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FA20 with CR 10.5:1 - is it worth?

General Engine Building Discussion

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Hi there.

A friend of mine is looking to buy a replacement engine for his BRZ - it is IAG Performance build stage 2 short block with 10.5:1 CR.

IAG Performance stage 2 FA20

Have anyone heard about the engines built by this guys?

And the main question is will it run DI on stock ECU and would it require any further mods as he is willing to stay NA, no turbo for now.

The main reason of that choice is we have no easy access to 98 or 100 octane, just 95 as max. I understand he can expect quite dramatic power loss, but at least engine should survive longer than the previous ones..

Hello yes, they have a great reputation and I would recommend them as a good engine supplier. lowering the compression to 10.5 will be very beneficial with your fuel but of course, you will be down a little in midrange hp, I don't believe you will have any issue running it on the factory Di but I advise asking for more information from them about it

regards Ross

Ross, thanks for valuable advise.

I have talked to them and first answer was that 10.5:1 CR is not a good idea if no turbo added and they would suggest 12.5:1 CR for NA, but in view of problem with quality of fuel, this is the way to go. They have also confirmed that stock ECU can be remapped with ease.

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