Hi, My wife has a physical aversion to deep bass sounds and they make her feel dizzy and nauseous. Unfortunately, our Daytona has a deep bass undertone to the exhaust sound that she doesn’t like. It isn’t the volume that she doesn’t like as we also have a 427 S/C Cobra with side exhausts, which is really loud, and we use a noise cancelling intercom to counter it. I read in a thread on Fchat recently that someone had suggested replacing the centre section of the exhausts with straight-through pipes for better breathing . Has anyone done this and if so, can you say what effect it had on the exhaust tone? Thank you, Paul
Hello Paul, as far as I remember there are two types of mufflers: - reflexion mufflers - damping low bass frequencies - a sequence of reflective walls in a steel housing - absorbtion mufflers - damping high frequencies - usually a straight tube with holes, surrounded by absorptive material as glass or steel wool - leading to a deep bass sound most men appreciate Unfortunately, reflexion mufflers have a higher drag, so they are not really popular in sportscars. But a sequence of 2 reflexion mufflers eliminating your absorption unit could solve your problem. Such components are available in race technology shops and can be tailored to your car. Remember: exhaust modifications have impact on drag and may require rejetting of your Webers Hope this helps!
Hi Paul I have a 1971 365 GTC/4. As you know, the C/4 motor is quite similar to the Daytona motor, although lower compression and not the same power output. And the motor has never been out of the car, which shows 35K miles so it's a little tired. These conditions obviously affect the motor's sound and noise. When I bought the car 2 years ago, it had a Quicksilver stainless exhaust system. I didn't like the way it hung so low that ground clearance, and appearance, were not to my liking. I had a local shop remove the center sections (all four of them) and run straight pipes back to the resonators. I was astonished how little difference it made in exhaust sound. It is slightly louder, but not annoying. I had already fattened up the idle jets (F860 to F865) and main jets (#130 to #140) to get rid of the midrange stumble that C/4's are well known for. No further fitting of idle and main jets was required. Again, you have motor that is inherently louder than what I have. But I must admit, I really love the sound I currently have. The shop here that is the only shop I trust to work on vintage Ferraris is owned by a guy who has several cars that have won awards at Pebble Beach and Palm beach concours events. One of them is a Daytona and he runs the same straight pipe set-up that I have. It is not obnoxious and sounds great. FYI.... your results may be different. Mike
Thank you Mike, that is interesting to know. My engine has been totally rebuilt and probably has less than 1,000 miles on it since and to my ears at least, sounds great, but it really effects my wife quite badly. It is my dream car, so it is very disappointing that it is having this effect on her.
Adapt a euro stainless steel system, that will quiet the exhaust and take away the " boominess base" sounds Gary Bobileff
I was thinking of replacing the first and second silencers with four straight-through stainless pipes and blanking off the loop from the headers into the first silencer.
That's what I did, not in SS but the regular old stuff, and put a crossover pipe just behind the headers on each side. Of course the "loop" is blanked off. One other note.... I did this same thing many years ago on my first C/4 that had a complete engine rebuild with 10.5:1 CR pistons. It was louder than the one I have now for obvious reasons, but again not too loud and no drone. I have the quicksilver SS exhaust system in a corner of my shop. Amazing how heavy they are.
Few years ago, while developing/fabricating couple of Daytona exhaust system modifications, including a “muffler delete” (while leaving resonators & tailpipes intact) setup and another shorter, side exit (before rear tires),i.e. “racing”-type setup (both constructed using stainless steel tubing) I conducted a series of comparison tests. These tests included multiple drives in two different US market Daytonas, both initially with OEM/stock exhaust, one with original exhaust (with 13K miles since new) & one with brand new reproduction mufflers & tailpipes coupled to NOS headers, and then with aforementioned modified setups. Each test (drive) was audio & video recorded with onboard camcorder + two different decibel meters for in-cabin noise/sound level readings in all (forward) gears at various engine and vehicle speeds while driving same roads/routes/lanes, using same gears & speeds at given road sections, etc. Additionally, one of my friends has a Euro spec Daytona with “muffler delete” (w/resonators & tailpipes) exhaust system similar to one I built and while his has not been decibel tested or a/v recorded, over the years I’ve driven it with that setup several hundred miles + been a passenger for many more and at least to my ear, it sounds pretty close to same as my setup. So based on my (limited ?) experience and aforementioned research findings, I would stay clear of any muffler delete type modifications if attempting to achieve OP’s objective. IMO, the easiest/simplest way to avoid any annoyingly low exhaust tone in a Daytona or similar High Performance vehicle is to drive it the way it was designed & intended to be driven, i.e. never let the RPMs drop/settle below 5K except when idling. And before anyone asks, due to privacy and proprietary reasons, I have no intentions or interest sharing any of the aforementioned onboard video footage here or elsewhere publicly, but happy to show privately to anyone expressing enough interest.
