Avera

@RajuPatel I commented above on some anticipated differences between the RACE and STREET header/OAPs and will not repeat here other than with regard to drone

As you suggest has been your before and after experience . . . even my current setup (headers/OAPs/sock muffler with valves held open), there is a considerable drone in lower rev range.

How much worse does adding the Crack Pretzel make the drone?

This brings me back to anticipating your provision of an in-cabin audio during 'routine' driving. We both know nothing can replace an in-person assessment, however, that simply does not appear to be an option.

Thank you again

Avera

RajuPatel

@Avera my bad for not clarifying this earlier.. I have the FULL Dundon setup from the headers to the Pretzel.. I am living and driving in the deafening noise world.. But unlike in your part of the world, I can use a over ear headphones to cut out the drone rev range noises.. sorry for this. I will however still make the audio/video clip and PM you... before the Crack Pretzel my set up was DUNDON headers, DD OAP's Schmidt Motorsport valved exhaust. That did not have the deafening drone. But it neither had the orgasmic symphony created by the crack pretzel. hope i am more clearer now..

Avera

@RajuPatel you were clear in stating you have the full Dundon setup (headers to Crack Pretzel)

What I was referring to is @jdmporscheguy has RACE headers/OAPs/CP, while I BELIEVE you have the STREET headers/OAPs/CP

My suggestion was that there is a significant difference between the RACE and STREET setups

How many more decibels? How much more drone? . . . in the RACE vs STREET setups?

I concluded the RACE setup is not desirable for my needs and interests . . . but have the STREET headers/OAPs

I look forward to your audio

Thank you again sir

Avera

jmartpr

Doubtful......that's +/- 80 hp from an exhaust. I had tried similar setups to what you have + M Engineering ECU flash Stage 2 93 oct + filters and I couldn't keep up with stock 991.2 GT3s at the track on the main straight
Dundon race could be +/- 5 hp above the street version which has been measured at +25-28 hp and the Crack Pretzel could be 10.
On a N/A car you wont gain a huge amount of power but the 718 is at the upper level of improvements with exhaust mods for sure, but not that much.
Better check that dyno and how they measure...or just use it to verify the delta (change) between stock and mods.

jdmporscheguy

Again, I am not going to get into it. You can believe what you want. However I do have the dyno sheet to back it up. Also, I am not using one of the OTS Softronic or M-engineering tunes. I did a custom tune locally by a reputable shop who holds multiple world records on different cars from their tunes.. I also have BMC Air Filters installed. Only thing I will say is my car makes over 430whp. I'll leave it at that.

M-Engineering and Softronic tunes are nothing close to custom dyno tunes. I have friends with both and they confirmed they don't even make the 25whp those companies advertise. Just saying.

My car keeps up with STOCK 991.2 GT3s all day long on back roads. I don't track so I don't know about track but I suspect it would be the same.

jmartpr

Backroads is not the same as track...and I'm talking about getting of the turn at the same pace/speed (55 mph) and they clearly pull away on a 1/2 mile straight. I top at 146 MPH and they have close to 155 MPH... from data gathered at the track.
I'm not doubting the dyno and what you say, it's just that dyno info can't be taken like that (absolute) as there are too many variables involved... and IMHO a header with muffler + flash (even custom) will never give you +80 hp on a 6 cylinder N/A car.
But anyway, that's not what the OP is looking for and your feedback on the Dundon full setup is pretty accurate.

BTW...M Engineering is Porsche Motorsports consultant in North America so they do know a few things about these cars. Again Dyno number will vary according to a lot of variables...including manipulating the dyno setup when doing the pulls.

jdmporscheguy

You're welcome. I also am not sponsored by Dundon even though I keep asking @Jamie@dundonmotorsports for one :P


I will try to answer your follow questions as best as I can from my own personal experience.

The decibel reading at 5k RPM is around 112-115dB and at WOT its probably in the 130s close to 140dB range. It's STUPID loud. I contacted @Jamie@dundonmotorsports at one point in the beginning of my Dundon journey and asked him the same question you are thinking about... "Will Catted OAP's make it less droney/loud".... his response was "Catted headers and OAPS will reduce the volume and drone a little and you lose a negligible amount of power (1-2whp), but the majority volume actually comes from the Crack Pretzel. That is what makes it so loud".

So I don't think there will be TOO drastic of a difference between having Street and Race with Crack Pretzel. Mine will definitely be noticeably louder, so you might find it a little more liveable but even with Street headers, @enduro posted his experience with Dundon headers and JCR rear and it was pretty similar description to what my experience was, albeit a little less extreme than mine haha

You can definitely manage it with throttle anyway, but just wanted to give you real world experience.


Tone is subjective and although I absolutely love how my car sounds and most people love what it sounds like between 6-8k RPM, many people DO NOT like the tone of my car under 3.5k RPM and actually prefer JCR or Soul in low RPM environments. Again, tone is subjective and as much as I would LOVE to try a full JCR setup, I'm not willing to pay $20k for it when I spent $20k on Dundon and am happy with it. If JCR sends me a system at a massive discount, I would love to compare and contrast between the two and do back to back dynos as well, but until then, I am more than happy with the sound and power of my Dundon setup and don't need anything more.


