Straight through or Cherry Bomb

Managed to pick myself up a new straight through mid pipe and new back box section for the 3.9 Disco. Just now trying to decide whether to just fit the straight through pipe and back box section as it is, or whether I really should chop the mid pipe and stick a Cherry Bomb in there. What d'ya reckon?

I assume I am right in thinking that just by taking the middle box out and replacing with straight through pipe, this wont jeopardise passing the MOT will it?

Not if the tester is DEAF!!!

stick cherry bomb on it it will sound sweet

MOT... Reason for rejection one two three.

A silencer in such 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 standard silencer in average condition.

I ran for ages with straight through centre and 300tdi backbox.

Was a bit raspy and didn't sound very professional BUT for the money it was a great sound!

If running a cherry bomb, get a big one and then shelve the back box.

discool said:

MOT... Reason for rejection one two three.

A silencer in such 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 standard silencer in average condition.

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But surely that would mean ANY vehicle with a loud / aftermarket exhaust would fail.

I reckon I am best just giving the MOT test station a ring to see what they say.

Just spoke with the garage who will be doing the MOT for me next week and they said they don't see that it will be a problem providing the emissions are still met. Lets crack out the tools

In that case you might as well remove all of the silencers and have a straight through to the back exhaust

My series V8 just has a huge stainless silencer at the back off an impretza and man is it loud! Gets through the test every year though
If you went for the straight through it would be way too loud,trust me I've tried it and it made my ears bleed at 70 mph!!

what you want is a straight pipe from each manifold to come out just at the back wheels on each side lol

I'm running a straight pipe and at speed you cant even talk to the passenger next to you without shouting, sounds awesome but I leave for work every morning at 5:15am!

Also she has a tendency to gurgle which I don't like and running on LPG she sounds like a chopper, like and old **** one~!

Urm, video!!

Went to go trial fit the new mid and end sections. It seems that with the new mid pipe and end section the joints are in different places to my current system so need to take it all off in one go from the section containing the cats, all the way to the back.

Had a problem with the bolts though that connect the flange on the end of the cat section to the middle box section. One of the nuts simply will not come off, regardless off how much wire brushing and spraying with WD40 I do. But I cant make out what sort of bolt these are. They dont appear to have a proper head on them to grab a hold of. Are they countersunk flat sided pins that once in wont spin round? Can you buy new ones from somewhere if I was to angle grind this stuck one off?

they're just m8 bolts. will just be badly corroded.

Mr Noisy said:

Urm, video!!

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Here's mine with a straight through

Landrover series 2a V8 straight through exhaust - YouTube

How to use a gallon of fuel in 4 minutes - YouTube

These are studs, and fitted in the similar way to a wheel stud.
If you break or strip the thread on one you will have to drill it out and then use a bolt and nut to secure a mid box.

discool said:

These are studs, and fitted in the similar way to a wheel stud.
If you break or strip the thread on one you will have to drill it out and then use a bolt and nut to secure a mid box.

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That's the sort of thing I thought they were. Drilling it out could be easier said than done with it on the car. Don't want to take the headers / cat section off as well. It is only the lower nut that seems stuck so I was going to angle grind the bolt between the two flanges where the bolt is exposed, then just tap the bolt remains out if it was just a bolt, then use a new bolt on that one. But if they are studs then even once I have chopped the bolt I guess it will be very difficult to get enough force and hammer the remaining stud out, amid I would think it would be very very difficult to get the drill in mad have enough force behind that either.

The top tip I found on the forum was to run the engine to get some heat. To the joint which I did, and bothnuts undid easy, and that was after 11 years. No doubt you could try a blow lamp.

Yes for drilling out the shud you will need a electric drill but with a couple of new HS drill bits it's do-able as they say.. and u won't have the mid box in the way.

Dremel???

discool said:

The top tip I found on the forum was to run the engine to get some heat. To the joint which I did, and bothnuts undid easy, and that was after 11 years. No doubt you could try a blow lamp.

Yes for drilling out the shud you will need a electric drill but with a couple of new HS drill bits it's do-able as they say.. and u won't have the mid box in the way.

Click to expand...

Good thinking on running the car up warm first. I suppose I just thought "I dont want to be going near it when its hot" but I guess this will help with the stuck nut. Will give that a try. Cheers.

Fair point about the middle box being out of the way and giving me more access.