So you can’t run a blow off valve or wastegate of sorts to get up to max boost early and then just bleed off the excess to keep the boost constant the rest of the rpm band?
Yes you can but you may not want too. With a centrifugal blower pressure vs rpm is not a linear function . A lot of things go into the equation such as. Blower wheel diameter and blade pitch but just as an example let’s say that doubling blower speed has the effect of quadrupling the output pressure and in doing so you are also quadrupling the heat generated. You can end up chasing your tail trying to find the right balance of how much pressure/heat your system can live with.
It's possible and has been done, some guys try to get a little more boost down low, other use it on an actuated switch to limit boost in lower gears for traction, similar to a boost controlled wastegate for a turbo. In the case where you are trying to increase boost down low, it will require you to spin the blower faster as you were discussing. When the wastegate is on the charge side of the system bleeding off boost, it is called a bypass valve. The issue with using a bypass valve to set your boost pressure at redline is you are spinning the blower harder than needed, which takes HP and creates more heat - but you aren't geting the benefits of the added boost. It will lose efficiency and make less HP at the same boost, because it is requiring more HP to spin faster than needed, and with reduced charge dencity (hotter IAT's). You wouldn't want to make a severe boost adjustment using a setup like that - like spinning it to make 15 PSI, but limiting it to 6PSI.
Ok so since you’re not an engineer or builder (and I’m not talking down to you so please don’t take it that way) look at it like this. If the parasitic drag that you talk about was greater then the benefit that receive you would be loosing hp rather than gaining it when you add a blower. Yes heat can be an issue but at 5 psi you aren’t generating a lot and if its enough to be a concern then a small intercooler can handle that.
I will have to look and see if there is a strainer on the water feed line. I bought the bought, stuck it in storage and went home. Coming out first weekend in August. Thanks for the great info.
If you bought it and stuck it in storage and then plan to use it, I would seriously advise you to get the boat fully serviced before first use. You have no idea what you bought has been serviced properly and you could have a real short day followed by an expensive repair bill that could have been avoided.
It was just serviced, he gave me the paperwork.
Yea they used my boat for their Beta and finalized the kit for the Mercury 525. I absolutely love it i haven’t had a lick of issue with the blower, had a few fuel delivery gremlins at the beginning but both ProCharger as well Deatch Werks went above and beyond to assist with dealing with and getting it all dialed in.
Yea yea i think i finally got it handled, but won’t be able to test it for another week or so! And thinking about that before hand as you told me the other day, shiiiiit I’ll toss that bimini in the dumpster before ditching the PC
So yes and no, and this is per ProCharger, they make different housings for different levels and rpm’s for boost. They also have some sort of clutching inside as well. I can start making boost at as little as 2900/3000rpm or at as high as 4000 rpm depending upon how you throttle it. Hard to grasp for myself but that’s simply watching the boost gauge and the VesselView.
Yes, you can run a smaller compressor housing and it will change the compressor map and be more efficient at lower boost levels, but at the expense of total HP it can support.Yea they used my boat for their Beta and finalized the kit for the Mercury 525. I absolutely love it i haven’t had a lick of issue with the blower, had a few fuel delivery gremlins at the beginning but both ProCharger as well Deatch Werks went above and beyond to assist with dealing with and getting it all dialed in.
Mine makes more power at the bottom than stock as i can pull a 32p to plane and doubt i could with just the 525 alone. But when it comes into boost it pulls so incredibly hard, it’ll literally bury you in the seats.
Yea yea i think i finally got it handled, but won’t be able to test it for another week or so! And thinking about that before hand as you told me the other day, shiiiiit I’ll toss that bimini in the dumpster before ditching the PC
So yes and no, and this is per ProCharger, they make different housings for different levels and rpm’s for boost. They also have some sort of clutching inside as well. I can start making boost at as little as 2900/3000rpm or at as high as 4000 rpm depending upon how you throttle it. Hard to grasp for myself but that’s simply watching the boost gauge and the VesselView.
www.procharger.com
I’ll see exactly but that’s how i recall them explaining it. It almost sounded similar to a Variable Vein Turbo but it’s also very possible that i completely misunderstood what they explained.Yes, you can run a smaller compressor housing and it will change the compressor map and be more efficient at lower boost levels, but at the expense of total HP it can support.
I've never head of internal "clutching", but they did recently come out with a variable drive system / smart controller to overdrive the blower at low speeds and tailor the boost level / curve thru the RPM range. Pretty bad ass, don't know anyone who has played with one yet but this is on their website:
i-1 UPGRADE
When it comes to achieving the largest power gains and the ultimate performance curve, the ProCharger i-1 programmable supercharger stands in a league of its own.
. If you have drive by wire this can be automated with a good efi computer. If you ha e a cable throttle it's called ME-fi
Does this MEFI have tables?Yes, it's called the throttle
