Loewenherz Racing

#20 - Refining My Modeling Software

  Thanks in no small part to the man in the tin shed, I've been able to improve the accuracy of my Rocket 2294 engine model in my software.  It's now quite accurate in predicting flywheel power of various engine configurations, from mild to wild.

As a result, I've now been able to finally settle on the intake configuration I'll be designing for, years after I started this project!  Long has the problem of runner length been problematic for packaging on the Rocket III.  I think I've finally come up with a solution to the problem.

Since I'm not a math genius and not an engineer I am using the Chrysler Ram Induction model so the formula for length is this:

(y / 60) 360 = x 

z / x = t

t*1125 = d

d/2 = L

L / f = m

x = crank degrees per second

y = RPM for desired torque boost

z = 720 - cam duration

t = time between intake valve closing and opening at target RPM

d = distance traveled by wave during t

L = length of runner required because sound must travel up, then back down

f = number of times the sound wave will travel up and down the tube

m = the actual runner length to be used

Since I've not yet disclosed the cam size I'll be using, I will not provide the formula with all my variables plugged in. Suffice it to say that 20" long runners from the TB to atmosphere add a considerable amount of torque below peak without destroying top end. 

Here is the estimated plot of using the 4" velocity stacks in Yellow/Pink vs 20" runners in Green/Blue vs the 4" runners on the smaller intake cam. 

It provides not only a big boost in bottom end torque, the area between 6000 and 7000 sees a little bump in power, and peak is up by 8whp.  The 6000-7000 range is critical in this effort as it's the area the record will be set.