EFI, Boost & Timing

Edited by farna - Nov/09/2018 at 6:46am

Thanks for clarification Farna. I thought that was what you were saying but I wanted to be sure I was understanding what you meant. In my configuration and by your verbiage the MSD pro billet should be considered a distributor-less type system as the firing is controlled by an independent crank trigger in the base of the unit. The only difference in the MSD distributor versus the standard crank trigger is that the initial timing would be set and of course the limitation of rotor to cap alignment (but that still allows a pretty wide range of selection I suppose the pro billet could drift a bit as the gears wear so that is always a potential downside. I really like that megajolt setup and it would be really hard to beat the dead on accuracy you would get from a keyed crank trigger setup like that. The extra flexibility in adjusting the spark map is nice too. 

shootist wrote: Rebel,  I have yet to get the car on the dyno at this point but I am guesstimating on the power output being in the 800HP range simply because my build was a redo of the procharged 401 done by Bob Woods for the HotRod article with some minor upgrades I obtained from talking to Bob and his brother. Basically we made tweaks to their build spec that they would have wanted to make for a second revision. Basically this is lighter rods and pistons and a roller cam rather than solid. I am guessing that should be good for at least 10-20HP but who knows. I am pretty certain it is at minimum making the same power or capable of it with a good tune. If my seat-o-pantsometer is accurate I would say it is a touch over 800 at the crank but I will let you know once I get some real numbers next spring. That article is here.  https://www.hotrod.com/articles/ccrp-1301-780-american-horsepower/ You can get my specs from my old thread below. http://theamcforum.com/forum/supercharged-401-build-w-pics_topic81131.html

Sure Rebel Machine. My cam spec is in my build thread on this forum if you want the details. The only difference between them really is that the cam I am using is a roller cam. Below are the specs from my build thread to clarify my setup. If you compare my cam specs to the HotRod spec you will notice an identical duration @ .050" lift on the HotRod build and mine. However, my max lift is larger and because it is a roller cam it means my valves open and close way faster while also remaining wide open for more of the duration. This results in flowing much more in and out with the same duration to the flat. We also should take into consideration that I also have less rotating resistance due to the rollers. Anyway, what I was trying to say in my last post was that when I asked the builder what he would have done differently he told me roller cam with a little more aggressive lift. So, that is what I did with my build.

I think you will love it once your get it done. If you are going with the flat tappet cam I would recommend using the same grind as the HotRod build but just increase the lift if possible. If you go roller cam I think you would be very pleased with my cam spec as it seems to work really good and I still build plenty of vacuum for power brakes and the EFI loves the smaller exhaust overlap and keeps the MAP and IAC from getting weird on you. The downside is you don't get that really radical cam lope but you gain a lot of other things worth that small sacrifice while still maintaining a good high performance sound. There is also nothing quite like ambushing someone unsuspecting when they think they could take you.