QUOTE(K3nnYkl82 @ Feb 16 2014, 08:13 PM)
nzh can kau dim ge la..
hows the new mapping doing
hehe poke him then
and apologies meant to write the review/feedback earlier but i want to do it right so that i don't miss out everything.
anyways here goes.
After the ASC installation i also got the car remapped and
K3nnYkl82 took the effort to fill in the gaps that i do not understood in the mapping profiles (i'm still having a hard time digesting the MIVEC intake/exhaust variables though, will need to spend some more classes with k3 again
)
The initial impression is that the engine is a lot less free-revving than before, however despite that the power delivery was abundant which i think the ignition advancement definitely helped a lot in that regards.
Now as the MIVEC timing was advanced (pushed ahead from 4k+ rpm to 3k or so in layman), it sorta filled in the gap between the 2-4k rpm when it comes to power delivery, and from observation, my rpm doesn't drop like a rock when my foot's off the accelerator - which would mean my power band/delivery is still being kept while i am not flooring the accelerator and it helps more especially if i am in an hesitation on my shifting if i want to upshift or not (and then downshift again once said road hogger is clear. yes i know i am lazy and generally i'm not suited for manual transmissions lol) after ending up tail gating a random road hogger on the fast lane while i'm speeding.
i think overall with the earlier MIVEC timings there would be plenty of reserves on power delivery as apparent in my dyno chart, there's still a LOT of room for improvement post 6k rpm as there was no significant signs on power loss at that point and as k3 explained before that our ecu mapping is only limited to 6500/7000 rpm so if you can have better delivery earlier you can better utilize the subsequent rpm's on better timings/mappings when previously you couldn't have done so.
On a rougher layman approach on observation, my fc shown on the car's meter cluster (yes yes i know it's not accurate and yes i use fuelly lol) was constantly over 10.x km/l despite driving like an idiot (testing ASC ma
) for the whole time with speeds on average being 120-160km/h under light traffic conditions with time being around close to midnight to 1am or so, traveling around subang > federal hw > loke yew > seremban highway > besraya highway twists > bukit jalil > seramban highway again > jln istana > mahameru > jln duta > jln kucing > mrr2
of course, there isn't without some minor drawbacks - as the free revving nature of the engine is gone, i kinda find the car a bit less fun to drive compared to before. the insane torque pulling on the first/2nd gears aren't as apparent as before which i do kinda miss them especially the funny 2nd gear wheel spins rofl.
not to mention the "lol mivec kicked in yo" on the 4k rpm was pretty much gone as well as the power delivery is very linear compared to before.
imagine the damn free revving nature of the engine (again do remember that i am using very low viscosity engine oil lol) and then the whole 4k rpm "mivec kicked in feel"
it isn't practical at all though for daily driving as you will need to keep your power band/rpm above 4k rpm as the power delivery is very low on especially the 3-4k rpm gap.
not to mention just as free the engine is able to rev, the rpm falls just as easily too when you ease off the accelerator
overall i'm a very satisfied customer/inspira owner just as everyone has under K3nnYkl82 's mapping
however i do feel that it definitely still have some room for improvements, or more specifically, tweaking for personal preferences
for future brain storming:generally, how does the DOHC for the 4B10 work? more so, in relation to the MIVEC intake/exhaust systems?
QUOTE
From the 4B1 engine family onward, MIVEC has evolved into a continuous variable valve timing (CVVT) system (dual VVT on intake and exhaust valves).[9] Many older implementations only vary the valve timing (the amount of time per engine revolution that the intake port is open) and not the lift. Timing is continuously independently controlled to provide four optimized engine-operating modes:[9]
[l]Under most conditions, to ensure highest fuel efficiency, valve overlap is increased to reduce pumping losses. The exhaust valve opening timing is retarded for higher expansion ratio, enhancing fuel economy.
When maximum power is demanded (high engine speed and load), intake valve closing timing is retarded to synchronize the intake air pulsations for larger air volume.
Under low-speed, high load, MIVEC ensures optimal torque delivery with the intake valve closing timing advanced to ensure sufficient air volume. At the same time, the exhaust valve opening timing is retarded to provide a higher expansion ratio and improved efficiency.
At idle, valve overlap is eliminated to stabilize combustion.[l]
the part on FC, retarding the exhaust valve, is this how the rpm is able to be kept steady and not fall like a rock? sort of like an exhaust back pressure that some exhaust tuners want to achieve and particularly in automatic transmission/daily ride cars?
on the low speed high load mode part described, is that how i am getting the very high revving/torque nature on the stock MIVEC timing when i am doing low speed 1/2 gear full throttles?
Generally as mivec engagement is good on FC/power, however it's not practical to have it further advanced because on lower speed/rpm it simply can't be feasible? on a layman understanding, similar to how 5th gear is the best fc/power (when it comes to the top end speed) however it simply isn't feasible to shift to 5th at say, 20kph simply because it'll take a damn long time to accelerate (assuming you don't stall the engine)as the transmission is dragging the engine down?
is this understanding correct?
also would the valve overlapping (which seems to be a contributing factor for the very nice engine note especially during high rpm) elimination during idle be a source of that horrible tractor like tappet noise? as 16 valves seems like a lot of nvh under non overlapping operation
interesting off note for the 4b12:
http://en.wikipedia.org/wiki/Mitsubishi_4B1_engineQUOTE
The cylinder head intake and exhaust ports and intake and exhaust manifolds are shape optimized for better volumetric efficiency. Mitsubishi lowered the friction of the engine by including elastic grinding of the valve stems, adopting a high-efficiency shroud equipped plastic impeller in the water pump and using 0W-20 low-viscosity oil. Mitsubishi increased the combustion efficiency by optimizing the design of the cylinder head intake and exhaust ports, by incorporating the MIVEC system on both intake and exhaust valves and by using injectors that give an ultra micro droplet fuel spray. To lower the engine's weight, Mitsubishi used die-cast aluminium for the cylinder block, plastic for the cylinder head cover and intake manifold, and stainless steel for the exhaust manifold. The engine features a compact balancer shaft module with an integrated oil pump. A silent chain is used to drive the camshafts. The compact balancer module, the silent chain, the stable combustion yielded by the intake and exhaust MIVEC system, and high rigidity designs for the cylinder head and cylinder block realize low vibration and noise.
Feb 16 2014, 06:36 PM
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