0 to 60 test

[kyleN20]

tonight i had my buddy ron in the car and i thought it would be a goo time to check 0 to 60 time. i used the timer in the car, and told ron, "hit the start button as soon as we start to move, and i will tell you when to start, when we did this, i yelled stop as we hit 60 and he hit the button, the time was 6.6, but i predict he hit hte button late or somthing, because that seems a tad fast

thoughts????

Kyle

[632 Regal]

do the 60-80 test...thats the one that tells the whole story.

[Marshy]

Don't forget that speedos tend to over-read slightly too. Hitting the button at about 65 is probably closer...

[BigKriss]

your friend would have to hit the button early, not late to read a faster time on the stopwatch.

6.6 sec is fast. My mothers e36 328 auto, does it in 8.2 (manufactures claims). I like the power of this car, its quick, but not too quick.

I would estimate my car is around 9 seconds. For a stick, i'm guessing high sevens at best (stock car in good condition).

[Paul in NZ]

7.7 i think is factory claim for a 535 manual,would be quicker if you didnt have to make thechange to third....

[Jose]

7.7 if you keep the car standard. Put 17' s on it, build in a kick ass stereo and bye, bye 7.7, it' scloser to 9 now...

[Rory535i]

7.7 if you keep the car standard. Put 17' s on it, build in a kick ass stereo and bye, bye 7.7, it' scloser to 9 now...

my 17's are the same overall diameter as my 15's

[Paul in NZ]

yes but they are probably heavier than the std wheels and the mass is carried more outboard than a 15,therefore harder to accellerate

[Rory535i]

yes but they are probably heavier than the std wheels and the mass is carried more outboard than a 15,therefore harder to accellerate

i doubt it would make much difference on a car that weighs 3500lbs. maybe on a mk1 golf you'd notice it... You might as well say that a half empty tank of fuel will decrease your 0-60 time in your E34. personally i don't notice any difference between driving with my 15's or 17's as far as acceleration.

[Mobius]

i doubt it would make much difference on a car that weighs 3500lbs. maybe on a mk1 golf you'd notice it... You might as well say that a half empty tank of fuel will decrease your 0-60 time in your E34. personally i don't notice any difference between driving with my 15's or 17's as far as acceleration.Wheel weight has a lot more effect on your suspension and ride than acceleration. That's not to say it has no effect on acceleration - see here (http://www.audiworld.com/tech/wheel13.shtml).

[DueyT]

Given that I don't like to drop the clutch from silly RPMs, I can fairly reliably pull 6.2-6.3s 0-60's, but that's an EAT-chipped 4.0L V-8 making around 305-310hp at the flywheel and around 260-265 at the rear-wheels. I'd say mid-7's would be more like it for you.

Of course, guys will also tell you that drag racing was not very high up on Munich's list of things to be good at...performance on the highway is stellar! That said, I could pull tree stumps out with my first gear (and that's with a 2.83 rear end). I redline at about 40 mph (65km/h) in first and I'm 500 rpm shy of redline in 2nd when I hit 60mph. Even with 255's, the rears will break loose if I put full throttle into the launch.

Cheers,
Duey

[SharkmanBMW]

Given that I don't like to drop the clutch from silly RPMs, I can fairly reliably pull 6.2-6.3s 0-60's, but that's an EAT-chipped 4.0L V-8 making around 305-310hp at the flywheel and around 260-265 at the rear-wheels. I'd say mid-7's would be more like it for you.

Of course, guys will also tell you that drag racing was not very high up on Munich's list of things to be good at...performance on the highway is stellar! That said, I could pull tree stumps out with my first gear (and that's with a 2.83 rear end). I redline at about 40 mph (65km/h) in first and I'm 500 rpm shy of redline in 2nd when I hit 60mph. Even with 255's, the rears will break loose if I put full throttle into the launch.

Cheers,
Duey

but as we enjoy the extra power our V8 powerplants put out... the fuel guzzling is very annoying!!!
I think my 0-60 is actually faster than a manual, the auto is so fast and smooth...
and it is for certain a quicker launch with the stock 15" than with 17", that is true.

[kyleN20]

there is no need to change to third for me, at almost redline of second, im hittin 60, noo need for a switch, if i pinged it in second on the redline, i would be at about 65 according to the speedo.

[DueyT]

but as we enjoy the extra power our V8 powerplants put out... the fuel guzzling is very annoying!!!
I think my 0-60 is actually faster than a manual, the auto is so fast and smooth...
and it is for certain a quicker launch with the stock 15" than with 17", that is true.
Chris, I try not to look at the gas gauge! :P

Actually, when I'm not dropping the hammer, I'm getting 31 mpg (27 US, 8.7L/100) on the 401/416 'tween K-town and Ottawa. Not too shabby... :)

Cheers,
Duey

[niall]

this outboard wheel mass is bull ****, i cant belive some of you guys actually
belive it, the difference it would make would be about the same as the driver
having eaten an extra burger at lunch time

the advice you guys should be giving to people doing 0-60 runs if your
so concerned about weight would be to take the spare wheel out and
run the car with only two gallons in the tank.

