Depends on lotsa of variables...Read the articles....or else cant help much...

Hi,

Can I know whether any sales agent around?

I am thinking of getting a Honda Jazz soon

Thank you.

Different stuff la wei.

4b11t does not have direct injection like the mazda skyactive.

Also, they run larger turbos which is dangerous if they run that high a compression.

Skyactive like most eco engines are meant to save fuel and be economic instead of producing large power figures and also to balance between power output and driveability with their turbine choices.

The same 4b11t in UK modeled fq-400 or fq440 produces 400 horses with the same internals i belive with just a turbo and cooling upgrade and maybe more aggressive mapping.

Conventionally yes, but new ones like those in ford ecoboost, vw is not. Partly due to direct injection being able to bring down temps in the combustion chamber to ward off pre-detonation.

For performance applications. Compression will still be brought down by increasing the stack height of the heads by various means and also the cheaper way.

I know that.
I just want to tell some1 that turbo usually runs on lower compression.

some1 copy the whole wiki but doesn't get what I'm talking about.

i gave example so that the discussion leads there, not open statement.
yes I agree that all that depends on manufacturers recommendation. but if u ask now outside, turbo use hi compression, what that guy will answer?

Turbo if u ask the old farts is usually going to mean performance way back when.

Nowadays, turbo just means filling up the deficiency of Naturally Aspirated engines in order to optimize every drop of fuel being burnt.

Coupled by having direct injection. It is even more easily achieved now if big power output is not the priority.

The m16a in suzuki swift sport does high comp on a NA setup without direct injection and Honda L15B in japanese fit does the same as well but with direct injection. The direction now is to make engines squeeze as much power out with minimal fuel expensed. Easier routes is just to force feed it which some still chooses NA route.

Either way, controlling pre-detonation is the main concern here. If it does not knock. The computer can jus order up more aggressive timings to produce more power. That is jus how it works.

yup....agreed...that's what I try to say.... but when somebody already have a fix mind that turbo engine mean lower compression, discussion will not lead to anywhere at all ....however when new tech surface it could be different scenario already....back then, low compression turbo setup is the way to go if chasing a big power but high compression build is the ideal for daily driving...however new technology surface, if can build high compression high boost engine and at the same can precisely control the fuel and ignition timing to get away with the detonation and pinking, why not...

If you don't mind second hand jazz...Nov 2015 S Specs to be precisely....please pm me...
Fully tinted, full mugen body kit, 16 inches Tyre R sport rim, Sony touch screen HU with reverse camera, very low mileage , taffeta white....

Actually, high compression high boost relies on a smaller turbine. While good as there is less boost lag and generally a more responsive engine. The turbo runs out of breath as the revs increases if you start messing with the setup of the car. In order to solve that problem, a turbo with a bigger compressor housing is needed to compensate with it being able to push more volume through the system. But, then it introduces boost lag which might not be desirable.

The simplest way to end the argument is to look at something which came from the factory and started off with it's design around performance. The most recent being the Ferrari 488GTB and the McLaren P1. Both force fed, both direct injected and has new ways of dealing with turbocharging. In chase of high performance. This cars all have big turbos in their setup, the good thing in the McLaren side of things is that it can utilize it's hybrid systems to cover when the turbos are spooling. But, the main point to this is that both still runs with compression ratio of less than 10:1. Although sounds low, but the figures are close to most NA setups if you do not overlook that part.

So, even performance cars have turned to higher compression but it will never be as high as our conventional boosted eco units.

Wah, so fast jual kereta kah?

Actually I am interested to trade in.

How much do you offer?


Thanks.

Planning to sell it at RM65k....

Alright

Thanks brader....

Bought for my son...but he dont want to drive it anymore.....he is more interested in riding his bike....rather than lying in the garage might as well sell to somebody who might need it....

This post has been edited by mym123: Aug 21 2016, 02:32 PM

Hi compression is for lean combustion, turbo for power (torque).

In research, everythg can be done, however in day to day use, reliability is a priority.

Im waiting for Nissan variable compression ratio engine to begin with. I wonder why they make it variable ratio?

Actually high compression not necessarily equates to a lean combustion. Lean combustion is actually good for power production in any scenario but it also increases thermal load on everything. This is why generally turbocharged engines run richer fuel mixtures to prevent heat blooms in the combustion chamber and knocking.

Actually.... variable comp ration is a rather risky and unproven tech. Saab attempted it but it got killed if i recall correctly.

I remember the tech was to be introduced with forced induction. Where either supercharging or turbocharging actually requires minimal amounts of energy to start moving, superchargers from the crank and turbochargers from the exhaust.

The idea is actually quite novel as in during low load, low rev situations. The system will actually run in high comp to maximize power outputs so it builds up enough torque / exhaust gas to crank/spool the super/turbocharger until boost pressure comes and the system will then lower the compression again to prevent pre-detonation from intake gasses getting too hot in the compression cycle.

You can imagine it is like a supercharger / turbocharger or twin turbo system where there is one in charged of spooling up in the low revs and the other when the exhaust gas builds up enough to spool the bigger turbine. But, as i said. There is too much risks involved as it is mechanical manipulation and if the reaction is not fast enough. It could be catastrophic depending on how high a compression it runs.

As you say, reliability first.

The heck... your son better becareful. Riding a motorcycle is more dangerous.

Not those sport bikes is it?

Yup....Nissan will introduced 1st world's production variable compression engine....the Nissan VCT that will be introduced in its Infinity model in coming Sept 2016 Paris Motor Show ....can have compression ratio of 8:1 for performance and 14:1 for fuel efficiency....so best of both world....high power and fuel efficiency ....

no....its not a sport bike....its only a Yamaha Y15ZR....yup....riding a bike is truly dangerous affair nowadays...

As long as dun rempit ok la.

One of the forummers Quazacolt in recent months got involved in a hit and run incident. So, must be very very careful even if not rempit.