To cool the oil enough for serious track duty, there’s a massive coolant/oil heat exchanger in the bottom of the engine. Something relatively unique to the LT6 is the positioning of the direct injection fuel injector; it’s underneath the headers and squirts into the cylinder on the exhaust valve side. Apparently, this comes from their Indycar engine tech. My guess is the exhaust side is a bit warmer so that would help vaporize the fuel better to improve combustion. Part of making the engine spin faster is to reduce the mass of everything that moves. The pistons look to have relatively short skirts and the cams are hollow.
In direct contrast to the very high flowing parts of the LT6 V8 is the Duramax 6.6L diesel V8. It doesn’t need to flow a lot at high rpm, just enough to make 910 lb-ft of torque at 1600 rpm. There is a turbo hiding under that intake manifold log thing. I’m guessing the plastic box with the Duramax label on it is for intake noise resonance tuning. The darker tube with bellows joints connected to the intake manifold should be cooled EGR. Cummins just got fined almost $1.7 billion dollars for cheating on their diesel emissions, but it looks like GM has the necessary hardware in place at least.
The rectangular cross section on the right/inside of the V should be the intake plenum runner thing. And the exhaust log is on the other side. Like I said, neither are exactly designed for very high velocity flows.
I have been out of the turbo game a while, but this looks like a Borg Warner turbo judging by the CHRA and Variable Geometry Turbine component designs. Turbos with VGTs need turbine wheels with full back disks for strength; the vanes impart a lot more stresses on the turbine wheel blades so the full back disk is required to beef everything up.
Diesels in work trucks are designed to last a long time, so this looks like a metal impeller wheel in the water pump. Unlike BMW and Porsche gas engine water pumps with their plastic parts.
10 comments
Dang, I was hoping to see to coaxial turbine turbo trickle down to the IC market before things went Full ICE.
Oops, I meant Full EV.
I’m curious to see if/when more e-turbo makes it onto cars. Mercedes has a Garrett e-turbo on one of their AMG cars. Genesis has a 48V electric supercharger and e-turbo uses the same 48V. With more cars coming hybrid like all the new super cars from Ferrari and McLaren, one logical step is e-turbo. Conversely, they could just say the electric motor does the torque filling.
Yeah, we have probably hit ‘Peak Turbo’ in our civilization, but I was kind of hoping to see the development of these turbos stretched out a bit more.
“The amount of turbocharger lag plays a key role in the driver’s perceived quality of a passenger vehicle’s engine response. This paper investigates an alternative method to the conventional design of a turbocharger turbine to improve the transient response of a passenger vehicle. The investigation utilises the Ford Eco-Boost 1.6 L petrol engine, an established production engine, equipped with a turbocharger of similar performance to the GT1548 produced by Honeywell. The commercially available Ricardo WAVE was used to model the engine. Comparing the steady-state performance showed that the axial turbine provides higher efficiencies at all operating conditions of an engine. The transient case demonstrated an improved transient response at all operating conditions of the engine. The study concluded that, by designing a similar sized axial turbine, the mass moment of inertia can be reduced by 12.64% and transient response can be improved on average by 11.76%, with a maximum of 21.05% improvement. This study provides encouragement for the wider application of this turbine type to vehicles operating on dynamic driving cycles such as passenger vehicles, light commercial vehicles, and certain off-road applications.”
https://www.mdpi.com/2076-3417/10/21/7452
Bummer this turbo didn’t make it into serial production. I wrote about it a while ago. https://motoiq.com/the-secret-turbo-in-the-ring-slaying-porsche-919-evo-honeywell-garrett-dualboost-for-gasoline-turbocharger/
Yeah, that’s the turbo!
“The amount of turbocharger lag plays a key role in the driver’s perceived quality of a passenger vehicle’s engine response. This paper investigates an alternative method to the conventional design of a turbocharger turbine to improve the transient response of a passenger vehicle. The investigation utilises the Ford Eco-Boost 1.6 L petrol engine, an established production engine, equipped with a turbocharger of similar performance to the GT1548 produced by Honeywell. The commercially available Ricardo WAVE was used to model the engine. Comparing the steady-state performance showed that the axial turbine provides higher efficiencies at all operating conditions of an engine. The transient case demonstrated an improved transient response at all operating conditions of the engine. The study concluded that, by designing a similar sized axial turbine, the mass moment of inertia can be reduced by 12.64% and transient response can be improved on average by 11.76%, with a maximum of 21.05% improvement. This study provides encouragement for the wider application of this turbine type to vehicles operating on dynamic driving cycles such as passenger vehicles, light commercial vehicles, and certain off-road applications.”
https://www.mdpi.com/2076-3417/10/21/7452
So true…there’s a snail shell design for maximum vortex compound combustion…but, that’s kinda secret, for now.
1. The GTD rear suspension looks to be based on the GT500 rear. Probably tweaked a bit and converted to inbound dampers. Lower arm looks very chunky, probably just a prototype still.
The front is very interesting. Based on other photos i have found online, the vertical height difference between the multilink lower “arm” pivot points looks to be over 2 inches.
The exhaust tips are probably very thin wall titanium, as they are made by Akrapovic.
2. The LT6 is impressive, the bore/stroke ratio is even greater than that of the 458.
And the design of the Z06 is what the C8 should have been from the start.
3. That WRX thing is hideous, oh my god.
Appreciate the comments! 3. To be fair, the WRX has never been a looker, ha!
Nothing says Nissan fanboy like a Nismo bathrobe. Nothing makes you look like more of a weirdo than a Nismo bathrobe. I’d rock one!