The main issue with VGT is heat, the additional components don't hold up well with heat. VGT mainly used by diesel because the peak exhaust temperature is lower than petrol combustion, so heat issue on diesel engines is less of an issue. Also, VGT somehow has better advantages in inducing EGR for emissions reduction.

Further, because of the ability to vary the exhaust flow, the turbine itself can be larger than non VGT type. With larger turbine also means larger exhaust, thereby mostly eliminating the need for a wastegate.

VGT on petrol are really on a handful of car that you can count with your fingers. And for these special application, very high grade materials (likely aerospace grade) will be used to construct the turbocharger. And with such aerospace grade materials, it is much more costly to procure.

He is "THE" god, previously on autoworld and now here. How dare you blaspheme his "supremacy"!? We are like little devils running around him, spreading "falsehood", "misinformation" and "misunderstanding" to the masses

This post has been edited by wkc5657: Aug 10 2017, 04:25 PM

Mazda's new HCCI Engine will make turbo engines obsolete. We can have the power and torque of turbo without the lag and high FC. FC of 30km/L is achievable which is better than hybrid so it also makes hybrids obsolete.

Some form of air charging is likely involved. 60% of automotive publications mentioned supercharging.

Fuel consumption is an unknown, just a theoretical number as there is no real life examples.

It's not here yet but it is found in the new 7.5 Golf. Specifically the EA211 1.5 petrol engine.

1st mass market petrol engine with VGT TC. The production cost impact probably offset by the sheer volume of cars they are selling now.

Even if it's not twinscroll, the design of its exhaust manifold that make port 1 & 3 clash with 2 & 4 to generate strong pressure allowing the new low inertia impeller to draw enough dense air from lower rpm. The design of the engine, air intake curved angle count as well.

Question is, you think local modshop knows how to come up with such manifold design? As told many times, they can buy the most advanced turbocharger from borgwarner but ability to put it to work is normally a no. It takes several factors that determine good efficiency, not like what modshop said, just put turbo and come up with their own piping can beat cars with stock turbocharger.

VGT mostly in diesel engine mainly because its design is more simple. Diesel engine has far more carbon buildup so it need s more simple straightforward approach to avoid high carbon buildup and difficulty in cleaning.

When popularity of stock cars with turbocharger came, there's already twinscroll turbocharger available. So they went for twinscroll turbo.

Still stuck with fairytale mentality? VGT design is far simpler than twinscroll. There's no such thing as VGT generating more heat. Whatever heat and pressure come from exhaust valve, turbocharger is just mechanism powered by exhaust gas. Diesel engines favour VGT because of simpler less carbon buildup and easy cleaning compared to twinscroll turbo.

Everyone knows that I only post facts and encourage people to find out and prove my facts right. Unlike the few here who cheated people into believing fairy tale. Even the downgraded fairy tale replies to you from me contain facts that you just need to complete the sentence. Those hated my comments mainly because they don't want the public especially customers knowing too much.

No, the question is - you are wrong about the turbo after insisting several times it's not the same turbo between Preve and Ecoboost. Now that it's irrefutably proven that it's the same turbo, why are you trying to pusing to manifold topic?

This further proves that you are a typical quack who knows nothing, and when proven wrong you try to taichi your way to something else instead of admitting that you KNOW NOTHING.

But I think most forumers can see that now.

Primitive turbo eh?

There's another Optima GT thread created by Korean supporter for mainly propaganda talk. This Optima GT thread is for open debate, brainstorm and discussion for all parties. If there's no point debating with me then why are you here? Can you prove all my comments are lies? The only thing that drags you down are more customers having too much knowledge and information. Unless you're with certain company products that you find too many smart customers threatening, otherwise there's no reason for you to be so desperate asking admin to remove all comments.

Success of online advertisements depend on number of different viewers. You can compare my Optima thread vs the other propaganda only Optima thread, how come my viewers and traffic far higher. Because public wanted not just pros and cons but other information and ways to evaluate cars.

