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Top Speed for an Ecoboost

dspenc8888

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^ That was my original thought, 3.15's on mine... But, now I don't know since some people say auto premiums, no PP are 3.31's.
Correct non PP premiums are 3.31 no cost or u can purchase as option 3.55 ...applies to auto or manual.

On base non PP models manual is 3.31 and auto is 3.15

PP has 3.55 or u can purchase 3.55 separately as stand alone option
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stangs-R-me

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To answer the OP's question ...

Say a 2015 EB can actually get up to 5500 RPM (max HP) in OD 6th gear, these would be the theoretical speeds at 5500 RPM:

3.31 M/T w/ 235/55-17" ... 186 MPH
3.31 M/T w/ 235/50-18" ... 187 MPH
3.55 M/T w/ 255/40-19" ... 175 MPH

3.15 A/T w/ 235/55-17" ... 198 MPH
3.15 A/T w/ 235/55-18" ... 199 MPH
3.55 A/T w/ 255/40-19" ... 175 MPH

Doug
 

stangs-R-me

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Correct non PP premiums are 3.31 no cost or u can purchase as option 3.55 ...applies to auto or manual.

On base non PP models manual is 3.31 and auto is 3.15

PP has 3.55 or u can purchase 3.55 separately as stand alone option
Per both the Order Guide and Ford B&P:
* The 3.55 stand alone option (455) is not available on EB, only V6 & GT ... the only way to get 3.55 w/ EB is w/ PP option.

* 3.31 is std. on all EB M/T (no 3.15 option)
* 3.15 is std. on all EB A/T

3.31 n/c opt. on EB A/T only shown on Ford B&P ... also I could add it to either a Premium or Base EB. Honestly think this is an ERROR on Ford's site as I can't find this fact anywhere else and I find it extremely hard to believe Ford would offer an optional axle ratio at NO COST.

Show us proof of a "Window Sticker" or other official Ford documentation of a car with A/T & 3.31 gears !!

Doug
 

neodark

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So back to not really knowing what's on mine. if 3.15s I may think of an upgrade to 3.55s down the line. with 3.31s not so much.
 

RubyRacer

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3.55 is perfect... except you can't get to 60 without shifting to third! So annoying.

I think you can literally get to 58mph when you bounce off redline in second. It's a very frustrating thing.

I would just raise the rev limiter, which I did with my SCT X4, but these cars die so much above 5500rpm that I honestly get the same 0-60s whether I push second gear to redline or shift to third so I can use the meat of the curve.

So, I guess my biggest gripe isn't necessarily the gearing, but rather the lack of power up top to make a small rev limit bump work.
 
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dspenc8888

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Similar power/weight numbers so forgive me if the info isn't helpful, but on a closed course (i'm not kidding about the closed part, no "Mexico" stuff) i've been able to get a '14 V6 to bury the speedo past 160mph. 3.73's, a tune, and BFG comp-2' with a speed rating of 168mph being the mods.
Wow, impressive:headbang:
 

dspenc8888

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Per both the Order Guide and Ford B&P:
* The 3.55 stand alone option (455) is not available on EB, only V6 & GT ... the only way to get 3.55 w/ EB is w/ PP option.

* 3.31 is std. on all EB M/T (no 3.15 option)
* 3.15 is std. on all EB A/T

3.31 n/c opt. on EB A/T only shown on Ford B&P ... also I could add it to either a Premium or Base EB. Honestly think this is an ERROR on Ford's site as I can't find this fact anywhere else and I find it extremely hard to believe Ford would offer an optional axle ratio at NO COST.

Show us proof of a "Window Sticker" or other official Ford documentation of a car with A/T & 3.31 gears !!

Doug
I have ecoboost premium non PP and Ford service dept validated I have 3.31 because that's what is on all premiums unless u opt for PP or 3.55 option, at least that's what I was told.

Would be nice to know for sure though because it makes more sense to upgrade if at 3.15. I won't upgrade if already at 3.31 to costly.
 

neodark

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Was that V6 Mustang @ 160 with the stock driveshaft/tires?

[ame]
 

stangs-R-me

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I have ecoboost premium non PP and Ford service dept validated I have 3.31 because that's what is on all premiums unless u opt for PP or 3.55 option, at least that's what I was told.

Would be nice to know for sure though because it makes more sense to upgrade if at 3.15. I won't upgrade if already at 3.31 to costly.
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 @ 69 MPH in 6th gear
If you've got 3.15's you'll be turning about 2000 @ 72 MPH in 6th gear

Doug
 
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neodark

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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
Awesome, thanks :thumbsup:
 

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stevnoof

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130 and steadily rising according to my gps but ford says it only does 121.
 

McCarthy

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Was that V6 Mustang @ 160 with the stock driveshaft/tires?
Yes i'm aware of the driveshaft failing. It was a stock driveshaft, but had proper W rated (168mph) BFG Sport comp-2 tires, 3.73 gears and a tune to remove speed limiter.

I lost the video but I still have a still of the speedo from it. Again, I would like to re-iterate this was done LEGALLY on a closed course. I'm all for having fun on public roads, but speeds like that are for tracks/runways/closed courses ONLY.

 

Papaya

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I'm all for having fun on public roads, but speeds like that are for tracks/runways/closed courses ONLY.

:D You never drove on the Autobahn? That was normal speed (220 kph) for me going to work to Frankfurt / Germany..... :headbang::thumbsup:
 

wildsailor

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I have ecoboost premium non PP and Ford service dept validated I have 3.31 because that's what is on all premiums unless u opt for PP or 3.55 option, at least that's what I was told.

Would be nice to know for sure though because it makes more sense to upgrade if at 3.15. I won't upgrade if already at 3.31 to costly.
For the Ecoboost (base and premium):
3.31 axle comes with the manual trans (non-PP).
3.15 axle comes with the automatic trans (non-PP)

3.55 only comes with the Performance Package and is not available as a stand alone option like it is on the GT or V6.
 

Alloy

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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?
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