GTM Performance Engineering: VQ37VHR Engine Build 700HP Power Package

gbrettin · 06-05-2012, 12:42 PM

I wonder if they will let those LTH go?

theDreamer · 06-05-2012, 02:19 PM

Quote:

Originally Posted by gbrettin

I wonder if they will let those LTH go?

Well with the TT kit they don't need them, so up to the owner if he wants to sell them.

gbrettin · 06-05-2012, 04:13 PM

Quote:

Originally Posted by theDreamer

Well with the TT kit they don't need them, so up to the owner if he wants to sell them.

Exactly my thoughts.

---

Meh, better not even think about those LTH. I have bigger and better things in the plans for next year.

erkthejerk73 · 06-05-2012, 12:55 PM

street racing and a miss shift i assume, red line 4th shift to 5th and go into 3rd...

Cmike2780 · 06-05-2012, 03:14 PM

I think everyone here were just curious as to what exactly happened, considering there are quite a few people on here with roughly the same mods. Knowing you guys at GTM are pro's at this, we just thought you would know more about the circumstance leading to the engine grenading.

valpozguy · 06-05-2012, 03:15 PM

Quote:

Originally Posted by Cmike2780

I think everyone here were just curious as to what exactly happened, considering there are quite a few people on here with roughly the same mods. Knowing you guys at GTM are pro's at this, we just thought you would know more about the circumstance leading to the engine grenading.

Agreed

sent from my SAMSUNG SINGLE TURBO SGH1717

theDreamer · 06-05-2012, 03:17 PM

I think there are to many variables to know exactly what happened, and I can easily see GTM not wanting or needing to know what the owner was doing when it happened or if the owner even knew. Guy could have been at the track two days before and when driving to work it blew.
Could have been all the bolt ons, driving it hard and the tune was just bad.

Mike@GTM · 06-05-2012, 03:28 PM

Quote:

Originally Posted by theDreamer

I think there are to many variables to know exactly what happened...

For the most part, this is true. Sometimes, one thing by itself may not cause a major issue, but when you start throwing other things into the mix, the combination can result in a serious problem.

Jordo! · 06-05-2012, 06:04 PM

I'm guessing oil pump failure... gee, wonder what caused that...

Flyboy · 06-06-2012, 04:00 PM

Quote:

Originally Posted by Jordo!

I'm guessing oil pump failure... gee, wonder what caused that...

I agree with that. Probably oil pump, or excess water in the Gas.

Either way, I wouldn't use any of the old parts and put new gas in the car.

conmam · 09-06-2012, 02:23 AM

Quote:

Originally Posted by Flyboy

I agree with that. Probably oil pump, or excess water in the Gas.

Either way, I wouldn't use any of the old parts and put new gas in the car.

No way oil pump failure could have crushed the starter and shear the flywheel bolts. Oil pump failure seizes and cause damage to the bottom end mostly. Over revving again, in no way can crush the starter and shear the flywheel bolts either.

Jordo! · 06-06-2012, 06:01 PM

Quote:

Originally Posted by Jordo!

I'm guessing oil pump failure... gee, wonder what caused that...

Hmm.

conmam · 09-06-2012, 02:19 AM

Quote:

Originally Posted by Jordo!

Hmm.

I I have to agree that replacing the factory harmonic balancer with an aftermarket lighter pulley will pose an incredible risk of killing your engine.

We are talking about a total engine eradication just like what you saw on the photos that Sam posted. This looks so much like what happened to my friend 9 years ago on his BMW 328 with the E36 motor series ( Inline 6 in this case ).

As we all know, the popular method for making power pulleys on E36 engines is by removing the harmonic damper and replacing it with an underdrive lightweight alloy assembly. This is a VERY dangerous product because this stock damper is essential to the longevity of an engine. The substitution of this part often results in severe engine damage.
It is also important to understand that while the engine in a BMW is designed by a team of qualified engineers who understood the engine characteristics inside and out, these aftermarket power pulleys are created by the people who do not understand many of the very important principles of physics.

To put things simple, it is not the underdrive feature that kills the engine, but rather the lack of dampening the harmonic vibration that the crankshaft generates every time after each cylinder firing sequence. When this sinusoidal harmonic vibration coincide with the phase vector of the engine RPM, resonance frequency will occur. When this occurs, it must be counterbalance immediately and that is the exact job of the harmonic balancer pulley. If not, the power under the sine curve will keep on increasing or accumulate exponentially and that will guarantee to destroy the entire engine and the possible surroundings, such as the starter in this case of this VQ37VHR engine.......