You said stick to topic but never posted relevant car talk comments. You already violated your own suggestion from beginning. So how many Optima GT being bought by genuine individual that has link to any of the subsidiary nor personnel so far and paid using own hard earned money? You can see VW at that price on the road. The lower sales volume Volvo V40 too can be seen on the road. Where is Optima GT?

The Koup 1.6T that is priced lower, there's rarely 1 on the road. The Civic turbo with similar price plenty on the road. VW Jetta 1.4T when priced at rm140k, you can see numbers of them on the road too. What does this tell you?

Your failure to tell the cons of preve turbo compared to pug turbo, Volvo turbo, Honda turbo, Hyundai Kia turbo, tells you knew nothing about proper turbo at all. A turbocharged car is evaluated from intake to engine to turbocharger to exhaust layout design and technology. Not just 1 of it could determine entire turbo system. Only ah Beng mentality that compared to own modified turbo can't tell the pros of cars that come with proper turbo. Next time save money and buy proper car with turbocharger, not modify existing junk and put turbo then suffer poor low end torque and worst FC..

Summary

Dr J : Preve turbocharger is primitive!
me : It's the same turbocharger used in Ford ecoboost
Dr J : NO!! Ecoboost turbocharger is twinscroll or VGT.
me : Read this article it say it's the same turbocharger
Dr J : Errr.....even if it's not twinscroll, they have different manifold!
me : So it's the same turbocharger
Dr J : You know nothing about proper turbo engines!!!

Yea that's about right.

shitstorm or brainstorm? That's the dangerous fine line between your debate and being ignorant. I dont see you accepting knowledge from anyone else.. btw.. your shit makes no sense to me... Most of the time.

Sekejap vgt, sekejap twin scroll..
Sekejap primitive..
Conman jay makeup ur mind which is which

Apa tu? Hahaha.

Wei, guys don't be too smart, you all are threatening him.

most silent reader including me notice this dares
notice the pattern already now hahaha

My version

Dr J : Preve turbocharger is primitive!
me : Elantra Sport use turbocharger from same company
Dr J : NO!! Elantra Sport turbocharger is VGT, boost to 1.5 bar. Preve primitive turbo low boost and lag.
me : Elantra Sport stock turbocharger is twinscroll and boost only to 0.9 bar.
Dr J : People like to round up 0.9 to 1.0! Elantra Sport VGT that activate from 1500rpm is not primitive!
me (thinking): Hmm, praise my car woh, saying it is not primitive.
Dr J : Elantra Sport won't sell well, I can help them boost the sale but I won't help them since they hurt friends.

Yea if he says something good about Korean car, you know what's coming next.

These are gold, we could not make this up even if we tried. They shoiuld make a movie out of this...

Oh wait they did, starring Jennifer Lawrence summore



This post has been edited by dares: Aug 12 2017, 04:41 PM

Aiyoh MockingJay movie

plan to get 2nd hand unit of tis car in the new future. the engine is promising....

From your wastegate talk, you proven yourself to know shit about the fundamentals of air charging, don't even go down to the intricacies of individual components.

VGT design is not simpler than twinscroll, you forget got additional components to do the actuation to change the exhaust flow angles before the impeller?

And you don't even understand what i commented, i never mentioned VGT generating more heat. You don't understand about heat effects on VGT, you just simply blurt out whatever you think is right.

As you like to simply simplify complicated things just for your understanding, instead of really understanding things the way it is.

Your talk about cleaning the turbocharger is just trash. You don't understand the construction of turbocharger. Both are complicated to clean in their respective manner and VGT should actually take more effort to clean as need to involve additional directional fins.

The only thing to complete in your sentence is full stop, hardly any verifiable facts in reality.

Ya i know, you don't need referencing because you remember things in your mind. Great infact. But you don't understand things in the first place, what you remembered and recall will just be plain falsehood. And when pointed out, you never go to verify and figure out, you just hold whatever your initially flawed understanding as sacred. With almost 40 years of accumulated experience, it still proves your understanding is simply FAIL....



This post has been edited by wkc5657: Aug 12 2017, 11:15 PM