Twincharging aside, will turbo engines (particularly economy engines) ever be able to mitigate the irregular shape of the torque curve when the turbo kicks in that penalises drivability, or is that considered a permanent trade off for the benefits of boost?
When we rework the turbo calculations to provide a better simulation of modern, quick spooling turbocharger tech, that problem will be fixed 
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I would like to add a question. When do you expect this to happen? I would expect sometime after the release of the UE4 update but I haven’t checked if there is an official date.
“After the tycoon part is mostly done” still is the official stance.
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Another question for you, will liftoff during sim lap times affect the turbo? obviously it might be out of the scope of the game, but i thought i’d ask
Definitely out of scope to simulate anything like that.
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You can get the torque curve to a normal curve so it doesn’t shoot up and then flatten out just by playing with the turbo sizes, if that’s what you mean?
Modern turbos begin to spool up from idle thanks to technology like twin-scroll turbines. That is what is meant here. Simply making a smaller turbo in the game now will spool up the turbo faster but you cannot get as much power from a small turbo. A twin-scroll turbo offers the quick spool of a small turbo at low RPM with the high power of a larger turbo at high RPM. Twin-scroll can’t be simulated yet.
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it will be interesting to see what superchargers bring. centrifugal would keep the torque rising throughout the rev range like a high cam profile engine, the old roots blower should deliver all of its power from idle before tapering off like that of a low cam profile engine, and then the screw blowers would be somewhere in the middle however they would be far more efficient than the other two options with lower boost levels
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Is it a reasonable request for a misfiring system to be implemented? Allow high RPM turbo engines to maintain drivability, a greater powerband, and quicker acceleration at the cost of atrocious reliability and fuel economy. I think Mitsubishi has them in Japanese Market Evolutions.
For balance, they could make them high-maintenance (They take no crap if something gets through the air filter) and higher loudness (From the higher-pitched whine compared to a roots-type). Technically though, there’s no reason a twin-screw would have lower boost levels. They’re actually a bit more efficient than a roots-style.
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Old Roots style, straight rotors, are not as efficient as newer hi-helix ones.
The Eaton kompressors of the latest generation have 4 rotor 160 deg twist.
ok it has been proven multiple times that a screw blower makes less heat and handles less boost than a “proper” roots blower. Where roots come into their own is at high boost levels 50-60psi is common among high end drag racers. A twin screw makes more power and less heat at lower boost levels however they become limited in the amount of air that can physically pushed into the engine at higher boost levels ie a unit which flows 3.5L of air per revolution can not actually flow more than 3.5L of air regardless of how much boost pressure is used, so just like a turbo, roots or centrifugal blower there becomes a point where a screw blower cannot produce more boost in most cases this is around the 20-25psi range. A screw blower has a very low parasitic loss at low boost levels however this multiplies rapidly at “large” boost levels, a roots has the same issues however the parasitic effect while higher is much more linear than a screw blower which allows for running huge boost levels (and heat) but at the cost of crankshaft reliability (a 6/71 will require 300HP just to run the blower but this is at any boost level). The other thing to remember is a roots blower can be massively over-driven to force the lobes to spin faster and push the air into he engine faster( it is still the same amount of air but now it is producing more revolutions per second ) a screw blower cannot come close in this respect as under-driving a screw blower tends to do nothing as now the blower is becoming less efficient as it ramps up the heat and parasitic loses.
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Where i used to work, we had a screw type compressor supplying the air to the workshop.
8-10 bar - 118-147 psi. I wouldn’t call that low boost. The design of the rotors is not different than those put on cars.
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Yes but what was powering it, i could say the same about ship engine turbos. The point i was making was yes a screw blower can make big boost but it no longer operates anywhere near as efficient especially when compared to a modern roots style supercharger. Comparing an air pump for a workshop or fixed engine to a supercharger built to suit a combustion car engine is like comparing an elephant to a tiger…nothing alike. You are talking about a lysholm i am assuming which are serious blowers and the largest thet make for petrol engines is 5l per revolution with a max recommended boost level of 20-30psi most petrol engines would have a smaller 1.9-3.8l unit with an intercooler and between 10-25psi.
edit. And was that air pressure in the tanks and airlines or boost pressire out of the air pump?
edit 2: my falcon is factory fitted with a 2.3l harrop blower. And i have 450kw at the wheels on 14psi with major fuel system upgrades and meth injection so anything bigger is only going to be supercar levels of power
Top Fuel uses screw type compressors nowadays, what boost do they get?
???
What you on about? Common supercars are still at 500-600hp, while 450kW is already above that. If you mean V8 Supercars, then… you’re not that far away either
60-80psi. Though as much as I love a twin-screw, they’re still just using 14-71 blowers (They aren’t allowed to use anything else like bigger blowers, twin-screws, centrifugal superchargers or turbos).
They also take about 500HP just to turn, which is awesome.