Think 5 times BEFORE you put in an underdrive aftermarket pulley. The risk is 1000 times the reward.... Not worth it at all......

conmam · 09-06-2012, 02:45 AM

Detail of engine complication and destruction without a properly designed and installed harmonic balancer:

1) Elastic Deformation
Though it is common belief that large steel parts such as crankshafts are rigid and inflexible, this is not true. When a force acts on a crank it bends, flexes and twists just as a rubber band would. While this movement is often very small, it can have a significant impact on how an engine functions.

2) Natural Frequency ( Resonance frequency )
All objects have a natural frequency that they resonate (vibrate) at when struck with a hammer. An everyday example of this is a tuning fork. The sound that a particular fork makes is directly related to the frequency that it is vibrating at. This is its "natural frequency," that is dictated by the size, shape and material of the instrument. Just like a tuning fork, a crankshaft has a natural frequency that it vibrates at when struck. An important aspect of this principle is that when an object is exposed to a heavily amplified order of its own natural frequency, it will begin to resonate with increasing vigor until it vibrates itself to pieces (fatigue failure).

3) Fatigue Failure
Fatigue failure is when a material, metal in this case, breaks from repeated twisting or bending. A paper clip makes a great example. Take a paper clip and flex it back and forth 90° or so. After about 10 oscillations the paper clip will break of fatigue failure.
The explanation of the destructive nature of power pulleys begins with the two basic balance and vibration modes in an internal combustion engine. It is of great importance that these modes are understood as being separate and distinct.
1) The vibration of the engine and its rigid components caused by the imbalance of the rotating and reciprocating parts. This is why we have counterweights on the crankshaft to offset the mass of the piston and rod as well as the reason for balancing the components in the engine.
2) The vibration of the engine components due to their individual elastic deformations. These deformations are a result of the periodic combustion impulses that create torsional forces on the crankshaft and camshaft. These torques excite the shafts into sequential orders of vibration, and lateral oscillation. Engine vibration of this sort is counteracted by the harmonic damper and is the primary subject of this paper.

Torsional Vibration (Natural Frequency)
Every time a cylinder fires, the force twists the crankshaft. When the cylinder stops firing the force ceases to act and the crankshaft starts to return to the untwisted position. However, the crankshaft will overshoot and begin to twist in the opposite direction, and then back again. Though this back-and-forth twisting motion decays over a number of repetitions due to internal friction, the frequency of vibration remains unique to the particular crankshaft.

This motion is complicated in the case of a crankshaft because the amplitude of the vibration varies along the shaft. The crankshaft will experience torsional vibrations of the greatest amplitude at the point furthest from the flywheel or load.

Harmonic (sine wave) Torque Curves
Each time a cylinder fires, force is translated through the piston and the connecting rod to the crankshaft pin. This force is then applied tangentially to, and causes the rotation of the crankshaft.
The sequence of forces that the crankshaft is subjected to is commonly organized into variable tangential torque curves that in turn can be resolved into either a constant mean torque curve or an infinite number of sine wave torque curves. These curves, known as harmonics, follow orders that depend on the number of complete vibrations (cylinder pulses) per revolution. Accordingly, the tangential crankshaft torque is comprised of many harmonics of varying amplitudes and frequencies. This is where the name "harmonic damper" originates.

Critical RPM's
When the crankshaft is revolving at an RPM such that the torque frequency, or one of the harmonic sine wave frequencies coincides with the natural frequency of the shaft, resonance occurs. Thus, the crankshaft RPM at which this resonance occurs is known a critical speed. A modern automobile engine will commonly pass through multiple critical speeds over the range of its possible RPM's. These speeds are categorized into either major or minor critical RPM's

.
Major and Minor Critical RPM’s

Major and minor critical RPM's are different due to the fact that some harmonics assist one another in producing large vibrations, whereas other harmonics cancel each other out. Hence, the important critical RPM’s have harmonics that build on one another to amplify the torsional motion of the crankshaft. These critical RPM’s are know as the "major criticals". Conversely, the "minor criticals" exist at RPM's that tend to cancel and damp the oscillations of the crankshaft.
If the RPM remains at or near one of the major criticals for any length of time, fatigue failure of the crankshaft is probable. Major critical RPM’s are dangerous, and either must be avoided or properly damped. Additionally, smaller but still serious problems can result from an undamped crankshaft. The oscillation of the crankshaft at a major critical speed will commonly sheer the front crank pulley and the flywheel from the crankshaft. I have witnessed front pulley hub keys being sheered, flywheels coming loose, and clutch covers coming apart. These failures have often required crankshaft and/or gearbox replacement.

