Turbo vs Atmospheric engine race track

[gruntguru]

. . .
Granted simple pressure is not the same as mass air flow, and experts may chime in on true equivalence.

If you can intercool to ambient, simple pressure ratio is the same as density ratio (and therefore massflow ratio.) So your numbers are not unreasonable.

[Tommy Cookers]

1988 the Turbo motors were both fuel and boost limited, na cars had unlimited fuel. Turbo cars won every single race.

Why turbo won every race,does it have more HP than NA engines?

Of course. The equivalency factor of 2 was not correct. (Simplistic) but with 60 PSI boost (or 75 PSI absolute), then 3000cc atmo engine at ~15psi ambient is roughly equivalent to 600cc turbo engine not 1500cc.
So ~600cc supercharged would have been a more correct equivalence for 3000cc NA.
Granted simple pressure is not the same as mass air flow, and experts may chime in on true equivalence. :)

(yes there's been some informative posts lately .......)

supercharging came c.100 years ago but equivalence (1.5x) came in 1938 (this then kept at Indy for decades)
then 3x in F1 eg WDC 1950-1, then 4x in F2 eg WDC 1952-3, then 3.33x in F1 1954-60, then 3x in F1 1961-65
so supercharging pushed out but returning after eg Le Mans and WTC gave 1.4x and F1 reverted to 2x in WDC 1966-88

now all the remarkable current F1 design and control features could be applied to benefit NA engines ....
remember eg from 100 years ago over-compressed aircraft engines (most SC but some NA) were the thing
(and eg restrictor F3 etc was of course over compressed NA)

a big argument against NA could be the inevitably larger heat dump to coolant via the larger area of combustion chamber
somewhat reflected in the old European horsepower taxes

[hsg]

Isolated anecdote - A very good engine builder I know well builds engines for the local MX-5 series. He's found that for the turbo engines (in the same car) to beat the n/a ones. they need to have 20% - 50% more power.

I dont think so.

We can compare turbo vs NA engine as two NA engines: car engine vs bike engine.

Car engine has more torque at lower rpm(like turbo).
When you put bike engine in car, in racing car engine will always win because bike engine dont have power at lower rpm, so overall you operate engine at lower average power.

Isnt it?

[BassVirolla]

Isolated anecdote - A very good engine builder I know well builds engines for the local MX-5 series. He's found that for the turbo engines (in the same car) to beat the n/a ones. they need to have 20% - 50% more power.

I dont think so.

We can compare turbo vs NA engine as two NA engines: car engine vs bike engine.

Car engine has more torque at lower rpm(like turbo).
When you put bike engine in car, in racing car engine will always win because bike engine dont have power at lower rpm, so overall you operate engine at lower average power.

Isnt it?

Turbos, pipes wastegates and intercoolers all have a something called mass.

When the car is the same and the base engine is the same or roughly similar, the turbo car will always be quite heavier. In a car well under a tonne it's not negligible.

Edit: Even more, if the engine is the same and you are doing an engine tuning, to achieve the same power the turbo will probably be the cheapest route. But also the heavier. I hope I've made my point clear.

[hsg]

Isolated anecdote - A very good engine builder I know well builds engines for the local MX-5 series. He's found that for the turbo engines (in the same car) to beat the n/a ones. they need to have 20% - 50% more power.

I dont think so.

We can compare turbo vs NA engine as two NA engines: car engine vs bike engine.

Car engine has more torque at lower rpm(like turbo).
When you put bike engine in car, in racing car engine will always win because bike engine dont have power at lower rpm, so overall you operate engine at lower average power.

Isnt it?

Turbos, pipes wastegates and intercoolers all have a something called mass.

When the car is the same and the base engine is the same or roughly similar, the turbo car will always be quite heavier. In a car well under a tonne it's not negligible.

Edit: Even more, if the engine is the same and you are doing an engine tuning, to achieve the same power the turbo will probably be the cheapest route. But also the heavier. I hope I've made my point clear.

question is if weight and power is the same, only moment/power curve is different

[Greg Locock]

So download optimumlap, make all the assumptions you want, then find a track that behaves the way you want.

[BassVirolla]

I dont think so.

We can compare turbo vs NA engine as two NA engines: car engine vs bike engine.

Car engine has more torque at lower rpm(like turbo).
When you put bike engine in car, in racing car engine will always win because bike engine dont have power at lower rpm, so overall you operate engine at lower average power.

Isnt it?

Turbos, pipes wastegates and intercoolers all have a something called mass.

When the car is the same and the base engine is the same or roughly similar, the turbo car will always be quite heavier. In a car well under a tonne it's not negligible.

Edit: Even more, if the engine is the same and you are doing an engine tuning, to achieve the same power the turbo will probably be the cheapest route. But also the heavier. I hope I've made my point clear.

question is if weight and power is the same, only moment/power curve is different

Sorry, but you don't quoted the right post.

I was saying that because of the comparisons in MX5 vs. MX5.

Makes total sense in this case.

Nevertheless, at equal weight, turbo wins with the same horsepower, I think, because of the average power you mention.

[hsg]

So download optimumlap, make all the assumptions you want, then find a track that behaves the way you want.

Isnt power curve of turbo always better than NA?
Area under operating part of power curve is always bigger at turbo, so that mean you are using higher average power over lap?

[Greg Locock]

Probably. I'm just pointing out there are tools available that would allow an objective examination of this rather than the usual waffle from the usual suspects.

