Lotus Elan

Exhaust system s3

PostPost by: Dieschelan » Sat Dec 04, 2021 2:35 pm


What is the best exhaust system for a S3? All the suppliers sell the same exhaust system? Probably double S exhaust?
Should I reuse a sprint manifold or better to put all the system in stainless steel?


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PostPost by: ill_will » Sat Dec 04, 2021 8:55 pm

Hi Diego,

I've tried two setups on an S3 (convertible) - both times using the same fabricated manifold rather than an iron one. When I first got the car it had a mild steel centre section and twin-pipe setup, with no s-shape bit under the boot floor (I think this may be the S4 style?) - it was pretty unpleasantly loud and rasping at around 3-4k rpm that I quickly swapped it out for a sprint style single, bigger bore, silencer, and centre section to match. This was better to my mind - less raspy at least.


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PostPost by: quaybook » Sun Dec 05, 2021 5:16 pm

On my S2 with a Sprint spec engine and fabricated manifold, firstly I used the standard spec (albeit stainless steel) transverse rear silencer which gave a lovely muted exhaust note, but this noticeably restricted the engine at high revs. So I replaced the standard transverse silencer with a Tony Thompson big bore one which is intended for racing. This made the engine rev much more freely but the noise level was, in my view, too loud for road use, particularly in the middle rev ranges. So I have now inserted an additional resonator box in the transverse front leg on the system which has made it quieter, but it is still just a bit too noisy for my taste. Kelsport do a big bore transverse silencer which may be better for road use - it might be worth asking them - but it is expensive.


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PostPost by: TrevorJones » Tue Dec 07, 2021 5:06 pm


I have the TTR SS large bore system from manifold through transvers box on my S3 and she will run up to 8K without an issue, I have to fit an extra tail pipe silencer (Merlin Motorsport) to get the Db below 100Db for Castle combe and it passes every year at 98Db. It really only gets too noisy on the street when running above 4k and on motorway runs, however the noise from the Weber's is more noticeable than the exhaust :D.

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PostPost by: David1953 » Tue Dec 07, 2021 7:38 pm

I do not think there can be a best system as it depends on what you are using the car for. road use, long distance touring or short outings, or track use.
I will say Double S make a very good product, and when they had a problem with manifold clearance they exchanged it for one that is possible to change with the engine in place!
Their life time warranty is really that, they have fixed problems for me more than 30 years after purchase.
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