FoaTech wrote:
The carb bodies have been modified into throttle bodies and will have injection. It is injector over the stack, but still injection. We will see what flow (air) it has too.
Yes, but what size butterflies?
The 40mm carbs that come on 308s are WAY too small, 48 is about the right size to make good power on those engines and I suspect the same is true on a 246. A 40mm on a nice 308 head is about a 10% loss, so really painful to see installed after you've worked so hard for every cfm in the head. The TBs on the frankenferrari are 54mm and are a little less than a 1% flow loss after I cut the shafts as thin as I dared and sunk and ground the screws smooth.
With carbs going big to make HP means losing the bottom end and street-ability, at least with simple carbs. But EFI means none of the concerns about vacuum or reversion down low applies. As long as you can measure the air flow somehow (I use the vacuum signal but a TPS or MAF also can work) you can supply the correct amount of fuel and it will run well. That means the correct size TB is go up until you you can't see it on the flow bench....if you play with it in DM you'll see it changes the runner taper and that changes the strength of the waves and power so you don't what to go too big...but flow restriction % are pretty directly power lost on most setups so you certainly don't want to go too small if there is any way to avoid it.
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