mid exhaust box replaced

Mainly for @RS250 castle combe

Changed the mid box today, the one i bought first was hitting the underside of the car, so it made a right racket when driving, mainly on the over run and cruising, was fine while powering up but really bad using the engine for braking.

I slightly modified the first box as it wouldn't fit, it was touching the underside of the tunnel where the gear lever assembly fits through.

The modification
IMG_20200604_171530 by Ian Austin, on Flickr

 

The view from under the car, it was catching the crest when going in and out of my workshop.

IMG_20200604_162526 by Ian Austin, on Flickr

So i ran the car up, placed my phone with a sound app, 0.5m from the exhaust and at about 45 degrees
This was the reading, it might not be accurate but it was to give me some sort of reference, most was on tick over, but then blipped it up to 4500rpm

Screenshot_20200604-144534 by Ian Austin, on Flickr

 

The difference between the two box's, bigger one is 6" diameter the smaller one is 4" diameter, both are 22" in length total, the exhaust pipe is 3" in diameter.

IMG_20200604_164931 by Ian Austin, on Flickr

Box fitted in and it now looks like there is a bit better ground clearance

IMG_20200604_171614 by Ian Austin, on Flickr

 

now to find out what the difference in sound is, think i will try and live with this and get to a track and see what they come up with as a level.

Screenshot_20200604-172832 by Ian Austin, on Flickr

 

I whacked the shite out of the big one with my little 4lb lump hammer and that was the best i could do, don't think it was ever going to fall apart.

 

It all depends who's measuring it, think i was 84db at Bedford with the 3" and a cat fitted, went to another and i'm sure it was around 87db, so will have to go to a track to find out for real.

 

I think i'm going to have to wait till i get to a track to really see what the level is