Turbo or supercharger?

[iamjajo]

I love it when people confuse real life with the game. It makes for some funny forum banter.

However, I prefer to supercharge my cars when I have a choice. I like the way they seem to increase power across the band. It suits my driving style better than turbocharging. You should try both; check your lap times, and decide which you like best.

 

[zero_speed]

I love it when people confuse real life with the game. It makes for some funny forum banter.

It seems to happen a lot around here lol.

I tend to stay away from TC or SC as much as possible. In game its seems that a NA engine is the way to go.

 

[EivlEvo]

2 pages of post and no one has answered his question lol. He is in the tuning forum asking which is better to use in game. So which is it??

The thing is that in game its the same answer as it is in real life. WHEN you have the choice (which you rarely do) you should choose something that suits what you're trying to do for the car? Its a subjective answer. You can probably make a better decision if you know a little bit about each type of charging, hence why I continued.

The trouble is, that there are a lot of people that understand charging very well, but have many of the difficult concepts completely wrong. That was one of the reasons I began to post in the first place since EVERYONE knows getting into these conversations often turns into exactly what this one is.

 

[EivlEvo]

My definition of lag is this; the RPM span between when you place your foot to the floor to when you hit full boost. That is always what I have heard lag referred too. So in that sense, it does seem we are talking about two different types of lag.

I'm really not trying to flame you, but there isn't a different kind of lag, and this is probably why we've had confusion. Lag is simply the time from where the turbo or supercharger goes from being a parasite, to becoming beneficial.

I don't get how this concept doesn't make sense to you. Maybe you have never turbo'd an N/A car before?[/QUOTE]

I have, but it isn't relevant? I'm more than qualified through my education to answer the questions.

Let me draw it out for you. Lets say the N/A engine makes 75 hp at 2000 RPM. The now turbo'd motor can make 75hp at 1600 RPM. So if you are making the same power but don't need to spin the motor as fast, you'll use less fuel.

It's a hard concept for most to grasp, but its real.[/QUOTE]

You are correct, but this is one of those "car guy myths" that is correct at heart, but actually totally wrong. If you'd like, we can do the math involved? But it'll be easier if you just think about what you're trying to say.

1. The RPM has nothing to do with fuel.
2. Horsepower has a direct effect on fuel economy.

So, if you have a 2.0L engine making 200HP at 6000 RPM, it will probably only be producing (arbitrarily) 130HP at 3000RPM. So if you drive along at 6000RPM all day, you'll burn more fuel because the engine is making more horsepower. If you drive around at 3000RPM you'll be using less fuel and therefor making less horsepower.

In your example if we have 75HP at 2000 RPM N/A and we're getting 20MPG, we might be getting 30MPG at 1500RPM (the RPM's are a tad unrealistic, but you get the point) and only make 50HP. If we bolt a turbo on the motor it will now be making 75HP at 1500RPM. This RPM is lower, but because of the added air of the turbo, more fuel is required, and as such you'll be getting 20MPG at 1500 RPM making 75 HP, and at 2000RPM you may be making 100HP but only 15MPG.

Next we can tackle why improving fuel economy from 15-19 MPG is twice the fuel savings as improving from 34-44 MPG.

 

[Gedi69]

Well thanks everyone for the info... It is a lot to take in but I'm getting the jist of it now lol

 

[TT3AZ]

It doest matter since we cant chouse supercharger or turbo on most cars, either the one or the other.

 

[articzap]

In your example if we have 75HP at 2000 RPM N/A and we're getting 20MPG, we might be getting 30MPG at 1500RPM (the RPM's are a tad unrealistic, but you get the point) and only make 50HP. If we bolt a turbo on the motor it will now be making 75HP at 1500RPM. This RPM is lower, but because of the added air of the turbo, more fuel is required, and as such you'll be getting 20MPG at 1500 RPM making 75 HP, and at 2000RPM you may be making 100HP but only 15MPG.

lol.

Amount of power made is based off of air flow swallowed by the engine. It doesn't matter if its N/A or turbo In my example it will be the same amount of air.

And you're right, RPM doesn't make a difference in direct fuel economy. A consumed amount of air flow will always require the a certain amount of fuel, and that doesn't change based on RPM.

 

[Rossticles]

Turbo lag isn't that bad in the game. Go with whatever gives you more power.

