Top Speed for an Ecoboost

[neodark]

So it looks like I can just buy the 3.31's since I have a base auto eco. But when I looked at the install for this, there are quite a few specialty tools they list to use. What can i expect to pay to have this installed? And would the gains be worth it versus cost/install?

I don't think you'd see a huge improvement... I would at least go with 3.55s to make it worth it.

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[Alloy]

I was iniitially thinking 3.55's but someone mentioned they would get tired of the drone and having to shift gears more often.

 

[EcoSwag1990]

I was iniitially thinking 3.55's but someone mentioned they would get tired of the drone and having to shift gears more often.

Drone? no drone here even with no resonator

 

[Alloy]

Ok cool. Then I just need to see what a reasonable price to pay for the upgrade would be.

 

[EcoSwag1990]

Ok cool. Then I just need to see what a reasonable price to pay for the upgrade would be.

For the cost of the upgrade including installation, you might just want do something else and enjoy the slightly better hwy mileage. In Texas i'd put it towards an intercooler. I've noticed a slight difference in power now that it's getting warmer out

 

[neodark]

^ Same here, intercooler first... Specially if in a hot/humid climate like FL.

 

[dspenc8888]

Has anyone with a premium auto non PP verified gear ratio of 3.15 on their car themselves?

Where would that label be so I can check?

Don't want to spend 1600 to go up to 3.55 if I'm already at 3.31, but if a 3.15 may need to rethink it.

 

[neodark]

I have one of those, not yet. Maybe I'll get under the car this weekend, been busy.

 

[Shanghai Dan]

There you have it ... "Ford Service Dept" validated it ... must be fact then.

Read through the Order Guide, or crawl under your car and look for a tag on your differential.

People on this forum typically know a lot more than ANYONE at you average dealer about these cars.


Another way to check would be to look at your RPM's at speed.

If you've got 3.31's you'll be turning about 2000 @ 68 MPH
If you've got 3.15's you'll be turning about 2000 @ 64 MPH

Doug

Wouldn't the 3.31:1 run a lower MPH for a given RPM as compared to a 3.15:1 rear end, since it's a shorter gearing? I think you might have those MPH/RPM pairings backwards...

 

[stangs-R-me]

Wouldn't the 3.31:1 run a lower MPH for a given RPM as compared to a 3.15:1 rear end, since it's a shorter gearing? I think you might have those MPH/RPM pairings backwards...

You are right, somehow I screwed up the math; were not even backwards !!

If you've got 3.31's you'll be turning about 2000 @ 69 MPH in A/T 6th gear

If you've got 3.15's you'll be turning about 2000 @ 72 MPH in A/T 6th gear

Maybe I was just testing to see if anyone reads my posts !!

Doug

 

[Shanghai Dan]

You are right, somehow I screwed up the math; were not even backwards !!

If you've got 3.31's you'll be turning about 2000 @ 69 MPH in A/T 6th gear

If you've got 3.15's you'll be turning about 2000 @ 72 MPH in A/T 6th gear

Maybe I was just testing to see if anyone reads my posts !!

Doug

I always blame such mistakes on my dyslexic calculator...

 

[stormtrooper]

Ive done 150.. Not fun on stock suspension... Lol

 

[Solow5.0]

The only place I see where you can pick 3.31 gears for an EB A/T is on the Ford Build & Price and it comes up at no-cost.

It is NOT mentioned in the Order Guide, nor is it on either cars.com or edmunds.com build & price.

I honestly think being able to pick 3.31 w/ A/T is an error on Ford's B&P, especially since comes up as no-charge.

Does anyone actually have a EB A/T with the 3.31 gears and window sticker proof showing it ??

Doug

All my window sticker shows is a Limited Slip Rear Differential....

 

[15svo]

Pp at full Bolt ons and tune 155mph and still pulling until I got out of it.

 

[dbmonster]

Went out to do some datalogging tonight and decided to see what she could do on the top end. Got right up to 160 and called it quits, but it felt like it was still pulling. I have the MAP phase 1 kit.

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