Analysis Report for Street/Strip Engine with Desired HP Peak at 6000 RPM
Peak Tq =298. @ 4500 RPM .97 Ft Lbs per CuIn
Peak HP =279. @ 5500 RPM .91 HP per CuIn
Maximum Exhaust System Backpressure 'Exh Pres' is 1.1 PSI.
This is typical for a street/strip vehicle with a free flowing,
full exhaust system. To simulate open headers, select the
'Open Headers' from the Exh System Type combo box.
Maximum Intake Manifold Vacuum 'Int Vacuum' is 1.1 ''Hg.
This is somewhat high and is limiting air flow and HP.
Maximum Fuel Flow 'Fuel Flow' is 183 lbs/hr GAS.
This is equal to 31.3 gallons per hour of fuel flow.
For an injected engine with one injector per cylinder, you will require
at least 23 lbs/hr injectors.
Mechanical Efficiency 'Mech Eff' is 69 %
at the current Peak HP RPM of 5500 RPM.
This is Very low and represents a real power loss in this
engine's current operating range. This can be improved by paying
close attention to details in the Short Block Specs menu.
The Maximum Average Piston Speed 'Piston Spd' is 3000 ft/min
at the Performance Calculations Maximum RPM of 6000 RPM.
This is somewhat high (if you want to run this entire speed range),
requiring light, high strength reciprocating components.
A street/strip engine should limit Piston Spd to a range of 3000-4000
ft/min. However, even to run at 3000 ft/min or higher, you will need
'better than production', high quality reciprocating components
(connecting rods & bolts, pistons, etc.).
Maintaining low Piston Spd and Piston Gs are critical for 'keeping the
engine together'. OVER-REVVING PARTS BEYOND THEIR INTENDED LIMIT IS
UNSAFE FOR THE ENGINE, YOURSELF AND BYSTANDERS.
Maximum Contribution to VE During Overlap 'Overlap %VE' is 0 %.
This is Very low for street/strip engines which typically show
3-8%. Low Overlap %VE will limit Tq & HP and is most likely is caused
by high exhaust backpressure, high intake vacuum, exceptionally poor
intake and/or exhaust tuning or too little valve overlap.
It is normal for Overlap %VE to dip (even go negative) at some RPMS.
You will not be able to eliminate these dips and still maintain high
Overlap %VE at other RPMs. However, you may be able to move the dips
outside your desired RPM band.
The Intake Runner Velocity 'Int AvgVel' is 363 ft/sec
at your 'Desired HP Peak RPM' 6000 RPM.
This is somewhat high and indicates you will need a larger Intake
Runner Diameter or larger Intake Port Diameter for less
restriction and stronger intake tuning.
For these engine specs, an 'Int AvgVel' of about 260 should work well.
If the 'Int AvgVel' is approximately 30-80 Ft/Sec higher than this,
you will likely improve torque below this RPM, but lose some HP.
The Inertia tuning of this intake is tuned to 5222 RPM,
which is close to your 'Desired HP Peak RPM' of 6000 RPM.
Since this RPM is about where the HP peak should occur, peak HP
should be good. If you specify longer and/or smaller diameter intake
runners, you will likely gain Peak Torque and lose some Peak HP.
The Exhaust Runner Velocity 'Ex AvgVel' is 425 ft/sec
at your DESIRED HP PEAK RPM of 6000 RPM.
This is somewhat high and indicates you will need a larger Header
Primary Diameter for less restriction and stronger exhaust tuning.
Exhaust tuning is usually best with 300 ft/sec 'Ex AvgVel'.
The % Exhaust to Intake Flow Capacity 'Total Exh/Int %' is 67.9 %.
This is somewhat low, and indicates you could improve performance
by improving exhaust valve flow and exhaust cam profile. The most
common 'rule of thumb' is to design for around 75% EXH/INT flow
capability.
End of Analysis Report
