Pretty good numbers on an FM2/MS
03-05-2015, 11:51 AM
#32
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Bottom end got ventilated, but not how you think.
The owner of the car let someone drive that was unfamiliar with anti-lag and no-lift shift. And turbos. And mechanical empathy. And common sense. Said nameless individual drove the car a few laps around Roebling riding the clutch quite badly, engaging the anti-lag rev limit. Their decided course of action was to, well, ignore the pits, keep driving around the track with his foot flat in the throttle, cannons going off underneath the car, at a 3500 RPM rev-limit.
The #4 con rod decided it needed to escape its prison and travel the world. The piston was cracked, I'm guessing from multiple flame-front detonation from the insane temperatures that must have developed. The flywheel and pressure plate were also glazed.
I'm kinda butthurt about it, but the car has a new bottom end now. The head got lightly kissed, but not enough to replace any valves. Probably.
The owner of the car let someone drive that was unfamiliar with anti-lag and no-lift shift. And turbos. And mechanical empathy. And common sense. Said nameless individual drove the car a few laps around Roebling riding the clutch quite badly, engaging the anti-lag rev limit. Their decided course of action was to, well, ignore the pits, keep driving around the track with his foot flat in the throttle, cannons going off underneath the car, at a 3500 RPM rev-limit.
The #4 con rod decided it needed to escape its prison and travel the world. The piston was cracked, I'm guessing from multiple flame-front detonation from the insane temperatures that must have developed. The flywheel and pressure plate were also glazed.
I'm kinda butthurt about it, but the car has a new bottom end now. The head got lightly kissed, but not enough to replace any valves. Probably.
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03-05-2015, 01:30 PM
#33
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I've gotten two PMs asking about anti-lag blowing up their turbo cars, so I'll post my response here so the community can weigh in or correct me:
Your FM2 car is fine. Anti-lag is something you won't see on 99% of aftermarket turbo installs. They're usually not enabled on the tune or ECU, and for many management systems, it's a specific upgrade that you have to buy a code for.
Anti-lag can be used in three common instances. Launch control (pretty rare), upshift (very rare), off-throttle (during a rally stage only). It's really, really rough on cars, and it's only used when you consider your powertrain to be a consumable part.
Launch control functionality (in the scope of these aftermarket ECUs) is pretty much limited to keeping the engine revving at a consistent RPM so you can let out the clutch in a more repeatable manner. This is normally accomplished by cutting fuel and spark in the same manner as the redline rev limit. For turbo cars, it would be beneficial to launch with the turbo spooled up, which is where anti-lag comes into play.
Anti-lag is something you should research and understand before enabling on your car. Most implementations retard the spark so the combustion event continues into the exhaust stroke, which creates a ton of exhaust gas without making much power. This is useful to spool turbos while keeping at a pre-determined RPM. The downside is that it is very rough on engines, exhaust valves, turbos, manifolds, and exhaust systems. As such, it is used sparingly on racecars, and really has no purpose on street cars other than to be really obnoxious (which is fun sometimes).
No-lift antilag comes into play on upshifts. You clutch in, leave the throttle pinned, the engine drops to a pre-determined RPM, you shift into a higher gear, then let out the clutch. As the engine drops to that pre-determined RPM, it does the whole delayed-ignition thing, which spools up the turbo so you have as much boost as possible in the beginning of the next gear. This is what happened to XP-4, as the clutch was pushed in (switch engaged) and the driver didn't realize he was slipping the clutch in fifth gear. For multiple laps.
An anti-lag event is very violent and sounds like a gunshot. Here are a few examples in video form:
When you hear a gunshot between shifts (Renault at 1:11 is a good example), that's the no-lift upshift anti-lag.
Your FM2 car is fine. Anti-lag is something you won't see on 99% of aftermarket turbo installs. They're usually not enabled on the tune or ECU, and for many management systems, it's a specific upgrade that you have to buy a code for.
Anti-lag can be used in three common instances. Launch control (pretty rare), upshift (very rare), off-throttle (during a rally stage only). It's really, really rough on cars, and it's only used when you consider your powertrain to be a consumable part.
Launch control functionality (in the scope of these aftermarket ECUs) is pretty much limited to keeping the engine revving at a consistent RPM so you can let out the clutch in a more repeatable manner. This is normally accomplished by cutting fuel and spark in the same manner as the redline rev limit. For turbo cars, it would be beneficial to launch with the turbo spooled up, which is where anti-lag comes into play.
Anti-lag is something you should research and understand before enabling on your car. Most implementations retard the spark so the combustion event continues into the exhaust stroke, which creates a ton of exhaust gas without making much power. This is useful to spool turbos while keeping at a pre-determined RPM. The downside is that it is very rough on engines, exhaust valves, turbos, manifolds, and exhaust systems. As such, it is used sparingly on racecars, and really has no purpose on street cars other than to be really obnoxious (which is fun sometimes).
No-lift antilag comes into play on upshifts. You clutch in, leave the throttle pinned, the engine drops to a pre-determined RPM, you shift into a higher gear, then let out the clutch. As the engine drops to that pre-determined RPM, it does the whole delayed-ignition thing, which spools up the turbo so you have as much boost as possible in the beginning of the next gear. This is what happened to XP-4, as the clutch was pushed in (switch engaged) and the driver didn't realize he was slipping the clutch in fifth gear. For multiple laps.
An anti-lag event is very violent and sounds like a gunshot. Here are a few examples in video form:
When you hear a gunshot between shifts (Renault at 1:11 is a good example), that's the no-lift upshift anti-lag.
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03-05-2015, 01:43 PM
#34
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I have spark cut launch control turned on and I have no clue how you wouldn't notice it, especially in an excocet, it sounds like you filled your exhaust with firecrackers.
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