free hit
counters
Naturally Aspirated 918? - Engine/Ancilliaries - The Lotus Forums Jump to content
Sign in to follow this  
JeepinMatt

Naturally Aspirated 918?

Recommended Posts

Forgive me if this has been mentioned before; like always, I try to search and research the crap out of something before I open up a new thread on it. Some of the recent threads floating around the Esprit V8 Tech Room have had me wondering - has anyone seen/heard of a 918 with the turbos removed? A good turbocharged engine can be great, but they can also mean extra heat, complexity, expensive repairs and weight. Hearing that the 918 has been so gimped from the factory has me wondering if there's still enough steam left in it when it's uncorked to put out good numbers without forced induction.

Share this post


Link to post
Share on other sites
Upgrade today to remove Google ads and support TLF.

Hi Matt,

According to Lotus own documentation on the flexibility of the engine, it was good for 280bhp in NA form:

LEW V8 Engine Tech

There was a race series invisaged for a front mounted NA 918, but it never materialised. Some engines were prepared by Janspeed and they produced 420bhp @ 8400rpm. One of the forum members here had a project to build a 4.0l NA 918, but that also never fully materialised. That project used a number of parts leftover from the original Janspeed effort (cams, pulleys, tubular exhaust manifolds etc).

I´ve managed to get my hands on the parts from that project and plan to build a 4.0l NA 918 later this year. I´m hoping for an output of over 400bhp, so it could make for a really cracking engine.

Cheers,

Mike S

Share this post


Link to post
Share on other sites

Anything's possible - if you have the money!

As Mike says, you'd want to crank up the compression ratio with new forged pistons, fit much more aggressive cams and redo the exhaust manifold and headers (easier with the turbos out of the way). Better flowing inlet manifolds and of course a new ECM. Obviously you can't just buy any of these from Halford so you're talking serious £££. It would be much more cost effective to replace the 918 with a decent NA engine - I think a few early Esprits have successfully been fitted with Audi V8s.

A nice improvement to the turboed 918 would be to replace the WWII T25s with GT25s but I doubt the flanges are the same and there isn't space to fit adaptor plates so you'd have to relocate the turbos elsewhere...

Share this post


Link to post
Share on other sites

Oh yeah, I've seen Hilly's S3 Audi V8 conversion and it looks sweet. I could only wonder how much it would cost to custom fabricate and fit a third-party engine/transmission. It's numbers like that that make me think that paying $$$ for UN1 and 918 upgrades isn't such a bad idea. Then there's the whole cool factor of having having a proprietary Lotus flatplane V8 back there. Not that I haven't thought of a BMW S62 V8 and 6-speed conversion. Sure would be cool to find a wrecked E39 M5 and yank the combo out of there...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  


×