Is it just us, or does it seems like Gen V LTs are popping up a lot faster than when the LS first got its start? It makes sense. A lot of the parts are similar and the market is already spooled up, but even so, we’ve already seen some nasty builds with the mill and it’s barely four years old. But, let’s get one thing straight, it has still been quite the learning curve.
With complex systems such as direct-port fuel injection, active fuel management, and variable valve timing on every single LT, there is a steep learning curve. Despite those challenges, one company that is always pushing the edge of what’s possible with GM’s latest platforms is Lingenfelter Performance Engineering (LPE). You can rest assured that they did not miss their chance when GM’s brand new LT came to town.
One of the biggest challenges for anyone who has gotten their hands on the General’s latest and greatest knows that, while it’s arguably a work of art in the arena of modern technology, it presents a lot of challenges when it comes to making big power. Lifters have to be changed for ones that can take big lift and duration, values for the camshaft advance/retard tables have to be worked out, but the biggest restraint on the platform so far has been fueling.
The stock injectors on the LT1 will support somewhere in the neighborhood of 600 rwhp before they run out of steam while the LT4 system can support somewhere in the range of 800. But after you’ve upgraded to (or started with) an LT4 system, one of the only options left was a larger fueling lobe on the camshaft. That allowed the aforementioned numbers to be attained, but after that, it was serious work to get them producing more.
Some turned to water/meth, while others decided that adding a set of port fuel injectors to the system was just what the doctor ordered. And both methods worked; but are they really ideal? Not exactly. While auxiliary injectors do work, phasing them in and out in areas other than wide open throttle (WOT)—you know the area the car spends most of its time—was hard to calibrate. It took a very experienced tuner to make this system work and it requires the use of a piggyback system to do it.
While it did function, Lingenfelter felt there had to be a better way. And that better way turned out to be a fuel system for the LT1/LT4 that is capable of supporting 1,500 horsepower. The dyno video above shows it making 1,435, but Mark Rapson of Lingenfelter tells us that the engine made over 1,500 during later testing—1,508 horsepower and 1,335 lb-ft of torque to be exact.
That was all accomplished with the direct injection system alone, nothing else! You may have heard of LPE’s 1,000-horsepower capable system, but this new one cranks things up to 11! Not only did they make insane amounts of power, they did so through the factory LT4 exhaust manifolds. That’s right, no headers on this bad boy.
The rest of the build consists of an LPE GT35 bumpstick featuring a 7.8mm fuel pump lobe, CNC ported LT4 cylinder heads, an LPE C7 intake manifold intercooler, twin GTX35R turbochargers, a 12mm big bore high-lift injector pump, LPE high flow fuel injectors, all running on MS109 fuel. And while that is a decent list of modifications, when you look at the big picture, that is relatively little to be belting out more than 1,500 horsepower.
What’s more, the internals on the LT4 remains unchanged from the factory. It still has the factory forged pistons, forged powder-metal connecting rods, and forged crankshaft. Sure, the entire rotating assembly is forged from the factory, but the fact that they can take this kind of abuse is unreal. Looks like the term “stock bottom end” might not mean so much in the future if they can support this level of power production-though the longterm viability of the components at that level is understandably questionable.
On top of that, the entire system is E85 compatible. And it doesn’t just fit the LT1/LT4 either. The kit will work on virtually any Gen V LT platform (minus the LT5, though it will probably work for it as well) including the 5.3-liter Gen V L83 and 6.2-liter L86 truck engines.
Lingenfelter’s kit uses 27 grams/second injectors to help supply enough fuel, combined with the larger 12.0mm bore injector pump and 7.85mm fuel pump lobe on the GT35 camshaft, to feed quadruple-digit power. And while it may be odd to see injectors rated in grams/second, they are a healthy 37 percent larger than factory squirters—the stock LT4 units are roughly 17 grams/second.
So, if you’re ready to make insane amounts of power, but don’t want to go to the hassle of adding supplementary fueling to your Gen V LT, give Lingenfelter a call. They’ll set you straight.