What's the point of having VTEC or any variant with a turbo?

There are two camshafts, all variable timing does is switch to the bigger cam.

There isn't one. If you have a turbo there is no need for any kind of VTEC at all.

>>17384523
need low-end torque/hp, have smaller cams.

need high end hp, get bigger cams.

can have both using vtec.

need more hp from a small engine, put a turbo on it.

these things are totally irrelevant of each other and their purpose is to maximize efficiency from the engine. without vtec you either lose low end power, or high end power depending which cam you're stuck with.
with the turbo you get more hp at higher RPM.

Hence why LS engines are shit, and anything with pushrods should not be used in anything that isn't focused around towing things.

>>17384571
But what's the point of having a bigger cam to feed more air if there's a turbo

>>17384575
I think you dont understand how VTEC even works.

The entire point of VTEC or VVT or changing the timing or lift of the valves is to allow for more air to come in with less restrictions at higher RPM. That's the entire point of high performance cams.

Thing is, turbos do exactly that. The high psi forces the air into the cylinder even with short timing or low lift

So what's the point

>>17384575
>need low-end torque/hp, have smaller cams.
w0t

Smaller cams dont magically make the cylinder fill with more air during low RPM. It just means the cylinder chokes more on high RPM.

Bigger valves are universally big across all RPM for torque.

The thing about high performance cams is that they cannot work at low RPM, therefore decreased torque.

There is no magic relation between cams or VTEC And torque at X RPM.

>>17384593
You need the air turbulence at low RPM because less air is needed.

>>17384618
>You need the air turbulence at low RPM because less air is needed.
You mean the high restrictive flow doing a venturi to increase fluid speed? no you dont NEED it. You might benefit from it but that doesn't really incluide cam as its an overall thing about everything from the air filter to the manifold. Even then the discussion about wether or not people can obtain low end RPM torque without using restrictive venturi flow to increase fluid speed, which would also increase torque at high RPM is very much alive today since modern technologies can implement anything variable with little weight or effort.

VTEC turbo have just variable valve timing on the exhaust cam

>>17384676
Are you sure there is no gain on the intake? and what's the point of exhaust VTEC?

>>17384729
>backpressure for emissions and small torque gains

>vtec activates
>less backpressure for more top end power

>>17384593
>Smaller cams dont magically make the cylinder fill with more air during low RPM. It just means the cylinder chokes more on high RPM.

It's not magic.
Shorter duration and lower lift mean better VE at low rpm due to higher momentum and inertia of air charge coupled with the valve closing earlier in the compression stroke.

The reason big cams work at high rpm is the same reason they dont work at low rpm. Same with a small cam. Thet work at low rpm because they dont work at high rpm.
VVT can switch between cam profiles to suit the engine operating condition.

Just using a turbo to pump air into the engine is not very efficient as the pump losses would increase with boost pressure. VVT is better in this respect.

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72KB, 323x323px

>>17384618
>You need the air turbulence at low RPM because less air is needed.

You are now aware VTECs only purpose is to lower emissions at higher RPM.

>>17384586
>higher lift = more air into the engine, even with fi
>more air = more fuel = more bang

by your logic why would anyone with a turbo car but bigger cams on? it's not that fucking complicated holy shit.

and by your logic everyone with a performance car should be driving around with massive fucking cams if it doesn't matter for lower end.

>>17385940
>by your logic why would anyone with a turbo car but bigger cams on? it's not that fucking complicated holy shit.
That's why i am asking for the reasoning. Hell, even why people go DOHC with turbos if the pressure from the manifold would be good enough even with a small SOHC cam with standar lift and timing.

>and by your logic everyone with a performance car should be driving around with massive fucking cams if it doesn't matter for lower end.

If you really want a fast N/A car, then yes.

>>17384575
oh hey there, abandon your other thread? >>17384642