Top speed
 

After researching Ive found that a bone stock FD has a top speed of 160. (170+ for Japanese models). Does anyone know if this is from the motor at redline, or limited by drag. If so what would the top speed be at 8000RPM (or more)?

If you had the ability to wind it up that far it may reach it...But the rx7 world record is 242mph

The top speed is limited by drag. The USA 5th gear tops out right around 200mph, but you will need quite a bit of power to get there.

honestly if i can hit 160-170 lol i doubt id have the balls to go faster than that..

i hit 150 once and i was crapping myself and i still think i coulc have went faster! i was scared of a deer or something running in front of me..

(this was done on a side road where nobody was) friends were at each end so nobody was going to drive ont he road for that 5 mins we had it.. everyone does it and the cops dont mind either for some reason they even come to watch sometimes and radar us just for fun.. no joke!!)

I assume we are talking about 170 Mph? If so, that's pretty good! (I'm a Canadian living in Tokyo we do Kph here!)

And why would the JDM version be faster?

Well, here is an FD going 215mph. Pretty sure it is a heavily modded 13b. It had a few aerodynamic issues.... :hahaha:

http://video.google.com/videoplay?do...arch&plindex=9

If you look closely you can see the front left corner lift.

top speed at redline is 202mph with non jspec gear ratios

doesn't the JDM have a speed limiter of 180 kph? i know the speedo only reads up to that speed and i've heard of a fuel cut but not sure if thats only on FCs

perhaps the stock ecu has a cut off.. but im sure if you upgrade that you can go as fast as you like..

The JDM cars have a shorter 5th gear than our USDM cars. At 160mph this allows them to be at a higher RPM which means the JDM car will be making more HP and thus will be able to reach a slightly higher top speed.

This is assuming that the speed limiter is bypassed, lol.

All JDM cars have a much shorter 5th gear. I found this quite annoying on long drives. My 180SX was always above 3800rpm at 65MPH. They gear there cars to be most fuel efficient at 85 kms/hr (53 MPH) as their max speed limit is 80kms/hr.
Their fuel cut is at 180kms/hr and at 107 kms /hr there is some stupid chime that goes ding *ding *ding until you decrease speed to 105.

All FDs top speed is drag limited.

when my car was almost bone stock with just intake and catback i got to a little over 160 after my car was done with a little bit of modding...... 170 and i ran out of room those tailights started getting close and getting there fast. i think i could have went a little more i dont think ill try it again 170 isn't too bad right :wink:

202????????
In your dreams. You can't even pull redline in 5th gear.

Reminds me of a bunch of high school kids trying to impress each other.

Heck the speedo goes up to 180, it must go that fast.

Published FACTS

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

Top speed 159 mph (you need a mighty long & wide road to do it)

April 94 issue............

0-100-0 19.8 sec

To put it in prospective.....

A 2006 Porsche Carrera GT weights 3043 lbs & puts out 605 hp.
It only manages a top speed of 205

This kind of crap should be in the lounge

Theyre talking about mathematical top speed based on gear. Someone already posted that to reach the gear limited top speed you have to have a LOT of power. Theoretically 5th gear at 9k rpm is mathematically 200ish.
My old FD only had intake and exhaust, + downpipe. It certainly did not need a whole lot of room to hit 160, or about 6500 rpms in 5th. Had it up to 7200 once and its right around 167-8.


You are magazine racing. Not much better.

I took the fd on a road trip this past weekend and got her up to 110 several times but noticed strong throbbing engine vibrations coming through the engine bay and had to pull the plug. Honestly it didn't feel like it had much else in it. I guess over 110 ish you just need a LONG road to get going.

Something is wrong with your 7. Mine would pull smoothly up to those speeds. In fact if all you can do is 110 than you arent even getting out of 3rd gear... change to 5th at around 145-150mph. Still pulled, not as strong but Id say 10 miles an hour climb in around 7 or 8 seconds at those speeds.

110 was attainable in a standing 1/4 mile... Not much room.

i pulled to 140 nice and clean once, could gone faster but eitherway it was still smooth as silk at that speed.

i think i read that the JDM 5th gear will only reach 182mph instead of the US 202mph. theoretically that is.

Fastest I'd ever gotten mine when stock was around 155, this was with a long 3 - 4 mile run. I've not "topped" it out with my new engine with all the mods, all I know is 145 comes up REAL fast, and...I just don't have a whole lot of reason to run much faster than that.
I must be getting old....

https://img218.imageshack.us/img218/...resizedci4.jpg

take a look at the speed! IN KMH! 282=176mph!
this was 2 months ago. & the car kept going but it stopped there (thinking the motor blew. But it was a spark plug!




NOW THE SPEEDOMETER WENT PASS THE 180 MARK SO I WAS HITTING 182 (POWER FC IS OFF BY 6MPH)

forgot to mention I have an auto.

I have hit over 175 mph in a basically stock FD it felt good too, only think that felt better and went substantially faster was my yamaha R1, 187mph and it was SOLID, like i was on rails!!!!!

i never said it would get there... all i meant was at red line the car would be doing 202 in 5th


by the way i've done 180 in my FD

the pfc is reading correctly. you cant trust your speedometer at that speed. you must have hit your limit. we had a thread discussing this very topic a few months ago. i am shocked noone just posted that...

