Top speed from factory

[Elp_jc]

155 due to driveshaft limitations.

I've seen that mentioned before, but it should be 163, since that's what the Bullitt does (maybe it's indicated, not real), and I bet it has the same driveshaft. But yes, many times a speed restriction is there for a mechanical limitation, and not just as a 'gentleman's agreement'. It pays to research that before assuming car would be fine at higher speeds.

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[Grintch]

Both the analog and digital speedo readout max out at 160 on 400a cars but the car can go over that with a tune but the speedo will just say 160 while RPMs are still rising.

Funny, my 250hp Focus ST has a 180mph speedo (pretty sure it is also limited to 155). It always made SOO much sense that my 165mph 2015 Mustang GT only had a 160 mph speedo.

Of course the with the rather short tracks I run, I am pretty sure I have never gotten it above 140. So a 155 late limiter vs a 165 early limiter vs an unlimited 170 or 175 (stock motor) is mostly academic.

 

[Aaron1085]

1: I went from the 19” PP1 wheels to 20” AFE wheels. How does that affect my speedometer (I don’t believe any calibration was done)

2: after installing the Whipple Gen 5, Stage 2 supercharger; does that leave the limiter in place or is it removed? (‘Stock’ tune)

 

[WD Pro]

1 : Just compare the tire height (or whatever radius / circumference metric you choose) of both your new and old tyres. Whatever the % difference in value is the same % you have altered your speedo - it’s probably nominal.

Can’t help you on number 2 sorry.

WD

 

[K4fxd]

There is a range where the car corrects for tire size. Your speedo is probably correct.

 

[BrianGT2015]

I maxed out my speedo and then some, No GPS to confirm. but I got catless long tubes, 2018 manifold, 2018 K&N intake, and tune. needle was at 160, when I let off it took a few seconds to drop. I have a 6 speed with 3.73 gears.

 

[crimson_crowd_eater]

It was my understanding that they were electronic limited to 157, but mine only does 154. Radar detector GPS speed said ~155. With the 10 Speed and 3.55's, I was at like 6800rpm in 7th so I didn't have much more speed left anyway.

 

[1958cyclist]

Can't verify this 100%, but factory limiter is 155 mph, but I seen videos...assuming that they are legit, of owners defeating the limiter and reaching just under 180...

 

[Melvis]

Funny, my 250hp Focus ST has a 180mph speedo (pretty sure it is also limited to 155). It always made SOO much sense that my 165mph 2015 Mustang GT only had a 160 mph speedo.

Of course the with the rather short tracks I run, I am pretty sure I have never gotten it above 140. So a 155 late limiter vs a 165 early limiter vs an unlimited 170 or 175 (stock motor) is mostly academic.

 

[Melvis]

I just traded in my Focus ST for a S550 with a Roush Stage 2. I found it hilarious that the Focus speedo was 20 mph more optimistic.

 

[Jmtoast]

It may have more to go but once that speed limiter kicks in the....go stops there.

Our limiter is 123mph.

 

[WD Pro]

Our limiter is 123mph.

Unless the cops are after you and then they will do 178mph ...

WD

 

[Jmtoast]

Unless the cops are after you and then they will do 178mph ...

WD

The Roush Phase 2 calibration has a issue where it gets stuck at 123mph when shifting from 6th to 7th. You have to manually shift but roush also has a 155mph limiter in the cal.

 

[WD Pro]

The Roush Phase 2 calibration has a issue where it gets stuck at 123mph when shifting from 6th to 7th. You have to manually shift but roush also has a 155mph limiter in the cal.

I know - I browse that forum every now and then

It was tongue in cheek, I was referring to the police chase guy that clocked 178 - I assume he may have been manual and / or aftermarket tuned ?

WD

 

[1958cyclist]

The 155 limit seems to be an industry standard for many high performance cars. These days, aerodynamics probably play as much of a role as horsepower, and the S550 is very well put together as far as aero goes.

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