[Paul in NZ]

this outboard wheel mass is bull ****

it aint ********,its a fact.The biggest performance gain you can make to a mountain or road bike is to get lighter wheels,the benefit is not just the weight saved it is also due to the inertia of light wheels vs heavy wheels.As well as most 17 inch whels being heavier than the 15 inch counterpart the actual rim is further away from the centre of the wheel so requiring more energy to accellerate it...


there is no need to change to third for me, at almost redline of second, im hittin 60
hmmm i am just short of 100 ks(actually 62 mph) when the rev limiter kicks in,3.64diff vs 3.46???

[632 Regal]

and get a lot more traction and miles per gallons cause they never want to stop spinning.


this outboard wheel mass is bull ****, i cant belive some of you guys actually
belive it, the difference it would make would be about the same as the driver
having eaten an extra burger at lunch time

the advice you guys should be giving to people doing 0-60 runs if your
so concerned about weight would be to take the spare wheel out and
run the car with only two gallons in the tank.

[niall]

why dont you wax your car first mate
then it will cut through the air easier,
did you learn that in physics too

[Paul in NZ]

yes i did and i will!

[digitaldragon03]

but as we enjoy the extra power our V8 powerplants put out... the fuel guzzling is very annoying!!!
I think my 0-60 is actually faster than a manual, the auto is so fast and smooth...
and it is for certain a quicker launch with the stock 15" than with 17", that is true.
Oh, it is VERY annoying. I think a V12 760Li gets the same mileage as out V8's do. You gotta pay to play though.

[Jose]

It seems our friend Niall didn´t track his car too much nor did he compete it street legal racing. Why do you think Kinessis and BBS are the real Mac Daddies of alloy performance wheels? It' s because they combine wheight loss and strenght into one package. A standard 5 series with 15 inches will be undoubtely faster than a 17 inch whelled 5 series. The difference is so big you will be able to feel the difference, if you don' t you are not aware of the enjoyment your car brings. We are talking about normal daily drive situations not track or sprinting days where stripping out your car is usefull. To give you an idea of 15 versus 17, yesterday we wanted to know for sure and fitted back the 15 inch slicks onto the turbo E28 and it ran in 4.87 sec to 65 and with the seventeens it did 5.84 to 65. The difference is not tremendous because this car only wheighs 1340 kgs and puts out 378 bhp at the wheels due to bi-turbo set up. On a normal aspired car the difference would be bigger..try it out yourself.

[Rory535i]

did u run slicks on the 17's too?

[Jose]

yes we did run it on 17 inch slicks too. The E28 is a daily driver but our friend/customer tracks the car really hard too, and he prefers the 15´s. The 17´s were a wrong buy according to him and only used for drifting.

[SharkmanBMW]

It seems our friend Niall didn´t track his car too much nor did he compete it street legal racing. Why do you think Kinessis and BBS are the real Mac Daddies of alloy performance wheels? It' s because they combine wheight loss and strenght into one package. A standard 5 series with 15 inches will be undoubtely faster than a 17 inch whelled 5 series. The difference is so big you will be able to feel the difference, if you don' t you are not aware of the enjoyment your car brings. We are talking about normal daily drive situations not track or sprinting days where stripping out your car is usefull. To give you an idea of 15 versus 17, yesterday we wanted to know for sure and fitted back the 15 inch slicks onto the turbo E28 and it ran in 4.87 sec to 65 and with the seventeens it did 5.84 to 65. The difference is not tremendous because this car only wheighs 1340 kgs and puts out 378 bhp at the wheels due to bi-turbo set up. On a normal aspired car the difference would be bigger..try it out yourself.

It seems our frien Niall did not take physics either... bigger wheels is the easiest issue to understand!
there have been many great posts here about the science of it..... HAVE A GANDER before you make more foolish claims

[DanDombrowski]

When I interpolated my 1/4 mile times, I was hitting 60 at about the 7.6 second mark, and thats with a 525i 5spd. Your times should be a bit faster than mine, but remember that when I hit the end of the quarter, my speedo shows about 98 and I'm actually trapping at 89.9. Like someone else here said, 65 is probably the right number to take a measurement from.

[grave77]

well Kriss I would say that it really varies ... depends on the Gas condition ... every refill it feels sort of differant I tested my car when I 1st got it ... it was early in the morning around 19C ... it made 6.9sec
next week I tried it noon time ... it made 8.4 sec. when I chopped off the Cat. and tuned the AFM it made 6.6. I used the speed alarm to hit the stopwatch off ... set it on 95 so when it's 100 ( 60 m ) it will beep. that will be better than observation.

