Je fais peut être du hors sujet (désolé Mirdwen), j'ai retrouvé où sur le net on parlait de la limitation du régime du moteur de la camaro.
C'est assez interessant.
Ca donne les limites des pièces du V8 et de la camaro quand on commence à faire des modifs lourdes dessus (bien sur, je n'ai rien vérifié et je prends l'info pour ce quelle est, juste une info, mais les gens autour de
Introduced in April 2009 as a '10 model, the fifth-gen Camaro is the newest entrant in the Big Three's renewed ponycar wars. Despite the car's late start, loyalists aren't taking a back seat to anyone; they've been beating on the cars, finding what goes wrong, and applying good old hot rodding engineuity to fixing the issues while giving the other guys a run for their money. Still, the new chassis remains a work in progress. Expect big improvements in the top driveline offerings for '12, but in the meantime, here's the scoop on the cars as they are now configured. Our consultants include hard-core Camaro specialists Lingenfelter Performance Engineering (LPE), Livernois Motorsports, IPS Motorsports, the School of Automotive Machinists (SAM), and other insiders. All quoted power levels except for the stock factory ratings are at the rear wheels. Remember, there is at least a 15 percent loss through the drivetrain with a manual trans, up to 20 percent with an automatic.
Engine
Fifth Gen Camaro Parts Failure Capital achievement: As of late 2010, Lingenfelter’s stout ’10 Camaro has run a best quart
6.2L (376CI) LS3 (Manual Trans)
The LS3 is factory rated at 426 hp and 420 lb-ft of torque for manual trans cars. Currently this is the preferred combo for serious performance upgrades, as it does not have variable camshaft timing (VCT) or active fuel management (AFM or cylinder deactivation).
Lifter pump-up (7,000-plus rpm): Replace with short-travel Comp Cams lifters, which require either adjustable rockers or carefully selected pushrod lengths.
Timing chain tensioner fails (550 hp): Install a Comp or JP Performance billet timing set.
Oiling needs help (road-racing or stroker engines): LS engine oil pumps bypass too much oil, plus poor oil drain-back and foaming is a serious problem over 6,500 rpm. Go to a modified aftermarket oiling system and pan. For road racing, consider an ARE dry-sump.
Fifth Gen Camaro Parts Failure Can’t spin this one: Don’t expect the stock balancer to last at high rpm or with big strok
Rods break (600 hp): Stock powdered-metal rods may break at the beam. Use forged rods.
Head gasket problems (600 hp): Upgrade to aftermarket MLS gaskets and ARP fasteners.
Pistons fail (600-625 hp, detonation and/or excessive boost): Replace the stock hypereutectics with forged pistons.
Crank good to go (900-plus horsepower): LPE turbo engines make more than 900 hp on stock nodular iron cranks.
Exhaust valves (over 10 psi boost): At this point, LPE swaps the stock LS3 exhaust valves with more durable Inconel or sodium-filled ones.
Fuel system upgrade (various): Install larger injectors at 450 to 475 hp. For over 6 psi boost or 500 hp, use a voltage booster. Upgrade the stock pulse-width-modulated nonreturn fuel pump at 575 to 620 hp. Livernois and LPE have dual-pump systems adequate through 750 to 800 hp. Beyond that use dual or triple high-capacity pumps and a return-style fuel system.
Fifth Gen Camaro Parts Failure Lost its bearings: Pushrod deflection from big cams and increased spring pressures causes
6.2L (376 CI) L99 (Auto Trans)
The 400hp/410-lb-ft L99 is used in V8 Camaros with an automatic. With both VCT and AFM, it's harder to modify in stock form. Short-block problems are similar to the LS3.
AFM problems (450 hp, 0.500-inch-lift cams, or high rpm): Half the lifters and their corresponding cam lobes are unique. Comp and LPE offer AFM-style cams, but they're limited to 0.500-lift because the special lifters don't work with a reduced base circle. If you raise the rev limiter beyond the L99's 6,200-rpm limit and then run up against it, Jannetty Racing says the AFM lifters will fail. Best option: Reprogram the ECU to delete AFM, then install a conventional cam and lifters.
VCT phaser woes: Valve-to-piston contact can occur with bigger cams from too much advance. Comp Cams has a phaser limit kit that allows aggressive cam profiles with up to 220 degrees duration at 0.050. Above this, either: increase intake centerline 2 degrees for every 4-degree duration increase, change pistons, or delete VCT; the latter requires installing a LS3 front cover and a conventional timing set.
Valve float: L99s don't have the LS3's hollow-stem intake valves. When switching to high-lift cams, LPE recommends installing lighter LS3 intake valves.
Transmission
Fifth Gen Camaro Parts Failure Break-fast: The mainshaft on about 10 percent of TR-6060-equipped Camaros produced within
6L80 Six-Speed Automatic
This new-gen GM trans is so sophisticated that it has a separate computer (TCM or transmission control module). Incorrect TCM tuning causes more problems than hard-parts failures.
TCM calibration: Reprogramming is required when changing engine rpm range, shift points, or rearend gear ratio. A significant power change increases engine acceleration rate, which changes the amount of trans slip; both impact when the shift needs to occur compared with when the TCM calculates it should occur. HPTuners has reprogramming software.
TAPshift lag: When enabled, on-demand manual gear changes are made via steering wheel paddles. TAPshift permits holding a specific gear around a road course without fear that the trans might upshift or downshift during a turn and destabilize the car. It also works well for a burnout, but input lag creates straight-line acceleration issues; for drag racing, reprogram to upshift automatically at a desired shift rpm.
