Sound pitch of the new F1 V8s

[OW]

I expected the new F1 V8s to sound heavier.

How is it that they still have a high pitch? Not as much as the V10s, but closer than I would have thought. Not like IRL cars or certainly not like Nascar.

Is the total displacement smaller than other race car V8s? (smaller cylinders) (relatively speaking?) (that would mean less horsepower)

Are the mufflers more like a go-kart chamber exhaust?

I think the revs are up and that can make a huge difference. Leading to failure though. Very interesting. (to me anyway)

Thanks for you comments, I'm a long time fan, just not that esoteric on the subject.

Gosh....sorry should have been in F1 forum, not Champcar.....oh well

[rjohnson999]

If the 20k RPM numbers being thrown around are correct, it's about the revs. Even if the revs are only 75% of that it would still be about the revs. CCWS Cosworths are at about 12k. IRL is about 10.5k. NASCAR is something like 8.5k at much bigger displacement.



I expected the new F1 V8s to sound heavier.

How is it that they still have a high pitch? Not as much as the V10s, but closer than I would have thought. Not like IRL cars or certainly not like Nascar.

Is the total displacement smaller than other race car V8s? (smaller cylinders) (relatively speaking?) (that would mean less horsepower)

Are the mufflers more like a go-kart chamber exhaust?

I think the revs are up and that can make a huge difference. Leading to failure though. Very interesting. (to me anyway)

Thanks for you comments, I'm a long time fan, just not that esoteric on the subject.

Gosh....sorry should have been in F1 forum, not Champcar.....oh well

[ChrisB]

I used to have the equation here somewhere... but the pitch is a function of both rpm and number of cylinders... displacement has little to do with it.

For instance... a V10 doing 10k rpm will actually sound higher pitched than an I-4 doing 12k rpm... or something like that.

[jcollins28]

Bore and stroke have a lot to do with the sound pitch of a motor. If you remember a few years back the IRL changed the cranks on their motor to get away from the "farm tractor with a hole in the muffler" sound that the IRL cars were known for.

[rjohnson999]

That had nothing to do with bore/stroke. It was a function of changing the firing sequence.


Bore and stroke have a lot to do with the sound pitch of a motor. If you remember a few years back the IRL changed the cranks on their motor to get away from the "farm tractor with a hole in the muffler" sound that the IRL cars were known for.

[Cam]

Bore and stroke have a lot to do with the sound pitch of a motor. If you remember a few years back the IRL changed the cranks on their motor to get away from the "farm tractor with a hole in the muffler" sound that the IRL cars were known for.

the shorter the stroke the higher the rev...... The higher the rev louder the schreek..

[jcollins28]

the shorter the stroke the higher the rev...... The higher the rev louder the schreek..


Exactly.

[jcollins28]

That had nothing to do with bore/stroke. It was a function of changing the firing sequence.

http://www.motorsport.com/news/article.asp?ID=22997&FS=IRL


INDIANAPOLIS, Nov. 17, 1998 - The engine specifications and manufacturer guidelines for the Pep Boys Indy Racing League for the years 2000 through 2004 were announced during a press conference this morning in
Indianapolis. The engine formula beginning in the year 2000 (for five
years) calls for the engine size to be reduced from 4 liters to 3.5 liters
and allows a new crankshaft which will alter the pitch and tone of the new
engine significantly.

[rjohnson999]

If the displacement change resulted in higher RPM, there would have been a difference in the pitch with the original crankshaft configuration. The big change, however, was a result of the change in firing sequence.


http://www.motorsport.com/news/article.asp?ID=22997&FS=IRL

[jcollins28]

If the displacement change resulted in higher RPM, there would have been a difference in the pitch with the original crankshaft configuration. The big change, however, was a result of the change in firing sequence.

Not according to that article nor to anyone else I have talked with. The motor was a 90 deg configuration and the new motor went to a 180. No where in that article does it state a new firing order.

[BMEP]

Not according to that article nor to anyone else I have talked with. The motor was a 90 deg configuration and the new motor went to a 180. No where in that article does it state a new firing order.

That's exactly what changing the crankshaft does (changes the firing order). In fact, the engine vibrates a LOT more (hurting reliability) but the firing order change is so beneficial for making power that it's worth the increased vibration.

A 180 degree crank makes a V8 behave like 2 4-cylinder engines and firing alternates evenly between the left and right banks.

[jcollins28]

That's exactly what changing the crankshaft does (changes the firing order). In fact, the engine vibrates a LOT more (hurting reliability) but the firing order change is so beneficial for making power that it's worth the increased vibration.

A 180 degree crank makes a V8 behave like 2 4-cylinder engines and firing alternates evenly between the left and right banks.

Yes of course but in this case the firing order was changed because of the new crankshaft which was changed to alter the pitch of the motor. The firing order was done out of necessity of the new crankshaft.

[rjohnson999]

It's always nice to see someone finally get it.


Yes of course but in this case the firing order was changed because of the new crankshaft which was changed to alter the pitch of the motor. The firing order was done out of necessity of the new crankshaft.

[jcollins28]

It's always nice to see someone finally get it.


That had nothing to do with bore/stroke. It was a function of changing the firing sequence.

Yeah I still don't think you get it.

[rjohnson999]

No atta-boy goes unpunished in your world, eh.


Yeah I still don't think you get it.

[jcollins28]

No atta-boy goes unpunished in your world, eh.

lol

[OW]

http://www.bimmerfest.com/forums/showthread.php?t=121203