I know I did between 155 and 160 in mine with pettit ecu and bolt ons.

i didnt reached the limit! i blew a sparkplug which was why i stopped. My rev limiter stopps @ 8500rpms so if i would of kept going i would barely hit 200!

top speed
 

i hit 280 km/h all the time, with a 4.30 rear end, i wanna go faster. I am switching to a single setup, anyone have an idea if there is a 5th gear upgrade or a better rear end ratio , so i can attempt 200mph, i'll have about 500 at the wheel once all is said and done, and the car will weigh roughly 2600 lbs

I think top speed cannot be entirely defined there are too many variables. You have to take into acount hp, torque, weight, gear ratios,diameter of wheels and tires,temperature,humidity,elevation blah blah blah.
loss of cooling effiency at higher rpms means less power. a larger wheel spinning at a given rpm compared to a smaller wheel means more distance covered by this wheel. weight of vehicle in relation to torque of course coefficent of drag based on areodynamics also colder weather and wet weather will result in denser air making it more difficult to attain a higher speed and traction too when you go that fast you will lose traction a little especially when the car starts to lift slighty and there is less weight applied to the tires going down hill also will mean there is less of a load on the motor too.

Im just saying I think there are too many problems to get a solid number. All we can do is get the highest speed for that particular day.

ive hit 180mph on the clock several times in my FD

Stock twins, 15psi, v mount, 255/35/18 on the rear with toyo R888 tyres. No aero mods except amemiya AD9 bonnect and standard smaller style spoiler. Standard engine ports too.

reminds me to a pic shot by a friend of mine, here on the german autobahn.

you clearly see the speed and the revs. 280kph = 174mph

http://www.mazdarotaryclub.com/forum...1&d=1084833175

I don´t exactely know the Modification state of the car.
Aerodynamics were stock!

I don´t know if this was the max speed. Maybe he could have gone faster.

do you have horsepower figures? (or rather, are they the same as what im reading in your sig? :) ) 487hp? i know the FD is pretty slick aerodynamically... but im wondering what HP it would take to reach 200mph (a benchmark that most exotics have a hard time reaching). obviously that would depend on body kit/wing/etc.... a 99 body kit and rear wing will definitely up the power needed to get there.

and even more importantly... does this car have what it takes aerodynamically to stay planted on the road at that speed?? i know everyhting is a blur past 140... but can you comment on how the front end felt? any detectable lift from the nose? did it feel light or planted? thanks :biggrin: heath

Wow, that's a low mileage car.

I taken my car with 99 spec 17" wheels to an indicated 140 which it reaches with ease, after that progress slows down a noticably, my only mods are cat back and Greddy SMIC.

Talking of stability, I have yet to drive a car that felt as stable as my Supra TT 6sp, even at indicated speeds of 180 it felt absolutley planted to the road and totally confidence inspiring. None of my friends cars including Ferrari 360, porsche 996 turbo have the same composure.

Finally, as a rough guide, most speedo's over read by about 10%, manufaturers do this on purpose so that there is absolutely no chance they can be blamed for you speeding tickets:icon_tup:

my Rex shows something around 6k ...
Unfortunately the reason is the change of the tachometer! :cool:

I see, must be nice to see the low mileage anyway, you can convince yourself that the car is virtually new for the added fell good factor !:icon_tup:

has anyone hit 200mph
 

That statement simply is not true, many times I have ran through construction zones where your current speed is posted, and its bang on within 1km/h. No manufacturer is going to take responsibility for a speeding ticket regardless of the circumstances, they have to adhere to safety regulations just like any body else, and misleading the public by 10% is a farce. Anyway I still would like to speak with someone who has hit 200mph in an FD street car.

I can assure you it is true, although it is not so common nowadays, I remember many car magazines in the 90's would publish indicated speed and true speed from their timing equipment when conducting road tests.

The idicated speed was always higher, not necessarily by 10%, some maufacturers were better than others and would over read by maybe 3%.

It's not really a question of misleading, if someone was caught speeding for doing 33mph in a 30 mph zone then the chances are that the speedo was indicating 'at least' 33mph but probably more. the result is that they have no excuse.

If a speedo under reads then it would be quite easy for someone to blame the manufacturer, and there's plenty of blood sucking lawyers who would pursue such a case.

Finally, most sat nav/GPS systems will also confirm this fact, many people I have spoken to on the UK supra forum have stated that their speedos over read by 7-10% compared to the speed shown on the GPS systems.
I wouldn't just make it up!:)

Fd Top Speed
 

there are two primary considerations:

GEARING and AERO DRAG

Gearing

the (US) FD has a .719 fifth gear.
the (US-manual trans) FD has a 4.10 rear gear.
stock sized rear tires 225/50/16 25 inch diameter 835 revolutions per mile.

the factory carries the top speed at 159-161 depending where you get your info.

let's do 7000 RPM in fifth:

7000 * 1.3908 (the inverse of .719)= 9735/4.1= 2374 * .95 (5% tire slip) =
2256/835 (revs per mile) = 2.7016 * 60 (minutes in an hour) = 162 mph.

