[hotrod2448]

Originally Posted by zenmaster

But what I was saying is that this faster piston acceleration also allows you to reduce the engine speed for the same amount of road speed, which means less heat generated.

No. The engine is linked to the rear tires at a given gearing, to go a given speed you must turn the same RPM regardless of power unless you are changing gear ratios.

I think you meant because the engine is making more power it now isn't working as hard to do the same speed.

[zenmaster]

Originally Posted by hotrod2448

No. The engine is linked to the rear tires at a given gearing, to go a given speed you must turn the same RPM regardless of power unless you are changing gear ratios.

I think you meant because the engine is making more power it now isn't working as hard to do the same speed.

You are right the gearing would be the same. The engine is simply able to produce more torque at the same RPM. What I'm wondering is if the RPM is the same, how can this cause more friction and oil temps to rise?

[2ABRUPT]

Originally Posted by zenmaster

You are right the gearing would be the same. The engine is simply able to produce more torque at the same RPM. What I'm wondering is if the RPM is the same, how can this cause more friction and oil temps to rise?

RPM won't. Revolutions per minute is a velocity. You can obtain that regardless of whether you add power or take power away. The coefficent of drag will stay the same and the oil will remove heat in portion to rpm. But there is a derivative to rpm. This is how fast you obtain a set rpm. This is the key to torque and power being obtained. It is also the key to how fast the oil heats up.

-M

[hotrod2448]

Originally Posted by zenmaster

You are right the gearing would be the same. The engine is simply able to produce more torque at the same RPM. What I'm wondering is if the RPM is the same, how can this cause more friction and oil temps to rise?

It has to do with load more than RPM.

Either way I'm reasonably certain it has to do with blocking cooling area and next to nothing to do with intake charge temp.

[XS4]

My experience with replacing cheap(er) factory plastic & aluminum intercoolers with high quality aftermarket ICs is this:
- ability to run more timing advance due to colder denser cylinder charging.
- less potential for boost leaks (factory intercoolers have plastic ends that are ah, crimped to the metal core, rather than a single welded construction)
- increased resistance to heat soak and temperature rise because the aftermarket IC sheds heat more efficiently than stock.

Preventing another component like the radiator from working efficiently by blocking it is obviously another story.

[2ABRUPT]

Originally Posted by hotrod2448

Either way I'm reasonably certain it has to do with blocking cooling area and next to nothing to do with intake charge temp.

Engine coolant is also different from oil temperature. Coolant flows through the head and the block. It also absorbs heat but doesn't affect oil temps.

-M

[hotrod2448]

Originally Posted by XS4

My experience with replacing cheap(er) factory plastic & aluminum intercoolers with high quality aftermarket ICs is this:
- ability to run more timing advance due to colder denser cylinder charging.
- less potential for boost leaks (factory intercoolers have plastic ends that are ah, crimped to the metal core, rather than a single welded construction)
- increased resistance to heat soak and temperature rise because the aftermarket IC sheds heat more efficiently than stock.

That's nice. It's not really what we are talking about but...

[hotrod2448]

Originally Posted by 2ABRUPT

Engine coolant is also different from oil temperature. Coolant flows through the head and the block. It also absorbs heat but doesn't affect oil temps.

-M

When you have a coolant to oil heat exchanger it does.

[IND-Distribution]

I don't sell intercoolers for the E92, but I can hopefully shed some light on the topic:

Adding an intercooler will not typically create horsepower without tuning. Although the cooler is designed to reduce the temperatures of the intake charge, the rapid increase in volume creates a drop in intake boost pressure. Think of the ideal gas law- pV=nRT. As temperature decreases, boost pressure drops as well. Without additional boost and fueling, the power gains that can be gained from a proper charge cooling system can't be realized.

The bottom line is that to get proper power by adding an intercooler, you need to add more boost.

Thermodynamics say that increasing engine output will always increase heat. Running more boost means you're running your turbos harder, you're flowing more CFM through the engine, and creating higher exhaust gas temperatures.

That all means that you'll see higher oil and coolant temperatures, apples for apples, when running more boost through an engine with an upgraded intercooler.

This isn't a failure of design on the part of the cooler's designer, it's simply a byproduct of dramatic power increases. At some power level, the stock cooling system won't be able to cope at all, and will need to be upgraded.

[zenmaster]

If the air is already more dense due to lower temp, why do you need to raise the boost? This is assuming there is no pressure drop on the upgraded IC.

[IND-Distribution]

A larger intercooler will always drop pressure. Some will have smaller pressure drops depending on core efficiencies, but all cores that are larger than stock will have some pressure drop.

[2ABRUPT]

Originally Posted by zenmaster

This is assuming there is no pressure drop on the upgraded IC.

You can't assume this. In 90% of the cases, an upgraded intercooler WILL cause pressure drop of some sort.

Increasing the boost is to bring your turbo back to the way it was. You'll experience more turbo lag too.

Poster above is correct... Increasing power is going to increase heat all around.

-M

[zenmaster]

Originally Posted by ilia@industry

A larger intercooler will always drop pressure. Some will have smaller pressure drops depending on core efficiencies, but all cores that are larger than stock will have some pressure drop.

