wear and tear.

[KMracer]

which do you think does more wear and tear on an engine?

a) roots supercharger- crankshaft snout stresses, always on full boost

b) turbo- rapid increase in boost in relation to rpm's.

my friend says its b. i say a.

[-Jayson-]

B for a few reasons

Turbos abuse the oil, this means you need more frequent oil changes and if you dont can cause problems. Turbos also generate alot more heat, from the turbo manifold, all that heat can get soaked into the engine. Also with a turbo you run the risk of accidentally over boosting. You will never have that problem with a supercharger.

[nissanfanatic]

Originally Posted by -Jayson-

B for a few reasons

Turbos abuse the oil, this means you need more frequent oil changes and if you dont can cause problems. Turbos also generate alot more heat, from the turbo manifold, all that heat can get soaked into the engine. Also with a turbo you run the risk of accidentally over boosting. You will never have that problem with a supercharger.

Abuse the oil?

Generate more heat?

Overboosting?

Never have any of those problems with a supercharger?

Define abusing oil.... It cools and lubricates the turbocharger. Kinda the same thing it does for your engine. More frequent oil changes are not needed. Every 3000 miles or 3 months is just fine. If you do a lot of racing, sooner is better. But that has nothing to do with turbocharged or not. Any car should follow that guideline, turbocharged, supercharged, nitrous, NA, stock, whatever.

Generates more heat.... Well actually the exhaust heat causes zero temp rise to the intake charge. The air is actually in the compressor about the time it takes for you to blink. Prolly less. Similar to you touchign a hot grill really quick. All of the heat is generated by compressing the air. Efficiency is a degree of temp rise. Less efficiency=more heat created. It is an exact percentage. Pressurizing air creates heat no matter what(or any fluid for that matter). It is a constant. Now whatever the temp rise is on what boost you are running, divide it by the percentage of efficiency of your compressor. Now that is the outlet temp. And roots blowers lose while centrifugal superchargers are roughly the same as a turbocharger except they don't have the unused energy efficiency factor. Besides, no more heat is "created" by the turbo. It doesn't make heat. It uses heat as energy. EGT isn't any higher when making more power. Things like AF ratio, timing, cylinder port/head design decide EGT. All extra heat created by making more power usually goes into powering the engine since it is a form of energy.

Overboosting.... Not a problem if you set your car up right.

Never have any of those problems with a supercharger.... Seems like you guys have a huge problem with heat

Truth be told, too many factors to decide which puts more stress on an engine. Stress would be a direct factor of torque curve vs displacement since torque is directly related to Peak Cylinder Pressure. Cylinder pressure=stress.

[KMracer]

Originally Posted by -Jayson-

B for a few reasons

Turbos abuse the oil, this means you need more frequent oil changes and if you dont can cause problems. Turbos also generate alot more heat, from the turbo manifold, all that heat can get soaked into the engine. Also with a turbo you run the risk of accidentally over boosting. You will never have that problem with a supercharger.

we are only discussing the things i mentioned. not in general, just those things. no heat, no overboosting. just 2 pf the exact same engines at 12psi. same intake temp, humidity, psi, a/f ratio. exactly the same. the turbos goes from little to no boost to full in a matter of 500 or so rpm's, does that make it harder on the engine than a supercharger which runs full boost constasntly?

[Black Lotus]

Originally Posted by KMracer

the turbos goes from little to no boost to full in a matter of 500 or so rpm's,

That's not true. Where you come up with that idea?
Turbo's appear to be harder on the exhaust valves. My high boost OEM turbo car has sodium filled exhaust valves, whereas the N/A version does not. On the flip side, a turbo car can be easier on the transmission and rear end, as it tends to lose boost on the upshift (if you shift gears normally) which spares the transmission a big torque bang when you pop the clutch out.

[nissanfanatic]

Its kinda hard to put a supercharger and a turbocharger side by side running 12psi. Different flow throws things off. They are both great choices and the driver/install/matinence ultimately determines which causes more wear.

My engine was stock NA and I went turbo. No problems thus far with valves.

[-Josh-]

Generally speaking on any car with FI, you're going to start getting the most wear on the piston rings, especially an engine that wasn't originally built for FI, that doesn't necessarily mean that those engines cant handle it, it just means they weren't built for it, and will show wear much quicker than a OEM turbo engine. Saying that a turbo causes more wear than a supercharger is like saying a V8 wears more than a 4 banger.

Also i think what Jayson meant about turbo's abusing oil is that, when you add a component such as a turbo that requires engine oil for lubrication, it's just one more thing the oil has to pass through and can lose viscosity much quicker. MOST belt driven superchargers however use their own lubricant and don't need it changed that often. There are some centrifigal superchargers that get tapped into the oil pan on installs and use engine oil but those are usually aftermarket superchargers, not OEM.

Also when you add forced induction you may find that your valv train components will see a little more wear than usual as you usually have to play with timing a bit.

As far as carbon on the exhaust valves, just run a fuel system service/cleaner through the system, that should clear them up pretty good every once in a while.

The reason I would prefer turbo's is simply efficiency, it's been proven time and again a good turbo will provide better gains than most good supers. Hot Rod Magazine has already said that turbo's are quickly becoming the prefered type of FI in racing today, among all car brands.

[KMracer]

Originally Posted by Z28Josh

Generally speaking on any car with FI, you're going to start getting the most wear on the piston rings, especially an engine that wasn't originally built for FI, that doesn't necessarily mean that those engines cant handle it, it just means they weren't built for it, and will show wear much quicker than a OEM turbo engine. Saying that a turbo causes more wear than a supercharger is like saying a V8 wears more than a 4 banger.

Also i think what Jayson meant about turbo's abusing oil is that, when you add a component such as a turbo that requires engine oil for lubrication, it's just one more thing the oil has to pass through and can lose viscosity much quicker. MOST belt driven superchargers however use their own lubricant and don't need it changed that often. There are some centrifigal superchargers that get tapped into the oil pan on installs and use engine oil but those are usually aftermarket superchargers, not OEM.

Also when you add forced induction you may find that your valv train components will see a little more wear than usual as you usually have to play with timing a bit.

As far as carbon on the exhaust valves, just run a fuel system service/cleaner through the system, that should clear them up pretty good every once in a while.

The reason I would prefer turbo's is simply efficiency, it's been proven time and again a good turbo will provide better gains than most good supers. Hot Rod Magazine has already said that turbo's are quickly becoming the prefered type of FI in racing today, among all car brands.

i agree with this 100%.
as for the wear thing, he admitted he was wrong.

[nissanfanatic]

Actually piston ring lands tend to take the most abuse....

No reason an OEM NA engine can't hold FI just as long as an OEM turbo engine if set up correctly and maintanied.

[-Josh-]

It's about the same amount of wear as the rings. Notice when you completely disassemble an engine it's got the piston ring grooves on the cylinder walls, but the rings are taking more damage than the actual cylinder wall. That's another sign of improper lubrication as well, but it's pretty normal on all engines.

[nissanfanatic]

Yea, most OEM turbo engines run piston oil squirters for each cylinder. Our KA's use them. Pays off too. My project engine I tore down still has factory cross hatching visible. And I dug the engine out of a junkyard.lol