Noise level inside Coupe - comparison with Roadster?

[ram_g]

Hi folks,

Thinking very strongly about getting back to the FFR fold for a second build, this time a Type 65 Coupe. Been reading the forums and of course most of my questions have already been addressed there.

One point that I'd like more information on is the noise level inside the Type 65, compared with a Roadster. I've heard that it is noisier.
- For those who have both, are you in a position to address "how much noisier"? A lot to where it is glaringly obvious? Just a little to where it isn't that noticeable? Something in between?
- What is the source of the noise - is it dual side pipe design compared to the singles on the Roadster? Is it mostly wind noise at speed due to the different shape? Is it reverberation inside the closed cabin?
- Can the noise be controlled by insulating the heck out of the cabin and rear hatch area?
- What about the FFR coupe windows - do they cut down on the noise? Or make it worse?

Thanks for all insights!

Ram

[KDubU]

I have read the pipes are louder or at least their position in relationship to the doors or something makes it that way. Paul mentioned this earlier this week I believe either in one of his posts or one where he was replying. Adding extra insulation in those areas may help.

[edwardb]

Have both and drive both. Although the Coupe not as much since it's new this season and still under stay-at-home orders. But certainly have observations which I've shared in my build thread. Yes, the closed cockpit Coupe is louder than the open top Roadster. How much louder is going to depend on a lot of things including engine, exhaust, insulation, and maybe mostly expectations. Both my Roadster and Coupe are Coyote engines with Gas-N pipes. So not quiet pipes. But relatively mellow compared to stock pipes. The only thing I would stay though is the Roadster is a Gen 2 Coyote and the Coupe is a Gen 3. I had Gas-N Roadster pipes temporarily on the Coupe during first starts and some general running. The Gen 3 Coyote definitely has a sharper more aggressive tone than the Gen 2. Quite a few differences between the two engines which in my experience results in the Gen 3 being louder. So that maybe contributes to my situation some. I don't think it would possible to insulate the Coupe more than what I did. Other than the areas between the body and the chassis in the area of the side pipes. Another builder even added a panel on the outside of the chassis area under the doors. That along with packing with insulation is a great idea IMO. I drive mine with the window kit and the blocking pieces in the quarter scoops. I can tell you it makes a difference. Even having the little sliding window open makes a difference. Look at the picture below and it's no surprise. See how close the side pipes and exits specifically are to the side windows, rear scoop, and your ears inside probably only 24" or so away. If controlling sound is a factor, definitely go with the heat and A-C package so it's comfortable to have things closed off.

Bottom lines for me? Coupe is louder. Don't expect it to be daily driver quiet. Not even close. The physics of a closed cockpit that echos every sound versus an open cockpit won't be defeated. Expect to wear earplugs. I've been playing around with several different varieties, and have found that with better earplugs than I've been using in the Roadster it's much better. To the point of not being an issue. Having said all of that, for cruising I've found that in 6th gear in my T-56 (similar to 5th gear in a TKO) and the Coyote around 2,000 at highway speeds, the sound is very mild and could easily do that for extended periods. The noise (and fun...) starts when you stick your foot into it. 4,000 - 5,000 (and up with the Coyote). The more I drive the Coupe the more I like it. So no regrets here at all. Hope that helps a little.

https://hosting.photobucket.com/images/ab234/edwardb123/IMG_1856.jpg?width=590&height=370&fit=bounds (https://app.photobucket.com/u/edwardb123/p/0038fa7c-9416-4e09-af94-7fc4f6580583)

[David Williamson]

I have a different comparison. A Mkll with stock FFR 4 into 1 pipes on a mildly modified 93 GT engine vs a Gen 3 coupe with Boig exhaust on a Levy Dart 363, very different engines. I have about 400 miles on the coupe from last year but I was running without the rear quarter windows and the side windows open, AC was not charged yet. I noticed less wind and road noise but about the same engine noise. I did have a resonance that I hope is reduced with the quarter windows in place. FFR may have changed the design of the pipes to make them quieter, my original FFR exhaust siytem was really loud, painful loud even with ear plugs. I have Dynamat in mine and overall it is no louder than the Mkll I have, and less wind/road noise at highway speed about 65 - 70 mph.
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David W

[edwardb]

I have a different comparison. A Mkll with stock FFR 4 into 1 pipes on a mildly modified 93 GT engine vs a Gen 3 coupe with Boig exhaust on a Levy Dart 363, very different engines. I have about 400 miles on the coupe from last year but I was running without the rear quarter windows and the side windows open, AC was not charged yet. I noticed less wind and road noise but about the same engine noise. I did have a resonance that I hope is reduced with the quarter windows in place. FFR may have changed the design of the pipes to make them quieter, my original FFR exhaust siytem was really loud, painful loud even with ear plugs. I have Dynamat in mine and overall it is no louder than the Mkll I have, and less wind/road noise at highway speed about 65 - 70 mph.
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David W

Good post and couple responses. You raise a very good point about wind and traffic noise. My very limited drive time with the Coupe has not included any expressway driving including continuous speed and traffic. That's a loud environment for sure in the Roadster and I'm sure will be different in the Coupe. So my initial response doesn't include that and is missing. I'm sure that will be an advantage for the Coupe. What I can say is my wife immediately noted the lack of wind and was all about not wearing hats and/or messing up her hair. An important consideration for sure. :o The other comment I'd expand on is the nature of the sound in the Coupe and didn't mention before. What I've noticed is that there's a low frequency sound in the Coupe. The earplugs I've used for the past few years (Etymotic Research ER20's) don't mask this sound like the Decibullz molded plugs I'm experimenting with right now. Perhaps this low frequency is the result of the closed cockpit. Or maybe it's unique to my combination of engine, exhaust, etc. I don't know. Just have observed that masking it out makes a big difference.

