GTM Performance Engineering: VQ37VHR Engine Build 700HP Power Package

Originally Posted by corbin09

4 days and still no clue what happened? WE WANT DETAILS! I am still refusing to believe this happened just by driving an untuned car with bolt ons.

Originally Posted by SAM@GTM

The car was never tuned. Customer just had straight bolt on and that is it .



Sam

Originally Posted by Mike@GTM

We've given you all the details.

I will say that there was no evidence of detonation: the valves weren't burnt, the pistons weren't melted or pitted. Granted, only the owner of the car knows what happened and we aren't necessarily privy to that information in the first place. Also, you need to remember that not every car owner really knows what is going on under the hood or what they did to cause a catastrophy. I've seen many a "deer in the headlights" looks from people with broken stuff. They just don't know and simply aren't able to understand that by doing X, Y can happen. By them not knowing, they have no way of communicating relevant information. I can't tell you how many times I've heard "I was just driving along normally, and suddenly it just blew up". They usually forget that the night before when they were ripping on it with reckless abandon something subtle happened that they didn't notice and the next day the nature of the true damage reared its ugly head when they were casually taking off from a stoplight and they're like "OMGWTFBBQ just happened!?!?...I didn't even do anything!!!".

Ultimately, there is always a level of uncertainty when modifying cars. The bottom line with this particular failure is that we've given you guys all the facts and you must draw your own conclusions as to the cause...not that you'd listen to us anyway as evidenced by some people's posts.

Also, there was no Nitrous Oxide involved or signs that it was ever installed. If there had been, don't you think we would have mentioned it?

Originally Posted by phelan

Angry much, Mike? lol

Well...probably as good an excuse as any to build something nice. It's a wreck going into GTM, let's see how it comes out.

Originally Posted by Xracer

Wow that is some serious damage, the flywheel bolts completely sheared off? That is some serious force. Its hard to tell from the pictures, but at a glance it actually doesnt look like pre-ignition is the cause for this. Generally with engines that fail from pre-ignition, they show evidence of the phenomenon prior to the actual failure. At the same time the cylinder pressures sky rocket, the temperatures do so as well. The shock and heat literally degrade and melt corners or sharper edges of the aluminium pistons and head. One thing to consider is the torsional vibration or resonance characteristics resulting from the Stillen pulley.

Although a billet pulley is good for reducing rotating inertia, I am a strong believer that they only belong on accessories ( AC, PS etc..) This can get pretty involved physics, wise but in a nut shell, your engine's rotating assembly behaves much in the way that your suspension does. Your car's suspension takes a step input (a bump in the road), the spring stores some of the energy, and the damper dissipates it. This spring-mass-damper system is just like an engine's combustion (the bump in the road), pistons-rods-crank (spring and mass)...but where is the damper?! Most OEM Crank pulleys are not solid metal through and through actually. Most have rubber embedded in them or a viscous fluid. The rubber or fluid is the damper.

This may sound far fetched but you'd be surprised what can happen when the rotating assembly in an engine experiences resonance. It could very well end up looking like that poor engine. In any spring-mass-damper system, if you chance one of the components, you change the response of the system to any input. And hey, these engines operate over a frequency range from 0 to 7500rpm... plenty of room for strange things to happen.

Anyways, absolutely nothing against stillen or anything. Just thought i'd bring awareness to the subject. Lack of tuning/knock is the most common reason for engine failure like that.