 

[No_OBsT33R]

With more power you don't have to put as much load on the engine to do the same amount of work, gearing further let's the new power be taken advantage of. Turbos are great that they don't fully boost all the time so you can save bucks staying out of high revs and WOT.

Look at the Chevy Cruise, it's a prime example of this at play. Tiny engine with a turbo makes power equal to much bigger engines but with better economy.

 

[Rotary Junkie]

Look at the Chevy Cruise, it's a prime example of this at play. Tiny engine with a turbo makes power equal to much bigger engines but with better economy.

1. It's Cruze. Don't ask why.

2. Naw, really? Doesn't mean a turbo version of the same size engine will get better fuel economy (and, generally, it'll get worse due to tuning it on the "safe" side at all times).


As for the turbo engine at low revs vs NA motor spinning a bit more... I bet it'd be a dead wash. Turbos have to be tuned "safe" compared to NA motors which means more fuel for the same output. The further you go in specific output the greater measures have to be made to prevent detonation... Counter to that is the NA engine would be suffering greater frictional losses.

 

[zero_speed]

The thing is that in game its the same answer as it is in real life. WHEN you have the choice (which you rarely do) you should choose something that suits what you're trying to do for the car? Its a subjective answer. You can probably make a better decision if you know a little bit about each type of charging, hence why I continued.

The trouble is, that there are a lot of people that understand charging very well, but have many of the difficult concepts completely wrong. That was one of the reasons I began to post in the first place since EVERYONE knows getting into these conversations often turns into exactly what this one is.

I get what your saying, but we are not talking about real life. He asked which is better in game, real world knowledge and application will only go so far. It is great that you guys are able to provide a ton of real world information, but it doesn't really help him decide what is best in game.

 

[articzap]

Turbos have to be tuned "safe" compared to NA motors which means more fuel for the same output. The further you go in specific output the greater measures have to be made to prevent detonation... Counter to that is the NA engine would be suffering greater frictional losses.

At WOT I agree with you, but for stoich during cruising, all cars even from factory work around a stoich value of roughly 14.7.

 

[VAjeeper]

As for the game goes, I'd agree that you just try a couple setups and complete some laps. People have different styles of driving, so there will be a setup that's right for your driving style.

Now for real cars, it seems theories could be discussed to no end. Turbo diesels get great mileage, they've got high torque at low rpm's, which makes me think rpm and airflow do play a role in fuel efficiency...

 

[EivlEvo]

I think just for the sake of this thread and the OP, I'm going to drop it. Obviously I've indicated why zap is wrong (though knowledgeable) but most of the principles he's on about are mixed up. I'd rather not sit here and go through the math involved (let alone trying to get it to show up properly on a msg board).

To be certain the OP's question gets answered. I think you'll find that for every car IN GAME that both a SC and a TC are offered, the TC is better in terms of the highest HP #. IN GAME, the SC will give you a smoother and more linear power curve, and the SC will be more exponential and typically peak higher.

As I mentioned. It will be entirely subjective. The biggest problems you'd encounter in game, is when the turbo's power kicks in (about 1/3 of the way through the revs from idle) you may get wheelspin, which for some vehicles can be difficult to control. This can be quelled by our lovely tuners though.

The only cars I can think of off the top of my head that both types can be applied to are:
1. The new miata.
2. The MR2's

There is one tune shop that tuned the same MR2 in turbo, SC, and NA. You can try all 3 and see what the deal is.

Its subjective. It always will be. What do you want to do with the car?

 

[Ronald6]

The Fireblade can use both TC and SC. In this car, and this car only to the best of my knowledge, the SC gives a much higher hp boost.

 

[FOURCED]

I feel like there's a lot of semantics being argued here and they get intermixed into thinking that people are making wrong statements. I'd suggest that people refrain from referencing some specific vehicle (in this case, everyones cobra?) because its irrelevant and is only showing its a subjective argument.

I referenced a Mustang Cobra as articzap mentioned it first and I happen to own one personally. It's actually a good example to use as it came with a factory supercharger, and there have been more than quite a few that have gotten rid of the factory blower in favor of either a twin screw or going to a turbo set-up.

1. "Lag" is in most of these cases, the incorrect term. Lag is generally the difference in the time from when you want "boost" (or compressed air) entering the engine, and when you get a noticeable amount. In some instances, we're talking about compressed airflow positively benefiting the motor, and in others were talking about lag.

