145 top speed

I pegged my old 89 hatch at 140....or so the speedo said. This was back in highschool so......like 10 years ago. Car was sloppy and felt toally unsafe at that speed. I'd never be able to get close or would even want to try that in my 88 vert with the 4.10's. I've seen too many car accidnets working for the fire department to ever want me to go that fast again. It's just not safe and once you get out of control at that speed theres nothing you can do. Save it for the track.
 
me 1500rpm = 60mph (honestly, my stupid 2:73 gearing pisses me off in town a lot)
27.5" ??? tall tires and 2:73 gearing + original 89 5 speed that came with the car.

I brought it up to 4000rpm once in 5th gear, what speed is that? 160mph??? HAHAHA I don't know, I suck at math, even the simple math. Whatever it was, the car felt okay (but VERY VERY VERY light on the road - bricks can fly with enough speed) I didn't trust my tires so I only went up to 4000rpm for a few seconds and let off... I know I could have brought it to 5000 pretty easy too.
 
I know most of theese people diddnt go that fast. Ive dne it on my bike and know what it feels like. Its windy and light on a bike so i can only imagine a car. You will also need a hell of a lot of room.
 
I've driven a Probe GT (of all things) to 145mph...the speedo was pegged. Believe it or not that car felt like it had more in it but was governed. I don't think a lot of people realize just how fast 145mph really is. The difference between 110 and 145 is VERY significant even though it's only 35mph more.
 
Here's the bottom line. On a stock car with stock gears, the top speed will be in 4th gear at about 145....once you put it in fifth you will most likely slow down or just barely maintain speed. Anyone that says otherwise is either lying or has inaccurate instrumentation. It takes gears (at least 3.55's) and quite a few bolt ons to get a fox past 150 and that will be in 5th gear. I have been to 150 in my combo...exactly 5k rpm in 5th...right in my powerband. My combo is far from stock; suspension, motor, and instrumentation...so I'm pretty sure most of you with stockish foxes probably haven't been as fast as you may think. At that speed the difference between getting to 145 and then getting to 150 is measured in miles and minutes...not feet and seconds.
 
I'd say it wouldn't take much...basic bolt ons....there are plenty of Fox's in open track racing that are approaching those speeds in the straights. But, then they have 13 inch brake rotors and racing suspension to keep them on the road.
 
140 is pretty fast, 170-180 is extremely different!!! btw: a stock fox will peg the speedo, no problem, how do I know? Ive had 5 of these things and all of them will bury the speedo, hell we got clocked in quinnett by beasts house doin 90 somethin, in the 4 banger notch lol. Ive had my 86 speedo wrapped around to the 15 before as well.
 
I didn't doubt your claim of 142mph. Theoretically, the top speed in 4th gear, with 3.08 gears, and 25.5" tires, is 143 mph at red line. It would only take 10 to 15hp over stock to get it there. But, unless you're putting out almost 305hp @ 3900 rpm, you are not going to get it up to 155 mph in 5th.

can you calculate my 4000rpm in 5th gear with 2:73 gears, at 60mph I'm dead on 1500rpm (my tires are taller than stock). :shrug: Car would not slow down in 5th, I wasn't flooring it, I know I could have taken it further too... I guess I have more power than a stock Mustang but the car didn't feel all too bad at those speeds, just real light. Also note that my car weighs less than 2800lbs.
 
can you calculate my 4000rpm in 5th gear with 2:73 gears, at 60mph I'm dead on 1500rpm (my tires are taller than stock). :shrug: Car would not slow down in 5th, I wasn't flooring it, I know I could have taken it further too... I guess I have more power than a stock Mustang but the car didn't feel all too bad at those speeds, just real light. Also note that my car weighs less than 2800lbs.

What size rear tires are you running?
 
can you calculate my 4000rpm in 5th gear with 2:73 gears, at 60mph I'm dead on 1500rpm (my tires are taller than stock). :shrug: Car would not slow down in 5th, I wasn't flooring it, I know I could have taken it further too... I guess I have more power than a stock Mustang but the car didn't feel all too bad at those speeds, just real light. Also note that my car weighs less than 2800lbs.

Dude you just mentioned that your car weights over 400 pounds less than a stock fox...UMMMM that might make a difference :shrug: I still say no stock fox will do much over 145...and if they do I think they would need a serious stretch of road.
 
140 is pretty fast, 170-180 is extremely different!!! btw: a stock fox will peg the speedo, no problem, how do I know? Ive had 5 of these things and all of them will bury the speedo, hell we got clocked in quinnett by beasts house doin 90 somethin, in the 4 banger notch lol. Ive had my 86 speedo wrapped around to the 15 before as well.

I wonder what a 96gt will do :rolleyes:
 
137mph (Garmin Quest) with top down

I have gotten to 137 (4th gear) mph according to my Garmin with the top down and it was not going any faster. Obviously the aerodynamics was the factor here. Except for the loud whistling from the top of the windshield, it was not as bad as I thought but I also got up there quick and after about 5 seconds of no more increase, coasted it down.

89 LX 5.0 5-speed convertible; Bone stock (including MotorCraft air filter) except for off-road X-pipe and CherryBomb Turbo's.
 
137mph (Garmin Quest) with top down

I have gotten to 137 mph (4th gear) according to my Garmin with the top down and it was not going any faster. Obviously the aerodynamics was the factor here. Except for the loud whistling from the top of the windshield, it was not as bad as I thought but I also got up there quick and after about 5 seconds of no more increase, coasted it down.

89 LX 5.0 5-speed convertible; Bone stock (including MotorCraft air filter) except for off-road X-pipe and CherryBomb Turbo's.
 
well i know for a fact that i've at least gone 85MPH...lol anything beyond that i cant prove unless someone wants to do the math, i run 3:08's, an 86GT WC T5, and 215/60/15 tires, i once went 2,900-3,000RPM in fifth gear downhill. that night almost ended my life so i wont be doing that again...
That works out to between 105 to 115 mph.


I don't think a lot of people realize just how fast 145mph really is. The difference between 110 and 145 is VERY significant even though it's only 35mph more.
Very true. One must remember that aerodynamic drag increases by the square of speed, and the power needed to overcome it increases BY THE CUBE!

If you want to double your speed, you need EIGHT TIMES as much power to do it.

Using your 110 to 145 mph example:
If a vehicle needed 100hp to reach, 110 mph, it would actually need 129 MORE horsepower (229 total) just to gain that 35 mph! It would take 800hp to get it up to 220mph.