The Street setup will have less drone for sure. By how much? I couldn't tell you. I suspect it would be noticeably less but not that much less. I should also mention I have my sound tube removed as well but it made 0 difference in drone reduction LOL


Conclusion, in cabin, if you drive it properly (above 3k RPM always), it's very reasonable and not too bad as I mentioned previously. I suspect the STREET system will add to the reasonableness even more so I don't think you will be upset in cabin. The real question with this setup is "Are you willing to be isolated from everything and everyone when driving (as people will not want to drive with you) and are you okay with receiving LOTS of attention (good or bad). My car is the star of EVERY porsche or other car meet I go to. I can't go anywhere without at least one person asking me to rev my car. I've had drivers on highway off ramps stop and ask me to rev my car for them once because they loved it so much driving with me on the highway LOL.

If you like LOUD, there is nothing on the market for the GT4 that competes with this setup. The only thing that I am not louder than is a full Dundon GT3/GT3RS with crack pipe. LOL

My buddy has Dundon Street headers with stock muffler and he's heard my car in person and driven behind me (and in parking garages LOL) and he won't get the crack pretzel. He says he can't do it. It's too loud haha.

Hope this helps.

If you have further questions or comments, please let me know. Happy to share my experiences to help you decide. I was in the same boat as you and when I was shopping, NO ONE had a Dundon setup and it was only ONE youtube video by EVS i believe that sold me on it.

Cheers.

jdmporscheguy

Appreciate your feedback regardless and at the end of the day, dyno numbers are just numbers. It's all about your butt dyno and how you enjoy driving the car. I'm pretty happy with my car's overall performance at the moment

Also, FWIW, I'm not saying M-Engineering or Softronic are bad companies, I'm sure they are great guys and great people and knowledgeable and know what they are doing. I am only speaking from my personal experience of friends with their tunes telling me they did not make the advertised numbers. That's all.

You are right though, dyno's are all different and read differently, and you can never replicate the same conditions as anyone else so best to take any dyno numbers with a grain of salt

Avera

@jdmporscheguy

You have been an amazing resource for me, as well as others with similar interests and questions. Thank you again.

Your enthusiasm for your setup comes through in spades.

If it were not for the non-spirited (routine) driving the roadways inevitably force upon me, I would already have the Crack Pretzel.

You clearly understand what I am trying to figure out . . . can I live with the Crack Pretzel during routine driving conditions? As I interpret all you have stated, it seems very possible to tame the decibels and some of the drone with throttle discipline.

The decibel control would be for the sanity of those around me (e.g., neighborhood entry/exit); the drone control would be for my own sanity.

At the end of the day – short of any in-person CP experience forthcoming - I am either going to keep the stock muffler or take a leap of faith and go with the CP.

@RajuPatel in-cabin audio is one piece to the puzzle I am eager to hear, no pun intended.

Avera

jdmporscheguy

Thanks for the kind words @Avera. As popular as Dundon is for GT3s, its very rare to see on GT4s (in my experience anyway) so if I can help someone decide if it's the right thing for them or not, I don't mind sharing my experiences.

You bring up something I forgot to mention and that is, if you do a lot of "routine" <3.5k RPM city driving, I would honestly just stick with stock muffler and Dundon headers. I can tell you from experience, driving in traffic or even cruising at 3k RPM for an extended period of time to keep it "quiet" inside and outside, it not an enjoyable experience. My personal hell is being stuck in traffic as my car is manual as well or having to go low speeds around 3k rpm for extended periods of time. The setup does not like it and was not meant or designed for low speeds.

I've been in a situation where I had to literally drive in first gear at 6-8k RPM for an extended period of time to avoid my ears getting blown up from drone because at the speed I was going, if I were to go into 2nd, it would sit at 2500-2800 RPM so I made the decision to save my own hearing over the hearing of the public and the cars behind me LOL

Hopefully you get the in cabin vids you are waiting for, but just keep in mind, video's give you an accurate full picture as they are somewhat distorted.



This is what I mean by distorted:

The exhaust is too loud for any camera to pick up the real sound. Take a look at these videos of what my car sounds like. Maybe they will help with your decision.

Videos:

https://www.veed.io/view/0710aea0-d6...ingWidget=true - notice my exhaust drowns out the wind noise AND the green GT4s aftermarket exhaust haha

https://www.veed.io/view/d4e8abab-a7...9-63aff23149ae

https://www.veed.io/view/b9c032a3-fa...3-08ed8b75f997

https://www.veed.io/view/8fc3813f-6c...b-41ae2b4b46ca - Random guy I met at a red light on the street recorded this and sent it to me on Instagram LOL

https://www.veed.io/view/873d9bc0-d5...8-87ff0223e39b

https://www.veed.io/view/63d5bf3b-35...f-b952706b5965

https://www.veed.io/view/1caeb1ed-e7...3-726f015c543c - Full Race Dundon vs Full Race IPE.

https://www.veed.io/view/49f519af-cc...f-314025c3c927

https://www.veed.io/view/871fa909-7e...b-b2557cbd61b2 - Lambo turned his car off when I turned my car on. He wanted no smoke

https://www.veed.io/view/ffa03834-35...0-c5723e5a6c43 - 5 minutes of spirited driving (windows up)

https://www.veed.io/view/1ca5c30b-62...c-702758f73b60

https://www.veed.io/view/d7838462-df...2-5a9936d6ad80

Those are just a few examples. It's also worth noting that inside the cabin vibrates with this setup. If you put your arm on the arm rest, you feel all the vibrations.

