SELOC Forums
I've just started fitting an Audi 1.8T in my elise S1, you can follow my progress in the thread above. There are about 5 companies offering the conversion, but mines totally DIY, I've never done one before.
My choice was between The Audi and Honda lumps, but having had a tuned VXR220 track car previously, I have a great love of small turbo engines and the Audi/VW unit is cheap, abundant and easy to tune in the UK/Ireland.
To be honest, so far its not proving a hard conversion, several guys have told me it took them a week of actual man man hours after the parts are sourced. Its quite small and the audi engine mounts can be used by putting spacers on the Lotus plinths. The Toyota gear linkage when fitted to the Audi, I've been told, gives the best gear change possible in an Elise. Driveshafts can be a combination of the Rover/Audi or a bespoke shaft is available. A fan assisted intercooler is usually added beside the left air intake and the single downpipe is only a few bends away from mating to a muffler in the standard position.
If there had been a Toyota lump in there already, i wouldn't have touched it, but its an excellent upgrade to the Rover engines.