gxlspeeder

How come the s5 turbo II doesn't redline like the other s5's? sorry if this is a repost

Sponge Bob Square Pants

It has a different engine.

gxlspeeder

i knew that, but how come mazda didn't make it with a 8000 rpm redline, why is it lower, besides the fact that they are different engines

j200pruf

iTrader: (4)

Because the turbo isn't effiecient enough to feed the engine at 8,000RPM. Wouldn't you rather make 200hp at 7,000RPM instead of 8,000RPM.

Evil Aviator

The S5 NA has lighter rotors.

The S5 TII engine is rated at a peak 200hp at 6,500rpm, and the horsepower declines past this point, regardless of the redline.

j200pruf

iTrader: (4)

the S5 turboII and N/A rotors weigh the same.
And my numbers were not meant to bee completely accurate, just get the point accross.

gambone

iTrader: (3)

As a rule of thum, turbo piston/rotary gas engines, can make there peak hp at lower rpm then NA engines. NA engines need more valve doration and this mostly better at higher RPMs and turbos have lose and thoes works better at lower RPMs. Does this fit your queston

Evil Aviator

All the literature I have read simply states that the lighter rotor and flywheel weights are what allow the NA engine to rev higher. You may need to go to SAE papers to find your answer.

gxlspeeder

thanks

Evil Aviator

I'll ask my local trivia gurus in the meantime. So far one theory is that the S5 TII intake is basically the same thing as the S4 TII intake, which is designed for 7Krpm max, and Mazda just figured that it was pointless to beat up the engine at higher revs for no performance return. However, I would like to see official Mazda statements as opposed to theories. So far the official Mazda statements that I have collected throughout the years do not address this issue.

Scott 89t2

I just thought it was because the turbo chokes the engine before 7k anyways so there was no reason to have it any higher....

BASTARD

iTrader: (4)

why have a 8,000 RPM redline when your peak power curve is over by 7,000 RPM

nonameo

because rpm sells...

just like MHz/GHz sells on a computer...

rynberg

Maybe, but Ghz actually DOES perform better. If you don't think so, you don't play UT2003....