T: Can the batteries be charged from the alternator?
TK: Yes*, but see additional notes:
If the alternator is stock, we suggest four or more standard batteries or Optima batteries, which will provide longer running times. These will be heavy, so you can eventually replace the alternator with a 200-plus-amp unit and switch to the smaller and lighter Odyssey batteries.
If the alternator is upgraded, battery technology has come so far that a standard car battery can now be replaced with a 13-pound 3x6-inch battery that has more cranking amps than a big conventional battery. Hawker-ODYSSEY has the best units, in our opinion. The additional batteries and the ESC-400 weigh less than the typical complete turbo kit.
T: How long does recharging take?
TK: You can recharge the batteries in a few minutes of steady-state driving with a high-output alternator.
T: How hot does the ESC get?
TK: The delta rise at 5 psi is only 40 to 50 degrees, which is very efficient. If the Eaton isn't ported, those numbers are a lot higher.
T: What do you see for the future with electric superchargers?
TK: Electric supercharger designs will be even better when automotive electrical systems go to 42 volts. The current draw at 42 volts is 350 percent less than at 12 volts, so the discharge/recharge rate will become even closer to 1:1.
T: What size engine will this work on?
TK: Testing has shown the smaller the engine, the higher the sustainable boost. If a 3.5-liter engine is running 24v, boost will peak at 10 psi at 2000 rpm and then drop off to 3 psi at 6500 rpm. A 1750cc engine would make 10 psi at 4000 rpm while dropping off to 3 psi at 13,000 rpm. The boost drop is linear, so that 1750cc engine would make 7-8 psi at redline, and launch at 15 psi using 24 volts. If a blow-off valve is used to bleed off excess pressure, a steady sustainable boost is possible until the capacity of the supercharger is reached. This means that a prepared 1.6-liter four-cylinder can run a sustained 15 psi at 36 volts to 6000 rpm.
Nissan Altima ESC Development Chronology12-11-03
Our completely stock Nissan Altima four-cylinder outfitted with an automatic transmission jumped from 105 whp to 184 whp with the ESC-400 at only 5 psi boost.
12-20-03
Moroso Motorsport Park was home this weekend to the Sport Compact Winter Challenge, and we took the Altima to MMP to test the ESC down the quarter mile. The weight of the car with speaker box, molded body kit, ESC-400 and batteries, etc was 3,780 pounds. The stock KADE 2.4-liter four-cylinder automatic ran low 18s at 78 mph with the ESC off, and ran a best 15.583 at 89 mph at only 5 psi boost. Traction with the ESC was a real problem, with 2.45 60-foot times on four attempts. This is faster than a 5.0 Mustang convertible.
1-6-04
Installed the ESC-400DR-550 (drag racing version) in the Altima, prepping it for Moroso on February 8. This unit is capable of 20-plus psi, so we had to set the pressure to 10 psi with the BOV. At 10 psi, it feels like a high 13-second car, and we'll add some parts to support the 10 psi. We're installing headers, an exhaust system and larger injectors. A dyno run is set for next Wednesday at South Florida Performance. We should see well over 200 whp on this stock long-block auto trans Altima.
1-8-04
Oops! Too much boost. Blew something on the Altima. We took some visitors for test rides and some burnout photos, and after more than 30 runs at 10 psi, the engine let go. The fuel cut leaned out the mixture too much. Time to pull the head.
1-10-04
We need pistons. Three pistons were damaged during the last run, and we're swapping another stock engine in the car. The ECU uses a fuel cut-off as a rev limiter, and that caused the engine to run too lean and burn the pistons. Ten psi seems just too high for a stock Altima engine.
1-14-04
Replaced engine with a low-mileage stock engine, added OBX headers, and an extra 550cc injector. The dyno run at a safer 8 psi gave us more than 208 wheel hp at South Florida Performance today! We won't ever run lean again with that 550cc additional injector. Next stop-Moroso February 8. We should run high 13s or low 14s.