That is interesting, I recall reading a couple of larger than stock ICs being mentioned in this very forum which claim to not have a pressure drop.

[IND-Distribution]

Unfortunately, there's no free lunch. If you look at the ideal gas law, it prohibits any kind of free temperature reduction. Lowering flow velocity will decrease temperature while decreasing pressure. Raising flow velocity increases temperature and pressure. So on and so forth.

[zenmaster]

OK, so what does it mean when these guys say that the bigger core IC's have less pressure drop than stock?

STETT
http://www.e90post.com/forums/showpo...1&postcount=23

Turbonetics
http://www.e90post.com/forums/showpo...5&postcount=54

Spearco
http://www.e90post.com/forums/showpo...0&postcount=44

[IND-Distribution]

A bigger core could still operate at a lower pressure differential than stock, if the internal fin design is more aerodynamically efficient. Assuming you're using a fantastic core, you could maintain the same or higher flow velocity through the core, in order to maintain the same or lower pressure drop as stock. This is assuming the stock intercooler is not particularly efficient, which is something that'd need to be tested.

Again, there's no escaping physics, and no free lunch. If you're reducing temperature, you're reducing velocity. If you're reducing velocity, you're lowering pressure.

[zenmaster]

Originally Posted by ilia@industry

A bigger core could still operate at a lower pressure differential than stock, if the internal fin design is more aerodynamically efficient. Assuming you're using a fantastic core, you could maintain the same or higher flow velocity through the core, in order to maintain the same or lower pressure drop as stock. This is assuming the stock intercooler is not particularly efficient, which is something that'd need to be tested.

I agree, the efficiencies of the stock IC should be tested. But the point was that these 3 intercoolers are all larger than stock and claim less of a pressure drop. This would seem to counter the blanket statement that increasing the size will increase pressure drop. It also calls into question that, using an upgraded IC, the turbo would necessarily have to work harder to produce more boost to maintain target pressure.

[Orb]

Originally Posted by ilia@industry

Unfortunately, there's no free lunch. If you look at the ideal gas law, it prohibits any kind of free temperature reduction. Lowering flow velocity will decrease temperature while decreasing pressure. Raising flow velocity increases temperature and pressure. So on and so forth.

Acctually this is not right....maybe your thinking about pressure losses?

You may want to consider viscosity in your argument.

Orb

[zenmaster]

Originally Posted by 2ABRUPT

Reducing intake air temp increases the volumetric MASS of the air. You'll get more power period (not just at low rpms) since the motor will burn more fuel/air charge per compression stroke and the power stroke will be more explosive which will cause the piston to move downward faster than before (more torque=more horsepower). This will increase friction which of course, causes more internal heat on the oil that is supposed to reduce friction.

How does what you are saying agree with this:

I installed my Spearco along with Procede on Sunday ... I didn't to too much testing , but I can say for sure that temperature decresed by 25-30 degrees ... I was pushing my car hard today in the city and the temp was around 225-240 ... Before Spearco FMIC i was always @250 and I wasn't pushing it at all ... So , I am glad with this upgrade ... Now waiting for V2 and DP's.

What he's talking about here are oil temps decreasing due to lower intake manifold temps. He is producing more power, but temps are actually lower...

[sg335]

This is good discussion. For arguments sake, let's assume that the car is running stock boost and does not have an upgraded ECU program/piggyback. So we would not generate more heat from more boost pressure over stock and I would agree that more boost pressure (11 - 14 psi) than stock will generate more heat regardless of whether or not you installed an aftermarket FMIC. So with stock psi, cooler/denser air will generate a more complete combustion and allow the car to run closer to max stock boost pressure (?). Does this more efficient combustion create more heat in the engine and therefore raise the oil and coolant temps?

[2ABRUPT]

Originally Posted by zenmaster

How does what you are saying agree with this:

What he's talking about here are oil temps decreasing due to lower intake manifold temps. He is producing more power, but temps are actually lower...

How do you know he's producing more power? He never measure his power output before or after the intercooler.

OK. Thinking more about it, it is very possible that if the temperature of combustion is decreased then the oil temperature could decrease as well. I still think that if the engine is required to run harder via increased boost, that the combustion heat will increase again and bring oil temps back up. The general rule is that heat is transferred all over the place.

-M

[leftcoastman]

Originally Posted by zenmaster

I do not understand the mechanism how this could happen.

Wow - I come back and we have a full blown debate with basis in science and facts. What happened to this place?

My meager input, given what has been said already: The Laws of Thermodynamics carry more weight in my book than the marketing pitches of Stett, Spearco and Turbonetics.

Ok one more thing: The accepted logic is that cooler IATs allow more fuel to be added to the combustion cycle. Given that the burning of fuel will result in one of two products (1) motion (2) heat aka inefficiencies, would it not be reasonable to assume that the additional fuel burned with an upgraded FMIC (over stock) would be less than 100% efficient?

That would imply more heat.

If these FMIC designers can create a 100% efficient internal combustion process, they might as well book their flight and hotel reservations for Stockholm, because Alfred Nobel has a gift for them.