Noticed on the highway, the rpm's at 70mph equal 3Krpm and at 80mph equal 3500rpm in fifth gear. This is cool since I have immediate turbo available for passing, but I was wondering if this was normal. All the other cars I owned usually dropped rpm's down to around 2500 when in fifth for gas conversation on the highway which would mean I would have to shift into 4th to pass anything.

Thanks,
Jed

 

yup, 80 is right at 3500

 

my automatic oz does about the same(in its top gear{4th}). i know its a completely different car but that sounds ok!

 

It is normal.

The gears are set up such that each gear change puts you right into the sweet spot where the power is...which is how just about every race tuned car should be.

Usually only commuter comfy cars make the 5th gear a highway gear. Those cars put the gear change into 5th right where the best fuel economy is.

 

Yes, your car is normal and your numbers are right.

Given the tires 235/45R17, the 5th gear ratio of 0.72, and final drive of 4.53...

We get:

Tire diameter = 25.33 inches
Tire circumference = 79.57 inches
Tire circumference = 6.63 feet

At 1000 RPM, the engine turns 16.67 times per second. The wheels turn 16.67/(0.72*4.53) = 5.11 times per second.

So the ground speed at 1000 RPM in fifth gear is 33.88 feet/second, or 23.10 MPH.

70 MPH = 3030 RPM in 5th gear
80 MPH = 3463 RPM in 5th gear

 

5th gear....... 55mph 2,500rpm and 80mph 3,500rpm.
those are the only two speeds I go.........

 

man somebody paid attention in math

 

No Doubt

 

Can someone please explain to me why it takes a long time to reach the set boost on the 5th gear?

Thanx.

 

You should be asking that question in the newbie forum or in the Evo engine/ tech forum.

SC~

 

80 for me is at 8100rpm

 

Hmmm..I hit max boost instantly in 5th.

Car manufacturers purposely put you somewhere in the main power band on purpose. LIke mentioned earlier it's for passing which also goes for safety.
But also you need to be able to climb a hill with all accesories on (a/c, lights, wipers, rear defroster) without switching gears. Highway cruise that is.

 

in third gear?

 

Roger, Moderator!!