Cold Start Daftness

[Otispunkmeyer]

kapiteinlangzaam said:

Isnt it for emissions, get the CATs up to temp ASAP.

My previous Mazda CX5 2.0 used to rev its tits off on cold start, so much so the user-manual made a point of explaining it. However, you couldnt hear its exhaust so no worries

Think it's particularly bad on the Mazda engines. But it is because of the longer 4-2-1 manifolds they employ to keep cylinder temperature down (helps when running 13-14:1 compression). So the cat is quite far down the line. Some very late combustion and elevated revs going on in order to bring it to temp as soon as possible.

[philmots]

My XFR has a standard exhaust and it's ridiculous on cold start.

Even restarting whilst warm you get a huge rev flare that turns heads, I think it sounds great. Love it.

[GrumpyTwig]

W124 said:

Quick question,

Does anybody know if the cold start theatrics from modern fast cars (M3/R type Jags/AMG/RS Audis etc) actually have any technical benefit in terms of warming the engine or Turbos/emissions gubbins. I know modern performance engines are wildly complex so maybe all the noise has some purpose. Surely it can't be just noise for the sake of it?

Neighbour has an M4. Lovely car but it's incredibly loud first thing in the morning. I've driven various performance Jags and Audis recently and they seem insanely loud on start up.

Just wondered if all the noise has a purpose other than theatrics.

Unusually heard an M4 on cold start recently and it's by far and a way the loudest car I've heard on cold start, sounded pretty bloody horrible imo.

[IanCormac]

Jaroon said:

My XFR with aftermarket exhaust is defiantly antisocial on my 3am starts.

Just to clarify, I'm OK to select drive almost immediately and move off sedately with no adverse effects except potentially the CATS? I've had compliments and vaguely mumbled complaints and would prefer not to annoy anyone.

Defiantly antisocial? You mean you've asked it to be quiet and it refused?

[W124]

Tedious update.

Bloody M4 at 6.20am. That's the whole fking street awake then. I wouldn't mind if it was actually a decent sounding thing. It's horrid. I must be getting old.

[HappyMidget]

Joe5y said:

Did you pass earlier? There was a rather loud rumble of a V8 but then a neighbour does have a de-cat'd Cayenne.

PS e60 FR55JOE

Realised in 7 years living here that I hadn't actually been around the loop so decided to give it a pass

[donkmeister]

turboteeth said:

My old E55 was subtle and quiet even on very cold start ups and I always dreamed of replicating the C63 blip...!

Here's something odd - the E55 engine was a development of the engine in the E500... My E500 does a startup bark, so either a previous owner had it flashed into the ECU or AMG decided not to have it on the E55.

[HJMS123]

I think the cars which blip the throttle on start up (F Types) etc are obviously theatrical but I think most performance cars with reasonably loud exhausts will sound loud at start up, I believe they have to gets the cats up to temp asap as the emmission tests are based on cats at full operating temps. I may be wrong but I imagine if they didn't have this feature they'd be in a tax band or two above.

To the poster who compared a 740i to an M135i start up ... I imagine the 740i exhaust to be much more toned down than 1 series. I think it all depends on how loud the stock exhaust is to how noticeable the cold start feature becomes.

[DaveH23]

I have a MK1 Mazda 3 MPS and this idles a little louder on a cold start.

Probably the only thing about the car I don't like.

[Mr2Mike]

W124 said:

Tedious update.

Bloody M4 at 6.20am. That's the whole fking street awake then. I wouldn't mind if it was actually a decent sounding thing. It's horrid. I must be getting old.

The M4's do sound particularly grim from a cold start. In their quest for the most obnoxious, farty, resonant exhaust note it appears that BMW modeled their system on a 20 year old Vauxhall Corsa badly fitted with a straight through exhaust.

[Benmac]

TonyG2003 said:

I like the idea on the new Aston Martin DB11 start up. Press the starter once quickly and get the full blaring start, press and hold the starter for the "don't annoy the neighbours at 4:30am" start.

