TonyG > New Race Car Build Thread
01-05-2013, 11:15 AM
#302
Three Wheelin'
01-05-2013, 06:03 PM
#305
Rennlist Member
Yep, as pictured. So I assume you'd have to have a hood scoop or opening of some sort. Wouldn't a motor like this want ram air induction? Excuse my ignorance, just haven't any experience with a setup like this.
01-07-2013, 05:57 PM
#306
Team Owner
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in theory, cowl hood or not, you have 2 pressure zones that work together to offer slightly supercharged, cool air;
1. wall of air smashes into the grill causing pressure to build at the back of the engine bay.
2. wall of cool air smashes into the windshield pushes downward onto the rear of the engine bay acting as a barrier to keep most of the hot air in the bay from getting to the filter, *provided the setup makes most of the flow to come from there, and only a small opening [pressure] from the bay.
1. wall of air smashes into the grill causing pressure to build at the back of the engine bay.
2. wall of cool air smashes into the windshield pushes downward onto the rear of the engine bay acting as a barrier to keep most of the hot air in the bay from getting to the filter, *provided the setup makes most of the flow to come from there, and only a small opening [pressure] from the bay.
01-08-2013, 09:03 AM
#309
Rennlist Member
in theory, cowl hood or not, you have 2 pressure zones that work together to offer slightly supercharged, cool air;
1. wall of air smashes into the grill causing pressure to build at the back of the engine bay.
2. wall of cool air smashes into the windshield pushes downward onto the rear of the engine bay acting as a barrier to keep most of the hot air in the bay from getting to the filter, *provided the setup makes most of the flow to come from there, and only a small opening [pressure] from the bay.
1. wall of air smashes into the grill causing pressure to build at the back of the engine bay.
2. wall of cool air smashes into the windshield pushes downward onto the rear of the engine bay acting as a barrier to keep most of the hot air in the bay from getting to the filter, *provided the setup makes most of the flow to come from there, and only a small opening [pressure] from the bay.
But, looking at this chart, you can see how the line goes down between the 10 and 14 dots... which I think is positive pressure. Perhaps because the air flow velocity is low?
01-08-2013, 09:28 AM
#310
Three Wheelin'
Van, you are correct. The high velocity of wind going over the hood windshield junction creates a low pressure area. Wind ramming into a radiator only flows as fast as it can exit. See the GT1 Corvettes for their method of exit which also provides downforce.
01-08-2013, 09:39 AM
#311
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my thinking is that the air that smashes into the windshield must force it's way into the stream of slower air above [more air into less space]. the result should be pressurized air at the base of the windshield.... and in the wind tunnel, you see extremely rapid decompression out the back... there's also what you guys are mentioning, but only some of the air in front of the grill can go into the engine bay. the rest of it mostly has to force it's way over the hood into space that's already occupied with slower moving air... so that's compressed air at the front of the hood..., and where can that compressed air go ?? .... as it reaches the windshield only a moment later, this already compressed air must force it's way into a second stream of even slower moving air above, which is also occupied [more pressure].... we think of the windshield as making some downforce. if this is so, then this should also indicate that some of that air could easily be routed to go into the engine [not the bay] instead of having to fight it's way into the airflow above... therefore, i believe the bottom of the windshield should be a zone of high pressure, which should further bolster the universal view that the rear of the bay is also a zone of high pressure..... maybe this is why cowl hoods don't win universal acceptance, as there's already slightly pressurized air at the rear of the hood. but with the 944 ??
found a vette.
.
found a vette.
.
Last edited by odurandina; 01-08-2013 at 01:07 PM.
01-08-2013, 09:49 AM
#312
Three Wheelin'
Wauw Tony.. This looks really amazing!
Also really digging your suspension.. If i ever have the money to build a racecar.. Your topic will be my guideline..
But, i'll be doing most of it myself so i'll have to start working on welding skills!
Also really digging your suspension.. If i ever have the money to build a racecar.. Your topic will be my guideline..
But, i'll be doing most of it myself so i'll have to start working on welding skills!
01-08-2013, 05:18 PM
#313
Three Wheelin'
my thinking is that the air that smashes into the windshield must force it's way into the stream of slower air above [more air into less space]. the result should be pressurized air at the base of the windshield.... and in the wind tunnel, you see extremely rapid decompression out the back... there's also what you guys are mentioning, but only some of the air in front of the grill can go into the engine bay. the rest of it mostly has to force it's way over the hood into space that's already occupied with slower moving air... so that's compressed air at the front of the hood..., and where can that compressed air go ?? .... as it reaches the windshield only a moment later, this already compressed air must force it's way into a second stream of even slower moving air above, which is also occupied [more pressure].... we think of the windshield as making some downforce. if this is so, then this should also indicate that some of that air could easily be routed to go into the engine [not the bay] instead of having to fight it's way into the airflow above... therefore, i believe the bottom of the windshield should be a zone of high pressure, which should further bolster the universal view that the rear of the bay is also a zone of high pressure..... maybe this is why cowl hoods don't win universal acceptance, as there's already slightly pressurized air at the rear of the hood. but with the 944 ??
found a vette.
.
found a vette.
.
Cheers,
Mike
