Anyone have any knowledge of this brand of exhaust - sounds incredible !!
Secret Weapon Exhaust
55513
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Firing order is 1-6-5-10-2-7-3-8-4-9. Stock: cylinder 1 opens exhaust valves, gas exits; 90° crank rotation later cylinder 6 opens exhaust valves, gas exits; 54° crank rotation later cylinder 5 opens exhaust valves, gas exits;
Now let's make one bank's exhaust pipe 25% longer
Let's say cylinders 1-5 is left bank and 6-10 is right bank just as an example. Left to right is 90° crank rotation difference and right to left is 54°, this essentially sounds mostly like an inline 5 mixed with a little bit of 10 cylinder frequencies or 5th engine order and so on. Only when both banks are connected and there is no phase shift between the banks, meaning left to right and right to left both take 72° crank rotation, then you get the maximum dominant frequency the engine is capable of.
So let's see.
You make left bank's exhaust pipe 25 percent longer. Cylinder 1 releases pulses. They take longer to reach the tailpipe now, which means cylinder 6's exhaust pulses do not reach the tailpipe 90° crank apart but 72° apart. So the distance between them shortened because cylinder 1 took longer. The other way around is the same, 5 releases pulses, 10's midpipe is now longer so it takes 72° crank instead of 54°. Since they are both at 72° crank now magic happens and you get a high pitch sound (I still don't understand why they only create the higher dominant frequency only when the intervals match or are close together, maybe some physics/acoustics person can explain, like I understand wave interference but i've never heard of "frequencies changing" due to interference and yet it works).
Now let's make the right bank midpipe longer by 25 percent and leave the left bank midpipe alone. 1 releases pulses, 6 is supposed to be 90° crank apart but now takes longer, but this is indeed a problem I think. We are just making the 90° interval longer, and the 54° interval shorter, and this is not what we want. This doesn't bring us to 72° on both banks. Engine will sound the same as before mod. Useless mod. So actually I think I was wrong. If you thought to yourself that it doesn't make sense then you are right.
Let's conclude that you probably do have to watch out which bank's midpipe you are making longer. Again, if someone knows better please correct this, but now that I thought about it more this is true and my previous statement that "it does not matter which bank's pipe is longer" is false.
No, I wasn’t trying to outsmart you because I noticed anything clever, I just didn’t get it on my own.
Just found this thread - which was interesting:
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As soon as all exhaust systems are ready, the team will announce they will start taking orders. I initially thought there were a lot of orders already, but they are holding off taking money for deposits until exhaust systems make it to USA.
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He says 33 percent longer. And specifically to make bank 1 longer (the one with the 90° interval).
I don't remember how I got to 25 percent lol..
We need to shorten the 90° interval by 18° to 72° which would be done with a 20% longer pipe.
But to get the 54° interval to 72° on the other hand we need a 33% longer midpipe of bank 1.
So we need 20% and 33% which we can't achieve at the same time. So do we now go with 26,5% longer xD
here is a quick sketch
In addition, won’t the change in effect length required to delay the pulses so that they arrive at the collector together change as the rpm changes?
meaning we can only “tune” it to be musical for a certain rpm?
Not sure I’m right on that because if it is the case, secret weapon seem to have managed it ok.
meaning we can only “tune” it to be musical for a certain rpm?
Not sure I’m right on that because if it is the case, secret weapon seem to have managed it ok.
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I don't think so since the firing intervals of course don't change with rpm, they are still 90°-54° crank rotation but that crank rotation obviously is faster the higher the rpm and you have a higher frequency of the exhaust and so on. But the intervals don't change.
Of course intervals don’t change but the time available for the pulses to travel the increased distance in the runner to coincide with the other pulse is shorter but the wave front will be traveling at the same speed pretty much.
of course what we’ve seen elsewhere doesn’t support this so again, I’ve probably got this wrong.
of course what we’ve seen elsewhere doesn’t support this so again, I’ve probably got this wrong.
Safi is great! Tell him Raf from Arizona is saying hi!
The pre-orders begin today. Exhaust systems for the 5.2 V10 are priced at $18,000.
To get your name on the waitlist, please DM me directly or email raf@nagengast.pl
Production & Delivery Schedule
Production is strictly limited to 30 units this year, with deliveries following this schedule:
To get your name on the waitlist, please DM me directly or email raf@nagengast.pl
Production & Delivery Schedule
Production is strictly limited to 30 units this year, with deliveries following this schedule:
- Batch 1: April 2025
- Batch 2: May 2025
- Batch 3: June 2025
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216 Posts
! ECU & Check Engine Light: This system does not include ECU software modifications. To prevent a check engine light due to the removal of catalytic converters, a remap is recommended, or alternatively, O2 sensor spacers may be used. Spacers are not included with the system.
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216 Posts
@Nagengast can you confirm this?
Comprehensive installation manual – Step-by-step instructions for installing the system without removing the powertrain (engine and transmission), depending on the installation method used. Full support available for any questions during the process.
Comprehensive installation manual – Step-by-step instructions for installing the system without removing the powertrain (engine and transmission), depending on the installation method used. Full support available for any questions during the process.
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216 Posts
What You Will Receive
Each system is engineered for maximum performance, precision, and durability, offering an authentic new and refreshed high-pitched experience. Your purchase includes:
- Resonance-free titanium valved exhaust
- State-of-the-art Formula 1-style headers
- Exclusive hard case
- Comprehensive installation manual – Step-by-step instructions for installing the system without removing the powertrain (engine and transmission)
- Lifetime manufacturing warranty
You'll receive headers and exhaust. And it can be done with engine in or out. A shop that hasn't performed it before will ask for engine out and ask more for the job. Yes, tuning is required or you'll have a check engine light on.
Correct.
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216 Posts
@Nagengast
Why has the narrative always been that you need to have the engine out to replace the headers?
Is that shops ust trying to "milk" labor hours?
Why has the narrative always been that you need to have the engine out to replace the headers?
Is that shops ust trying to "milk" labor hours?
I wouldn't necessarily say "milk", rather cautiously make sure that every bit on the car is installed correctly. It's one of those Good/Fast/Cheap situations for unexperienced shops - can't have all three. Now, a shop with a lot of experience of installing headers can get all 3.
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Thx for the info.
This is very interesting.
Time to go post this question on the FB page!
#troll
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