6000 = 139
8000 = 185
9000 = 208

with an auto trans 3.90 rear gear:

6000 = 146
7000 = 170
8000 = 194
9000 = 218


AERO

once you have the gears you need to deal w the main issue: AERO DRAG.

the formula to solve for hp required to run a particular speed is interesting. it is all frontal area and drag coefficient and the hp required goes up with the CUBE OF THE SPEED!

FD

Drag Coefficient (R1) .31
Frontal Area 19.26 sq feet

let's solve for the flywheel hp to run 162 mph.

the formula looks like this:

(.31 * 19.26 * 162^3)/146,600 = 173 hp
to this number (173) we add 5% transmission, 6% driveline and 60 hp to drive the tires.

total flywheel hp to drive an FD 162:

173 + 9 + 10 + 60 = 252 flywheel hp.

hp to drive the FD 180 is 315 flywheel

hp to drive the FD 200 is 410 flywheel

hp to drive the FD 225 is 558 flywheel

notice how cubing the speed is catching up with us.

from 180 to 225 is a 25% increase in speed.

the HP needed has gone up 77%.

i have run my car to 170 on the main straight (6000 ft) at Brainerd Int'l. at the time i ran no rear wing and the R1 splitter. it was rock solid. any FDs having a high speed problem need to look at setup. alignment, tire balance and aero.

i am quite intrigued at the standing start mile long events. if all works out this year i would like to do either the Texas Mile or the Maxston Mile. i would be wanting to run 200. there are some good Mile videos out there on the web.

drool.

howard coleman

top speed
 

Well that brings up a couple interesting points. Firstly if anyone knows what sort of drag is the stock 94 touring spoiler adding, and also does vehicle height play a role in drag. I am also considering a rear diffuser, will that only help the air under the car become, less turbulant, or will drag be added as well. Secondly regarding the gearing issue, what are you guys running, I was thinking of switching to a 3.90 rear end, or potentially a taller fifth gear if such an item exists. Any advice appreciated.

Oh, and regarding the speedo issue, I do see the merit in the arguements I just havent experiemced anything like that nor have any of my friends.

i've hit 300km/h on the apexi on a cold night with downpipe, cat-back, HKS Twinpower, air-pump removal, supra pump and 0.8bar. Car wasen't even lowerd.
Flat surface.

The fastest I've ever had mine up to was around 165-170 mph. It had PLENTY more in it, but I saw no reason to go any faster...at least not on that road.

I was in the 150's and ran out of balls.....:sweatdrop

coefficient of drag STOCK 0.290

everything factors in wheelbase, tire width, tire circumf., wheel diameter, overall height, overall width and ground clearance.

when talking about rearend ratios the lower the number the lower the top speed but you will get there faster.

woops sorry i meant lower the number the higher the top speed.

thanks gmonsen.
4th monday this week.lol

"coefficient of drag STOCK 0.290"

that is correct. i noted my Cd number was for the R1.

overall frontal area can be reduced by running a lower ride height.

overall frontal area is increased by larger tires.

BTW, if you are running a front mounted intercooler and a non 93-95 front end,
think Hummer, you can kiss the Cd goodby.

Hope to see you at the Texas Mile Howard.

It just so happens I'm building a widebody rx7 with landspeed racing in mind. I know you guys will hate since I'm swapping an ls motor but it's all in the name of R&D to obtain a high mph with the fd body. The car has undergone extensive bodywork and is awaiting paint at the moment. My drivetrain is in finishing stages and will be shipped in the next few weeks.

Here's the setup: 93rx7, custom widebody, adjustable pitch rear wing, lowered on coilovers, BBK, fiberglass hatch, doors, hood, and front cover, warhawk LS7 427, Procharger F1R, tranzilla 6sp, cobra rear w/3.08s.

I'll be shooting to have this car on the mile next spring with a projected fw power of 1350, projected weight of 2500, and projected top speed in the standing mile of ~240. Redline in 6th is 315mph. This tranny is far from at standard t56 and uses customized gearing in every gear with gears made of a much stonger alloy than the stockers.

Given good conditions, this is a very attainable goal. I'll keep you guys posted.

the fastest Ive ever had my car was 175mph or at least thats what the speedo was saying although im kind of inclined to beileve it i dont think i would be spinning the tires at those speeds. I was going down the kilpatrick turnpike here in oklahoma city and hit 150mph and flew past a speed trap when i saw his lights turn on I kept my foot in the firewall till he turned of the lights andthen i pulled the car into a used car lot and went for a walk. lol

I run 145mph in 4th at 8,000rpms and im not trying 5th. J-spec trannie higher 5th with 4.30 rear gears and 500h/p. Traps 129.6 1/4mile.:Wconfused

I dont mind you going v8 but be careful. these cars tend to think they are airplanes at those speeds. props for the r and d but make sure you are doing most of it in the wind tunnel. there isnt really a learning curve at those speeds you either get right or you a have a pretty good chance of dying cage or not.

would a v mount affect the CD as much as a fmic?