[KDubU]

Gotta day what’s up with all these red coupes? ;) Very sharp looking.

[ram_g]

Thanks guys! Those rear quarter window block offs - I know the scoops are from FFR in the kit, but are there straight up block off windows also?

Sorry I haven't yet read all the Type 65 build threads - I am sure the answer is in there! I sound exactly like all the newbies on ffcars that I would shake my head at - "can't you read the forums first!"...

[David Williamson]

yes the rear quarter windows do come with the optional side windows but both Paul and I made them larger and removable. The low frequency rumble or resonance I have is not blocked by ear plugs. Yea both of us went red and it seems it has become a popular color.
David W

[ram_g]

This low frequency resonance - does it occur only when there is an air opening to the outside - e.g. the sliding window is slightly or fully open, or no windows are installed, or the quarter panel block is not installed? Does it go away when all air openings are *completely* closed off?

If yes, this is a Helmholtz resonance, and the only way to fix it is to ensure that there are no air openings at all.

See https://en.wikipedia.org/wiki/Helmholtz_resonance and https://jalopnik.com/why-do-slightly-opened-car-windows-make-that-awful-soun-1447498738

I would imagine that all FFR fixed roof cars might have variations of the same.

[John Dol]

yes the rear quarter windows do come with the optional side windows but both Paul and I made them larger and removable. The low frequency rumble or resonance I have is not blocked by ear plugs. Yea both of us went red and it seems it has become a popular color.
David W

David,

You mean the quarter scoops come with the window kit or the 1/4 scoop block of windows?

Thanks,

John

[edwardb]

The acrylic side scoops come with the kit. The optional side window kit includes pieces of acrylic that are meant to block off the scoops if you want. The problem is they're supposed to be put on with screws. Not a very elegant approach if you want to take them in/out. Plus not in a very friendly place behind the high-back seats. Erik Treves posted an idea in his build thread of making a piece that slides in/out. I expanded a bit on that idea. In my build thread here: https://thefactoryfiveforum.com/showthread.php?26630-Edwardb%92s-Gen-3-Type-65-Coyote-Coupe-59-Build-Complete-and-Graduated&p=375735&viewfull=1#post375735. David's may be similar.

Regarding the low frequency rumble, I'm not so sure it's air pressure or whatever. At least in my case rises and falls with engine RPM. Beautiful day here in Michigan today. So stay-at-home or not, my wife and I just did a 20 mile cruise in the Coupe. I'm getting more and more used to it. The earplugs I'm using now make it quite comfortable. She came right and said she'd rather ride in the Coupe than the Roadster. Hmmm.

[Dave Tabor]

I have about 4K miles on my Gen III Coupe and since no matter what pipes I run (Corvette side-pipes with changeable cores) I have to wear ear plugs. I'm painting my car now, body-on- I've been removing all of the sound-deadener/insulation which consisted of the 'mat'-type black rubber/foil stuff and high-mass vinyl. I should re-coupe 50+ lbs, easy. Probably another 10 lbs to go as I filled the area under the doors with both of the above. Still have to wear ear plugs so why make the car slower. Felt good ripping that stuff out-the trashcan got heavy quick...

Dave #17

[Chris @ Forma]

I have both a coupe and a roadster and our coupe is substantially quieter....The secret is twin EFR turbos. We are running straight 4" round side pipes and the turbos take so much energy out of the exhaust both in heat and sound. Both are running Gen 2 Coyote motors. Secondary advantage (or primary, depending on perspective) is 700WHP.

[cob427sc]

I have built and driven 4 roadsters with various engines and side pipes and one early coupe. The coupe had a much modified 351 with the stock pipes and it was loud from the start and got much louder as the mileage built up. As it got louder a strong resonance built up inside the car at highway speeds. I don't know if FFR has changed these pipes from what I recieved in my early kit, but I honestly believe that after 1000 miles straight pipes would be quieter. The roadsters were all quieter on the exhaust side, louder on the wind and street noise although wind wings do help a lot in the buffeting.

[David Williamson]

Got the Coupe back on the road agian finally, my insurance company was giving me a hard time with the appraised valuation so after about 10 years I dropped them, moved 3 cars and saved some big $$. Anyway with the rear quarter windows in the resonance is reduced but still lots of exhaust noise so yea ear plugs are required on the highway. Overall the sound level is about the same as the Cobra just very different. Interesting fact, we found out the I-phone gyro thinks the phone has turned when you hit it a little in 2nd gear and your video goes sideways.
Still a list of stuff to do but guess I am close to graduation, watch for some pics in the next few days.
David W