I was watching Bullitt tonight. Steve McQueen's Mustang makes some great noises during the chase scene. (That green VW again? And how many hubcaps was that?) When he shifts from a lower gear to a higher gear, there's a distinct "brr.. brrr" sound. Is it over-run? Speed-shifting? What? Here's a very similar sound from a flathead Ford: http://www.vanpeltsales.com/FH_web/shifting_gears.wav What makes this double-vroom-vroom upshift sound? Thanks, --Matt
Wow, thats a flattie?! Sounds SWEET! Now, back to the 'brr..brrr' noise.. I have no idea, but alway's wondered what was doing that myself..
It's made by a right foot on the gas pedal...by someone who knows how to make a set of twice pipes talk.... Brian
Ah... The right foot and the gas pedal. As opposed to, say, the left foot and the headlight dimmer switch? Or perhaps his right pinky and the cigarette lighter? Or Miss Scarlet and the candlestick in the billiard room? First, how about dropping "The" from your HAMB name, Catholic? Not only does it sound self-important, it sounds downright silly, considering that there are about a billion Catholics. You ain't The Only One. Second, the audio file I linked to is on Glenn VanPelt's excellent and comprehensive flathead website. It's an encyclopedic treasure chest full of flathead information. To suggest that, along with his other great sound clips of of various Ford flatheads, he slipped in a clip from a Mustang, is stupid. Sorry to be short with you guys, but I'm looking for a real answer from someone who knows. Come on, guys! What's that sound?
wouldn't surprise me if Bullitt ripped off the flathead sound! i expected to click on this this morning and have the question answered by someone knowledgeable. i guess it's up to idiot's liek me to take guesses! guess number one: it's due to the ****erfly's of the carb slamming shut and bouncing open when you release the throttle to shift, "throttle flutter"? possibly due to the high vacuum when you back off at 6000+ rpm? guess number two: i don't know about this one, it wouldn't apply to many engines. but again vacuum is a factor, this time the vacuum advance in the dizzy, as the engine winds down, the vacuum advance is reacting to the chaning engine operating conditions, so the advance is modulating the timing curve as the engine coasts, changing the sound of the exhaust note as the advance changes. both guesses straight outta my ***. i've been running around with some obnoxious straight pipes, that when you coast in gear, do a kind of rythmic brrr brrr brrr brrr. which brings me to another, just plain harmonics of the engine. ever notice how cruising at a steady rpm, your engines sound will kind of "pulse"? i often wonder about what those harmonics mean to the engine. modern factory manuals have some real interesting reading on diagnosing vibrations in cars. back to the brr brrrr...i don't think it's power shifting, cause those sound like fairly slow shifts, with my straight pipes, i've found the need to "drive" to fit the exhaust note, if i shift slowly, i get a healthy rap out of the pipes in between gears, when driving at night in residential areas, i make sure to bang gears very quickly, and get no rapping between gears.
Thanks, ray, for well thought out response. I really appreciate it. You're no idiot. I think you're right when you say that it's probably not power shifting, and that they sound like fairly slow shifts. I like your guess #1, that it's the ****erflies snapping shut and then re-opening under throttle. And it's a good observation tht if you shift quickly you don't get the rap. Does anyone else have any thoughts?
Seriously though...I think he is just slamming the throttle wide open and tapping the clutch to shift. The RPM spikes as he taps the clutch and makes that beautiful Brrrr...sound. Been a couple of years since I saw the movie though... Simply a good driver who has the ability to power shift. McQueen was one cool SOB wasn't he? We lost a good one way too early there...
Download BOXITT to hear some of the sounds and have a good laugh too! Almost sounds like hes just closing the throttle while the standard trans is in gear to control engine speed. Of course ALL the chase scene isn't in this little "Movie"...LoL http://www.pocketmovies.net/detail_264.html
Thanks, Bill. But why is it a double Brrrr? Why two spikes? That link you posted is great. I really like the way they mixed the sound for when they catch air over the crests of the hills.
