This technical tuning review details the internal engine modifications made. The motor was pulled, built
internally, and put back in to the car, for tuning. Much of the work here revolves around the Drag Cartel all-
motor camshafts (Stage 4).
What you see here is just a solid foundation, much work remains to be done with respect to the intake,
intake manifold, and throttle body set-up. To establish this foundation, the motor was built with readily
available off-the-shelf parts, without resorting to custom parts and machining. This will demonstrate what
gains can be achieved when changing from an internally stock motor to an internally built motor, without
changing the bolt-ons or the car.
Tuning Specifications:
- the same bolt-ons were installed on both the stock motor and the race motor
- the motor was carefully assembled to exact specifications
- the motor was broken in on the dyno, using Valvoline 10W40 oil and Lucas Heavy Duty Oil Stabilizer
- Autolite OEM equivalent spark plugs were used during motor break-in
- an oil change to Valvoline 5W30 oil was performed prior to tuning
- NGK BKR7EIX spark plugs were installed prior to tuning
- extensive low cam angle tuning resulted in 30 degrees all the way up to 5,850 rpm
- extensive high cam angle tuning resulted in 30 degrees from 5,850 rpm until redline
- in reviewing threads here about these cams, advancing more with shelf pistons was not recommended
- the ideal iVTEC cross-over for this motor was found to be at 5,850 rpm
- air fuel ratios from 12.5:1 up to 13.8:1 were tested and the ideal level was found to be 13.2 to 13.4:1
- ignition timing advance was found to be best around the 31-33 degrees mark
- all testing was done with 93 octane premium unleaded fuel
- engine temperature was maintained consistent at 177-183 degrees for all WOT pulls
- intake air temperature was maintained consistent at 98-105 degrees for all WOT pulls
Observations:
- even with these aggressive cams the engine idles very nicely, like stock
- it drives very smooth, at all partial throttle load points
- the Drag Cartel camshafts and SuperTech valves/springs set are not quiet, but they work very well together
- while not publicly advertised, all cam specs were provided
- the camshafts retail for $990
Chassis Dyno Used:
Brand - Dyno Dynamics
Model - 450
Type – magnetic eddy current retarder
Dyno Testing Results:
- 240 whp and 174 tq with Drag Cartel Stage 4 camshafts and higher compression pistons installed
- 199 whp and 156 tq with OEM K24A2 camshafts and OEM pistons installed
Dyno Charts:
See below.
1. with OEM camshafts and OEM pistons (10.5:1 cr) installed
2. with Drag Cartel camshafts and higher compression pistons installed
3. comparison of the two
Engine Specs:
- K24A2 short block
- OEM sleeves (87mm bore)
- 12.5:1 Wiseco pistons & rings
- Manley I-Beam rods
- ACL bearings (STD)
- K20A2 oil pump (& pan)
- K24a2 crankshaft
- Fluidamper K20 crankshaft pulley
- K24A2 head (unported)
- Drag Cartel camshafts (Stage 4 – all motor)
- OEM K20A2 camshaft gears
- SuperTech flat valves, dual valve springs, retainers, seats, cotters
- valve clearance set to 0.009 intake, 0.012 exhaust
- new OEM head gasket, valve seals, cam chain, upper cam chain guide
- ARP head bolts
- Hasport intake manifold adapter plate
- Hondata intake manifold heat shield gasket
Bolt-ons:
- Six Sigma Racing stainless headers
- KTeller stainless 3” exhaust with a Magnaflow resonator and muffler
- Euro Accord intake manifold
- Euro Accord 62mm throttle body
- short ram intake with a mesh high-flow filter
- Fuel system (Walbro in-tank pump, Precision 650cc injectors, GE fuel rail, Aeromotive fpr)
Vehicle:
1995 Honda Civic Si
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