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-   -   FD Top Speed (https://www.rx7club.com/new-member-rx-7-technical-256/fd-top-speed-976954/)

Joe Rajacic 11-15-11 01:34 AM

FD Top Speed
 
Ok - how fast will a stock FD go with the 160 MPH speed limiter disabled?

Hoe hard would it be to disable it?

Joe

funkjaw 11-15-11 03:11 PM

I doubt it will go faster than 160 even with the limiter disabled. Even if it says 160 on the speedometer, it probably isn't going that fast.

RX7Soldier 11-16-11 05:00 PM

unless you have modifications under the hood and drive train :)

boostmonkey 11-16-11 09:15 PM

my question would be around engine upgrades also. is this car stock?

CrispyRX7 11-16-11 09:53 PM

What speed limiter? Guys I know regularly exceed 160 on the track. Is the limiter in the stock ECM?

Regards,
Crispy

chivpar 11-16-11 11:33 PM

I have done 170 in my swapped Fd. felt like it was about to rattle to pieces

funkjaw 11-17-11 11:12 AM

Personally I am an FC guy so I can't say for sure if there is a speed limiter on FDs but after some research it would seem they don't have speed limiters.

However, he is talking about a stock FD, and I doubt a stock FD with stock body can make it passed 160mph. It's probably drag limited to ~160 or less.

Joe Rajacic 11-19-11 03:51 AM

FD Top Speed
 
Back in 1998 my friend had a stock FD with 13000 miles. In 5 th gear it accelerated real hard all the way up to 160 mph where the speedo said we were all done. It felt like it could go faster so after research ( I don't remember where) we found out there was a top speed limiter at 159 MPH. Does anyone have an original owner's manual to see if that information is there?

bean12147 11-19-11 05:02 AM

Is it true that a lightly modded FD can reach 300km/h with the right gearing 3.9 rear end

CrispyRX7 11-19-11 05:57 PM

IIRC a stock manual FD with a 4:10 rear end is geared for 199mph at redline in fifth gear. Stock, it doesn't have the power to get there but it is geared for that speed.

Regards,
Crispy

BlueTuner 11-19-11 10:23 PM

Sooo basically your looking at about 150mph on stock, my auto with everything besides a porting, that includes intake all the way to exhaust, pfc, suspension, i was able to hit 170mph, going off the pfc and felt fine, could of probably hit 185, but at 170, doesn't matter, its gets sketchy.

funkjaw 11-20-11 12:53 PM

Road & Track Feb 1992 issue..........

Top speed 159 mph (drag limited)

rye lou 11-20-11 09:38 PM


Originally Posted by CrispyRX7 (Post 10868415)
IIRC a stock manual FD with a 4:10 rear end is geared for 199mph at redline in fifth gear. Stock, it doesn't have the power to get there but it is geared for that speed.

Regards,
Crispy

That's wild. 199 mph is flying!

dgeesaman 11-21-11 04:48 AM

Bottom line: the FD is limited by drag/power to 155mph. With more power higher speeds are possible, heck you might even find a way to max out the gearing.

Also note that stock speedometers are off on a percentage basis. So it will show you going 55mph when you're doing 52mph. At 150, that's a 10mph difference plus other errors. So you need special equipment to perform any kind of real top speed run.

Joe Rajacic 11-24-11 02:56 PM

Thanks for all the replies.
I remember vividly the time my friend and I ran the FD. We were at 100mph and floored it. The acceleration was brisk. The speedo was climbing very fast through 120, 130, 140. At that point I said out loud - it feels real stable; at this rate of acceleration we should hit 170( looking at the tach and seeing several more thousand RPM left to redline).. But just as we hit 160 (on the uncorrected speedo) it felt like the car just stopped accelerating. Note - we were still accelerating hard from 150 to 160. This was a 1993 with about 13000 miles and all stock. I realize every car is different and the speedo could be off. It just FELT like an electronic speed governor at 160, hence my original question.

Happy Thanksgiving to all

Joe

Federighi 01-27-12 09:50 PM

I've hit 155 with light engine/ aero mods & I'm sure a heavily modified FD will greatly exceed that.


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