I've listened to this clip a TON of time's trying to figure this out... Here's one thought that came to mind for me........ If you listen to the clip you posted, the second time the noise is made, you can hear the engine rpm down in the first "brr" (sounds to me like he's throwing in the clutch and letting off the gas at the same time, and high rpm's create the 'brr' or engine decelleration) then he hit's the gas one time without releasing the clutch (for what reason i have no idea), and again, the 'brrr' noise of the sound matches when he first throw's in the clutch for the next gear. Then he releases the clutch and hit's the gas again to pull another gear. I actually think it's just the engine decelerating from high rpm's making the brr noise, it just has a very unique sound to it at that rpm. This is what i've come up with so far..... Just listen to it a few time's..pay attention to when he's letting off the gas.. What the hell do i know though
Hate to burst everyone's bubble, but most of the sound you hear in the movie is dubbed in from a non-synchro 5-speed GT40. I know it ****s and I hate to belive it myself, but it looks to be true. -Dean
Dosn't burst my bubble at all.. i still think it sounds great! The 'non syncro 5 speed' would also explain why the second 'rev' before catching the next gear...
I can get the same noise out of my 302 windsor with 289 heads. Basically I don't totally back off but rev it twice. I think it's my pipes, the wag has standard manifolds with 2" pipes and straight through mufflers. It runs a four barrel straight gas system. My mates think it sounds like a ski boat
I used to run a really stout clutch and even w/ synchos, i'd rev match the shifts somewhat like that. if not, it'd grab really hard and feel like the dash was gonna fall out of the car.
Yeah, I think Pakrat nailed it... Those small block Fords sure do sound nice don't they Mule? My old 68 Mustang had a similar sound when you'd back off the gas. I had a 289 with manifolds and 2" duals...ran the Mopar BB mufflers up close to the engine and sneaker pipes out the sides ahead of the rear wheels. No balance tube... Man...it sounded EXCELLENT! Hmmm...wonder if the dubbed GT-40 was a small or big block?
Damn, why's everybody getting all technical and stuff? I'ts simply the sound from the pipes...The "brrs" everybody is talking about is simply the pipes backing off..... you wind it up in one gear, as you are mashing in the clutch, you let off the gas, tap the throttle once as you are sliding into the next gear, the back on the throttle as it slips into the next gear....standard operating procedure for old, big trucks ( flatbeds, dump trucks, etc). Especially when you don't want to use the clutch...wind it to the right rpm, pressure on the gear shift, let off the throttle, it slips out of gear...blip the throttle once while in nuetral, slides right into the next gear, back on the throttle....never touching the clutch.. I guess the point that the sound clip was from a car with a non-syhchro five spd would further support this...as that would be similiar to the old trucks with non-synchro higher gears.... On the same subject, ever split-shifted a two-spd rear on a heavily loaded truck with loud pipes? Sounds like you are gonna go through gears forever...low side first, dump clutch, high side first, dump clutch, back to nuetral, shift rear back to low side, into second, wind up, dump clutch, high side second....and so on... damn, I gotta quit before I get the urge to go load up a load of logs... Brian
Those small block Fords sure do sound nice don't they Mule? Yeah I like it. My mufflers are just before the diff. it's split all the way. Sounds sweat win you give it sh!t. Mind you I just blew both head gaskets so I'm hangin to get the heads back. Driving the wifes canyonaero is driving me nuts
Coincidently NPR did a segment on "Best Movie Car Chases" last week and they had an interview with the guy who worked out the stunt driving. One of the main things that made this such a good chase was the new approach to the sound design. They were completely conscious of the small details. Although he didn't mention the "brrt..brrt" eh did point out at the start of the chase when the traffic light (on Army St.) turns to green you here a "click-click". That's the sound of the magnets in the lights. So yeah, they definately wanted you to hear all of this stuff and be thinking about it because it draws you in. I think the sound in either the driver blipping the gas going through nuetral or tapping the clutch to down shift. ( What I heard was on downshift. Same noise?) I'm wouldn't be surprised if that is a GT40. It's a small block Ford for sure.
I always thought it was just blipping the throttle twice during shifts, just because it sounds cool, and not because it would be needed on a syncro Mustang, but if it is indeed dubbed from a non sync GT40, that would be another reason. We should be able to confirm this trivia ! BTW: Steve McQueen died way too early !
I had a friend with a GTI, he'd double clutch it during power shifts, because the synchros were either worn or simply wouldn't catch up in time.
That sound you hear is the same as european rally drivers do,as you change gear you slip the clutch a little to keep the revs up in the ratio you have just changed to .It helps the engine speed up on the up change and gets the engine ready for higher rpm on the down change..............don't do the engine much good although it works a treat..................Marq
My vote is for double-clutching as well. There are several reasons to double-clutch on an upshift, not just downshift. The old Liberty crash boxes not having synchros is one reason, worn synchros/dogs is another, & to match your engine speed to the gears saving the synchros on a "weaker" trans is yet another. All particularly useful on a hard run where you're really getting on it.
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