I have today a MSD Atomic EFI and a MSD Distributor in place. This runs very well together. With my new highly tuned stroker engine (614hp) a Holley 750cfm 4150hp is foreseen.
Now I think about applying the Atomic EFI but with a fuel pump upgrade. This should support engines up to 625hp. So all good.
However I realised now that my camshaft is over the suitable limit of max 250 at .050“ duration with 253/261. The MSD tech support said not a good idea to go higher than 250. The setup is not made for this.
i think this has only to do with the insufficient vacuum produced by my sharp cam at idle which creates problems for the EFI. But increasing the idle will potentially overcome that issue, I believe. True or false?
Now I investigated the EFI market and found the MSD Atomic -2 upgrade. Goes up to 650hp has not the limitations on the camshaft as far as I can see. But the product interestingly is discontinued. Nevertheless it continues in a 1 to 1 fashion in the Holley Sniper-2 EFI. Anyway my helping hands informed me about the severe issues with the Sniper-1 version especially with HF irritations due to bad alternators etc and the likes. So I was sceptical but learned that the Sniper-2 is not an upgrade to Sniper-1 but rather Atomic-2 has been transferred to Sniper-2 and hence is the stable MSD system in a new Holley housing. To be confirmed here?
In principal I am personally convinced about the manifold advantages from an EFI system but do you see also disadvantages over a Holley carby setup? Especially when the engine is highly tuned and requires a lot of air to perform?
Comments and advise appreciated.