[hunter81]

What I don't entirely understand is why they are toning the engine down. The 2.0t makes 241 hp and 273 lb.-ft. of torque in the C300. In the Q50 2.0t, it's 208 hp and 258 lb.-ft. They also list a 0-100 km/h (0-62 mph) time of over 7 seconds for the Q50 versus low 6's for the Benz. Is MB making them tone down the engine as a provision for getting to use, manufacture, and distribute it?

 

[djohnson]

What I don't entirely understand is why they are toning the engine down. The 2.0t makes 241 hp and 273 lb.-ft. of torque in the C300. In the Q50 2.0t, it's 208 hp and 258 lb.-ft. They also list a 0-100 km/h (0-62 mph) time of over 7 seconds for the Q50 versus low 6's for the Benz. Is MB making them tone down the engine as a provision for getting to use, manufacture, and distribute it?

Just guessing but I would guess that Infiniti is opting for a lower boost that will improve wear rates. The high boost turbos have lots of blow-by around the piston rings, which makes changing oil much more regularly a necessity. And then there is the valve stem sealing issue with positive intake manifold pressures. And the valve cover needs to be able to withstand hundreds of pounds of force that will try launch it through the hood of your car (unless it is vented).

If an engine is only designed to last 10,000 miles, then boost as much as possible. But if you want an engine to last 200,000, you have to reduce the boost. Which is why Infiniti will be introducing a 3.0 L Turbo. It is likely the sweet spot between boost/power and wear - at least for now.

I personally think turbo is the way to go from a power density point of view. But there are lots of little issues associated with a positive intake manifold pressure. The higher the boost, the bigger these challenges become.

I don't think the Infiniti community would like the idea of changing oil every 2500-3000 miles. I think the Benz community would be much more amenable to the higher oil change rate IMHO.

 

[djohnson]

more.....

Just to emphasize the positive pressure issue associated with a turbo, lets assume that the intake manifold that is under pressure has a top surface area of 1 square foot. It probably has more but lets use this value as an estimate.

And, lets assume that the boost pressure from a turbo is 1 atmosphere or 14.7 psi. This is a pretty high number. Most turbo boost pressures are much lower (1/2 or less).

In theory, this kind of configuration would make the power of a 4 cylinder engine equal to an 8 cylinder engine because you can get twice the amount of air in each of the 4 cylinders.

The math is simple:
1 square foot = 144 square inches
144 square inches * 14.7 pounds/square inch = 2116.8 pounds

2116 pounds of force is a lot of force to contain.

 

[David_in_CT]

Because everything is about what other people think...

People who care what other people think get MB CLA250 - the Honda Civic of MB

 

[mattreading22]

We just had training on Wednesday, and they will be releasing the 2.0L turbo, as well as the 3.0L twin turbo that is going in the coupe. These will arrive early this next Spring before the coupe comes out. Should be interesting to see the differences in performance between the motors coming out!

 

[convex]

We just had training on Wednesday, and they will be releasing the 2.0L turbo, as well as the 3.0L twin turbo that is going in the coupe. These will arrive early this next Spring before the coupe comes out. Should be interesting to see the differences in performance between the motors coming out!

Coupe?! That should be sexy.

 

[mattreading22]

Coupe?! That should be sexy.

Yes, the coupe will be coming out next fall with a 3.0L twin turbo, and possibly an upgraded model with around 450hp as well. This is all what was told to us in training. They will however be bringing out the TT motor before hand in the Q50 next Spring.

 

[hunter81]

Just guessing but I would guess that Infiniti is opting for a lower boost that will improve wear rates. The high boost turbos have lots of blow-by around the piston rings, which makes changing oil much more regularly a necessity. And then there is the valve stem sealing issue with positive intake manifold pressures. And the valve cover needs to be able to withstand hundreds of pounds of force that will try launch it through the hood of your car (unless it is vented).

If an engine is only designed to last 10,000 miles, then boost as much as possible. But if you want an engine to last 200,000, you have to reduce the boost. Which is why Infiniti will be introducing a 3.0 L Turbo. It is likely the sweet spot between boost/power and wear - at least for now.

I personally think turbo is the way to go from a power density point of view. But there are lots of little issues associated with a positive intake manifold pressure. The higher the boost, the bigger these challenges become.

I don't think the Infiniti community would like the idea of changing oil every 2500-3000 miles. I think the Benz community would be much more amenable to the higher oil change rate IMHO.

Thank you for the info. I've tried to look up info on the internet before on how boosting can stress and engine, but hadn't gotten that much detail before.

I thought, however, that Benzes usually had longer oil change intervals. Something like 10,000 miles or so. I know they use synthetic. I'm not sure if Infiniti also regularly uses synthetic, but I know my dealer does.

 

[hunter81]

Yes, the coupe will be coming out next fall with a 3.0L twin turbo, and possibly an upgraded model with around 450hp as well. This is all what was told to us in training. They will however be bringing out the TT motor before hand in the Q50 next Spring.

