FRS stock top speed

[Borchert97]

Originally Posted by Overdrive

Could be Europe and the rest of the world don't have any limitations in place (Autobahn needs make a good case, after all), but looks like it's just shy of 150 if you have enough time and road to get there. Tom certainly loves what it can do at any speed.

I wouldn't doubt that the USDM version comes with a speed limiter. Oh well, when 2017s get tunes I'll do away with that.

[PNW-BRZ]

Originally Posted by MurderousPandas

Define stage 1, 2, and 3

Sent from my HTC6535LVW using Tapatalk

Just to get an Idea of roughly what their car can do (obviously there are some huge differences in each stage).

Stock
Stage 1 (Tune)
Stage 2 (Naturally Aspirated Mods e.g. Header/Tune)
Stage 3 Forced Induction (Turbo/Super)

AT vs MT as well, since AT should be able to attain higher speeds.

[paulca]

https://www.thrillist.com/cars/your-...-japanese-cars

[paulca]

Originally Posted by humfrz

Hi ya, paulca
Your figuring appears to be accurate ........
However, the values I used are a bit different.
I used:
160 WHP (averaging several values reported on the internet)
density = 1.3
Cd = .27
frontal area = 21.2 sq. ft. (figure published by Car & Driver)
Plugging those numbers into the formula, my abacus gives me a calculated top speed of a stock 2013 FR-S, of roughly ......
157 MPH.
(I think your estimated frontal area of 2.28 m squared is a bit high)
Your thoughts ......??

I think we are dealing with theoretical aero drag limit. It would be interesting to plug in the equation for tyre and bearing drag or "total mechanical resistance" and see how that modifies things.

As my previous post (link) highlights, particularly in US and Europe speedometers are usually out by up to 10%, usually reading over, often deliberately to prevent owners suing manufacturers. Coupled with the only confirmed reports being of 149mph indicated (in Germany) could suggest the max top speed actually demonstrated is 149 - (149*10%) = 149-14.9 = 135 mph.

I recall the original published figure from Toyota was 137mph.

As to the electronic limiter suggested above, I believe this is far more likely to be wind with changes in wind speed causing sudden drops in the cars velocity as the power in versus aero drag out equation suddenly unbalances and the car slows.

I believe the electronic speed limiters used as an agreement between German auto-manufacturers to stop the ever increasing autobahn top speed wars in the 1990s is set to 155mph.

[humfrz]

Originally Posted by paulca

I think we are dealing with theoretical aero drag limit. It would be interesting to plug in the equation for tyre and bearing drag or "total mechanical resistance" and see how that modifies things.

As my previous post (link) highlights, particularly in US and Europe speedometers are usually out by up to 10%, usually reading over, often deliberately to prevent owners suing manufacturers. Coupled with the only confirmed reports being of 149mph indicated (in Germany) could suggest the max top speed actually demonstrated is 149 - (149*10%) = 149-14.9 = 135 mph.

I recall the original published figure from Toyota was 137mph.

As to the electronic limiter suggested above, I believe this is far more likely to be wind with changes in wind speed causing sudden drops in the cars velocity as the power in versus aero drag out equation suddenly unbalances and the car slows.

I believe the electronic speed limiters used as an agreement between German auto-manufacturers to stop the ever increasing autobahn top speed wars in the 1990s is set to 155mph.

Wouldn't the "total mechanical resistance" be taken into account in the measurement of WHP .... ??

Maybe speedometers are off a bit ...... but, the speedometer on my FR-S reads within one MPH of what my GPS indicates (at about 60 MPH).....

This has been fun ......


humfrz

[paulca]

Originally Posted by humfrz

Wouldn't the "total mechanical resistance" be taken into account in the measurement of WHP .... ??

Maybe speedometers are off a bit ...... but, the speedometer on my FR-S reads within one MPH of what my GPS indicates (at about 60 MPH).....

This has been fun ......

WHP is most likely measured by clamping something to rear wheels. Even if it's a rolling road it does not account for drag from the front wheels etc.

Dyno's are notoriously diverse in there results anyway. I read an article where a journalist took the same car to 10 different performance shops and got ten different readings, the spread across the results was significant. I can't remember the actual figure but it was something like 12%.

Dyno's need to be calibrated carefully and often and most are not. Different performance shops are at different altitudes. Different weather / temperature etc make differences. The only useful Dyno results is when you switch some part of other and test on the same machine on the same day and even then the only reliable figure is the delta.

The fact that your speedo reads accurately does not mean the one in the mentioned video is reading accurately.

[humfrz]

Originally Posted by paulca

I call bullshit on anything over 140 in a stock car with stock wheels.

OK, there, paulca, my theory is that it is possible for an FR-S to exceed 140 MPH and I've tried to show why I believe that.

What do you base your theory on, that a FR-S cannot exceed 140 MPH ......??




humfrz

[Tcoat]

All the official documents show a top speed of 140-145 mph (even the manufacturer can agree). Now of course that could vary a bit but there should not be any stock cars doing much more than that.

[Overdrive]

I uh, did just post some video evidence of an Autobahn topout...can't really call BS on that.

[paulca]

Originally Posted by Tcoat

All the official documents show a top speed of 140-145 mph (even the manufacturer can agree). Now of course that could vary a bit but there should not be any stock cars doing much more than that.

Got a reference for that?

[humfrz]

Well, now @paulca ....... again I ask, what is your basis for believing a stock twin can't exceed 140 MPH ...... ??

humfrz - just another hot, smoky day in Puyallup

[paulca]

Originally Posted by humfrz

Well, now @paulca ....... again I ask, what is your basis for believing a stock twin can't exceed 140 MPH ...... ??

My basis is:

• I believe the manufacturer figure was 137mph.
• That I have not seen evidence of one going faster than 137mph that can't be accounted for by speedo over-read.
• That young-ens on forums have a tendency to exaggerate.
• People generally on forums tend to exaggerate.
• People generally don't understand the square law of air resistance and believe that a small increase in HP gives a large increase in speed.
• American's in particular tend to exaggerate.

[Impureclient]

Originally Posted by paulca

[*]American's in particular tend to exaggerate.

That's a very homophobic statement there, bud!

[Tcoat]

Originally Posted by paulca

Got a reference for that?

Of course I do. The old Scion site gave the top speed as 145mph but it is of course gone now.


You will have to settle for the OFFICIAL Subaru documentation at 143 MPH (230 KPH)


http://www.subaru.com.mt/13brz_spec.html