Probably.

Attachment 158717

:lol:

All FI.

The ROI just isn't there for a NA engine, unless you absolutely want to have a monster NA engine that's gotta be FA based. Do you want to be the firsT?

Well my motor fully tuned on 91 vs stock FA20 tuned on 91 would have been roughly similar. Slightly lower for my motor.

This is all moot as the cam control was not working so power was not optimized.

CR is around 11.8 and hitting MBT on 91 octane.

Hi Mike, due to the legislation in my forced induction is illegal. Most modified cars here which are not boosted from the factory tend to be highly built NA cars. Totally understand that the $/hp is not in favour of an NA build.

In my case I'm not really looking at the quantitative gains, rather trying to change the nature of the torque curve, to make the car subjectively more fun to drive. I did an analysis of several driver's cars studying their torque curves, as I was surprised at how some relatively lower powered cars I have driven felt a lot more fun. Once I equalised for the weight, I realised that the nature of torque delivery matters to the sensation while driving.

https://i.imgur.com/5BGZ72n.png

I then pulled some dynojet reports of stock cars such as the S2000, E46 M3, Ferrari 458 and others... the purpose was to better understand the shape of the curves, the actual torque was not important to me and probably inaccurate when compared.

I extracted the main graph from the study and attached it for you to have a look. Anyway, the need for a 'top end rush' is my own interpretation of the engine character that gives pleasure to me. Anyway, I have to thank you Mike, for all the invaluable advice so far.

@nav which cars did you find the most enjoyable in terms of power delivery?

im looking to shift the torque curve 1000 rpm to the right, and limit rpm to around 8,000 where I hear the oiling system can't keep up. So the idea for me is to move peak torque, sacrificing some low end along the way.

Well, you do hit a hard limitation on flow at the higher RPMs, so cams will help, but you'll also want to do some head work to achieve that.