Hi Paul, While I would not say that a Daytona actually "drones" (I associate that term with more of a swell in volume at a certain range of speeds) there is no doubt that it has more of a 'baritone" than, say, your Dino. Does the sound bother your wife only at highway cruise? Only at idle? All the time? If it is mostly at idle or (slow-ish) cruise, I know you had some issues with how your carbs were tuned, and I would start with getting that sorted out; if the engine is not running right, then that could be a contributor. I would also do a comprehensive check for exhaust leaks, and verify that the exhaust system has not already been modified (or is not a stock unit, but rather some non-Ansa reproduction); anything that is amiss on either of these fronts could well cause a real case of "droning". Another real possibility is that when the restorer reversed the competition mods to your car they did not put all the sound-deadening back; you might want to pull-up the carpets and see whether all the burlap/"tar" matting is there. I realize that you don't think the volume of the sound is the issue, but without that matting, you could well be getting some weird resonances that are similar to "drone". Just some random (and somewhat generic) suggestions, Alex
Thank you Alex. The issue seems to be predominantly at low revs and I was thinking the same regarding the carb setup. I’m going to get them properly setup before considering any other mods. I wouldn’t describe the sound as “droning”, more a sub-bass undertone. It isn’t even loud, but being being very low frequency, it permeates everything. I’ll report back once the carbs have been done. Thank you again. Paul
Thank you for your detailed reply Timo. As per my previous reply to Alex, I’m going to get the carbs properly setup and see what, if any difference that makes before doing anything else. Paul
Make sure that you are clear with the shop about what represents the important running condition (for your wife’s comfort). At idle it is pretty easy to play around with stuff, but once you are off-idle you are into not really being easily able to replicate running conditions (unless the shop as access to a variable-load dyno of some kind). Even at idle, you need to comprehend what temp (of the engine) range is the most important. My car got delivered to me with the carbs adjusted for easy cold-start; engine ran poorly once the oil temp started to get “off the peg”, and was a lot worse when the oil was at 80C-or-so. You want to make sure that the shop understands what your needs/goals/sensibilities are. “Done correctly” is not as well-defined a thing as one might assume…
with or without choke? if without then the mixture has beeen too rich and so problem when engine warms up. the more it warms up the more the engine not running well it also depends if you drive on sea level or in the mountains
No chokes (some previous owner had removed them; sigh...). I redialed things long ago, and car is a lot better now. The altitude variability is another good point; don't have your carbs tuned in Denver, CO, if you live in San Francisco, CA...
You’re welcome. While setting carbs correctly is obviously essential for enjoyable driving, I’m not sure it will make much difference in exhaust tone unless they’re really off to begin with. Good luck.
Hello Paul and fellow car enthusiasts, I'm Niklas Braun, a 33-year-old software engineer in the automotive industry, and I'm excited to be part of this forum. I've actually experimented with exhaust modifications on my own vehicles, although not specifically on a Daytona. Replacing the center section with straight-through pipes is a common mod for enhancing airflow and altering the exhaust note. It tends to give a more aggressive and pronounced sound. However, since your wife has a sensitivity to deep bass sounds, it's essential to proceed with caution. While it might improve breathing and performance, it could potentially exacerbate the low-frequency tones that bother her.
Hi Timo, I agree and I don't think they are that far off at present, but we may as well start off in the best possible position. I also accept your previous point about keeping revs above 5,000rpm, but in reality, this isn't always possible on long trips, especially when having to drive through towns and cities in Europe. Regards, Paul
in germany a lot of cities limited the speed to 30 km/h, even on main roads. more stupidity I think is not possible. justification: noise protection just now I´m during cold weather happy in thailand. but when I drive with a car in germany in such a 30 km/h zone I only use 1st gear that everybody may enjoy the noise and with me BB with 30 km/h it turns around not even 3000 rpm - so a little increase idle and even my van ( renault master ) I use only 1st gear
Yes, we have an idiot Mayor in London, who has imposed a 20mph (32kph) limit across most of the city, in the name of polution reduction, which of course is nonsense because no vehicles are designed to operate at their most efficient at 20mph.
It has been possible ever since the gods of motoring created multi-gear transaxles/-missions along with clutches to help us mere mortals select and maintain speed appropriate rpms without holding the true spirits of our beloved horses as hostages behind barely open throttle plates. Perhaps it’s me but I’ve never quite seen the point of needing/using 4th, let alone 5th at speeds below 100mph in cars like Daytona. But then again, I’ve never understood adding a power steering into them either, so…
You may be lucky enough to be blessed with roads and conditions that allow you to stay above 5,000rpm. We’re not so fortunate in Europe, and especially so in the UK. That isn’t to say that we don’t have some stunning driving roads, because we do, but they’re generally connected to towns or cities where traffic becomes more of a problem and you can’t sit with the engine at 5k in crawling traffic or at standstill. i have no intention of fitting power steering either. Paul
Paul, I was just ribbing you. I understand we all acquire/have our leisure cars for variety of individual reasons. Some have them for enjoyment of just looking at them, some just for sharing/showing them off at C & Cs or shows, some for tinkering with them, etc. I've always bought/owned my cars for their originally intended use, i.e. driving and preferably the way they were designed/engineered to be driven. Unfortunately, with speed limits topped to 75 MPH around here, not to mention way too much traffic and poorly skilled other road users, we don't really have great ways to enjoy high performance/- speed GT cars and why I personally no longer have interest in owning anything like a Daytona*, let alone more potent road cars. * I still enjoy working on and reproducing parts for them, although I'm loosing interest in latter.
We have some fabulous roads in the UK and across Europe to enjoy cars like this, but we can’t avoid having to pass through towns and cities unfortunately. I have driven our Cobra all over Europe and the plan is to do the same with the Daytona.
had the Daytona out for a drive yesterday. what a glorious sound at 6000 rpm but no way to sustain that in any gear for long. the stock exhaust is perfect to me.
