determine what turbo size is correct ??

I have a pair of .57 trim TO4E's that I got essentially for free and would like to use if possible. I'm a little worried that the .57 trim is going to be too small because according to my best mathmatics I need a pair of .63 Trim T04B's to get the job done. I'm basing this math on one turbo per 3.0 liter cylinder bank and a crank horsepower output of 300hp per cylinder bank....I know this isn't 100% perfect but I can't think of any other way to calculate exhaust flow requirements per turbo

Any help at all is appreciated !!

 

multiply 2.2cfm for every 1 crankshaft hp = zero loss exhaust system

or in your case 660cfm per side

 

660 cfm exhaust flow through the hot side of the turbo ???...or 660cfm output from the cold side ??

And how does this correlate to the compressor map for the turbo ??....anyone know how to convert CFM to lbs/min ??

 

CFM x .069 = lbs/min......660cfm/bank = 45.54 lbs/min

Thats ALOT more than what a T04B will flow and still stay in the middle of the compressor map.....is this correct ???

EDIT: I'm obviously missing something here because according to this math I'll have to run a pair of T66's to get 600FWHP out of a 6.0 liter motor....I KNOW that isn't right !!!

 

that is for the exhaust, not sure what you'd need on the intake, however a single 4" will flow quite a bit of air.

 

OK....I'm gettting this figured out, bear with me for a minute here and I may have answered my own question....and then I'll tell you all how to go about doing this.

 

OK...Got it.....I need a pair of Turbonetics "V Trim" T04B Turbochargers. Here's how I figured it out:

First I had to figure out how much air my engine was using per bank...this math is CID x RPM / 3456 x .9 x .069 /2 (the .9 is an average of my VE table, the .069 converts CFM to lbs/min and the /2 gets me per bank numbers) here are those numbers:


1000rpm 3.27lbs/min
1500rpm 4.91lbs/min
2000rpm 6.54lbs/min
2500rpm 8.18lbs/min
3000rpm 9.81lbs/min
3500rpm 11.45lbs/min
4000rpm 13.08lbs/min
4500rpm 14.72lbs/min
5000rpm 16.35lbs/min
5500rpm 17.99lbs/min
6000rpm 19.62lbs/min




Then had to figure out the Pressure Ratio I wanted: that math is (Req PSI + 14.7) / 14.7 or (7psi +14.7) / 14.7 or a Pressure Ratio of 1.48

Then I took the Pressure Ratio and Multiplied it by the N/A lbs/min to get actual turbocharger lbs/min flow requirements:

1000rpm 4.84lbs/min
1500rpm 7.26lbs/min
2000rpm 9.68lbs/min
2500rpm 12.13lbs/min
3000rpm 14.52lbs/min
3500rpm 16.94lbs/min
4000rpm 19.36lbs/min
4500rpm 21.78lbs/min
5000rpm 24.25lbs/min
5500rpm 26.62lbs/min
6000rpm 29.04lbs/min

This gave me a place to start looking at compressor maps and figure out what compressors will flow the kind of air I need to flow at a pressure ratio of 1.48....all of this led me to the Turbonetics "V Trim" T04B turbocharger !

Remember...All of this is PER BANK.....so I'll be flowing almost 60lbs/min @6000rpm when all of this is done !!

 

http://www.forcedinductions.com/consumption364.htm

 

Smartass.....

 

I may be a little late but check out this spreadsheet.

Turbo calc spreadsheet