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Need "Turbo schooling'--post for you tech heads

1041 Views 16 Replies 7 Participants Last post by nate, Apr 11, 2002

Guest84

Discussion Starter · Apr 11, 2002

Okay, now I've heard this mentioned by more than one source, and even read an article or two that references "Turbo burning"...why exactly do "Turbo-engines" shorten the life of their respective engines? Higher RPM=higher wear and tear? School me please.

1 - 17 of 17 Posts

in_d_haus

· #2 · Apr 11, 2002

It's not the higher RPM, you control that with your foot. It's more the higher compression ratio of a turbo/SC engine. Remember you are ramming air into the cylander above atmospheric presss so it is already compressed when it gets in to the cylander (boost pressure)

It also tends to be a hotter air charge, a result of: 1) the hot exhaust gasses on one side of the turbo heating up the unit and the incoming air and 2) when ya compress something the resultant is energy in the form of heat. (the air gets hot)

An intercooler will help this as it takes the charge and cools it.

Additionally people don't just drive a turbo car like granny in her '52 Buick. Plus the higher compression ratio increases the chance of detonation and preignition unless higher octane fuel is burned.

That's some of the basics... theres stresses set up by the additional power on bearings, piston rings and the entire reciprocating assembly in general.

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Guest84

Discussion Starter · #3 · Apr 11, 2002

in_d_haus said:
It's not the higher RPM, you control that with your foot. It's more the higher compression ratio of a turbo/SC engine. Remember you are ramming air into the cylander above atmospheric presss so it is already compressed when it gets in to the cylander (boost pressure)

It also tends to be a hotter air charge, a result of: 1) the hot exhaust gasses on one side of the turbo heating up the unit and the incoming air and 2) when ya compress something the resultant is energy in the form of heat. (the air gets hot)

An intercooler will help this as it takes the charge and cools it.

Additionally people don't just drive a turbo car like granny in her '52 Buick. Plus the higher compression ratio increases the chance of detonation and preignition unless higher octane fuel is burned.

That's some of the basics... theres stresses set up by the additional power on bearings, piston rings and the entire reciprocating assembly in general.

Cool thks! Why do you suppose that BMW hasn't make a "Turbo" model yet?

nate

· #4 · Apr 11, 2002

Ripsnort said:
Cool thks! Why do you suppose that BMW hasn't make a "Turbo" model yet?

There have been Turbo BMWs

in_d_haus

· #5 · Apr 11, 2002

Yup, a 2002 turbo is a nice find...

31st330i

· #6 · Apr 11, 2002

yeah, at least two turbo cars. the 2002 turbo and that 745i that was in Roundel around November/December.

Mr Paddle.Shift

· #7 · Apr 11, 2002

and this too...

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The HACK

· #8 · Apr 11, 2002

in_d_haus said:
...the higher compression ratio increases the chance of detonation and preignition unless higher octane fuel is burned.
...

I thought this is the biggest reason why Turbocharged cars normally have much shorter engine lifespans.

The HACK

· #9 · Apr 11, 2002

31st330i said:
yeah, at least two turbo cars. the 2002 turbo and that 745i that was in Roundel around November/December.

BMW has a couple of V8 turbo-diesels in production right now I believe. They don't have gasoline turbo's anymore but they used to have a lot of turbo'ed engines like their F1 engine in the '80s was a turbo'ed 4 banger. I think the engine in the M1 was a turbo as well.

Guest84

Discussion Starter · #10 · Apr 11, 2002

Cool, good info.

nate

· #11 · Apr 11, 2002

The HACK said:
I think the engine in the M1 was a turbo as well.

Nope, 3.5L I-6 NA

The HACK

· #12 · Apr 11, 2002

nate328Ci said:
Nope, 3.5L I-6 NA

Man I must be getting old. This is like the 2nd time you've corrected me on this (or someone else did). Keep thinking that the M1 motor is a turbocharged 4 bagger like the 3.0 liter F1 engine of the late 80's.

Damn haven't even hit 30 and my memory is already going down hill. Can only imagine what being an old fart like TD is like. :lmao:

nate

· #13 · Apr 11, 2002

The HACK said:
Man I must be getting old. This is like the 2nd time you've corrected me on this (or someone else did). Keep thinking that the M1 motor is a turbocharged 4 bagger like the 3.0 liter F1 engine of the late 80's.

Damn haven't even hit 30 and my memory is already going down hill. Can only imagine what being an old fart like TD is like. :lmao:

It's the same motor used in the E24 M635 and E28 M5 :bigpimp:

Hopefully you won't be as bitter as TD

ALEX325i

· #14 · Apr 11, 2002 (Edited)

The HACK said:
I thought this is the biggest reason why Turbocharged cars normally have much shorter engine lifespans.

That's my understanding as well, and that's why I don't think it's a good idea to turbocharge engines that are normally aspirated... The block is simply not designed to handle the boost...

Edit 1:

Engines designed with turbocharging in mind (i.e. Audi's 1.8T, 2.7 BiT, etc), do support the extra boost and should last just as long...

Edit 2:

Actually, I take that back... Turbocharging was clearly an afterthought on the S4. I think that's why so many blew... :dunno: (of course, several onwers intentionally increased boost in order to produce more power)

nate

· #15 · Apr 11, 2002

ALEX325i said:
That's my understanding as well, and that's why I don't think it's a good idea to turbocharge engines that are normally apirated... The block is simply not designed to handle the boost...

Edit 1:

Engines designed with turbocharging in mind (i.e. Audi's 1.8T, 2.7 BiT, etc), do support the extra boost and should last just as long...

Edit 2:

Actually, I take that back... Turbocharging was clearly an afterthought on the S4. I think that's why so many blew... :dunno: (of course, serveral onwers intentionally increased boost in order to produce more power)

The Supra Turbo is the best example of high boost durability.

ALEX325i

· #16 · Apr 11, 2002

nate328Ci said:
The Supra Turbo is the best example of high boost durability.

Sure. But the Supra's engine can be described by my Edit 1, right?

nate

· #17 · Apr 11, 2002

ALEX325i said:
Sure. But the Supra's engine can be described by my Edit 1, right?

Yup...

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