Attached picture is the normal reaction I get from people.



Cheers.

Avera

@jdmporscheguy

Wow, you keep providing some great information!

Thank you for posting direct links to your videos, as I do not have any social media accounts, including Instagram

I do almost no city driving; I am in a suburban area with typical stop lights and occasions where I get behind other cars and have to drive in a ‘normal’ manner for variable stretches

Still, except for take-off, I can keep the RPMs up by throttle control and gear selection. Honestly, I could count on one finger the number of times in a week I reach 4th gear. I like to keep things wound up . . . and when in a forced pace of slower local traffic, I just concede and move along in 1st gear at low throttle

Different people describe ‘drone’ in different ways. Currently, my Dundon header/OAP/stock muffler with valves held open has that deep, thunderous drone at low RPMs. The kind of drone one experiences in any car cabin when only opening one window

The other type of drone is what people typically describe as ‘high resonance.’ Although all drone might be due to high resonance, I relate this description to a higher pitch; a more piercing type drone.

In your first video attached – filmed from OUTSIDE rear of the car – I can literally hear/sense that piercing (high resonance)-type drone. In a subsequent video from inside the cabin, I can see your tach and believe the drone occurs between 3-4K RPM?

Your last video was the best for me, as I got a true sense of what the inside of the cabin sounded like during some routine and spirited driving. Honestly, in that last video, I sensed absolutely no drone or extreme decibels . . . did you have the Dundon set up on your car in that last video???

Thank you again

Avera

jdmporscheguy

Yeah, I only go into 4th gear for a few seconds on the highway on my way to 5th and 6th Majority of my time is spend in 1st, 2nd and 3rd.

The only time my car drones is between 2000-3000 RPM and then again around 5-5.5k RPM a bit. The thunderous drone you talk about happens down low and also at idle, the high resonance drone happens around 5-5.5k RPM if that makes sense. High resonance usually happens when you step on the gas hard I'd say. Or if you get stuck between too cars and you are revving the car hard with windows down......thats ear piercing drone!

Yes all of the videos are with the full dundon setup.

I keep telling people its not as loud inside the car as it is outside haha they dont believe me till they sit in the car. Just gotta know what RPM to drive at for the most fun is all

I do keep a paid of Motorsport earplugs in my glove box for passengers that need it because I'm a nice a$$hole

enduro

@jdmporscheguy Awesome data points!

Seems a lot of those are you just half throttlin around and ppl are still making faces. LOL at everyone backing up before you fire it up. Based on the reactions, I'd say yours is a LOT louder than mine under part throttle conditions. Random dude who recorded you is the best.

Mine is sorta reasonable until around 4.5k to 5k RPM when it opens the valves, after which it's pretty nasty regardless of throttle position. But even after the valves are open, I'd say yours is a lot louder. My experience has been that cats, even high flow, are a pretty decent muffler, especially once they're warm. I'd say they're somewhere near the middle of no cats and OEM cats for muffling. One cool thing about yours is it sounds -clean-, which is one of Dundon's selling points (no rasp).

One thing I haven't been able to yet capture properly is the awesome that happens when you go under a big bridge or in a tunnel. Sounds like an F1 race is goin down.

Wish I had the opportunity to demo a crack pretzel just to see what it's like for a week or two, but I don't think I could do it long term. I'm confident it'll get me kicked off my track.

enduro

I'm just happy something like a Crack Pretzel can still exist.

Avera

@enduro

Thank you for chiming into the discussion

Forgive me if I am mistaken, but don’t you have the Dundon Street headers/OAPs with JCR muffler?

If my memory serves me correctly, your setup sounds REALLY GOOD even with the limitations of online video/audio . . . I am sure it sounds even better in person

For those following along, it should be apparent that I am trying to get to next level LOUD with RSR-like tone . . . without unbearable drone.

The Crack Pretzel offers the loud and the tone . . . and I am trying to figure out if I can live with the drone? @jdmporscheguy has provided me great insight into the latter, which I continue to process it in my mind

I am typically more compulsive than undecided, but this muffler component has had me waffling all over the place . . . a day or two ago I thought my decision was down to either keeping stock muffler, getting Crack Pretzel, or waiting for Dundon valved muffler

After all the great feedback I have received, I realize keeping the stock muffler or waiting for the Dundon valved muffler are not of interest

I sense I will wake up one day very soon and just pull the trigger . . . on either the Crack Pretzel or SOUL Valved Exhaust. The hooligan in me wants the Dundon insanity, while the little voice of reason inside my head says SOUL is the more reasonable (livable) option

First-world problems for sure, but I could think of worse things to be passionate about

Avera