Theoretically maximum RAM air pressure explaine

Need advice on which oil to use or which tyre best suits you? Share your topic and get help here.
Post Reply
User avatar
VT1000r
Posts: 58
Joined: Wed Nov 07, 2018 12:04 am
Location: tennesee

Theoretically maximum RAM air pressure explaine

Post by VT1000r »

Hello, I posted something about RAM air exactly 364 days ago it just so happened to be my last post until now. I've done a lot of research on RAM air and studying fluid dynamics quite a bit in general like venturi effect and aerodynamic drag for subsonic vehicles, very interesting stuff, anyway an easy formula to calculate theoretical maximum, so no losses in system, for RAM air is
(MPH)^2 X .0000176 That will give you a number in PSI. So as you can see it's no magical free turbo at least not at any speed your going to reach on a motorcycle. At 200mph the maximum psi is going to be around 0.7 PSI at 150mph it's 0.4 PSI and at 100mph it's only 0.176 PSI. A LOW boost turbo is around 7psi so as you can see it's not that much but in racing every little bit counts.
Last edited by VT1000r on Tue Dec 01, 2020 12:29 pm, edited 1 time in total.
User avatar
misnblu
Posts: 108
Joined: Wed Aug 05, 2020 1:30 pm
Location: Gulf Coast Mississippi
Contact:

Re: Theoretically maximum RAM air pressure explaine

Post by misnblu »

VT1000r wrote: Tue Dec 01, 2020 10:22 am Hello, I posted something about RAM air exactly 364 days ago it just so happened to be my last post until now. I've done a lot of research on RAM air and studying fluid dynamics quite a bit in general like venturi effect and aerodynamic drag for subsonic vehicles, very interesting stuff, anyway an easy formula to calculate theoretical maximum, so no losses in system, for RAM air is
(MPH)^2 X .0000176 That will give you a number in PSI. So as you can see it's no magical free turbo at least not at any speed your going to reach on a motorcycle. At 200mph the maximum psi is going to be around .7 PSI at 150mph it's .4 PSI and at 100mph it's only .176 PSI. A LOW boost turbo is around 7psi so as you can see it's not that much but in racing every little bit counts.
Good information.
Now I can take this bit of information to some of the car forum guys that think ram air is useful for their engines and all their scoops and funneling they do. :lol: :thumbup:
1998 Honda SuperHawk aka FireStorm
https://www.dwn4lif.com
My website 👆
User avatar
fabiostar
Posts: 7542
Joined: Sat Jun 01, 2013 3:53 pm
Location: sunny belfast

Re: Theoretically maximum RAM air pressure explaine

Post by fabiostar »

i seem to remember ,i think it was Roger who mentioned that it has little to no effect until the bike reaches 110mph? but as you say for racing it all counts.
the older i get,the faster i was :lol:
User avatar
freeridenick
Posts: 1574
Joined: Fri May 23, 2014 1:30 pm
Location: Derbyshire

Re: Theoretically maximum RAM air pressure explaine

Post by freeridenick »

It's right at the top of the rev range when a trick motor can't suck enough air 'cause the airbox is empty. 1 atm is the figure I have in my head but I haven't worked that out in psi. I think mine could maybe cope with a bit more air but I'd try a programmable ECU first.
User avatar
8541Hawk
Posts: 2066
Joined: Sat Jul 21, 2012 5:21 am
Location: Bella Vista, AR

Re: Theoretically maximum RAM air pressure explaine

Post by 8541Hawk »

freeridenick wrote: Wed Dec 02, 2020 7:49 pm It's right at the top of the rev range when a trick motor can't suck enough air 'cause the airbox is empty. 1 atm is the figure I have in my head but I haven't worked that out in psi. I think mine could maybe cope with a bit more air but I'd try a programmable ECU first.
1 atm is 14.7 psia at sea level :thumbup:
Loud pipes don't save lives, knowing how to ride your bike will save your life.
User avatar
freeridenick
Posts: 1574
Joined: Fri May 23, 2014 1:30 pm
Location: Derbyshire

Re: Theoretically maximum RAM air pressure explaine

Post by freeridenick »

8541Hawk wrote: Wed Dec 02, 2020 9:15 pm
1 atm is 14.7 psia at sea level :thumbup:
So way off the formula above. Interesting. I'll see if I can find the source of the figure I had in my head.
Post Reply