Ram Air

[JDJP]

Ok,
Don't quote me on this, but I think I read that the holes In the hood are to alleviate excess pressure in the engine compartment? Could someone explain to me exactly how these things work? I was thinking ram air would a better use of holes in your hood. Is ram air a possible mod?

Also,
What is the widest tire you could put on those rims? I think the fat tires look better, and I don't mind the extra traction. Id like something a little wider than 285s.

Thanks
JD

 

[fullsagd]

in a way it does, there is a higher pressure zone in front of the car when it is in motion and the openings in the front allow air flow through the rad and in this case the intercooler. the vents allow the air to flow through by utilizing the differential pressure between the stagnation point, and the vents(the shape of the vents are designed to create a lower pressure zone at nozzle exit). this will increase flow across the exchangers and allow for a higher heat transfer (cooler charge of air to s/c and less demand by the coolant pump) there are lots of good website explaining coefficient of drag and nozzle efficiencies, you could probably find some good profile images to make things make a little more sense. the ram air will give more airflow as well, but i'd have to guess the capacity of the increased intercooling vs. ram air gave better performance results which is why it is like it is. there is a front pic of the car which can give you an idea of the flow through the cores and out the vents, and i'll include an ok website the i found. i can't shed any light on the tire question, but i hope this helps.
dave

http://forums.dragid.com/showthread.php?s=&threadid=27733 (2nd pic down)
http://www.grc.nasa.gov/WWW/K-12/airplane/drag1.html
http://www.princeton.edu/~asmits/Bicycle_web/Bernoulli.html

 

[05retro]

I cant remember which magazine had an article on the 05 Mustangs used for racing. But it said that because of the nature of the front end so much pressure is put under the hood that during one race the hood was ripped off. They added EXTRA hood pins and blocked off some of the grill to limit underhood air. The result: The radiator support was ripped out. Long story short, the heat extractor would limit underhood air pressure and keep the hood from being ripped out. But lets face it, its not needed. Those that get this car would obey the speed limit anyway

 

[Mickey21]

On a 9.5 inch width tire, 285 is about as big as I would want to put on that wheel. I have 275 BFG's on my front 9.5 inch wide 2004 Cobra Replica rims and that is about enough. 285 wouldnt be much different. I have 315's on my rear 10.5 wide wheels and they look even with the front wheels. I had originally 285's on the rear's (temporarily - they didnt make a 315 in the type of tire I needed at the time). I never tried the 285's on the 9.5's though... 285's will work fine on those 9.5's. Any more and it would start pulling the tire walls inward.

 

[sam_abuelsamid]

Ok,
Don't quote me on this, but I think I read that the holes In the hood are to alleviate excess pressure in the engine compartment? Could someone explain to me exactly how these things work? I was thinking ram air would a better use of holes in your hood. Is ram air a possible mod?

Also,
What is the widest tire you could put on those rims? I think the fat tires look better, and I don't mind the extra traction. Id like something a little wider than 285s.

Thanks
JD

Actually since this is a supercharged engine, ram-air would be kind of pointless since there is already a mechanical device forcing pressurized air into the engine. Ram-air at best is just a sort of passive supercharging, and on most porduction vehicles that claim to have it is probably more form than function.

 

[AvalancheSVT]

some indy cars actually develope boost from the air entering thier scoops on downhill slopes.

then again, they're usually clocking 200mph...

you gotta get serous velocity in order to get a real functional ram air thing goin. for the most part is just to supply cooler denser air to the intake.