111r. Small upgrade ideas...

111r. Small upgrade ideas...

Author
Discussion

MrC986

3,481 posts

190 months

Sunday 11th November 2012
quotequote all
I have no silencers/exhaust boxes on my 911 & it passes the MOT no problem though my local test station do lots of classic & sports cars hence are used to a bit of noise. Removing the cats would be a different matter! I had a mk2 Elise for 2 yrs from new without cats and also a sports exhaust....it set off car alarms at Touchwood, Solihull biggrin

nick_j007

Original Poster:

1,598 posts

201 months

Sunday 11th November 2012
quotequote all
MrC986 said:
I have no silencers/exhaust boxes on my 911 & it passes the MOT no problem though my local test station do lots of classic & sports cars hence are used to a bit of noise. Removing the cats would be a different matter! I had a mk2 Elise for 2 yrs from new without cats and also a sports exhaust....it set off car alarms at Touchwood, Solihull biggrin
One has to respect that wink So how do you cope with an MOT with no cat and loud exhaust?

otolith

55,899 posts

203 months

Tuesday 20th November 2012
quotequote all
I've just had my ECU reflashed by Essex AutoSport, should get it back tomorrow. I ended up just going for the lowered cam change - it will be interesting to see if it improves the car as much as people say.

nick_j007

Original Poster:

1,598 posts

201 months

Tuesday 20th November 2012
quotequote all
otolith said:
I've just had my ECU reflashed by Essex AutoSport, should get it back tomorrow. I ended up just going for the lowered cam change - it will be interesting to see if it improves the car as much as people say.
Would be interested in your views and experience of this. Thanks.

otolith

55,899 posts

203 months

Tuesday 20th November 2012
quotequote all
Pretty good so far, they were very helpful by email, I posted the ECU to them on Saturday and it's done and ready to be posted back to me today. I've got a Dynolicious plot I did the other day, starting off in second and running through to peak revs in one gear. You can clearly see the cam change in the graph, so it will be interesting to do it again with the reflash. I think the subjective difference might be more significant than the objective one.

jfk01

106 posts

183 months

Tuesday 20th November 2012
quotequote all
As far as I'm aware .. and I could be wrong, there is no noise test required to pass an MOT ..
I think the term they use is "the vehicle must have an effective silencer "
....
Find a tester who loves motors and jobs a good un..
Just to add .. there's a world of difference between an enthusiasts pride and joy and a boy racers dangerous Nova ... glad my Mot tester thinks the same!

nick_j007

Original Poster:

1,598 posts

201 months

Wednesday 21st November 2012
quotequote all
jfk01 said:
As far as I'm aware .. and I could be wrong, there is no noise test required to pass an MOT ..
I think the term they use is "the vehicle must have an effective silencer "
....
Find a tester who loves motors and jobs a good un..
Just to add .. there's a world of difference between an enthusiasts pride and joy and a boy racers dangerous Nova ... glad my Mot tester thinks the same!
I know little about the MOT test, and I'm surprised that there is no limit or volume test taken re the decibels. Why would I be offered a cat conversion kit that allows me to change it before the MOT?

Thanks.

otolith

55,899 posts

203 months

Wednesday 21st November 2012
quotequote all
The method of inspection for noise is;

"assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered to be average for the vehicle"

and the condition for rejection is;

"a silencer in such a condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a silencer in average condition"

So it is subjective, and with a sympathetic tester noise should not be a problem for anything reasonable.

The big issue with having no catalyst is emissions. It is there to get rid of the oxides of nitrogen, carbon monoxide and unburnt hydrocarbons coming out of the engine, and the latter two of those pollutants are measured in the MOT. The standard that the emissions are judged against depends on when the car was registered (and whether it is even in the database).

If - as is more likely the more recent your car is - your emissions are too high without a catalyst fitted, you aren't going to need a sympathetic tester, you're going to need a bent one. Or to stick the catalyst back on for the test.

nick_j007

Original Poster:

1,598 posts

201 months

Wednesday 21st November 2012
quotequote all
otolith said:
The method of inspection for noise is;

"assess subjectively the effectiveness of the silencer in reducing exhaust noise to a level considered to be average for the vehicle"

and the condition for rejection is;

"a silencer in such a condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a silencer in average condition"

So it is subjective, and with a sympathetic tester noise should not be a problem for anything reasonable.

The big issue with having no catalyst is emissions. It is there to get rid of the oxides of nitrogen, carbon monoxide and unburnt hydrocarbons coming out of the engine, and the latter two of those pollutants are measured in the MOT. The standard that the emissions are judged against depends on when the car was registered (and whether it is even in the database).

If - as is more likely the more recent your car is - your emissions are too high without a catalyst fitted, you aren't going to need a sympathetic tester, you're going to need a bent one. Or to stick the catalyst back on for the test.
That clarifies it beautifully, thank you!

Nick

MrC986

3,481 posts

190 months

Wednesday 19th December 2012
quotequote all
nick_j007 said:
MrC986 said:
I have no silencers/exhaust boxes on my 911 & it passes the MOT no problem though my local test station do lots of classic & sports cars hence are used to a bit of noise. Removing the cats would be a different matter! I had a mk2 Elise for 2 yrs from new without cats and also a sports exhaust....it set off car alarms at Touchwood, Solihull biggrin
One has to respect that wink So how do you cope with an MOT with no cat and loud exhaust?
p

I sadly never got to MOT on my Elise as I sold it for a 968 sport & then got into 911s though my 911 strangely has no real exhaust either now & that too passes the MOT without a problem. The 911 just like the Elise makes alot of noise on start-up with the auto choke running & also when you start to rev it in excess of the test rpm & on overrun. I had considered 200 cell cats but wouldn't remove
them entirely.

Ps how is the new car other than hopefully wrapped safely up in the garage till better weather comes? A friend has bought an 07 111R & is well impressed smile