Audi FSI coversion

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Audi FSI coversion

#1 Post by 930hde » Mon Feb 18, 2019 4:33 pm

Hello All on the LPG Forum,
I have only just registered so your upgrade must be working fine.
For the last 2.5 years i have been driving an Audi S4 2005 which i had converted,much to the disgust of Audi purists that would prefer to pour money down the drain.Tarantini system.
The car has been fantastic and i have driven it hard for around 55k miles with no problem whatsoever,apart from it being a bit sore on spark plugs.I have just sold it on Ebay where there was massive interest and it fetched a £1k more than i expected.
I have now bought an RS4 and in my wisdom i didnt do any homework,and expected that as it is the V8 4.2 (BNS code)engine similar to the S4 that i could convert it to LPG as well.
Not so im afraid as the engine is FSI which i have learnt arent that easy to convert.So my question here is, does anybody have any experience in converting an FSI engine.
Thank you very much for any info you may have.
Regards Sean.

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Re: Audi FSI coversion

#2 Post by Gilbertd » Mon Feb 18, 2019 4:56 pm

I've just moved your post to a thread of it's own rather than leaving it in with the BMW Valvetronic thread. You should get a better chance of someone seeing it.
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Re: Audi FSI coversion

#3 Post by topsie » Mon Feb 18, 2019 8:14 pm ... n-lpg-kit/

Not exactly what you need, but shows kits are abailable for petrol engines with direct injection.

Interestingly, FSI (fuel stratisfying injection) was initially to work in a similar fashion to valvetronic, however combustion was controlled by the injector opposed to infinitely variable valve timing with a fully open throttle body. With a specifically designed piston crown and inlet manifold, in certain load conditions the engine could operate with a lambda of 3 (ultra lean burn). This was quickly dropped due to poor running characteristics when changing over from stratospheric injection to normal combustion and a plethora of problems.

The problem for LPG conversions operating indirect injection is the signal to inject will come far too late in the cycle - i’m guessing that’s why a engine code specific ECU is required.

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Re: Audi FSI coversion

#4 Post by LPGC » Tue Feb 19, 2019 10:57 am

Adding to what Topsie said..

I recently answered some queries about converting direct injection engines and explained why special ECUs are required, post #3 on

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Re: Audi FSI coversion

#5 Post by 930hde » Tue Feb 19, 2019 1:42 pm

Hello Simon,
Thank you very much for your reply,i have read your previous post but im afraid i am not that techy.Give me a hammer and stilsons and i can get an engine out but port injection and pulse times are a bit over my head im afraid.
Are you aware of or do you thinkits possible to convert the Audi V8 FSI BNS engine, as i havnt had a definitive no off anyone yet?
Again thanks for any feedback given.

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