BlackFC_NYC

My speedo cable is busted, but the other morning coming home from work i got a chance to kinda open her up on the LIE..

I was in 5th gear and i had it at 6k for a bit, and then 5k(which isent that fast i know)

just curious how fast 6k is in 5th gear is in a S4.

Thanks!

Relisys190

iTrader: (4)

pretty much you were at top speed. about 135-140 (s4)

the highest i've gone in my fc was 125.. i got scared... it was relitivly smooth and stable.. again, children... dont try going 125 on a daily basis. it is dangerous and extreamly illigal. you will go strait to jail.

Besides the point. at 125 i was at 4500-5k rpms

again, quite exhilerating.

-Markus

BlackFC_NYC

with my other motor i had in the car...i had the car in 5th at 6.2k and i let off before i died.

chris_stampe

Umm my s4 was at 5.4k in 5th and i was damn near 160, but I had messed up tires. My spedo was only readin like 148, but the calculators seem to work pretty good so u can just go use one of those.

BlackFC_NYC

is that accurate?

Grey_Ghost_#7

in theory yes, but take account drag ,rotating mass, etc etc.... i know in 4th gear pegged its like 138mph range. not that i know... I never speed

c-squared

Based on your tire size, and gearing, 146 mph at 6000 rpm.

6200 rpm would be 151 mph, and 6550 rpm would be 160 mph.

C. Ludwig

iTrader: (27)

What's drag and rotating mass have to do with indicated and actual speeds? If a given tire is spinning at a certain RPM it doesn't matter if it's on a parachute, a bus or an RX-7 it's going a certain speed.

At any rate the calculator tells me 7k in 4th with 225/50-15s is right around 140 with a 4.10 rear gear.

Chris

petex

it depends if you're runing stock-sized tires or bigger or smaller tires/rims. If size is not stock, than you have to count for speedo error. Bigger than stock, your speed is higher than speedo, if smaller than stock, your actual speed is lower than speedo.

rx_7_driver

how do u figure this out? the fastest i'v gotten to was 6k in fith gear how fast is that realy? the car is in the sig. tires r 215/45/r17


-Shawn

dr0x

With that tire, your speedo is showing 1% faster than you are going. So even at 100, you are only off 1mph or so.

petex

your speedo is calibrated for stock sized tires, and those are 15x6 rims with 205/15/60 tires. If you use different rim/tire combo and your wheel outer diameter was changed your speedo might not be acurate.

try this:
http://miata.net/garage/tirecalc.html

petex

using link above I've got:

Speedometer reding non-stock tire is 0.03% too fast.
When your speedo reads 60MPH, you are actually traveling 59.8 MPH.

dr0x: just curous, how did you get that 1% (did you round 0.03% up?), I asking because I dont know the formula and I would like to know :-)

dr0x

No- I didnt notice he had a NA. I used TII info.

BlackFC_NYC

looks like around 6k in 5th gear im pretty damn close to 160.....
since right now i have stock sized rims and tires

Capn' Wankel

Just to remind all of you guys that are pedal heavy here......Realize that when you are traveling upwards of 4000 rpm that your water pump can't do it's job. I used to haul *** around the 75 and 275 exchanges donig about 140-150 in my GTU but it really isn't all that good for the cooling system. No water is circulating when you are above 4k rpm so everything in the block is just heating up in place.

-Lee

rx_7_driver

well i think the large hill i was going down helped me out alot to get that fast, it just sucked when i got to the bottom, i bottomed out pretty bad


-Shawn

BlackFC_NYC

ouch