06-02-2012, 03:54 PM
Problem with VNTs is....
You MASH it at 30 in 4th, it'll bog, blow coal, then as the turbo slowly spins up, it suddenly overcomes the bogging, sends the exhaust pressure mental, spins the turbo up, drops the LDA, huge load of fuel, promptly lights up the clutch with silly torque then keeps lighting up the clutch until the torque dies off, then it "feels" as if the engine is reducing in power, when it's just coming into it's stride, then they lift off, producing the most GASH graph you've ever seen.
You've got to tickle them through the low RPMs, light throttle, then start bringing in the throttle as the boost builds, all the way 'till it's fully on boost, by which time your foot should be close to the floor, and hold it to wherever the owner's balls will let them take it... Unless you've got experience of driving larger turbo and pumped Diesels you just don't know by the noise what the engine is doing, sounds sad, but you definitely get a feel for what's going on via the noise...
Which is why I just wish some dyno operator would let ME control the throttle once you're on for the run... It'll never happen though...
You MASH it at 30 in 4th, it'll bog, blow coal, then as the turbo slowly spins up, it suddenly overcomes the bogging, sends the exhaust pressure mental, spins the turbo up, drops the LDA, huge load of fuel, promptly lights up the clutch with silly torque then keeps lighting up the clutch until the torque dies off, then it "feels" as if the engine is reducing in power, when it's just coming into it's stride, then they lift off, producing the most GASH graph you've ever seen.
You've got to tickle them through the low RPMs, light throttle, then start bringing in the throttle as the boost builds, all the way 'till it's fully on boost, by which time your foot should be close to the floor, and hold it to wherever the owner's balls will let them take it... Unless you've got experience of driving larger turbo and pumped Diesels you just don't know by the noise what the engine is doing, sounds sad, but you definitely get a feel for what's going on via the noise...
Which is why I just wish some dyno operator would let ME control the throttle once you're on for the run... It'll never happen though...
