Boost and engine airflow calculators

[JBrady]

Here is an interesting and useful calculator to determine boost targets based on engine size, blower size, pulley size, etc.

http://www.modularfords.com/forums/...or-for-positive-displacement-blower?p=1088426

Here is a useful engine airflow calculator

http://www.modularfords.com/forums/...flow-rate-calculator-for-a-4-stroke-IC-engine

 

[JustenGT8]

I had a play...the supercharger Vol eff is very significant in determining the resulting boost and small changes mean big differences in results. The simple one on the Soarer website is a better bet....i've used it twice now to calc the SC pulley size and both times it's been within a psi.

 

[Thermactor]

I had a play...the supercharger Vol eff is very significant in determining the resulting boost and small changes mean big differences in results. The simple one on the Soarer website is a better bet....i've used it twice now to calc the SC pulley size and both times it's been within a psi.

link please?

 

[JustenGT8]

lazy bugger

http://planetsoarer.com/boost/boost.htm

 

[JBrady]

I had a play...the supercharger Vol eff is very significant in determining the resulting boost and small changes mean big differences in results. The simple one on the Soarer website is a better bet....i've used it twice now to calc the SC pulley size and both times it's been within a psi.

Whatever works best for you.

That said there is a field for supercharger volumetric efficiency on the calculator I referenced (VEsc =) line 10

Was there a problem you noticed?

 

[JustenGT8]

Whatever works best for you.

That said there is a field for supercharger volumetric efficiency on the calculator I referenced (VEsc =) line 10

Was there a problem you noticed?

that was my point...get this input wrong and your answer is rubbish. eg. in the example show he quoted an SC eff of 0.9!! damn high, even for turbo. most are more like 0.5...which will then give nearly half the boost.

the simple table on the soarer site, regardless of how they calc'd them, seems to give a good real world number for a UZ with a roots SC.

just a comment

 

[hypronet]

that site is ok, if your running the small SC, but no-good for me as mine is a bit larger then those

if you like, i have a spreadsheet that i created that i have posted up on this site a while ago

it will tell you what your SC drive ratio, SC internal speed, SC cfm flow & LPM, engine cfm flow & LPM, increase cfm flow & boost.

All you have to do is enter in pulley sizes, SC size, engine size & rpm

yes i know, it doesnt allow for intercooling or VE or PE or island flow, these are more required if your after hp figures

i know this is closet to being right as im about .2 out on psi from spreadsheet to car setup

there is a link to where it is on this site
http://www.lextreme.com/forums/showpost.php?p=101319&postcount=30

___________________________________________
http://www.lextreme.com/forums/showthread.php?t=9037
[FONT=&quot]:sgrin:There is No substitute for cubic inch, except for BOOST !!!![/FONT]:sgrin::burnout:
"91 LS400" Argo rods, CP pistons 9:1, Custom Tighte Cams, Whipple supercharger 20psi, Torsen Lsd,
Dual TB's, Whiteline swapbars, 97 RZ Supra brakes, Airbag & controller

 

[Adandos]

Shameless plug: My horsepower calculator ...

Doesn't ask you to estimate numbers like VE... it calculates it for you... very easy to use ...

http://horsepowercalculators.net

Here's an example of me doing a calculation (in a video I uploaded just yesterday)

http://horsepowercalculators.net/tuner_report/tuner-report-2-twin-supercharged-bmw-m5

 

[JBrady]

that was my point...get this input wrong and your answer is rubbish. eg. in the example show he quoted an SC eff of 0.9!! damn high, even for turbo. most are more like 0.5...which will then give nearly half the boost.

the simple table on the soarer site, regardless of how they calc'd them, seems to give a good real world number for a UZ with a roots SC.

just a comment

I would think volumetric efficiency of 90% would be believable. Even the older 3 lobe 5th gen Eaton 112 listed at Magnuson Products hits that at 10psi and slightly higher at 5psi.

http://www.magnusonproducts.com/images/mp112g1.jpg

The 6th generation 4 lobe TVS units have much better inlet to airspeed so they do even better with numbers approaching perfect.

The source for the below image with much more data
http://www.smokinvette.com/corvette/articles/eaton-tvs-supercharger/

Now, if we are talking adiabatic efficiency then 90% isn't going to happen more in th 60-70% range. Old roots would be in the 50%.

 

[JustenGT8]

ah my bad...jumped the gun there, read vol eff and assumed they meant Adiabatic eff.

 

[SuperRunner]

lazy bugger

http://planetsoarer.com/boost/boost.htm

These numbers are way off for a 1UZ.

I just put a 2.8 pulley on my M112. With the stock 3.2 I was getting 5psi, and now I am getting a wopping 7.5psi. GRRR!!!