Hanging the exhaust. AAAARGH!!!

[DavidL]

I'm trying to get my exhaust to fit, and using the build manual for the convertible, since it's the only one I have access to, but I'd imagine the instructions for the coupe would be similar.

I've made three brackets - MM09, MM10, MM11 - as detailed in the drawings section, and now I'm trying to get them to fit with a new SS exhaust from Alistair.

First question: the rubber bobbins mentioned. The bobbins I've managed to get have a rubber depth of 19mm (that's the total length including the steel washers bonded to them). Should I be using the deeper type, as used to support the rear of the gearchange? If not, and I'm using the correct sort, then I presume the exhaust must get bolted to MM11 (the flat plate with a bend in it) before MM11 gets attached to the bobbins.


Next question: is the exhaust as supplied by Alistair to the same specification as the original Midas exhaust? MM09 (short length of 25mm x 3mm with a twist at one end) doesn't seem to be anywhere near where it needs to be to attach to the "front" end of the back box, given that I can only find one 8mm hole in the spare wheel well. I can always make another bracket, but I'd like to mount the system the same way as the original, if possible.


Finally, MM10 (a "U" shape with one short leg, which supports the tailpipe) - using a 19mm deep bobbin, there is very little clearance between the body and the top of the tailpipe - a few millimetres.


Finally, what clearance should there be between the fuel tank and the exhaust? I'm looking at somewhere in the region of 5mm, which really doesn't seem very much. I don't know what temperature I can expect that part of the exhaust to be, but I'm concerned about such a small distance between the tank and the exhaust.

[Stuart]

Both MK3's I've had have had the longer bobbins. My first car had a tweaked club exhaust, even then it wasn't a great fit.

Here's Alan's Maniflow

[DavidL]

Both MK3's I've had have had the longer bobbins. My first car had a tweaked club exhaust, even then it wasn't a great fit.

Here's Alan's Maniflow

Oops - too fast!

I can see the forward mount there, which definitely looks like the bobbins are longer. That might even help to get MM09 to work, too, and MM10 with a longer bobbin would help the body-to-tailpipe clearance.

Thanks, off to MiniSpares' website for me!

[Hans Efde]

Here's a pic from my exhaust:

I got fed up with these small bobbins. They have a short life. These I found in a local store, have the same height, but twice as wide, so much stronger. I think they belong to a Renault van.

[Moneypit]

With the restriction in movement , rather than hanging mine from the floor I've mounted it top side of the rear subframe with 2 lots of bobbins.I haven't got a photo but it rests nicely above the handbrake cable.

[DavidL]

I had assumed that the various bits of the exhaust system would all line up nicely to be bolted together - maybe I was spoiled by the factory SS system I bought for my Bronze.

I bought an LCB from Minispares, can't remember which one it is but there's a little nameplate attached to the centre pipe. I bought the front and rear sections of the remainder of the system from Alistair, not realising that there's a centre section as well! Fortunately the existing centre section of my existing system was stainless and almost complete, so that's staying. The bit of that which is missing is unfortunately the bend at the end, which was cut off to fit a one into two system with a central north-south back box.

I fitted the LCB. First problem was that it exits very close to the side of the tunnel. (This is complicated by the fact that I may have had the Y-piece upside down, but the problem seemed to be with the angle of the downpipes, not the included angle of the Y-piece.) I sliced most of the way through the tail of the Y-piece, creating a wedge shaped gap, then closed it up and welded it - it's now got sufficient clearance for the woven flexy section to fit. While I was pondering the aforementioned butchery, I realised that the new front section (that fits onto the Y-piece) is too long, by about 3 or 4 inches - maybe it's intended to fit a standard Metro downpipe, not an LCB? It's too much to remove from the Y-piece, so I'll have to remove it from between the flexy bit and the "crushed" gearchange clearance bit of the pipe. Fortunately, I'd already bought a section of SS piping which happens to have the same ID as the OD of the front section, so that can be cut and sleeved relatively easily. After my patchy welding job on the Y-piece, I think I'll be using clamps for that!

I suspect that the next thing I'll find is that the rear of the front section doesn't quite meet the middle section.

I had also bought a 45 degree bend section of SS pipe which I'd hoped would fit where the missing bend had been removed. Needless to say, the angle is wrong, by about 3 or 4 degrees. I'm waiting for a bit of flexy pipe for that, although I could try another cut-and-shut job...


...is it always like this?

[Hans Efde]

I didn't have that sort of problems, only small adjustment issues. My SS specialists exhaust (well documented in an other thread) was a bit lower than the original, perhaps because there is a difference between a Mini and Metro LCB system. I also cut a piece from the Y-piece to make room for the flexible piece. Because there was a difference in diameters I had a adaptor pipe made at a local SS shop and they welded it all together quite nicely:


The small adaptor pipe made it possible to join it with the middle section. But sometimes you have to play with it and even change the position of the brackets. I had a problem with my rear exhaust alignment (and stresses in the bobbins causing them to crack very quickly) and in the end changed the position of the bracket above the rear subframe (at the end of the tunnel). This one (also not the fatter bobbins):

It helps when you loosen everything (also the exhaust clamps) and move everything around until it hangs stress free and then fasten everything. If that's not possible, it's best to go to an exhaust shop and have the exhaust bent to shape (if they have a bending machine).