Torque management damage: Disabling torque management completely can cause failures. LPE says, "With a clutch-to-clutch trans like the 6L80, some torque management is needed to reduce the torque momentarily and allow time for the clutch for the desired gear to engage."
Torque converter (500-plus horsepower): LPE reports zero failures, IPS is confident through 500 hp, and Livernois says it has "a stock converter in a '10 Camaro that makes over 750 hp with close to 100 quarter-mile runs along with street driving." Precision Industries, TCI, Yank, and others sell high-stall converters. A triple-disc converter and custom trans tuning will ensure the converter stays locked up in Overdrive even on high-power mills.
Fifth Gen Camaro Parts Failure Tooth decay: Missed shifts can damage synchro blocker rings and the main-gear clutch-engag
Hard-parts failures (over 575 hp): With correct programming, Livernois and others report minimal internal hard-parts failures through 575 to 600 hp. Rossler builds beefed 6L80s. It says the 3-5 reverse clutch usually fails first, followed by the 4-5-6 clutch: "We add more clutches, machine special steels, and use better materials." Fully built Rossler 6L80s have withstood 1,000 hp on a chassis dyno; 750 hp is more realistic for long-term street durability.
TTC TR-6060 Six-Speed Manual
Like stick-shift Dodges and Shelby Mustangs, V8 Camaros use TTC TR-6060 six-speeds. Enabling GM's launch control feature can minimize the chances of trans or rearend failure. RPM Transmissions' fully blueprinted Level 6 TR-6060 can handle more than 1,000 hp.
Mainshaft breaks (random): On some early production '10 Camaros, the mainshaft can fail ahead of the output splines due to an overly large machining radius. Although 475 hp is probably the critical risk point, RPM says it can sometimes "fail bone stock, even with factory-original tires." GM's fix is a redesigned chamfer, improved metallurgy, and a different heat treat. The new 'shaft can be retrofitted, but that requires a complete teardown. Reference GM service bulletin PIP4666.
Rear support bearing upgrade (650-680 hp): Unlike some other TR-6060s, the Camaro version lacks a rear support bearing. The Camaro extension housing is machined for the bearing, but it is not factory installed. Livernois advises adding the bearing over 650 hp. The bearing, plus an improved 9310-steel mainshaft machined for it, is sold as a kit from RPM Transmissions and The Driveshaft Shop.
Synchro blocker ring (525 to 625 hp and/or abuse): Early production has brass rings, while later has carbonized rings. Carbon is more forgiving, but brass rings are stronger if you're a hot shoe.
Clutch problems (600 hp): Although SAM maintains that "bone-stock power will take the clutch out running on sticky tires—even a drag radial," most other sources say serious clutch problems start around the 600hp to 650hp level. Upgrade as appropriate to aftermarket clutches. LPE runs a triple-disc RPS carbon clutch in its 1,240hp drag car.
Hydraulic clutch actuation issues: IPS has seen soft clutch engagement and difficulty getting the car in gear after multiple dragstrip passes. Apparently heat buildup causes a clutch fluid viscosity breakdown. Bleed the system often and use a higher-quality clutch fluid.
IRS and Driveshaft
Fifth Gen Camaro Parts Failure Kicked in the ass: On its third dragstrip launch running Hoosier slicks, this aftermarket
The V8 Camaro's IRS (independent rear suspension) has 218mm (8.58-inch) rear gears and a clutch-type limited-slip diff. The gears are unique. Stock ratios are 3.27 or 3.45:1; Richmond has 3.70 and 4.10:1 ratios. The current stock rear is marginal for serious high-perf use.
Rear suspension flex (450 hp): IPS reports toe-arm failures as low as 25 to 50 hp over stock. Pfadt has stiffeners; BMR offers adjustable units. Excessive wheelhop can damage the rear trailing arms, contributing to differential problems (Pfadt and LPE have upgrades). Hotchkis sells a Chassis Max Brace to control unwanted suspension movement.
Rear subframe flex (475 hp): The stock subframe bushings allow excess cradle movement, causing lost power and bad traction. Replace with solid or polyurethane bushings for better rear-cradle durability and improved handling. Pfadt is one source.
Gears fail (500-plus horsepower): Only a three-series Posi carrier is available, so the pinion gets really small as gear ratio increases. Tire type and driving style influence longevity big time.
Halfshafts break (wheelhop, 500 to 600 hp): The more severe the wheelhop, the sooner the drive axles break. The stock computer calibration limits axlehop, but that also limits performance. Knowing when to back off the throttle is the cheap fix, followed by lighter-weight wheels and tires (because they have less inertia), and ultimately stouter aftermarket axles.
Posi problems (various): Jannetty says the stock Posi is weak: "It's prone to one-legger burnouts; the breakaway torque is way too low." Its Posi mods include upgraded clutch packs and a different preload spring. With a tuned Posi and revised internal gear preload, clearances, and patterns, the stock rear can take up to 750 hp, but 650 hp is more realistic for daily driving.
Driveshaft issues (over 5,000 rpm): Most report that the stock two-piece driveshaft is surprisingly robust. LPE's 9-second Camaro uses a shortened, stock, two-piece 'shaft, but with an improved center support to prevent the middle slider from twisting and binding. However, The Driveshaft Shop maintains that "anything with a slider is unstable over 5,000-rpm driveshaft speed." Its solutions range from a stouter two-piece unit with a CV joint or a one-piece aluminum or carbon-fiber 'shaft.
