19 lbs of boost @ 5000 RPM on a M90? ITS POSSIBLE
#41
Senior Member
Certified GM nut
Join Date: Feb 2003
Location: Georgia
Posts: 2,095
Likes: 0
Received 0 Likes
on
0 Posts
![DrJay is on a distinguished road](https://www.gmforum.com/images/reputation/reputation_pos.gif)
![Default](https://www.gmforum.com/images/icons/icon1.gif)
It depends on how much pressure you allow. The TB on a Vin C was checked at 444cfm without the screen. The supercharger, however, pulls much much more than that. It pulls enough in to put 8.5 pounds of pressure on the intake. I started wondering how much the engine actually pulls though....
Welp I suck at math but I get the feeling we can figure this out to a fair amount of certainty. I only know the m62 though, but this'll give you an idea.
The crank is 6.875" and the stock pulley is 2.55" So:
6.875 / 2.55 = 2.69
5000rpm * 2.69 = 13,450rpm for the blower
1rotation = (assume) 95% of 62ci = 58.9ci of air
we need cubic feet so 58.9 / 12 = 4.9CF per rotation
4.9cf x 13450 rpm = 65905cfm
65905 / X = Y | Y / 14.7 = 8.5psi(known)
So 8.5 x 14.7 = 124.95 | 65905 / 124.95 = 527cfm
So the engine would need to draw in 527cfm in order to maintain 8.5psi.
NOTE: I get the feeling something is wrong...well at least the last two lines. Someone who'* better than me can maybe pick up/verify?
Welp I suck at math but I get the feeling we can figure this out to a fair amount of certainty. I only know the m62 though, but this'll give you an idea.
The crank is 6.875" and the stock pulley is 2.55" So:
6.875 / 2.55 = 2.69
5000rpm * 2.69 = 13,450rpm for the blower
1rotation = (assume) 95% of 62ci = 58.9ci of air
we need cubic feet so 58.9 / 12 = 4.9CF per rotation
4.9cf x 13450 rpm = 65905cfm
65905 / X = Y | Y / 14.7 = 8.5psi(known)
So 8.5 x 14.7 = 124.95 | 65905 / 124.95 = 527cfm
So the engine would need to draw in 527cfm in order to maintain 8.5psi.
NOTE: I get the feeling something is wrong...well at least the last two lines. Someone who'* better than me can maybe pick up/verify?
Thread
Thread Starter
Forum
Replies
Last Post
Toddster
Trouble shooting + Test Procedures
0
03-21-2009 06:24 PM
SSEimatt93
Performance, Brainstorming & Tuning
5
03-26-2008 12:05 PM