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!

 

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



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 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

 

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

 

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 !

 

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!

 

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

 

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 *****.....

 

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.

 

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?