance improvements between the Soul OAPs vs the JCR exhaust with stock OAPs? Thanks!

Alpha Ice

I've also been chatting with him off and on and would love to do the silenced link pipes as well. I'm not quite ready for the big genatalia mod lol.

Westcoast

@IL_Pete I knew that you would like the sound, as I have said all along the JCR Valved Silenced Race rocks and the addition of a OAP pipe (GPF delete) amplifies to another level, but that intensity may be too much for everyone. All of my posts about the JCR, the CG valve controller and the Akra Link-pipes have said this, a great sounding system but not for flying under the radar, although I still find that with the CG controller set to the PSE control and in the 'off' setting you can still drive it daily if your right foot is behaving, but I can still have the full meal deal when I want it for blasts in the country or at the track.

My impressions are pretty much the same as yours, the JCR system along with the OEM OAP (saving some money) would give most of the sound I want and easily be a daily driver (I only have one car).

IL_Pete

When I got the Soul OAPs, I thought maybe I could feel some performance increase, but for me it was more about fixing the broken stock sound, which it does very well for a modest price. I went from that to the JCR exhaust with stock OAPs, and I immediately felt an increase in power both from a dead stop and pulling through the RPM range, and a sharper throttle response. I was blown away by that - I wasn't at all expecting a dramatic difference, so I was quite pleasantly surprised by that. Now adding the OAPs to the JCR exhaust, I can feel even more increase, not as much additional off the line, but in pulling through the RPM range, particularly at 5500 RPM plus. Before, 5500 plus was of course very exciting. Now it is a little bit terrifying!

No matter what I end up doing with the OAPs, the JCR Exhaust is here to stay, that is for sure.

IL_Pete

Yes, your inputs have been very helpful, thank you!

I now more so understand and agree with your comments above about "I still find that with the CG controller set to the PSE control and in the 'off' setting you can still drive it daily if your right foot is behaving". I didn't fully understand that at first, because the sound levels with just the OPF Delete OAPs were more so RPM dependent and not as much throttle level dependent. The JCR exhaust is very much so throttle level dependent with regards to volume. I totally agree, with the JCR exhaust and a VC and OPF delete OAPs, and the VC off to leave the control to the PSE logic, whether or not the PSE is on or off the volume is very dependent on throttle level. So you learn to keep it quiet by behaving with the right foot, exactly as you say.

You had also commented that Cold Start is much quieter and more manageable with VC off and PSE off - very true! My neighbors greatly appreciate that you gave me that tip.

Thanks so much for all of your help, quite frankly I am not sure I would have gone down this path without your inputs, and I am very glad I did.

BrianShaw23

Great feedback, thanks! Going to consider the JCR exhaust for sure.

IL_Pete

Okay, so yesterday morning I had the Soul OAPs swapped back to the stock ones. Of the three configurations (1. Soul OAPs plus VC, 2. JCR Exhaust with Stock OAPs plus VC and SS Delete, and 3. JCR Exhaust plus Soul OAPs plus VC and SS Delete), I like this configuration I just went back to (#2, JCR Exhaust with Stock OAPs plus VC and SS Delete) the best - for my needs.

Nothing of the three is perfect, each have their pros and cons. The last combination was excellent on Country Road drives, but was probably a bit loud from an attracting attention and annoying people perspective. But it was pretty epic! I am glad I tried it, I would have wondered otherwise. The drone was a bit much for me, rough in cruising around town in all 3 settings (let's call those setting A. VC off, PSE controlling - PSE off, setting B. VC off, PSE controlling - PSE on, setting C. VC on, valves always open. Worst in setting C, progressively less in B and A, but still bad enough in a where it is bothersome, for me. I cruise the Country Roads in Setting C, and even in that use case the drone was bothersome a bit in accelerating from a stop, in first going through that 1800 to 2100 range there is a little "honk" of resonance, and then in the 3000's it comes back a bit, chills out just below 4000. Also you hit the 1800-2100 drone when taking a 90 degree intersection turn in second gear, quite often, especially a right hander (for us left side drivers), which is typically tighter. North of 5000-5500, it is absolutely glorious!! And because the JCR Exhaust is very sensitive to throttle level (where as previously reported configuration 1 with just the Soul OAPs is more so just RPM sensitive), north of 5500 with heavy throttle is outright EPIC!

But alas that was still a bit loud for me, and I don't like the drone. As soon as I drove it home from the installer yesterday changed back to config #2, I was like "ah..., the drone is gone, whew". There is still a very slight amount of drone in the same spots with configuration #2, but it is very minor and not really annoying at all. In settings A and B, it is least noticeable.

The JCR exhaust by itself in config 2 sounds terrific. There is a really great tone to the JCR exhaust that is sort of lost when you add the OPF Delete OAPs, that tone from the OPF delete dominates. With just the JCR exhaust, it sounds very Motorsport, very "sophisticated", I really love it. It is loud enough to be great fun, and turns heads and all that. It has a decent amount of burbles (in Sport mode on the Sport Chrono, which I always drive in), but zero pops and cracks, like configs 1 & 3 had. I can live with that.

