How about an example from a guy who has put together more engines than any of us combined? Tony Mamo...https://ls1tech.com/forums/dynamomet...ed-engine.html

Going to tell me he is wrong too?

 

Did you actually read what I posted or just want to argue? Let's try this....

The MMS 235 is a LARGER intake runner than a stock LQ9 even likely when ported , but FLOWS a ton more. Even if you wanted to argue they were the same intake runner size, fine, guess what the MMS heads flow more.
Wierd...that sounds familiar....

 

Again, CFM the engine requires doesn't change with boost, the density of the charge is increased - hence more power... The blower does not add cfm air in the cylinders, its the same cfm just a denser charge... not that difficult to understand. So if you optimize the heads to what the motor requires N/A it will make more power, then add a blower, make the charge more dense then power will go even higher, but the cfm in and out of the engine is the same regardless of being N/A or blown..

 

The 235 head flows more air and has higher port velocity even with the larger port vs the 799 head. Its a superior design in every way. A blanket statement such as more cfm is always better when boosted is wrong. To assume a head with a bigger port has slower air speed than a head with a smaller port is also wrong. There is more to it. You only need as much air that the cylinder requires for a given RPM and then after that point you maximize air speed to get that air in as fast as possible. A more efficient head will benefit boosted setups more than an NA application. You can't just dismiss air speed because you are supercharged. If that was the case all boosted ls1s would be running the biggest ported head you could possibly fit without valve fitment issues. Superchargers simply make the air more dense, otherwise knows as increasing the amount of oxygen in an intake charge so more fuel can be burned and make more power. So you want good heads to draw in more of that densely charged air to burn more fuel to make more power.

 

​​​​​​Its readily apparent we're not going to agree on this subject so I will agree to disagree and we can leave it there. But feel free to post that example of anything boosted that you've built.

 

That's exactly the point, you're not DRAWING in anything. It's a pressurized air charge that is forced in. CFM rules on a boosted setup because air speed is helped because it's a pressurized charge.

 

Ok, lets agree to disagree.... I will go with Darrin Morgans advice...

http://www.powerandspeedpodcast.com/?p=342

 

Wrong - Wrong - Wrong........ Jeez, nothing is forced in... you are changing the density of the charge. the valve/port shape/ air speed is what dictates the flow into the cylinder, the boost is just providing a more dense air charge, DENSER CHARGE/MORE FUEL = MORE POWER... The CID of the engine doesn't change, the motor only flows what the CID dictates..

 

The air is going to want the flow into the path of least resistance. When a supercharger increases the atmospheric pressure the air is going to want to be drawn naturally into the cylinder because there is less pressure in the cylinder as the Piston comes down and intake valve opens. Assisting that air by increasing Port velocity makes a good set of heads even more vital than with a naturally aspirated engine.

 

Don't forget that you only make boost when you are spinning the blower as well. The blowers RPM is dependent on crank rpms so if you are cruising or city driving, port velocity is very important for crisp throttle response and overall driveability. The supercharger makes more power numerous ways and it is not purely due to atmospheric pressure. The charge is compressed and cooled as well. Both increasing density. The boost effect is natural due to atmospheric pressure differences but dependent on RPMs. It's not so cut and dry as one might think.

 

Ok guys, whatever you say. Arguing that air is not forced into an engine on a forced induction setup is about as dumb as arguing that a torque converter cannot multiple torque You guys keep at it with those boosted setups you've designed, built, tuned, and raced....

OP...Sorry for the side track. I also run a D1 Procharger and think you still have room to grow at 700whp before moving to an F1 series. You've got some options and a thick deck 235 would likely drop the boost level and pick up power. Good luck with whatever you decide.

 

okay dude, And good luck with your 11.2 second 700fwhp boosted motor.

 

Thanks, good luck with your boosted setup....oops...

 

After reading that I, I realize my knee jerk reaction and advice were wrong. Also I think in a way we are all agreeing and disagreeing at the same time. I think we all agree we can add a few pounds of boost to make power. On some setups it would make sense to go that route, on others better flow and optimizing the path would make more sense.

After re reading the OP's post and realizing he's at 17 psi already and running meth "100% of the time", increasing boost and increasing temps would not be a good idea. Therefore on this setup I would optimize the flow, which will increase the power and also lower the boost psi by opening up restriction, and be more efficient and safer.

If this were a lower boost setup i'd say go for boost first. On this setup, going for the heads & intake may be the smarter choice. At some point all motors start backing up more and more of the boost so increasing boost has diminishing returns at a point, and if you're at that point boost is not the answer, if you're seeing linear gains psi by psi and keeping IAT in check go higher.

I think we all know increased boost can get more air in the cylinder, but I think we are arguing over the best way to get it in there, reducing restriction is always the best way (aka increasing flow) but we are mixing in at what cost ($$$) to the argument and pushing against upgrading heads. But we don't have OP's budget and shouldn't advise him based on how we feel about our own.

OP if you have the money for heads and intake, do it, it only makes the over all hg ceiling higher. And you can make more power with lower IAT's and boost if you go the better flow route.

 

I'd spend my money with Mamo before spending it with Mast. Mast won't stand behind their heads.

 

Preach brother preach!!

 

Right on. With Mamo you KNOW you will get good results! You WILL spend some money, but you WILL get what you pay for! Mast is good, but not for the money they want for their stuff. They are VERY proud of themselves...

 

Just a friendly opinion. To the statements I have bolded. I really don't think I've ever heard this before. I cannot believe this from real world. Have you ever seen, in real life, a procharger spun with no piping? They can move a lot of air. So let's think of the intake charge, & how air is forced in, & it's not just the same charge it was N/A. Just a different density. We have PSI which is pressure. So think of the valve just starting to open. As where the piston has not even begun it's stroke yet. Air is going to be forced into the cylinder as trying to equalize pressure. If the motor was N/A this would not be happening. The cfm in/out will not be the same. Yes, denser air does make more power. If the air was also cooled, through a system, lower than ambient air temp., that's more power.

 

@pooter....most of what you posted I was not arguing. I did not simply say turn the boost up. I was arguing cfm vs. velocity and drawn vs. pushed. That's all.

@soflo....save your fingers, not worth it. Just like that torque converter

 

Lol.