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Over Port M90 Video!



It actually didn't sound much different. I have the blower...and sold it to a guy...and he put it on his car...or well, I put it on there and it killed nearly 3* of knock (He had 7+ at times)...but driving around it just sounded like a typical ported M90...I don't know why in tha video it sounds like it does...because it doesn't sound that loud in real life. Plus...he said he didn't really notice much difference and I think the reason he dropped a bunch of knock is because it was so hogged out it wasn't even making boost.
 
Bio248 said:
i used a CNC lathe for the outlet and h-bar, but i used a die grinder and wire wheel for the inlet.
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I'm sure you meant "Mill" not lathe.

Bio248 said:
dude, go to a physics class, seriously.

when air is compressed it heats up. if the blower is more efficient and can move more air with less effort, it will not heat the air up as much. therefore a ported blower should net cooler outlet temperatures, which will in turn net less boost. colder air is denser.

its not that the air coming into the blower is colder, its that the blower can now compress the same amount of air and not heat it up as much.
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Bio248 said:
cooler outlet temps mean less boost. an intercooler does the same thing.
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All respect, but don't supercharged cars make more boost in cooler weather?
The supercharger moves a given volume of air, no matter what the temperature. Cooler air has increased density over warm air,meaning that in a given amount of area ( psi means "pounds per square inch) there is more oxygen molecules because they are smaller. So lower inlet, outlet temps = more boost = more power.

Now whether these inlet temp reductions do to porting are noticable on the boost gauge is another matter. I've seen inlet temp reductions on the Cobra Mustangs from porting reduced by as much as 35 - 40 deg F. and they sometimes pick up as much as 1 psi on the gauge.

I have'nt datalogged the GTP to monitor inlet temp reductions so I'm not sure what typical gains are.
 
The molecules dont change size based on temp... they distance between them changes.

PSI = measure of restriction which has a million and one factors. Can't have a million variables and just one control.

Blower outlet temps are what we're discussing.

Boosted cars make more boost in cooler temps because the air is denser.

PSI is a measure of pressure, not volume. In a given volume, not area which is 2 dimensional, the air will contain more oxygen yes, but only because the molecules aren't moving as much. Not because they changed size. Unless I just dont know enough about bond lengths which is very plausible.

The issue with cars is that we dont like/want to cool the incoming air cooler than the ambient temperature. Its too costly. There are such kits out there though.
 


I should have said "outlet" temp reductions, my bad.

Yeah, I know what we are talking about.

BTW, not to be a smartass, but I've actually built a supercharger flowbench - www.stiegemeier.com thats me running it in the middle of the homepage, Bob is a good friend of mine and asked my to construct this to evaluate the improvements from porting and eliminate the variables the car produces.

I built the bench and worked with an EE from Boeing on datalogging inlet outlet temps, air volume, pressure etc. to calculate cfm which is what we are really talking about. The amount of air we can move through these little blowers.

:th_beer-toast1: to all, I'm here to have fun and share and learn with the rest of you.
 
alkygto said:
I'm sure you meant "Mill" not lathe.
Click to expand...

yeah, doing it on a lathe would be kinda akward.

alkygto said:
All respect, but don't supercharged cars make more boost in cooler weather?
The supercharger moves a given volume of air, no matter what the temperature. Cooler air has increased density over warm air,meaning that in a given amount of area ( psi means "pounds per square inch) there is more oxygen molecules because they are smaller. So lower inlet, outlet temps = more boost = more power.

Now whether these inlet temp reductions do to porting are noticable on the boost gauge is another matter. I've seen inlet temp reductions on the Cobra Mustangs from porting reduced by as much as 35 - 40 deg F. and they sometimes pick up as much as 1 psi on the gauge.

I have'nt datalogged the GTP to monitor inlet temp reductions so I'm not sure what typical gains are.
Click to expand...

yes, we make more boost with cooler air. i have seen as much as 14-15 psi on a 3.4 in the dead of winter up here while in the summer i would only make like 9-10 psi.

however, our cars dont have blowers that make true boost. the roots blowers we have create boost in the LIM, not the blower itself. you can relate level of boost with heat created in this sense. the more boost youre making, the more heat youre making. because the outlet temps are dropping, so should your boost level. this is only applicable because our blowers do not make the boost by themselves.
 
Yes, boost or pressure levels in the lim are a measure of restriction in a sense because the engine is'nt able to use all the air injested by the supercharger. Hence boost "loss" from ported heads, headers and camshafts. Well, once you get into cam lift, duration and overlap profiles its much more complicated, not to mention the effects of increased plenum volume.

Yes, roots blowers are merely fans that move air, not compress it internally, but they are putting more air into the engine than it can through engine vacuum. You get increased boost in the winter because the air is more dense, the supercharger is moving the same volume of air. Thats why I said the real discussion should be the volume of air moved through the blower.

Temp reductions from porting are due to the improvements in the air path making it more efficient. Like taking the kink out of a garden hose.
 




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