Comparison 17x MPH NA vs 17x MPH FI
Discussion
Pah and I swapped a drive of each others cars so he can pip in, but interestingly the new GTS doesnt seem to drive much different from the old VE in general terms/dynamics.
Aside from that, his 700bhp blower car interestingly drives very sedately at anything up to say 1/3 throttle. Like your granny's car even.
But push the throttle down and the push gets ever more intense until it becomes very strong.
Quite progressive actually and not really on off, other than a little noticeable switch I suspect as the vacuum valve closes, but its not very perceptable.
Compare that with mine, which is like an explosion at any minor throttle positions and roasts tyres from a roll at most/any speeds in 1st and 2nd. The FI car does not roast them from a roll as a general rule. However as the rev's climb mine becomes less violent and ends up just pulling hard, obviously not quite a strong as Pauls setup.
So for low speed, off idle and stop start I would say mine was far more explosive. 600ftlb starts pretty much from idle. I came away impressed at the top end of Paul's car, but a bit disapointed at the bottom end. Perhaps there is torque management and throttle gain tables involved. But in an auto I could definitely see the requirement for a higher RPM stall if tune activity fails to free up additional off idle torque.
No point owning a V8 if you can only get the power at illegal speeds. Much better its availalbe from idle.
Though as Paul commented its a very different driving experience and not something most people are used to. I had something similar with the higher stall auto in the LS1 camaro. That would roast tyres on demand, basically using the stall to multiply the torque.
So just some random thoughts, Paul might want to add a few thoughts and comments.
Ignore if irrelevant
Aside from that, his 700bhp blower car interestingly drives very sedately at anything up to say 1/3 throttle. Like your granny's car even.
But push the throttle down and the push gets ever more intense until it becomes very strong.
Quite progressive actually and not really on off, other than a little noticeable switch I suspect as the vacuum valve closes, but its not very perceptable.
Compare that with mine, which is like an explosion at any minor throttle positions and roasts tyres from a roll at most/any speeds in 1st and 2nd. The FI car does not roast them from a roll as a general rule. However as the rev's climb mine becomes less violent and ends up just pulling hard, obviously not quite a strong as Pauls setup.
So for low speed, off idle and stop start I would say mine was far more explosive. 600ftlb starts pretty much from idle. I came away impressed at the top end of Paul's car, but a bit disapointed at the bottom end. Perhaps there is torque management and throttle gain tables involved. But in an auto I could definitely see the requirement for a higher RPM stall if tune activity fails to free up additional off idle torque.
No point owning a V8 if you can only get the power at illegal speeds. Much better its availalbe from idle.
Though as Paul commented its a very different driving experience and not something most people are used to. I had something similar with the higher stall auto in the LS1 camaro. That would roast tyres on demand, basically using the stall to multiply the torque.
So just some random thoughts, Paul might want to add a few thoughts and comments.
Ignore if irrelevant
Interesting, but no surprises by the sound of it.
Maybe missed a trick not taking some data - it would be nice to relate the perceived shove (due to change in acceleration I assume, i.e. jerk) of FI against the linear (but consistently strong) acceleration of NA.
e: That reads a bit like I'm threads
tting - I really appreciate the subjective aspect, and it's what I'm striving for on my car. It sounds like you haven't gone combing through both tunes yet. From experience (and as Ringram well-knows), MAF vs. MAFless, or tweaks to throttle follower/cracker alone (/etc.) is enough to really change the way a car drives...
Maybe missed a trick not taking some data - it would be nice to relate the perceived shove (due to change in acceleration I assume, i.e. jerk) of FI against the linear (but consistently strong) acceleration of NA.
e: That reads a bit like I'm threads
tting - I really appreciate the subjective aspect, and it's what I'm striving for on my car. It sounds like you haven't gone combing through both tunes yet. From experience (and as Ringram well-knows), MAF vs. MAFless, or tweaks to throttle follower/cracker alone (/etc.) is enough to really change the way a car drives...Edited by Mud_ on Sunday 7th August 14:18
Both cars DBW, Pah will confirm my comments for the most part, well the variance in feel anyway.
Ive actually detuned mine a bit in regards to the throttle gain. But if you think about it, its correct that the smaller engine off boost will have less power. Duh.
So pootling around the 6.2 with low compression and tiny cam will be docile especially off boost, (under 50kpa IIRC)
Whereas the NA will have access to its full displacement at idle. Tip the larger 85mm vs 102mm throttle and wham more air = more power..
Its not rocket science.
Ive actually detuned mine a bit in regards to the throttle gain. But if you think about it, its correct that the smaller engine off boost will have less power. Duh.
So pootling around the 6.2 with low compression and tiny cam will be docile especially off boost, (under 50kpa IIRC)
Whereas the NA will have access to its full displacement at idle. Tip the larger 85mm vs 102mm throttle and wham more air = more power..
Its not rocket science.
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