Boost/RPM Formula?
Thread Starter
TECH Fanatic
Joined: Nov 2001
Posts: 1,986
Likes: 1
From: Centrifugal City
Boost/RPM Formula? If I'm seeing 12psi at 6200rpm, is there a formula to estimate the boost at 3k, 3.5k, 4k, 4.5k, 5k, 5.5k, etc?
It's hard to watch the gauge while on the dyno or driving.
What is the best way to data log boost also?
TIA.
It's hard to watch the gauge while on the dyno or driving.
What is the best way to data log boost also?
TIA.
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
Auto meter has some new guages out that record the data on a SD card and you can play it back on your computer. They are the nexus line and they are proud of them $$$. Im not sure about the forumla.
i do my turbo by locking in a gear too high so it revs slower where I can look. Like on the freeway i will go to 3rd with the converter lock.....that way I get time to see the boost come on. (3.23 gears)
Try this forumla. I think this will give you what you are looking for.
Using a little bit of algebra:
Let (P1) equal your initial pressure, which would be 12psi.
Let (N1) equal your RPM at your initial pressure, which would be 6200 RPM.
Let (P2) equal the final pressure you are looking for - the unknown.
Let (N2) equal your RPM at your unknown pressure.
Now just set it up like a proportion.
For example, say we are looking for your pressure at 4000 RPM. Write your proportions like this: (P1) over (P2) equals (N1) squared over (N2) squared.
Now just plug in the numbers: 12 / P2 equals 6200 squared / 4000 squared. Just solve for P2. Should see about 5 psi at 4000 RPM.
Hope this helps.
Brian
Using a little bit of algebra:
Let (P1) equal your initial pressure, which would be 12psi.
Let (N1) equal your RPM at your initial pressure, which would be 6200 RPM.
Let (P2) equal the final pressure you are looking for - the unknown.
Let (N2) equal your RPM at your unknown pressure.
Now just set it up like a proportion.
For example, say we are looking for your pressure at 4000 RPM. Write your proportions like this: (P1) over (P2) equals (N1) squared over (N2) squared.
Now just plug in the numbers: 12 / P2 equals 6200 squared / 4000 squared. Just solve for P2. Should see about 5 psi at 4000 RPM.
Hope this helps.
Brian