[AR3-GP]

There are more variables such as weight, what kind of car, what kind of engines etc.
In general a turbo engine has the upper hand regarding:
- weight
- usable powerband
- efficiency
- durability
- cost
- flexibility

NA engines have the upper hand in:
- smoothness (no turbo lag)

Electric engines have even smoother delivery, that’s why the combination of a turbo engine with an electric motor is so good.

This is very old but I don't think all of this is true.

Porsche raced their 911 in the GT category at Le Mans. They always raced with the naturally aspirated flat 6 engine. The explanation given was that although the 911 Turbo is the halo and highest performing model in the range, adding turbos adds more points of failure. This is not ideal for a endurance racing car.

Toyota lost the 2016 24 hours of Le Mans in dramatic fashion due to a boost leak on the final lap. These things don't happen with naturally aspirated engines.

I wouldn't definetely not rank turbo engines ahead of n/a engines in terms of durability or cost.

[hollus]

Probably. I'm just pointing out there are tools available that would allow an objective examination of this rather than the usual waffle from the usual suspects.

Optimum lap is free, relatively easy to use, simple enough and fast. Yet quite good.
Seconded, get optimum lap and test.

[hsg]

There are more variables such as weight, what kind of car, what kind of engines etc.
In general a turbo engine has the upper hand regarding:
- weight
- usable powerband
- efficiency
- durability
- cost
- flexibility

NA engines have the upper hand in:
- smoothness (no turbo lag)

Electric engines have even smoother delivery, that’s why the combination of a turbo engine with an electric motor is so good.

This is very old but I don't think all of this is true.

Porsche raced their 911 in the GT category at Le Mans. They always raced with the naturally aspirated flat 6 engine. The explanation given was that although the 911 Turbo is the halo and highest performing model in the range, adding turbos adds more points of failure. This is not ideal for a endurance racing car.

Toyota lost the 2016 24 hours of Le Mans in dramatic fashion due to a boost leak on the final lap. These things don't happen with naturally aspirated engines.

I wouldn't definetely not rank turbo engines ahead of n/a engines in terms of durability or cost.

But here is talk about performance(lap time) not durability.

[AR3-GP]

There are more variables such as weight, what kind of car, what kind of engines etc.
In general a turbo engine has the upper hand regarding:
- weight
- usable powerband
- efficiency
- durability
- cost
- flexibility

NA engines have the upper hand in:
- smoothness (no turbo lag)

Electric engines have even smoother delivery, that’s why the combination of a turbo engine with an electric motor is so good.

This is very old but I don't think all of this is true.

Porsche raced their 911 in the GT category at Le Mans. They always raced with the naturally aspirated flat 6 engine. The explanation given was that although the 911 Turbo is the halo and highest performing model in the range, adding turbos adds more points of failure. This is not ideal for a endurance racing car.

Toyota lost the 2016 24 hours of Le Mans in dramatic fashion due to a boost leak on the final lap. These things don't happen with naturally aspirated engines.

I wouldn't definetely not rank turbo engines ahead of n/a engines in terms of durability or cost.

But here is talk about performance(lap time) not durability.

I was referring to a point made by the person that was quoted:

There are more variables such as weight, what kind of car, what kind of engines etc.
In general a turbo engine has the upper hand regarding:
- weight
- usable powerband
- efficiency
- durability
- cost

Of course, from a performance point of view, the Turbo does more with less.

[ENGINE TUNER]

Isolated anecdote - A very good engine builder I know well builds engines for the local MX-5 series. He's found that for the turbo engines (in the same car) to beat the n/a ones. they need to have 20% - 50% more power.

I dont think so.

We can compare turbo vs NA engine as two NA engines: car engine vs bike engine.

Car engine has more torque at lower rpm(like turbo).
When you put bike engine in car, in racing car engine will always win because bike engine dont have power at lower rpm, so overall you operate engine at lower average power.

Isnt it?

Turbos, pipes wastegates and intercoolers all have a something called mass.

When the car is the same and the base engine is the same or roughly similar, the turbo car will always be quite heavier. In a car well under a tonne it's not negligible.

Edit: Even more, if the engine is the same and you are doing an engine tuning, to achieve the same power the turbo will probably be the cheapest route. But also the heavier. I hope I've made my point clear.

Your point is far from clear. Do you know what else has mass? ....Fuel, and turbo cars are far more fuel efficient because they don't have to rev as high to reach the same power as NA. 2 cars, same power, 1 turbo, one not, same mass before engine and fuel included, turbo car WILL ALWAYS WIN. Plain and simple.

[ENGINE TUNER]

There are more variables such as weight, what kind of car, what kind of engines etc.
In general a turbo engine has the upper hand regarding:
- weight
- usable powerband
- efficiency
- durability
- cost
- flexibility

NA engines have the upper hand in:
- smoothness (no turbo lag)

Electric engines have even smoother delivery, that’s why the combination of a turbo engine with an electric motor is so good.

This is very old but I don't think all of this is true.

Porsche raced their 911 in the GT category at Le Mans. They always raced with the naturally aspirated flat 6 engine. The explanation given was that although the 911 Turbo is the halo and highest performing model in the range, adding turbos adds more points of failure. This is not ideal for a endurance racing car.

Toyota lost the 2016 24 hours of Le Mans in dramatic fashion due to a boost leak on the final lap. These things don't happen with naturally aspirated engines.

I wouldn't definetely not rank turbo engines ahead of n/a engines in terms of durability or cost.

NA must run at a higher average rpm to produce the same power as a turbo. That is what makes Turbo cars more efficient and durable. Yes, more possible points of failure, but much lower stress put on reciprocating parts within the engine which tend to cause major failures.