Refitted standard exhaust tonight

Soldato
Joined
31 Oct 2002
Posts
13,891
Location
Newcastle upon Tyne
I've been doing a fair bit of motorway driving recently and couldn't hear my music at the speeds I like to drive at so I decided to refit my standard exhaust to see if it made a difference.

It's certainly a lot quieter but the ITG filter still makes it sound purposeful when you put your foot down. It definitely feels like there's a fair bit less power now, my butt dyno can tell the difference as above 80 it feels damn slow compared to before.

Could it just be the ECU relearning it's parameters or do you think the Quicksilver exhaust really allowed the car to breathe much better?
 
Soldato
Joined
18 Oct 2002
Posts
20,701
Location
England
Sounds about right to me, no doubt it is slower, but bear in mind losing the exhaust rasp will probably contribute to the car feeling slower too. Crappy weather on the way soon so you may as well keep the power and noise down untill Spring rears it's head. Wet roads & rocket Elise = certain death. :p

I've got problems ahead along similar lines. I may have my hand forced soon where my job changes to involve a lot more travelling - maybe 30k a year. I've actually said thanks but no thanks but I may have my hand forced. If that happens it's bye bye DC5 because I just dont think I can do 30k a year in what's effectively a track weapon not a cruiser. :/
 
Soldato
OP
Joined
31 Oct 2002
Posts
13,891
Location
Newcastle upon Tyne
I don't think it's the lack of noise that makes it feel slow as I've still got a nice induction noise, it definitely feels much slower above about 80ish though.

I'm gonna leave it for a few weeks at least anyway, see how I feel after I've done a few hundred motorway miles. Maybe when I've got my new rear speakers in I'll just turn the stereo up and drown out the exhaust noise and it'll be fine.

My other option is to get a 2bular exhaust, not as loud as the Quicksilver but still sporty sounding and gives a few extra BHP. I'm also wondering what actually gives the most power for the least noise on an Elise, ie would a sports cat and standard exhaust give more power than a standard cat with sports exhaust but without the additional noise?
 
Soldato
Joined
18 Oct 2002
Posts
20,701
Location
England
Sports cats can be pricey.

I dont know what your exhaust configuration is tbh. But one solution is no cat and standard cat back. If that's still too noisy then sports cat and aftermarket cat back or stock cat back.

Quite a few Teg boys run race manifold (decat) into the standard cat back system and only lose a few ponies & it does keep the noise to sensible levels.
 
Soldato
OP
Joined
31 Oct 2002
Posts
13,891
Location
Newcastle upon Tyne
This is what the standard exhaust looks like

2nd one from left is Quicksilver (mine) - next one is standard exhaust. There's only 1 silencer on my car (obviously due to where the engine is located) and as you can see the QS is pretty small so you can imagine how it sounds :D

tievo2%20ss%20lots1%20lots2%20attach.jpg


The sports cat is around £400 I believe and is said to give 7BHP and something like 11lbs torque I believe.
 
Caporegime
Joined
21 Oct 2002
Posts
26,394
Location
Here
Im know how you feel. Quite enjoy the quiet exhaust of the s2000. Airbox lid off makes it sound mental when you boot it anyway and you don't get any of the annoying overrun noise.
 
Caporegime
Joined
21 Oct 2002
Posts
26,394
Location
Here
eidolon said:
PDF showing the noise difference between standard and QS stainless

At 7000 rpm the standard exhaust is 94dB the QS is 102db (plus whatever noise my ITG is making :D)

Oops, looks like I'm not gonna get on any UK tracks with the QS

Depends on the frequency of the noise. Tracks measure dbA rather than db. dbA is db with an A weighting curve. Depending on the frequency then the weighting adjusts the noice to how the human hear percieves the 'loudness' of sound

400px-Lindos2.svg.png


At low frequencys you can see it has a big effect.
 
Soldato
Joined
18 Oct 2002
Posts
5,600
Location
Surrey
30K a year == time to buy a second car. Assuming they are buisness miles the first 10K would be at 40p a mile = £4000 less petrol and consumable costs the next 20K is at 25p a mile = £5000 less petrol and consumables (about cost in reality).

This is more than enough to buy a motorway machine. My MG is far from the track weapond that a ITR or an elise is but I'm still much happier on the motorways in my laguna with cruise and climate and sound deadening.

HT
 
Man of Honour
Man of Honour
Joined
23 Dec 2002
Posts
10,025
Location
London
My guess is that some of your performance change will be placebo because of the lowering of noise.
Recently added a K&N typhoon to my MX5. Probably makes zero power difference, and when taking it easy sounds like standard. Gun it and it howls like race car, love it. Definitely the compromise I was after.
 
Caporegime
Joined
11 Mar 2005
Posts
32,201
Location
Leafy Cheshire
Mr_Sukebe said:
My guess is that some of your performance change will be placebo because of the lowering of noise.
Recently added a K&N typhoon to my MX5. Probably makes zero power difference, and when taking it easy sounds like standard. Gun it and it howls like race car, love it. Definitely the compromise I was after.

When did you add that, still go a stock back box?

Oh sort out a heat shield BTW helps loads!
 
Soldato
OP
Joined
31 Oct 2002
Posts
13,891
Location
Newcastle upon Tyne
I'm almost certain it's not placebo to be honest. I drove the car with the Quicksilver then changed the exhaust, an hour later when it was done I drove the same roads again and it definitely didn't pull as well after 80 whereas before it was pulling hard right into silly speeds.

Even this morning on my way to work (ie. roads that I drive every day) it felt noticably slower.

Maybe I'll take a detour via the roads around Castle Combe tonight for some more "testing"
 
Man of Honour
Man of Honour
Joined
23 Dec 2002
Posts
10,025
Location
London
Firestar_3x said:
When did you add that, still go a stock back box?

Oh sort out a heat shield BTW helps loads!

Still got the standard exhaust. Heard several aftermarket ones recently and don't really fancy any of them. They all sound like they'll give me a headache.

I added the Typhoon around 2-3 weeks ago. Was offered it at half price, which seemed too good to miss.
 
Back
Top Bottom