Crackling exhaust volume
Crackling exhaust volume
Author
Discussion

Tacchino

Original Poster:

324 posts

178 months

Thursday 24th May 2012
quotequote all
Anyone got a logical explanation of why my Cerbs exhaust noise changes between hot sunny days and cooler evenings/mornings.

On a nice hot day (like yesterday) she sounded like a squadron of angry Lancasters on a high intensity bombing run.
Every time you come off the gas it was like a rapid firing heavy cannon!

Went out again in the evening and we're back to the more normal small arms fire.

This morning she's still in "normal" mode.

Any clues as to why it changes so much?


scotty_d

6,795 posts

218 months

Thursday 24th May 2012
quotequote all
I take it you mean pops and bangs on over run? It might just be when the exhaust gets really hot. I Notice mine is very angry when i have been sat in heavy traffic then get some clear road the car is nice and toasty with heat soak through the exhaust cloud9


Tanguero

4,535 posts

225 months

Thursday 24th May 2012
quotequote all
Heat soak in the exhaust, air density, relative humidity?

prettyboyben

170 posts

203 months

Thursday 24th May 2012
quotequote all
I always assumed that it was the exhausts expanding and so just generally being louder and accentuating all those lovely pops and bangs. I need to get my chimaera to make some of that noise!!! Haha!

Tacchino

Original Poster:

324 posts

178 months

Thursday 24th May 2012
quotequote all
prettyboyben said:
I always assumed that it was the exhausts expanding and so just generally being louder and accentuating all those lovely pops and bangs. I need to get my chimaera to make some of that noise!!! Haha!
Better fit an AJP8 engine then biggrin

pjac67

2,040 posts

276 months

Thursday 24th May 2012
quotequote all
Tacchino said:
prettyboyben said:
I always assumed that it was the exhausts expanding and so just generally being louder and accentuating all those lovely pops and bangs. I need to get my chimaera to make some of that noise!!! Haha!
Better fit an AJP8 engine then biggrin
No need for that wink

tejr

3,434 posts

188 months

Thursday 24th May 2012
quotequote all
On a hot humid day the exhausts pop like theres no tomorrow.. from a cold winter start they are quite quiet to begin with and get louder as they warm...

I always put it down to the slight expansion of the exhausts and hotter gases travelling at higher velocity (which = louder) and being more a more volatile exhaust mixture when hot

Edited by tejr on Thursday 24th May 11:13

Tanguero

4,535 posts

225 months

Thursday 24th May 2012
quotequote all
I wonder what difference the ambient temperature makes to the fueling? If the ECU enriches it at higher ambient temperature that would explain it.

Mark.

11,104 posts

300 months

Thursday 24th May 2012
quotequote all
Seems I might have found different.

Cold crisp days, warm engine she sounds like Armageddon, on warmer days there seem to be less pops and bangs, but still enough to make children cry hehe

scotty_d

6,795 posts

218 months

Thursday 24th May 2012
quotequote all
prettyboyben said:
I always assumed that it was the exhausts expanding and so just generally being louder and accentuating all those lovely pops and bangs. I need to get my chimaera to make some of that noise!!! Haha!
Run it on 101 ron fuel it will sure Pop and bang away if your exhaust has been sleeved smile Not quite as good as a cerb but can give it a run for it's money.

camel_landy

5,421 posts

207 months

Thursday 24th May 2012
quotequote all
Tacchino said:
Anyone got a logical explanation of why my Cerbs exhaust noise changes between hot sunny days and cooler evenings/mornings.

On a nice hot day (like yesterday) she sounded like a squadron of angry Lancasters on a high intensity bombing run.
Every time you come off the gas it was like a rapid firing heavy cannon!

Went out again in the evening and we're back to the more normal small arms fire.

This morning she's still in "normal" mode.

Any clues as to why it changes so much?
Your Lambda sensors are knackerd... wink

M

Pursyluv

1,949 posts

198 months

Thursday 24th May 2012
quotequote all
Can 101 ron be bought on the forecourt?

chibbard

1,554 posts

284 months

Thursday 24th May 2012
quotequote all
Haha, i nearly made somebody drop their mobile phone they had next to their ear once.