Centrifugal superchargers do in fact experience this... when you roll into the throttle in a centrifugal blown car they will start to "build" boost but don't reach their full PSI they're pullied for until its towards the top of the RPM band. A roots style or twin screw supercharged car suffers from NO LAG. Take a ride in a car that was factory supercharged and you will see just what I'm saying. Whether its an older Mini Cooper S, an older Cobalt SS, a new ZR1 Corvette or my Cobra they will all make the boost they are pullied for as soon as the gas pedal hits the stop. On my car in particular (sorry to bring it up again here!) it doesn't matter if its pullied for 17 or 23 psi... as soon as I mat the pedal it will make the target boost level. This is why the torque curve of these cars mentioned have nearly flat torque curves as they make peak torque fairly low in the RPM band.

2. Don't be so quick to say that a turbocharger uses "wasted" potential energy. This energy is NOT free, and no energy is, this is the first law of thermodynamics for a reason. For the same reason why you'd rather have a 3" diameter exhaust over a 2" diameter exhaust, you'd rather have no turbine in your exhaust stream than have one. So a turbo DOES cause horsepower to be lost, and it DOES create heat that is bad for the car, and as such it DOES rob horsepower. There is simply no way around it. Superchargers ALSO do this, but they do it DIFFERENTLY, and in most (but not all) cases, a supercharger will eat up more power than a turbo.

Alright you got me on that one... however I didn't say wasted energy I said it was "basically free" as its exhaust energy that is produced via the combustion process. A turbocharger will produce back pressure at the exhaust ports which will result in a pumping loss, however a turbo will still be more efficient. A turbo will make more power at a given boost level than a supercharger will because it is more efficient.

3. When discussing the efficiency of a supercharger vs. a turbocharger, you're mentioning that a SC can NEVER be as efficient as a TC. What I'm trying to say is, there are superchargers that are within <5% differences in efficiency than a turbocharger. HOWEVER, when you really get into this, it's more of an apples and oranges argument rather than a forced induction argument since a supercharger is actually very different than a turbocharger in the way they handle their business and the problems they cause. That's why I say its a subjective argument.

Whether it's as close a 5% in efficiency or 25%, its still not *as* efficient as the turbo, which is what I was getting at. If you need some reading material on why this is the case then you can go here and do some reading:

http://www.modularfords.com/forums/showthread.php/74284-Terminator-Table-of-Contents

There are several threads in the Table of Contents there that talk about efficiency of blowers/turbos and get into equations regarding the subject.

If you want to get into a thermodynamics debate over all this then I'll go ahead and concede as I'm not too savvy on that subject. You can talk to one of our administrators on the subject on the above board (his S/N is black2003cobra) as he has extensive knowledge about thermodynamic properties and theory. The man has forgotten more about that stuff than I'll probably ever know

The closer the displacement of the blower gets to the displacement of the engine the more you'll notice supercharger lag. I know Kenne Bell has done extensive testing to show that their 2.8L blower was the largest blower that efficiently worked on the car. You can shove any size blower you want on there though. Just remember, as it gets larger it robs a lot more horsepower, so it'll be harder to get spinning to full boost as quickly. Most people don't experience supercharger lag because not many idiots are stupid enough to over blower a car.👍

Ah the ole' Kenne Bell "PDF propaganda" files that are all over their website... I take those with a grain of salt. Don't believe everything you read on the internet... if you do then I've got some nice oceanfront property in Montana that I'll sell you. The 3.4L works very well on a stock cube/compression 4.6L and it doesn't seem to have any problems spinning the rotors up as soon as I hit the pedal. The quickest/fastest twin screw Cobras in the country (both record setting cars actually) have been powered by a Whipple 3.4L.

I assure you I'm not an "idiot" that has overblown my car... I've learned a thing or two about the car in the 7+ years I've owned it now



Shannon

 

[mesaboys3]

It's really depends on which one fits you or the car better, you can see how much it will raise the PP rating on the car and you might want to go that way. You could also want to go with what you feel like just depends on what your prefer. I always go with a High range Turbo or the Supercharger if it raises the PP higher than the High Range Turbo

 

[Sm0k3:D]

Its subjective. It always will be. What do you want to do with the car?

