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YOUR RESEARCHOverpriced bling you?ll never see - orange cap mod
Leading reported evidence
Check no leaks
Performed · outcome unconfirmed
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Overpriced bling you?ll never see - orange cap mod
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Leading evidence: 'Check no leaks' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check no leaks' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
Certainly any/all parameters can be changed with a tune.
Overpriced bling you?ll never see - orange cap mod
Use cap
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Overpriced bling you?ll never see - orange cap mod
Replace air/fuel parameters
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Suggestion
there is a certain air/fuel parameter manually set and the cap/block off might change the air/fuel parameters?
Overpriced bling you?ll never see - orange cap mod
Replace driving style, or
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Suggestion
I would suspect that you may have unconsciously changed your driving style, or that the parameters for " injector shutdown on decell" were met during your road test.
Overpriced bling you?ll never see - orange cap mod
Replace driving style, or
No successful repair reported for this finding.
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1
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Suggestion
I would suspect that you may have unconsciously changed your driving style, or that the parameters for " injector shutdown on decell" were met during your road test.
Overpriced bling you?ll never see - orange cap mod
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35 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Generation: 20261027T173940Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
So, drunken ebay shopping resulted in the purchase of a super overpriced ($65 usd), but ever so nice machined replacement for the orange cap airbox mod (from Denmark):
I used the cap from a quart of Castrol Edge oil. It fits perfectly and it was free. But if it gives you joy knowing that it's in there, then it's worth it.
It shouldn't have any effect on performance as it is only sound related. The Helmholz box has no outlet or inlet to the airbox. I'm guessing the the difference is only in perception.
Hello,
i am interested in doing this mod, but can’t find the instructions, as the “smiley” link no longer works. Is it as simple as plugging the hole and reinstalling the hose?
Thanks, in advance, for your help with this.
Update: installed this and noticed I lost the nice burble I used to have when I let off the gas...
@Porschetech3
we need your help!
Why did that happen? Do I need to give the ECU longer to adapt.
Ive taken it out already...
It's contentious - I know there is no power to gain but perhaps the turbulence the box creates helps with the pulses etc.
Anyone into thermodynamics? I need answers! Haha
The burbles, crackles, pops, on deceleration are caused by fuel that is not burned completely in the cylinder and is burnt in the exhaust. Our cars have a program in the DME that shuts down injectors during decell at certain times/temps/rpm, then turn back on near idle. On 991 and newer cars the DME is programed to "waist" some fuel during decell to deliberately cause more burble,cracks, and pops..It does sound cool. I had a friend who was complaining that his 996 didn't have any sounds on decell, I advised him to crack the throttle slightly during decell to keep the injectors ON during decell to induce the burble,cracks, and pops, he was pleasantly satisfied.
I would suspect that you may have unconsciously changed your driving style, or that the parameters for " injector shutdown on decell" were met during your road test. The elimination of the Helmholtz Resonator would have no effect on the decell sounds on closed throttle.
Thanks Porschetech3! Might give it another shot
Actually
@Porschetech3
one last question - sorry! Would a tune make a difference? I.e. there is a certain air/fuel parameter manually set and the cap/block off might change the air/fuel parameters?
Certainly any/all parameters can be changed with a tune. It would all in the hands of the programmer/tuner.
But, I can't see the elimination of the Helmholtz Resonator having any effect on the Mass Air Flow unless it had a "leak"?? Have you checked it for a leak/seam split?? Maybe you could swap it back and forth a few times along with road tests to get a definative answer if anything other than noise at above 5k RPM is happening.
Thanks! Yep checked - no leaks. Might but it back in but I could have sworn it felt slightly less punchy down low - my imagination? Perhaps...
I can't really hear anything but the exhaust at over 5k so I don't think this mod is for me.
Had problems finding part number for orange cap from Caplugs. If helpful for others the item # is CPT-19 and they will still send out a free sample. The said, it didn't make any difference in sound in my stock 99. But I am usually around 3,000-4,000 rpm so perhaps that's a factor.
I mainly noticed the increase in noise when I had a stock exhaust, which was too quiet. I used to hear precisely zero intake noise, and IMHO the orange cap just adds that layer back into the mix. I'd hear a distinct intake resonance/howl somewhere near 5k at full throttle and some other low rpm instances when you're applying throttle under load. Zero sound change at low load and low throttle angles.
With fisters it's almost unnoticeable for me, except with the windows up where I can still hear the 5k resonance under hard throttle.
Zero impact on performance either positively or negatively.
I stuffed a rag into the Helmholtz resonator - you don't have to cap it off; you merely need to stop it doing its job.
Admittedly, an old shop rag is not quite as sexy as billet aluminum.
Here is my video of the mod. I have sound clip with the Fister D exhaust with the Orange cap mod. The following are options for this mod:
(1) Castrol GTX oil bottle cap, (2) CAparts.com - free sample of CPT-19, (3) caps from Lowe�s/Home Depot
https://www.youtube.com/watch?v=jiJSAEBCV5k&t=1s
This is a source reference. Confirm exact model applicability in the original material.
