RDU Ratio

[AJP turbo]

There isnt enough power to pull top speed in top gear in most cars...and the gear before top gear is usually too short...so drag limited in top gear is usually where it happens

[AJP turbo]

Auggie, you can calculate all you want but if you really want to know then get out there and do it...cant change the final drive and i dont think changing the shift point will help much

[Auggie]

Yup AJ your right and I will do just that. But in the mean time I want to know what gear will give me the best results. If I use 6000 RPM(tach has a red line at 6500) here's what I came up with.

Engine RPM = 6000
Tire Diameter = 28.0"
Gear Ratio = 2.77
Trans Gear Ratios = 4.484, 2.872, 1.842, 1.414, 1.00

4.484 = 40.3 MPH
2.872 = 62.9
1.842 = 97.9
1.414 = 127.7
1.00 = 180.5  SO: To go 140 MPH + I would use 5th gear and have to reach at least 4800 RPM. It would be nice to change 5th gear to a 1.200 ratio at 5800 to go a 140.0 +. I wonder if the engine would be able to keep pulling past 4800 RPM in 5th gear to go 150.0 MPH + ?

    Auggie

[AJP turbo]

Shouldve  got a pp

[Auggie]

Yup, the 3.16 rear gear ratio would have been an advantage. Are there aftermarket gears available?

    Auggie

[AJP turbo]

You want drop thousands?

Best best would be to swap the final drive in the tranny since its an oem part

[Auggie]

Nope and I think I will stand pat, at least for now.

    Auggie

[FoMoCoSHO]

OK, my second question was "What is the max RPM of these engine"?

    Auggie

It is 6700

[Auggie]

Hey thanks FoMo, I was wondering if anyone knew!

    Auggie

[AJP turbo]

OK, my second question was "What is the max RPM of these engine"?

    Auggie

It is 6700

You mean they are capable or stock?..auggie you can make it what you want

[BiGMaC]

OK, my second question was "What is the max RPM of these engine"?

    Auggie

It is 6700

You mean they are capable or stock?..auggie you can make it what you want

My SHO continued making power to about 6750... Goes a bit higher... The dynos are somewhere here in the thread about dyno for drown pipe install.... And that was before I tuned.

[Auggie]

Yes AJ, I would like to know at what RPM to shift at (I could use paddles) for max performance for my completely stock 2015 SHO. Right now it will shift at 5700 in drive. Would shift point RPM in sport be any different?

    Auggie

[FoMoCoSHO]

@ Auggie

There is a shift point calculator with some examples in the tranny section.

http://www.ecoboostperformanceforum.com/index.php/topic,5796.0.html

To really be accurate you would need your own dyno sheet but even without you will see that the optimal shift points between PP and nonPP are very different.

[AJP turbo]

Bigmac im skeptical on the car still making power at that rpm...any chance there was a bad pickup on the rpm lead to the computer from the dyno?

And auggie the back pressure get so bad at high rpm i cant see much over 6200 being beneficial...watch wastegate duty cycle skyrocket to maintain boost at redline

Sport shouldnt be different...there is basically a pedal multiplier when in sport..thats alot of the reason shifts are held longer and downshifts sooner because you are actually deeper into the pedal...i leave it in S when i race...i think the paddles are stupid

[Brucelinc]

Red line is 6250 on the ecoboost.  The rev limiter kicks in at not much more than that.   Maybe some tuners defeat the limiter.  I am glad mine still has it.  I would not wind my engine to 6700.