Harmonic Dampers
Crankshaft failure can be prevented by mounting some form of vibration damper at the front end of the crankshaft that is capable of absorbing and dissipating the majority of the vibratory energy. Once absorbed by the damper the energy is released in the form of heat, making adequate cooling a necessity. This heat

should be dissipated in order to keep the damper at optimal operating temperatures. While there are various types of torsional vibration dampers, most Japanese and BMW engines are primarily designed with "tuned rubber" dampers.

It is also important to note that while the large springs of a dual mass flywheel absorb some of the torsional impulses conveyed to the crankshaft, they are not harmonic dampers, and are only responsible for a very small reduction in vibration. That's why there is zero problem when you replace the 370Z dual mass flywheel with a lighter quality flywheel, such as Jim Wolf Technology one.

In addition to the crankshaft issue, underdrive pulley size can cause slowing down the accessories below their designed speeds, particularly at idle. Slowing the alternator down can result in reduced charging of the battery, dimming of the lights, and computer malfunctions. Slowing of the water pump and fan can result in warm running, while slowing of the power steering can cause stiff steering at idle and groaning noises. This is NOT acceptable from a reliability standpoint. It is possible to implement design corrections and avoid these scenarios, but this would require additional components and/or software.

blackonorange · 06-05-2012, 06:59 PM

Scary stuff in here

06-05-2012, 03:14 PM	#5 (permalink)
Cmike2780 A True Z Fanatic Join Date: Jun 2010 Location: Long Island Posts: 5,059 Drives: slowwww Rep Power: 30	I think everyone here were just curious as to what exactly happened, considering there are quite a few people on here with roughly the same mods. Knowing you guys at GTM are pro's at this, we just thought you would know more about the circumstance leading to the engine grenading. __________________ [09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R] [ArchitTEK Photography]

06-05-2012, 03:17 PM	#7 (permalink)
theDreamer A True Z Fanatic Join Date: Feb 2009 Location: Texas Posts: 30,879 Drives: 370z Rep Power: 4211	I think there are to many variables to know exactly what happened, and I can easily see GTM not wanting or needing to know what the owner was doing when it happened or if the owner even knew. Guy could have been at the track two days before and when driving to work it blew. Could have been all the bolt ons, driving it hard and the tune was just bad. __________________ theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN theDreamer's Silvia // URAS // GREDDY Houston Zs // Facebook // Twitter // Instagram

06-05-2012, 06:04 PM	#9 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 419	I'm guessing oil pump failure... gee, wonder what caused that... __________________ Enjoy it. Destroy it.

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06-05-2012, 12:42 PM	#1 (permalink)
gbrettin A True Z Fanatic Join Date: Oct 2010 Location: Portage, MI Posts: 2,301 Drives: Tricycle Rep Power: 589151	I wonder if they will let those LTH go?

06-05-2012, 12:55 PM	#4 (permalink)
erkthejerk73 Track Member Join Date: Mar 2011 Location: cincinnati Posts: 927 Drives: 13 F150 FX4 eb Rep Power: 16	street racing and a miss shift i assume, red line 4th shift to 5th and go into 3rd...

