GTM Performance Engineering: VQ37VHR Engine Build 700HP Power Package

370Z Purist

subbed for build progress, more pictures, 700 horsepower, and tons more conjecture on what made the engine turn into a bomb

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-Phil

"Since one of my brake light bulbs just went out, the forum told me that my piston rings are about to blow."

sparky

Is this thread dead? Was sub'd for updates!

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Tward

Way over my head. I read this in Psychology class, and had more fun reading about this rather than listening to my professor ramble on lol.

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R.I.P Garrett Uekman

Cmike2780

I understood "aftermarket pulley, make engine go BOOM!"

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conmam

Yeah.... Sad but true. Years ago, I did not want to believe it myself. I was going to purchase this kind of underdrive pulley for my 95 Supra 2JZ-GTE. But when my friend's E36 motor crashed violently , then I had to sit down and analyze the situation and found out about this harmonic issue.

Motion Lab

Nothing better than a true harmonic balancer. I personally use the Fluidampr for my 2006Sti. I feel its even more important if you have other lighten components like a flywheel. These hollow "lightweight pullies" just seem like a poor idea.

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

RCZ

Damn that's a lot of damage. Whether the harmonic balancer effect is real or not, pulleys are not worth this kind of risk. I guess I got lucky because I used to have the same thing on my car.

03WhiteGT

It's been four months; any progress / updates?

Thanks,
Jeremie

SS_Firehawk

I still don't think an aftermarket pulley did this. The stock crank pulley is not a harmonic balancer or damper. It doesn't look like one, it looks like a pulley to me. Seriously, it only has a small rubber gasket and that is it. The pictures, story and diagram are great... but we aren't removing a harmonic balancer and putting on a crank pulley, we are removing a crank pulley and putting on a lighter crank pulley. The crank and pulley fusing together doesn't cause motor failure either. Now a lightweight crank failing, I have seen on this motor.

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conmam

" The stock crank pulley is not a harmonic balancer or damper ", really ?? Think VERY hard again. Take one out of your car and inspect VERY carefully of its construction and consult the automotive engine design engineers if you are still in doubt.

For engine that have internal balance shaft, you do not need a harmonic balancer. But for most motors out there without internal balance shafts, everyone of them come with crank harmonic balancers.

SS_Firehawk

I'm not an idiot and you are taking this out of context. I was very OBVIOUSLY talking about this motor. I know what a harmonic dampener, balancer (whatever you feel like calling it) is, how it works, and what they look like. The VQ37VHR motors are internally balanced using counterweights int he crankshaft and DO NOT come with an external dampener. I've inspected my old crank pulley, it looks just like my lightweight pulley, just heavier. Some manufacturers do use both an internally balanced crank and an external dampener. A good example are the LS motors. My explanation is not copied and pasted, but I'll be more than happy to tell you your wrong by citing examples of how motors can be balanced. And if needed, I will out research you at every angle to backup my argument unless there is irrefutable evidence telling me I am wrong. I challenge you to try.

Edit: More food for thought. How do you spin a motor up to 7500 RPM and not balance it internally? How do you spin a motor at 7500 RPM and have a heavy A$$ dampener hanging off of it?
The Nissan Engineers answered this question for you.

I'm not saying your whole copy and pasted explanation is incorrect, what I am saying is that I do not believe an aftermarket crank pulley caused this failure by allowing resonance to occur in the engine.

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370Z Purist

I still believe that the crank pulley houses some dampening. The only way to tell definitively is to cut it apart.

As for why the motor exploded, it probably has a combination of issues, such as running full boltons with no tune, probably being driven into the ground, and the fact that the pulley was replaced.

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-Phil

"Since one of my brake light bulbs just went out, the forum told me that my piston rings are about to blow."

roplusbee

So what happened to the build?

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370Z Purist

I would think four months is just enough time to grab the new block from Nissan and perhaps start tuning and dynoing right around this point.

I'm sure he's still trying to get his wallet back together at the moment...

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-Phil

"Since one of my brake light bulbs just went out, the forum told me that my piston rings are about to blow."