I want to take a nice pic in photomode... XD

(Sorry, I could'nt resist XD)

Now seriosly. IN GAME there's a diference in how the engine gives you the power. I think the best you can do is try both and choose the one you like more.
Don't worry about efficiency, you aren't paying the fuel. It will be nice if someone does a efficiency test IN GAME. Maybe it would be useful for enduro races if it is an huge diference... XD

In real life, most manufacturers uses turbo. There is a reason for doing that: Efficiency (in the normal way of normal people of using a car).
Efficiency is a serious bussines everywhere but USA. (They like big cars, with high weight, with big engines) So you can't talk about american cars if you're talking about efficiency. (I love american cars, but this is not the point)
Why you can't buy a superchargued diesel? Because if you want to buy a diesel you don't want a fast car, you want an efficient car. So you get a turbo diesel.

 

[thevictor390]

I've noticed in GT5 that adding the highest pressure turbo almost always results in significantly more peak power than the supercharger, even if it's not an ideal powerband. It makes the car more difficult to drive but it should be quite a bit faster with the power difference. On my RX-8 it's a matter of nearly 200 HP.

 

[articzap]

Ah the ole' Kenne Bell "PDF propaganda" files that are all over their website... I take those with a grain of salt. Don't believe everything you read on the internet... if you do then I've got some nice oceanfront property in Montana that I'll sell you. The 3.4L works very well on a stock cube/compression 4.6L and it doesn't seem to have any problems spinning the rotors up as soon as I hit the pedal. The quickest/fastest twin screw Cobras in the country (both record setting cars actually) have been powered by a Whipple 3.4L.

I assure you I'm not an "idiot" that has overblown my car... I've learned a thing or two about the car in the 7+ years I've owned it now

People have been experimenting with large blowers on Cobalts, which is the realm I come from, although don't own. They have experienced supercharger lag. It's not just propaganda, and when you plot compressor maps, it shows it.

 

[FOURCED]

People have been experimenting with large blowers on Cobalts, which is the realm I come from, although don't own. They have experienced supercharger lag. It's not just propaganda, and when you plot compressor maps, it shows it.

I could see that happening on a Cobalt, as its a four cylinder you're talking about. That isn't me insulting the car for being only a four cylinder... as you pointed out the bigger the blower the more power it takes to turn, a motor with half the cylinders as a V8 having to work harder to spin a bigger blower might experience some sort of lag associated with it. I have never experienced any such lag with any of the blowers that have been on my car, and there have been three now counting the stock M112.

Actually you do have a valid point and I see what you're saying... what I was talking about is don't take KB's word for it based off their "PDF" files they put up on their website. Trust me... the 3.4L is not too big for a standard bore/stroke of a 4.6L. A 4.0L would be a different story though



Shannon

 

[articzap]

I could see that happening on a Cobalt, as its a four cylinder you're talking about. That isn't me insulting the car for being only a four cylinder... as you pointed out the bigger the blower the more power it takes to turn, a motor with half the cylinders as a V8 having to work harder to spin a bigger blower might experience some sort of lag associated with it. I have never experienced any such lag with any of the blowers that have been on my car, and there have been three now counting the stock M112.

Actually you do have a valid point and I see what you're saying... what I was talking about is don't take KB's word for it based off their "PDF" files they put up on their website. Trust me... the 3.4L is not too big for a standard bore/stroke of a 4.6L. A 4.0L would be a different story though



Shannon

Agree'd. 👍

 

[Smackinjuice]

2008 Cobalt SC 215 HP and 190 tq or something
2010 Cobalt TC 260 hp and 260 tq at 2000 rpms

TC's are just better

 

[boomee]

is there a list anywhere of wich cars can be both supercharged and turbo charged?

 

[boomee]

2008 Cobalt SC 215 HP and 190 tq or something
2010 Cobalt TC 260 hp and 260 tq at 2000 rpms

TC's are just better

are u kidding the cobalt REALLY not good example

 

[Smackinjuice]

Why is the cobalt a bad example? it's the most recent car I know of to have a supercharger first gen, then a turbo the 2nd. Up to date and straight from the production.

So why is that a bad example?

 

[articzap]

Why is the cobalt a bad example? it's the most recent car I know of to have a supercharger first gen, then a turbo the 2nd. Up to date and straight from the production.

So why is that a bad example?

Two very different motors. I know way to much about those cars.