Interesting!

 

[djohnson]

I thought, however, that Benzes uqually had longer oil change intervals. Something like 10,000 miles or so. I know they use synthetic. I'm not sure if Infiniti also regularly uses synthetic, but I know my dealer does.

That is a really good question. The interval between oil changes depends on several factors:
1. Compression Ratio
2. The number and type of compression rings around the piston.
3. Oil amount in the reservoir
4. Driving Type
5. Type of oil


I checked several Benz forums and indeed, some of the Benz cars have oil intervals of 10,000 miles. Then again, many of the forum participants change oil every 3k-7.5k miles.

What we do know is that more compression rings cause greater friction and less MPG but greater oil change intervals.

If the intention of a turbo is to get greater fuel efficiency with good reserve power, the tenancy is to put fewer compression rings on the piston. This necessarily allows for more blow-by, especially in a high boost condition.

And if you have an oil reservoir that has fewer quarts of oil to save on weight and space (which improves MPG), you will need to change oil more frequently.

So, you see, it all depends on where the emphasis is placed on engine design.

What does seem apparent is that there is some good stuff coming. Both direct injection and turbos have been around for a while. But each has had problems/obstacles. The first generation of direct injection engines had significant issues with injectors fouling. I think Hyundai had real issues in its first attempts. And turbos always had lag.

Now, the technology has evolved. Direct injection now offers good reliability. And by redesigning turbo systems and driving them with electric motors instead of exhaust systems and shortening the path to the cylinders, lag is almost non-existent.

But I am not sure I want to be an early adopter for these engines. May be 2nd generation.

 

[hunter81]

By the way, my typing is "uqually" way better.

 

[Truth]

Yes, the coupe will be coming out next fall with a 3.0L twin turbo, and possibly an upgraded model with around 450hp as well. This is all what was told to us in training. They will however be bringing out the TT motor before hand in the Q50 next Spring.

Any idea's on pricing? I'm curious how much the 3.0 TT will cost. And if there is a 450 HP version I'm guessing these will run around 70-80K to compete with the M3/4?

 

[hunter81]

Any idea's on pricing? I'm curious how much the 3.0 TT will cost. And if there is a 450 HP version I'm guessing these will run around 70-80K to compete with the M3/4?

I'm hoping that there is little to no price change for the new engine. I would be surprised if it were anything significant.

 

[Truth]

I'm hoping that there is little to no price change for the new engine. I would be surprised if it were anything significant.

I would hope but I can't imagine the price remaining the same for more HP and Torque. Especially some special edition with 450 HP. The IPL was hella expensive for hardly any performance gains. I'd imagine some sort of big break kit, suspension upgrade and alot of parts that were going to go in the Eau Rogue. I"m going to guess starting price would be 65K once built it will be pushing 70-75k

 

[hunter81]

I would hope but I can't imagine the price remaining the same for more HP and Torque. Especially some special edition with 450 HP. The IPL was hella expensive for hardly any performance gains. I'd imagine some sort of big break kit, suspension upgrade and alot of parts that were going to go in the Eau Rogue. I"m going to guess starting price would be 65K once built it will be pushing 70-75k

I'm talking about just the 330 hp 3.0tt version that I've heard about. Yeah, 400 or 450 hp will definitely be more money.

Yeah, the IPL was a flop. The modifications didn't make the car any faster.

 

[Truth]

I'm talking about just the 330 hp 3.0tt version that I've heard about. Yeah, 400 or 450 hp will definitely be more money.

Yeah, the IPL was a flop. The modifications didn't make the car any faster.

Oh no doubt, I thought there was going to be a 2.0 version with the 200 something Hp. Then the 3.0 with 400, then a Sport or something with 450?

 

[hunter81]

Oh no doubt, I thought there was going to be a 2.0 version with the 200 something Hp. Then the 3.0 with 400, then a Sport or something with 450?

I originally heard it would be a 2.0t, the existing 3.7 and a 3.0tt that would make 400+.

Since then I have read the 3.7 would go away and would be replaced with the 3.0tt. The 3.0tt would have a 330 hp version and a 400+ hp version.

Because the 3.7 is so old, I think the latter version makes more sense. Even at 330 hp, the 3.0tt should be more efficient and have better torque.

 

[Truth]

I originally heard it would be a 2.0t, the existing 3.7 and a 3.0tt that would make 400+.

Since then I have read the 3.7 would go away and would be replaced with the 3.0tt. The 3.0tt would have a 330 hp version and a 400+ hp version.

Because the 3.7 is so old, I think the latter version makes more sense. Even at 330 hp, the 3.0tt should be more efficient and have better torque.

Ahh that makes more sense.

 

[David_in_CT]

I refuse to drive turbo - never have and hope never will

 

[Fateswarning]

By the way, my typing is "uqually" way better.

I couldn't even spell "If" correctly in the darn title.