Replacement exhaust system

[wparslow]

Hi, having just had the head, valve guides, hot cam etc fitted to my 130/5 it will now be going for a bottom end rebuild which will give me the opportunity to fit different pistons and a more aggressive cam once done.

In order to optimise the breathing it would be nice to get a new exhaust system fitted including the manifold but I don't want the car to get too noisy internally once done. The current system has an annoying booming resonance between 3k and 4.5K revs (just where you don't want it).

Any advice as to a good exhaust system for a warmed up engine (told it will produce 140bhp+ once completed). Also I've always fancied a twin tailpipe exit look, any of you know of a supplier of such a thing?

ONce again many thanks to the bard for your assistance,

Wayne

[rgh0]

Wayne

A good big bore tubular header system (TTR supplies a suitable unit)combined with a matching 2 inch tale pipe and two straight though mufflers is what you want. A small muffer just to the rear of the gear box as close to the chassis as possible and the largest muffler you can fit in the tunnel under the boot should work and produce acceptable noise levels for a road car and no loss of power potential for a developed motor.

Ground clearance over speed bumps is a little restricted with the mid mounted muffler but oK in my experience. If you have a standard Lotus chassis some modification will be required to get the big bore header system to fit past the top of the chassis.

Rohan

[wparslow]

Thanks Rohan, do you know anyone who can supply the back bits of what you suggest?

Wayne

[sk178ta]

J P Exhausts Ltd at Macclesfield tel 01625 619916 were featured in C&SC last year as an excellent supplier of bespoke systems. As it`s the other end of the Cat and Fiddle, one of the top 6 driving (and dangerous) roads in the UK, I called in about my S3 exhaust. First class service, very helpful, and not overly expensive.
Jim

[theelanman]

JP's have done the one on my +2 and my m100...
the other +2 came with one already on but I can definately vouch for JP's work.....and cost.....value for money for bespoke systems....
cheers
G

[freddy22112211]

On a slightly different note: it's always seemed to me that a stiffly mounted exhaust is not quite right when the engine can move around a bit, and fitting has to be just right as well. Has anybody used one of these flexible joints on the elan? Or are they not so good - loss of power/other problems?
Gordon

[wparslow]

Thanks for the JP tip guys - when you say value for money/not too much money can you give me a rough idea for a full system including manifold?

thx again

Wayne

[theelanman]

IIRC the +2 was ?150 but that was without manifold (and about 6 years ago) and the m100 was ?315 with everything....
he did quote me a price for the complete system on a 65 MGB roadster which I think was about ?300 incl manifold.....
ring the guy up he's very helpful!!!
cheers
Gareth

http://www.jpexhausts.co.uk/index.html

JP Exhausts Ltd
Goodall Street
Macclesfield
Cheshire
SK11 7DU
Tel +44 (0)1625 619916
Fax +44 (0)1625 511158

[email protected]

[rgh0]

Wayne

My bits were custom made for me by a small company called "Ferndale Exhausts" here in Melbourne not much use for someone in the UK.

In Australia custom headers are around A$500 for a 4 cylinder like the Lotus and the custom tail pipe and mufflers is around A$300.

Rohan

[Hamish Coutts]

Wayne,

Another mod you can apply is to make sure the exhaust at the back protrudes a wee bit past the bumper. (say, 1") That will keep the shock waves coming from the exhaust clear of the body work and stop some of the resonance/booming inside the car.

I got a new stainless system from Paul Matty and this has the longer tail pipe. The system sounds nice and has a very 'hot' sounding tickover . It's also a lot quieter inside the car.

Hamish.