CFM rating question

[chevyII]

Im checking into installing a NACA duct on my hood to draw air into the engine. after some research The max CFM is needed to calculate flow rates. I will probably never run a 70 but I think its better to go a little bigger so say a 70 series at 5800-6000RPM. Im going to put one on each side may have the other one feed the intercooler.

 

[Joe Lubrant]

Originally posted by chevyII
Im checking into installing a NACA duct on my hood to draw air into the engine. after some research The max CFM is needed to calculate flow rates. I will probably never run a 70 but I think its better to go a little bigger so say a 70 series at 5800-6000RPM. Im going to put one on each side may have the other one feed the intercooler.

There are quite a few 70 series type turbo's 70, 71, 72, 74, & 76.

Depending on the maximum compressor airflow which is normally expressed in lbs of per min, you could divide that number by .069 and it will convert it to cfm.

Example: a turbo compressor that is capable of 88# of air per min. would convert to 88\.069= 1279.4 cfm. with no other minor corrections taken.

Hope this helps?

 

[chevyII]

I guess I meant a 70mm, maybe a GTQ if that makes a difference.

 

[Joe Lubrant]

Originally posted by chevyII
I guess I meant a 70mm, maybe a GTQ if that makes a difference.

Not sure?? The Jury seems to be still out on that rascal!!

Dave Bamfords(PT70GTQ) TSM 248cu.in V6 put down an 9.57@142 in a 3500++# car. It actually made by calc approx. 800+hp to the rear wheels thru a TH 400 tranny with a some what loose converter. I believe that would be somewhere in the 900-950hp flywheel range, if you consider driveline losses.

So as a minimum I would think 90# air/per min. appox. 1305cfm. To be safe maybe just use 1400cfm?? Just a good guess for your application.