jlo0109 wrote:I was reading wikipedia about the VK56DE engine..which one is yours? Armanda?Titan? or QX56? They are all only pushing about 20~30 hp more than the original engine..Why would you want to do all that work for that 20~30 more hp and add up a crap load of weight onto your car? O_oSorry if I am wrong.. explain to me :]!
Dyno charts of Titans show that they either have little drivetrain loss or are underrated by about 15-20 HP. So it may be that they are starting with a bit more than the factory ratings would suggest. However, the motor makes gobs of low to mid-range torque. The peak HP also occurs at a measly 4900 RPM. Based on factory ratings, this would mean the VK is still pushing 326 lb-ft of torque at 4900 RPM. A cam that can provide better breathing up top could easily bump up the HP by allowing the motor to operate at much higher RPMs. V8's tend to have great natural balances so it should be able to withstand some higher revving. It may be limited most by a 92 mm stroke, but that's not terribly high either (A KA24 can safely rev to just over 7000 RPM and has a 96 mm stroke). Conservatively, if you could make 300 lb-ft of torque at 6500 RPM, it would be putting out 371 HP. I suspect you can get more torque somehwere up there with this motor and rev it out more too. By comparison, the new 5.7 L Tundra motor is pushing 357 lb-ft of torque at 5600 RPM where it makes it's 381 Peak HP with only a tenth of a liter more in displacement and a slight edge with it's higher compression so it's not unrealistic. If you could make even just 325 lb-ft of torque at 7000 RPM, you'ld have yourself 433 horsies to play with.
Bear in mind here that the Titan's VK is only cranking out about 67 lb-ft of torque per Liter at it's peak. The VQ in the G, by comparison, is at about 77 lb-ft per Liter depending on the version. There is likely some room to bump up the overall torque output as well.
There is a lot of potential to play with by doing such a swap. Not to mention the roar of a huge V8 if you open the exhaust up even just a little bit.