Yes, that seemed like a nice idea when I watched Harry Metcalfe's video review of it.

[kiethton]

I hate to say it but I move into my flat this weekend. I also just got my bike license and use the below to commute, first time this morning.

The video shows the bike just after a cold start last night, my neighbours may hate me - I leave the house @ 5:45 every weekday morning...sounds far louder in person unfortunately

[Blaster72]

Mr2Mike said:

W124 said:

Tedious update.

Bloody M4 at 6.20am. That's the whole fking street awake then. I wouldn't mind if it was actually a decent sounding thing. It's horrid. I must be getting old.

The M4's do sound particularly grim from a cold start. In their quest for the most obnoxious, farty, resonant exhaust note it appears that BMW modeled their system on a 20 year old Vauxhall Corsa badly fitted with a straight through exhaust.

The Focus RS is the same, sounds broken when it's cold and even more broken when in sport mode. I'm sure all those misfires/backfires can't be good for the engine.

[HJMS123]

The guy who lives in a house next to my small apartment block has a 14 plate Astra VXR and the cold start on that can be heard from my bedroom, it's not overly loud but I can still hear him in the mornings. I have a feeling he has an aftermarket exhaust although it's not too loud when on the move.

[theseoldcars]

Blaster72 said:

The Focus RS is the same, sounds broken when it's cold and even more broken when in sport mode. I'm sure all those misfires/backfires can't be good for the engine.

They're designed (and mapped) to do it, so I wouldn't worry too much about that.

[Loyly]

kiethton said:

I hate to say it but I move into my flat this weekend. I also just got my bike license and use the below to commute, first time this morning.

The video shows the bike just after a cold start last night, my neighbours may hate me - I leave the house @ 5:45 every weekday morning...sounds far louder in person unfortunately

They always do. This is my Daytona idling after starting on a mild day. Sounds low and rumbly here, as the camera microphone misses out the high frequencies. It's not quite Austin Racing loud but even the Triumph tech commented on the volume of it, which is at the top end of how loud I'd be happy with.

https://youtu.be/gbtXdoEH7sM

[Mr2Mike]

kiethton said:

I hate to say it but I move into my flat this weekend. I also just got my bike license and use the below to commute, first time this morning.

The video shows the bike just after a cold start last night, my neighbours may hate me - I leave the house @ 5:45 every weekday morning...sounds far louder in person unfortunately

That is anti-social and really nothing to be proud of. If I'm using my bike early in the morning I wheel it out, get all my kit on so as soon as I start it I pull away.

[kiethton]

Mr2Mike said:

kiethton said:

I hate to say it but I move into my flat this weekend. I also just got my bike license and use the below to commute, first time this morning.

The video shows the bike just after a cold start last night, my neighbours may hate me - I leave the house @ 5:45 every weekday morning...sounds far louder in person unfortunately

That is anti-social and really nothing to be proud of. If I'm using my bike early in the morning I wheel it out, get all my kit on so as soon as I start it I pull away.

Believe me I will be doing just that: bike pushed out of the garage, make sure that all's locked and i'm fully dressed and ready to go, get on the thing, start it and drive off. Only issue is with where the garages are I've got to ride past the entire building before reaching the road

[Flibble]

My GT86 does it - roughly 2k rpm on a cold start for up to 30s, combined with lots of valve overlap. The induction noise is rather nice when it's running like that, but it is loud.

[Jaguar steve]

Benmac said:

TonyG2003 said:

I like the idea on the new Aston Martin DB11 start up. Press the starter once quickly and get the full blaring start, press and hold the starter for the "don't annoy the neighbours at 4:30am" start.

Yes, that seemed like a nice idea when I watched Harry Metcalfe's video review of it.

Having a choice would reveal a lot about the attention seeking narcissism of anybody using the theatrical noisy start rather the discrete quiet one.