cariacou

Hello.

I have the 2011 v6 automatic, and want to do suspension and gears for my next mods.

For gears, I have heard lots of advices of 4.1 or 3.73 on the automatic (6-speed).

However, changing gears will affect the top speed. I do drive (very) fast, and am concerned about that.

How can I compute the top speed at 6,000 rpms for these gears ?
anybody can help me ?

thanks !

cariacou

oh, and I forgot a couple precisions:

- yes, I removed the factory governor limit
- by fast I mean I'd like to be able to hit 150

mac's mustang

make sure you have a driveshaft that can handle that speed

kzonts

Yeah. What he said! Where are you planning to drive 150mph? LOL

Nuke

150 MPH? In the 3.7L? Hmmmmmm...I don't think so, not without a good bit of additional performance mods plus the previously mentioned drive shaft. IIRC, the stock 3.7 is good for about 120-125 MPH. Where are you driving triple digit speeds, let alone "150"?

danzcool

Yeah, if you stick with the stock driveshaft you are going to want the lowest gear ratio possible to get the highest speed before going critical... but then you need more power to get it going.

Jasoon

Vintage Fail... thanks for that btw.

Murgatroy

Wow, you really don't like the newer V6 do you? I keep seeing posts from you lacking any citation and really coming down on them. Is it because spec for spec, it is equal to your 'manly' V8?

There are plenty of reports of the V6 making it to 150MPH with a new driveshaft and a tune. Even the video above shows the car going nearly 140MPH before catastrophic failure.

However, this time, unlike the last time I proved you wrong, I am not going to bother citing my sources. Since you won't bother to read them and you will continue thinking the 3.7 V6 is a much inferior car.

Now, I am sorry to come off confrontational, but as a new member (but experienced mechanic and Mustang owner) I expect better from someone with such a high post count.

However, I do agree with you, unless the car sees continual track days, there is no reason to ever go that fast. And even then, there are a lot more modifications that are required for the car to be safe and manageable at those speeds on a track.

99GTvert

There should be a top speed gear calculator somewhere online for the new sixxer stangs with either auto or manual transmissions. I know they exist for the older models.

I'd go with something like a 4.10 but that's just me (..on a closed course with the appropriate driveshaft/tires/etc).

Screwed around online and found this:

http://www.cargister.com/calculator-gear-ratio

You have to play with it and enter the gear ratios for each gear in the transmission but it should at least give a rough idea.

I'm pretty sure the new V6 is not spec for spec equal to Nuke's lightly modded car...

Murgatroy

You are right. I suppose I should have specified stock for stock `05-`09 4.6 V8 versus `11-`14 3.7 V6.

I really wasn't trying to be confrontational. I promise.

However, as I have posted before, the 0-60, HP and 1/4 mile are almost identical. The V8 has the advantage in torque, but the V6 has the advantage in mileage.