| Tenacious B: Part 2 (cont.) After some initial engine pulls, a few issues came up that needed dealing with up front. Foremost among them was timing, which the guys deliberately left un-tuned to illustrate what a huge difference it makes. After degreeing the cams and adjusting the gears, though, advancing the exhaust six degrees and retarding the intake eight, the team was rewarded with an almost instant 60 horses.
Problems arose with fuel tuning as well, apparently caused by the staged injection. The way it was set up, the primary injectors would solely juice the motor until it reached about seven psi of boost, roughly 300 hp, and then the secondary injectors would come online to augment. Unfortunately, the transition was not a particularly smooth one, the larger secondary injectors essentially flooding the engine, so the guys ended up tossing the four 550cc primary and four 800cc secondary injectors and going with a single set of primary 1200cc injectors.
Finally, the engine was only receiving about 18 psi of boost from the turbo at 7800 rpm, a blower that by all indications does not become efficient until it reaches 25 to 30 psi (just to put things in perspective, a car on the street with a turbo runs around 20 psi of boost). This was attributed to the low-octane fuel the crew was utilizing, just a little better than pump gas at 105 octane. Regrettably time ran out so no further pulls were done with hotter-running gas, but for any future tests the guys will be using 116 octane that should result in at least 30 psi of boost.
So, after 65 pulls, or roughly two race seasons' worth of drag racing runs, our much-ballyhooed power plant achieved 536 hp and 361 lb-ft of torque at 7800 rpm receiving only 18 psi of boost. But trust us, there's much more to come.
Channel Group: Torque and Power Page 1 of 1
Printed on Jan 9, 2003 at 11:59:35
Test Discription: Accel. Test - 300 rpm/second
RPMEngTrq
lb-ftEngPwr
HpFuelA
lb/hrFuel B
lb/hrA/F
Ratio 5100179.7174.50.00.00.0 5200190.7188.80.00.00.0 5300203.9205.80.00.00.0 5400212.9218.90.00.00.0 5500252.3264.20.00.00.0 5600256.2273.20.00.00.0 5700277.2300.80.00.00.0 5800313.3346.00.00.00.0 5900318.9358.20.00.00.0 {{{6000}}}322.1368.00.00.00.0 6100336.8391.20.00.00.0 6200339.4400.70.00.00.0 6300336.3403.40.00.00.0 6400342.6417.50.00.00.0 6500337.2417.30.00.00.0 6600344.3432.70.00.00.0 6700335.8428.40.00.00.0 6800329.4426.50.00.00.0 6900329.2432.50.00.00.0 7000340.9460.80.00.00.0 7100340.9460.80.00.00.0 7200344.3472.00.00.00.0 7300354.1492.20.00.00.0 7400347.3489.30.00.00.0 7500344.8492.40.00.00.0 7600342.9496.20.00.00.0 7700354.0519.00.00.00.0 7800361.1536.20.00.00.0 SuperFlow WinDyn Software
connect
Automotive Racing Products: 805/339-2200
Dart: www.dartheads.com
Electromotive: 703/331-0100
Ferrea: 954/733-2505
Holley: 270/782-2900
JG Edelbrock: 310/781-2222
Moroso: 203/453-6571
Payn Technologies: 248/362-0283
Race Engineering: 561/533-5500
Snap-on: www.snapon.com
Tial: www.tialsport.com
Turbonetics: 805/581-0333
VT Competition Engine Development: 517/272-7728
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