Thanks Eddie for all the Info. GT Performance out here does my work . The reason i run 1/4 Rac Fuel is the Lakes I go to out here don't have anything more than 89 Octane. So i use soem race fuel to raise the Octane. I have a 100 Gal. tank on my Freightliner and I just add a bit to keep from having low octane.

That makes sense on the fuel. Gary at GT is a great guy. You are in good hands with him. If you have any more questions, I would be happy to answer them.
Here are a few pics of a dry sump 598 ci I'm building with a 5L EfI Whipple. I also included a pic of the oil filter adapter that I use. Notice the plug in the "OUT" hole. This passage leads straight to the rear main cap where the stock oil pump goes. That is why you don't need to block off the main cap. They also make an adapter that has only 1 large port in it and the oil can go into either hole in the block. In that case, you must block off the rear main or you would not have any oil pressure, since all the oil would go right back into the pan.
Eddie

A few more.

what horsepower does drysumping start to make sense? 800? 900?

Is it only good on blower motors?

In a pleasure boat, I don't do it until about 1100 hp. It is more rpm dependent than hp dependent. At real high rpm's, the crank counterweight and the rods will start to "dig a hole" in the oil from windage. It can become so bad that it will uncover the oil pump pickup.
It is not just for SC engines. Higher rpm NA will benefit from it also. You typically see it on larger SC engines because of the stroke and power. The larger the stroke, the heavier and longer the crank is and the farther it sticks down in the pan. In that case, it is more likely to create a ton of windage.
One other thing. For me, the larger the engine (hp), the more oil I want in it. All of that power creates heat. The less amount of oil you have, the faster it will heat up. You may not be able to keep the heat managable. When you get a pan much over 14 qts. it becomes hard to control all of that oil. No matter how many baffles and trap doors you have, the oil starts to slosh around and leaks occur. The oil will inundate the rear main and the rear pan seal and it will eventually start to leak. Those seals are not made to be submersed in oil.
With a dry sump tank, I run 5 gal. of oil with no worries of leaking.
Hope that answered your questions, Eddie.

Thanks Eddie, very informative!

My pleasure.

I'm trying to understand the "dry sump" methodology. I don't want to sound ignorant, can you expalin the oiling system, like a diagram or explanation of how the oil flows?

it is just what the name implies. on a " wet sump" the oil is stored in the oil pan and sucked up and into the motor thru the oil pump pickup which is ALSO in the oil pan. the oil circulates thru the motor and " drips" back into the pan thru gravity. the downsides are that the crank splashes in the oil which aereates it and causes drag and the oil itself is subject to g forces and can be forced away afrom the pickup and thus starve the motor with catastrophic results.

on a dry sump, the oil is stored in a carefully designed tank away from the motor. therre is a seperate EXTERNAL pump that is actually several individual pumps bolted together driven by a toothed belt drive off the crank. one of the " stages is " pressure" . this sucks the oil from the tank and delivers it under pressure to the motor , usually into the filter housing. the oil circulates and collects in a very shallow and carefully designed pan which is being sucked dry by the other " scavenge" stages of the pump. they deliver the oil back to the tank. you will hear talk of " over scavenging" ie, the pump actually sucking hard enough to pull a vacuum in the bottom end. sometimes this is effective... sometimes not. but the bottom line is that the system is a much more effective and reliable oil system for any motor that sees sustained hi revs or significant g loads. the power benefits are minimal but real. no one does a dry sump to make power because the pump and drive losses will often offset the windage gains... but there are some gains anyway. It is done because in hi reving hi g load environments, its the best way to keep the motors alive.

It's not much different than a standard wet sump system. Obviously there is more plumbing involved since the pump in on the outside of the engine.
If you reference the pics that I put above, I used a 4 stage pump. It has 3 scavange sections and 1 pressure section. One side of the pump has the inlets and the other has the outlets. On my pump, the 3 scavange lines go to the inlet side of the pump but there is only 1 #16 line going back to the tank. The pump has internal passages that connect the 3 sections together internally. This just simplifies plumbing since I only have to run 1 large line back to the tank instead of 3. The 3 scavange lines all hook to the oil pan. As soon as oil drains into the pan it is sucked up by the pump by these lines and goes through the pump and back to the tank. That is why it's called a dry sump.....there is no oil that stays in the sump of the oil pan. All of the oil is stored in the tank, which in my case is 5 gallons.
There is a line at the bottom of the tank that the pump pulls from. There is a lot going on inside of that tank. It is not just a wide open tank. There are several baffles, etc to help remove the air from the oil. When the oil is returned to the tank, it is aerated and bubbly. It needs time to get the air out so you are not pumping air filled oil to the engine. A correctly built tank is very effective at removing the air.
After the oil goes through the pump, it is then just like a wet sump system. It goes to the oil stat,the filter, the cooler, and then into the engine. After it goes through the bearings and the valvetrain, it drains back to the pan where the scavange lines pick it up. It then starts all over. Hope this answers your questions.
Eddie