exhaust route

[Uboat]

Hi,
Can anybody please give advice on how to route the exhaust under the car (+2 130/5)?
My present exhaust runs well under the whole of the car from the manifold and backwards (see photo) which gives me ground clearance problems.

1. Is there enough space to draw the y-piece of the exhaust/the central pipe to the side of gearbox continuing in the drive shaft tunnel (I understand that my 5-speed gearbox is bulkier than the 4-speed)?

2. Any experiences of piping big bore manifolds passed the gearbox? How about ground clearances of these?

/Ulf

[45bvtc]

You need to run the exhaust pipe, from the manifold pipes, alongside the main casing of the 5-speed gearbox before bending the exhaust pipe back to the centre (of the chassis), like so:

[Uboat]

Thanks,

Have you noticed if the bends will restrict exhaust flows on higher revs?

What car do you have 45bvtc? I have a cross-section situated behind the gearbox between the two chassis beams, which I do not see on your car.


/Ulf

[45bvtc]

Smooth 30? bends will not restrict the exhaust flow in this application. The larger diameter exhaust pipe, however, will increase noise and slow down the exhaust gas flow; larger is not necessarily better, but you'd need to have your engine on a dyno to observe.

As for my cars; I've had both a 1974 Elan +2S 130/5 (New) and a 1971 Elan Sprint, converted to 5-speed, as per photo (recently sold after 37-years of ownership). Oh, and a 1972 Europa Twin Cam (New).

I'm now into Audi: RS3, TT roadster, and an A2.

[Uboat]

Thanks again 45bvtc,

What dimension would you recommend for the central exhaust pipe?

/Ulf

[45bvtc]

I used 45mm outside diameter stainless steel - and don't forget to add a skid-plate between the pipe and the silencer (especially if you're visiting the UK, speed humps and all).