I have my weird criteria of how it sounds at different speeds with both windows fully down on country road drives, with the AWE wind diffusers. With that very specific criteria, 3rd gear sounds awesome at pretty much all speeds, 4th gear however is not quite loud enough for my tastes. Particularly at 70-80 mph, the increased wind noise starts to drown out the exhaust note, and I like to hear the exhaust at all times, to me that is part of the experience of this magical car. My solution to that is that I don't shift to fourth nearly as much as I used to. I still do when ripping it in 3rd to quiet the car down, then slow down in 4th and then go back to third. But now I cruise on the Country Road drives more so in 3rd, because the exhaust sounds so much better there, at north of 4000 rpm at basic cruising speeds. The throttle response feels great there too, I like to be driving above the balance point of the throttle, where when you let off the throttle you get engine braking and some burbles. It keeps it very alive and fun and interesting, as you slightly modulate throttle and speed to manage through hills, turns, and slow down in areas where there are houses and driveways.

Another interesting thing here is with regards to performance. With just the OAPs, I really didn't feel much in increase in performance - maybe just a little bit of torque. (There is another thread here talking about that, the consensus seems to be 5 HP and/or foot-pounds of torque, at best.) As I reported previously here, going from just the OAPs to the JCR exhaust with the Stock OAPs was a HUGE difference! Significant increase in torque of the line, and increases in torque across the entire range. As I said, I wasn't expecting that, and that was a very pleasant surprise. That increase in performance combined with the great tone of the JCR exhaust with just stock OAPs, and it not being too loud relative to configs 1 and 3 with spirited driving (but still being plenty loud and fun) is why I like config #2 the best.

So here is the most recent and very interested finding. While doing the just the OAPs doesn't seem to add much on its own, adding the OAPs to the JCR exhaust had a very significant performance increase (measured via the butt dyno) above 5000 RPM. It turned into a BEAST up there in that RPM range! I had that configuration installed Tuesday morning, and did 1 hour plus Country Road blasts for the next four days, and thus had a lot of experience with that. It was very noticeable in 3rd gear, it was glorious borderlining on terrifying! And then yesterday I drove for 4 hours and 173 miles, and very specifically experimented with that again. Yup, that beastly pull at those higher RPMs was gone. Don't get me wrong, it still pulls like mad up there, but the seemingly infinite and terrifying pulls were noticeably gone.

Very interesting! My theory is that once you uncork the exhaust, that the incremental improved flow of deleting the OPFs makes a difference, much more so than without a more free flowing exhaust. That was the primary drawback of going from config #3 to config #2, losing that insane pull in the high RPMs. But then again, it was probably not at all a good thing to be enticed to take 3rd gear to high RPMs under heavy throttle on a regular basis!

That is the biggest surprise to me of this big experiment of the different configurations, that the bigger differences for me were the experiences in performance, not as much the sound. It is certainly a combination of the performance AND the sound, but quite frankly I expected it to be 90% about the sound.

For my needs, #2 is best - but if I were tracking the car (which I am not at all currently, maybe someday), I would take #3 for the combination of performance and sound, and put up with the drone (and use JCR silencers for tracks with noise limits). That configuration is pretty amazing, I can see why many like it!

I do wish the JCR Exhaust with Stock OAPs was just a touch louder, but I am totally fine with it as is, and it is clearly the winner of the three configurations for my needs. It is regrettable that the combination of exhaust plus OPF delete upgrades on these 4.0 cars creates the drone. I guess that is what it is, everyone seems to be experiencing that, across all brands. The SS Delete probably helps a LITTLE, but it is not at all a fix for the drone, IMO.

That was a lot of work, but great fun!

UncleDude

What an experiment! I have been convinced for some time, that the rear section is the best modification for those who seek a more blended tone. I have driven a car with your setup (your current setup) and that drone boom around 2000 seems to come and go very quickly on light throttle. Thanks for sharing all your thoughts!

Alpha Ice

I'm not wanting to contribute towards supporting the cost of experimenting... But I would love to see your thoughts on a silenced oap like CG by chance... Or ideally JCR.
I have the JCR manifolds, and just ordered a Fabspeed valved exhaust, my car should arrive near the end of October and I'm not expecting to get both installed before I have to put the car away... But I'm looking forward to getting my time with it stock and then adding a bit of power and sound with the manifolds.
I would probably only look into adding silenced oaps down the road. But given your awesomely detailed reviews with others experiences, I think that would be my last preferred item to change since it is such a wildcard. I might be interested in doing the big genatalia mod possibly. But it would be a pain to have to swap or replace those if it were to be too much.

Thank you so much for all your detailed work IL Pete! I'm only 5ish hours from your Savage Geese roads.... I might have to make my way down there next spring.