09-06-2012, 02:45 AM	#14 (permalink)
conmam Base Member Join Date: Oct 2010 Location: Billings, Montana Posts: 164 Drives: 370Z Touring 6MT Rep Power: 15	Detail of engine complication and destruction without a properly designed and installed harmonic balancer: 1) Elastic Deformation Though it is common belief that large steel parts such as crankshafts are rigid and inflexible, this is not true. When a force acts on a crank it bends, flexes and twists just as a rubber band would. While this movement is often very small, it can have a significant impact on how an engine functions. 2) Natural Frequency ( Resonance frequency ) All objects have a natural frequency that they resonate (vibrate) at when struck with a hammer. An everyday example of this is a tuning fork. The sound that a particular fork makes is directly related to the frequency that it is vibrating at. This is its "natural frequency," that is dictated by the size, shape and material of the instrument. Just like a tuning fork, a crankshaft has a natural frequency that it vibrates at when struck. An important aspect of this principle is that when an object is exposed to a heavily amplified order of its own natural frequency, it will begin to resonate with increasing vigor until it vibrates itself to pieces (fatigue failure). 3) Fatigue Failure Fatigue failure is when a material, metal in this case, breaks from repeated twisting or bending. A paper clip makes a great example. Take a paper clip and flex it back and forth 90° or so. After about 10 oscillations the paper clip will break of fatigue failure. The explanation of the destructive nature of power pulleys begins with the two basic balance and vibration modes in an internal combustion engine. It is of great importance that these modes are understood as being separate and distinct. 1) The vibration of the engine and its rigid components caused by the imbalance of the rotating and reciprocating parts. This is why we have counterweights on the crankshaft to offset the mass of the piston and rod as well as the reason for balancing the components in the engine. 2) The vibration of the engine components due to their individual elastic deformations. These deformations are a result of the periodic combustion impulses that create torsional forces on the crankshaft and camshaft. These torques excite the shafts into sequential orders of vibration, and lateral oscillation. Engine vibration of this sort is counteracted by the harmonic damper and is the primary subject of this paper. Torsional Vibration (Natural Frequency) Every time a cylinder fires, the force twists the crankshaft. When the cylinder stops firing the force ceases to act and the crankshaft starts to return to the untwisted position. However, the crankshaft will overshoot and begin to twist in the opposite direction, and then back again. Though this back-and-forth twisting motion decays over a number of repetitions due to internal friction, the frequency of vibration remains unique to the particular crankshaft. This motion is complicated in the case of a crankshaft because the amplitude of the vibration varies along the shaft. The crankshaft will experience torsional vibrations of the greatest amplitude at the point furthest from the flywheel or load. Harmonic (sine wave) Torque Curves Each time a cylinder fires, force is translated through the piston and the connecting rod to the crankshaft pin. This force is then applied tangentially to, and causes the rotation of the crankshaft. The sequence of forces that the crankshaft is subjected to is commonly organized into variable tangential torque curves that in turn can be resolved into either a constant mean torque curve or an infinite number of sine wave torque curves. These curves, known as harmonics, follow orders that depend on the number of complete vibrations (cylinder pulses) per revolution. Accordingly, the tangential crankshaft torque is comprised of many harmonics of varying amplitudes and frequencies. This is where the name "harmonic damper" originates. Critical RPM's When the crankshaft is revolving at an RPM such that the torque frequency, or one of the harmonic sine wave frequencies coincides with the natural frequency of the shaft, resonance occurs. Thus, the crankshaft RPM at which this resonance occurs is known a critical speed. A modern automobile engine will commonly pass through multiple critical speeds over the range of its possible RPM's. These speeds are categorized into either major or minor critical RPM's . Major and Minor Critical RPM’s Major and minor critical RPM's are different due to the fact that some harmonics assist one another in producing large vibrations, whereas other harmonics cancel each other out. Hence, the important critical RPM’s have harmonics that build on one another to amplify the torsional motion of the crankshaft. These critical RPM’s are know as the "major criticals". Conversely, the "minor criticals" exist at RPM's that tend to cancel and damp the oscillations of the crankshaft. If the RPM remains at or near one of the major criticals for any length of time, fatigue failure of the crankshaft is probable. Major critical RPM’s are dangerous, and either must be avoided or properly damped. Additionally, smaller but still serious problems can result from an undamped crankshaft. The oscillation of the crankshaft at a major critical speed will commonly sheer the front crank pulley and the flywheel from the crankshaft. I have witnessed front pulley hub keys being sheered, flywheels coming loose, and clutch covers coming apart. These failures have often required crankshaft and/or gearbox replacement. Harmonic Dampers Crankshaft failure can be prevented by mounting some form of vibration damper at the front end of the crankshaft that is capable of absorbing and dissipating the majority of the vibratory energy. Once absorbed by the damper the energy is released in the form of heat, making adequate cooling a necessity. This heat should be dissipated in order to keep the damper at optimal operating temperatures. While there are various types of torsional vibration dampers, most Japanese and BMW engines are primarily designed with "tuned rubber" dampers. It is also important to note that while the large springs of a dual mass flywheel absorb some of the torsional impulses conveyed to the crankshaft, they are not harmonic dampers, and are only responsible for a very small reduction in vibration. That's why there is zero problem when you replace the 370Z dual mass flywheel with a lighter quality flywheel, such as Jim Wolf Technology one. In addition to the crankshaft issue, underdrive pulley size can cause slowing down the accessories below their designed speeds, particularly at idle. Slowing the alternator down can result in reduced charging of the battery, dimming of the lights, and computer malfunctions. Slowing of the water pump and fan can result in warm running, while slowing of the power steering can cause stiff steering at idle and groaning noises. This is NOT acceptable from a reliability standpoint. It is possible to implement design corrections and avoid these scenarios, but this would require additional components and/or software.

06-05-2012, 06:59 PM	#15 (permalink)
blackonorange A True Z Fanatic Join Date: Jul 2011 Location: Saskatchewan Posts: 1,078 Drives: 09 370z Rep Power: 17	Scary stuff in here