Anyone fabricated/bought a cold-start silencer before???

OK, this may "sound" stupid but I need to silence my car when cold-starting. I live in PC country up here in Canada and sometimes I have to start my car very early in the morning to make a 2-4 hour hike to a driving event (and not be late).

The problem is my California 30 (Cali30) has a high-flow Capristo exhaust system and cold starts sound like my house blew up. It's ear-shattering. You can hear it very clearly even with my garage doors closed. I don't give a rat's doo-doo for PC mentalities but I think it's uncivil to wake people up at 6 or 7 am on Sunday by starting your loud car. I already forestalled early startup on one occasion and it's a drag. The sound from my car is otherwise easily modulated once the engine is warmed up.

I am seriously contemplating to fabricate a pair of exhaust hoses to connect the valved exhaust pipes in my car into a "high capacity" muffler so I can kill the noise at startup. I may have to ensure the hoses don't get blown off the exhaust pipes when I start the engine.

Has anyone else made or bought such an item? I would prefer not to "reinvent the wheel" if there are pitfalls to this idea. Thanks in advance!!

 

LOL!

...because that's too inefficient a solution and anyway, it's just the first 1-2 seconds that's too loud, the rest of the 2-4 hours hike sounds way better with the upgraded exhaust.

 

My cold start literally sounds like an explosion. It definitely has to do with the low back pressure of the exhaust system so the Vortex Cones would likely help reduce the volume of noise.

I think I only need to baffle 2 of the exhaust pipes because the gas coming out of the other 2 exhaust pipes always pass through the muffler. I believe the loudness comes from the pipes that pass gas straight through when their valves are open.

FWIW, the Forza Componetti (exhaust) Valve Controller has a 3rd setting which forces the exhaust valve to be ALWAYS CLOSED. Unfortunately, I have the Capristo one which only has the 1st two valve settings: ALWAYS OPEN and open by the ECU. I think the ECU is programmed to open the valves in a cold startup because it is not as loud when I restart the car after warm-up.

Since I only need to use a baffle when I start up early in the morning, I will not permanently install it as the loud startup actually sounds very cool, just not when it's so early in the morning.

Thanks for your thoughtful suggestion!

 

John, thanks for suggesting the exhaust discs. I've never heard of them before and they do look interesting. While I believe they are designed to be permanently installed, they offer me optional ideas to follow up on.

At the moment however, I am leaning towards just closing the exhaust valve for 2 of my exhaust pipes by swapping my Capristo valve controller for a Forza Componetti controller.

 

Thanks for catching that issue with the vacuum operation of the valves.

Forza confirms their controller uses engine vacuum to close the valves but says the cranking engine may generate enough vacuum to close the valve quickly, before the gas that causes the BANG will reach the muffler. I believe they're right because it's the initial intake stroke(s) that first creates engine vacuum and that would be driven by the starter motor before the first ignition occurs. The gentleman I spoke to owns 360 with a cat-delete exhaust and he is able to keep the valves closed for a quieter cold start. He mentions cold start is louder because the ECU dials in a richer initial air-fuel mixture to warm-up the cat faster, to reduce emissions. The problem with high-flow exhaust systems is that this air/fuel mixture gets past the cat (or no cat) section much faster and then ignites further down the exhaust plumbing. Closing 2 of the 4 exhaust pipes will create enough back pressure and slow down the flow. By enough? I don't know but it worked for his 360. In a way, it would mimic what the factory engine start cycle was designed to do, which is to let the extra rich air/fuel mixture burn inside the cat, to heat it up more quickly.

The other trick Forza told me is to make sure the ENGINE START cycle does not interrupt current flow to the controller as that would reset the valve controller. I can ask my dealer about that. Once I get past the first 1-2 seconds I can open the valves again and let the engine warm up as normal because cold idle isn't that loud.

Forza says keeping the valve closed should only be done for brief moments. I believe some track drivers do that before reaching the section(s) on race tracks where the noise sensors are located.

Interesting problem to say the least. I can always try it. My Cali30 apparently works with the less expensive E3 Forza controller, $295.

 

That's a fair and logical question. The answer is that I purposely make my garage slightly drafty so I cannot soundproof it.

In this part of Canada, we get very cold winters (way below 0°C) for several months and cars that go through repeated cold/heat cycles in the winter tend to rust or get moldy. My Ferrari is not driven in the winter but my pickup truck is parked in the same garage. If I repeated warm up a previously frozen car, possibly several times a day, it creates a lot of condensation as warm relatively humid air hits the cold car surfaces.

From personal experience, the best temperature to maintain my garage is around 4°C. I do this by leaving gaps around the garage doors (my windows are air-tight). The garage stays above 0°C (freezing) because its attic is connected to the house and stays warmer than 4°C.

I can only drive my Cali30 for 6 months out of 12.

 

Thanks! Here she is, I love her to bits and always pop open the hood after a drive to let the engine bay cool off more quickly.

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Yes, the gaps I leave for the air are big enough that sound will escape just as easily!

It's nice that the AM Rapide S has such a civilized and thoughtful feature. I'm sure it's much appreciated. Do you also own a Rapide S?

 

Marco, thank you for your compliment! I dropped her off for another round of upgrades today.

As for the AMs, they do sound lovely. I had also considered a Rapide some years ago but decided to get a small car instead as I no longer needed to provide chauffeur duty. My interest went from Rapide to a 6MT Vantage roadster, to a 6MT DBS Volante, to the Maserati GT full-size convertible and finally to the California. 2+2 and a DCT transmission was just the right medium for me.

BTW, I have found the solution to my cold start bomb problem.

I was asking my tuner if he could swap my Capristo exhaust valve controller for the one from Forza Componetti. He said yes and then asked me why I needed to do that. When I explained to him about needing to close the valves at startup he then told me I could do that with the Capristo.

To make a long story short, I have attached an excerpt from a Capristo instruction sheet - frankly I don't know if my tuner ever gave me the instruction sheet after he installed the controller, but at least he has now explained to me and saved me about $600 worth of merchandise, shipping and installation labour.

I tested the Capristo remote control (I have the older 2015 version but the newer 2016 model works the same way).

My "normal" cold startup is always so loud that my unprotected ears would hurt quite a bit from the noise. When I held down buttons 1 and 2 simultaneously, the startup was still loud but was not painful any more. So it worked. I tested it last night and this morning at 0650 and the noise level was consistent. Tolerable. I cannot make it any less noisy unless I change the mufflers, which I won't.

So the Capristo controller is quite flexible although the Forza unit does allow the owner to close and then re-open the valves at any time, which is useful for racers who need to silence their cars as they pass the noise sensors at race tracks with a silly low noise limit. Our local ex-F1 track does not enforce a noise limit.

Problem solved - lesson? Always ask your installer to show you all the packaging and documents after they finish installing an upgrade!!! I have also attached the actual instruction sheets for the 2015 remote control which I have, and the instruction sheet for the newer 2016 Capristo controller.

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