It's possible on the street ... though a dyno would be "safer" ... but who's going to let you pull that kind of speed on their dyno??

To all the BS talkers, believe what you want. It just proves that i have the gonads and you don't.

 

I like the flash highlights, which proves the car was stationary, as does the distinct left turn orientation of the steering wheel.

Don't dig the hole any deeper!

 

ok, im questioning things again... this is bad, i wish i had something better to do! anyway, i came upon this picture which is of a 99+ rx7 in england. 7K RPM nearing 160MPH. youre telling me that with 1K RPM more he could go 40MPH faster??? wow i feel like a real dork...... but so should you cause youre reading this

p.s. (how do you post a picture directly to the forum page... html? i guess i should learn how to do that with my spare time.... and also learn how to post an avitar if thats the name of it)

 

damn forgot the picture... i tested it to make sure i can post and now it says i cant post the same image twice... ok well here->

https://www.rx7club.com/forum/attachment.php?s=&postid=2027994

 

Dude, just do the frigging math, if you don't believe us......

BTW, later years of FDs had 4.33 gears instead of 4.10, so it's not an apples to apples comparison. A 4.33 gear car will top out rpm wise at about 185 mph or so. Also, the car in the pic you have may have larger diameter rear tires, which will affect the final drive ratio (and speedometer accuracy).

 

I've had mine to 176 with a cold air intake, Racing Beat catback, and the purple CPU, and it was still pulling. There is no way in hell you could take your hand off the wheel at that speed. When you steer, you steer 1/4 inch at a time. Anymore than that, and you're going to look like the intro to the $6,000,000 man.
I read some info a few years ago. It said that the total top speed attainable gearing wise of a 5 speed FD was 197. It said that the automatic was a little higher.
I don't know how true those claims are though. I think the car could hit 200 with the right power. I have a 93, so I have the 4.10's.

 

You should feel like a dork. For some reason you are failing to realize that engine, gear, wheel and tire changes will result in different readings from the speedo at different RPMs.

225, 300, 250 and 400 HP RX-7s have different performance characteristics. This is simple. Why can't you comprehend it?

 

That's kind of incorrect. As long as your transmission internals are stock, the rpm vs. indicated speed will remain constant since the sensor is located at the output shaft of the trans.

 

I've done about 145 in mine so far and thats with an auto. Still had room to go but thought I should slow down.

 

Oh and yeah I would belive Ray is crazy enof to do something like that. Knowing the guy personaly and yeah I would say hes crazy enof to do that in his car.

 

Uh....wait a minute. It is a simple mph per rpm calculation. I know my car get about 28 mph per 1000 rpm, for example. That is a constant that doesn't change.

 

That can change if you install 4.33 gears or run rear tires that are bigger diameter than stock. However, as ISUposs pointed out, the INDICATED speed will not change. Your ACTUAL speed will.

 

the 99+ rears are the same diameter.... just wider. i didnt know they changed the diff gear ratio, so i was just wondering about the picture. thanks for setting me straight guys.

 

To all you guys spouting out all the BS talk about you can't do that with this size whatever and wind resistence being blah blah blah .... Quit the BS and go test out your theories.

Go find a nice long, straight, FLAT stretch of highway, with little to no traffic and try it out for yourselves?

It's very possible with the right conditions. Just make sure to have the right tires in good shape, tight suspension, and the f/r spoilers ... I have had mine past 175 mph with plenty left of the tach. Stock wheels/tire size, stock ride height, with tokicos set on 5.

The only thing I do suggest is that you have a fairly mod'd car with some decent power (much more than stock) and brakes in good working order. That way it won't take as long to get up to speed and back down. No sense blasting down the highway for very long ... right?

 

these 2 are more liek it

 

2

 

OMG That pic looks just like the one I took 6 yrs ago in my car. Is it possible that it's actually my car??

 

You will be going 0 MPH at 0 RPM. Gears are linear. So go drive at 4000 RPM in the gear you want to consider, look at the speedometer, and then double the reading. That is how fast you would be going at 8000 RPM.

Of course, tires change diameter at speed, and the speedo doesn't really indicate your speed all that accurately, but the test above is otherwise technically sound and will give you a decent estimate if you don't have the patience, math skills, or trust to believe the calculations. Of course, I guess you do still have to trust that the test is valid.

-Max

 

brilliant method! i have forgotten most of my phisics but its slowly coming back to me. i had believed that everyone was accurate... just had a few questions. i think these discussions are great though! it helps everyone develop a much better understanding of our cars, and always ends up with us going much deeper than the original question. i think we all learn tons from this forum!!! so props to everyone that contributes

 

1000 rpm mph 25.106242021749317
1500 rpm mph 37.65936303262398
2000 rpm mph 50.212484043498634
2500 rpm mph 62.765605054373296
3000 rpm mph 75.31872606524796
3500 rpm mph 87.87184707612262
4000 rpm mph 100.42496808699727
4500 rpm mph 112.97808909787193
5000 rpm mph 125.53121010874659
5500 rpm mph 138.08433111962125
6000 rpm mph 150.63745213049592
6500 rpm mph 163.19057314137058
7000 rpm mph 175.74369415224524
7500 rpm mph 188.2968151631199


This is the mph the car will do on stock 225-50-16's in 5th gear... (0.719) with the stock rear axle (4.100)
This only goes up to 7500 and we have another 500rpm after that... also drag and all that stuff...

personally ive only hit about 160ish... it gets kinda scary at that speed oh and the possibility of passing a cop.

 

The 99+ wheels were 17x8 in the front and 17x8.5 in the back

STEPHEN

 

Each one of those goes up appx 12.55mph per 500rpms so if you take it up to 8000 that would be 200.84mph or rounded up to 201 which I think someone said was the max earlier in this thread

STEPHEN

 

Numerically 200mph is possible but in the real world that's only going to happen if the car is going off a cliff. Unless of course it's a full blown land speed car like what Racing Beat ran on the salt flats.

It really depends on horsepower. My car (CAI, IC, Y-pipe, DP, and CB @ 13psi) will pull EASILY up to 140, but 140 to 160 seems to take forever. And anything beyond that definitely takes time and a good stretch of road. I have the R1 wing though which causes some drag.

 

sorry, i didnt mean to write diameter of wheel, i meant diameter of tire mounted to it.

 

Wow... Really? 140-160 shouldn't be that slow..