[grave77]

can I know if u reached the 6000 RPM at each shift?

[grave77]

I agree to all of that ... I have tried the 15", 16", 17" and now the 18" no differance at all the only thing is that it would burn out when I use the 15" more than the bigger ones ... I would notice more when 2 guy ride in the back seat .... and eating a big heavy burger meal will give more acclaration as u wont be able to lift ur foot off the acclaratot :D

[grave77]

well that adds another fact that this is the reason the weight is on the inner edge of the wheels and not the center. I notic that every day when I go to work ... 60Miles highway.
I still didn't feel that differance. I changed the rears from 235 to 255 @ 17" and now its running 265 @ 18" still the same. I would agree on the tire shape more than size. ( snow, dirt .... etc )

[niall]

2 words

Bull ****

[niall]

bigger wheels is the easiest issue to understand

like rory 535i says,
his 17's are the same diameter as his 15's maybe you should
have read that bit before making a foolish post

[Mobius]

Yeeesh.. I posted this on the first page, but I think some people must've missed it, so I'll try again: http://www.audiworld.com/tech/wheel13.shtml - The general conclusion: Every extra 1lb of wheel mass is roughly equivalent to ~2lb of dead weight.

[Paul in NZ]

The general conclusion: Every extra 1lb of wheel mass is roughly equivalent to ~2lb of dead weight.


What about I'? Well, the moment of inertia of a "punctual mass" [m] (a mass concentrated in a point) at a distance [r] from the axis of rotation is [m*r^2]. That is,
the moment of inertia depends critically on the distance between the mass and the axis of rotation.

Note that those calculations are for wheels of the SAME size..if you go to bigger wheels the mass moves further out from the axis so with 17 in wheel that are heavier than std wheels there is a double whammy

[Mobius]

Note that those calculations are for wheels of the SAME size..if you go to bigger wheels the mass moves further out from the axis so with 17 in wheel that are heavier than std wheels there is a double whammyYou have a point; except in this case there is no differentiation between wheels and tires; he merely assumes (pessimistically, as he says) that "all of the mass increment is located on the periphery of the tire." So, unless you're changing the overall diameter of your rolling stock (which, if you're doing the whole "+1" thing, you're not changing) - the theory still applies.
(Edit: And if you did change your overall diameter, the change in the effective gear ratio would probably become more influential than increased wheel weight)

You're correct in that the effect of adding weight AND moving the majority of the weight outwards has MORE of an effect than adding weight alone; but in any case, the overall result will not be greater than the 'pessimistic' 1:2 ratio calculated there.

[niall]

no doubt your formula's are correct , but
i still think the question stands,

would it make a noticeable difference,
and more so would it make more of a difference
than having less fuel in the tank, also one of these
guys did the time with his mate in the car, i think
that the 130lbs at least for his mates weight would
be alot more influencial than this rotating mass stuff

[granit_silber]

You have a point; except in this case there is no differentiation between wheels and tires; he merely assumes (pessimistically, as he says) that "all of the mass increment is located on the periphery of the tire." So, unless you're changing the overall diameter of your rolling stock (which, if you're doing the whole "+1" thing, you're not changing) - the theory still applies.
(Edit: And if you did change your overall diameter, the change in the effective gear ratio would probably become more influential than increased wheel weight)

You're correct in that the effect of adding weight AND moving the majority of the weight outwards has MORE of an effect than adding weight alone; but in any case, the overall result will not be greater than the 'pessimistic' 1:2 ratio calculated there.

I'm so glad I was a music major. :)
-ashley

[araine901]

Rotating mass will make a signifcant difference. My '66 911 has a hp to weight ratio of just over 13:1 My kt100 kart has a hp to weight ratio of 29:1 (both with me in them) Both of them 0-60 in about the same time around 6.0 seconds. The fact that the roataing mass 6" mag wheels and limited running gear skews the commonly held theroy that it is all about the hp to weight ratio. If I took the fuchs alloys off of my 911 and put on some steel wheels and took out the same amount of weight added by the wheels from say, the gas tank, the car would 0-60 slower.

[DanDombrowski]

Sorry Mobius, but that derivation is wrong. Its close, but its still wrong. The problem is that when you have a system of both linear and kinetic energies, the overall system torque is NOT the torque that is causing the wheel to gain angular momentum. The reason his derivation is wrong is because his starting equation is wrong. If you start with the kinetic energies of each rotating and translation portion of the system and take the derivative with respect to time twice, you end up with

Torque (engine) = I (system load) * alpha (angular acceleration of the driveshaft, wheel, etc).

The torque in this case, the engine torque, it NOT the same torque in the equation T=I*a of just the wheel. If it were, the inertia of the car would be equal to the inertia of just the wheel, and we would have very very fast cars.

Then,

Torque = Isys*alpha = Iwheel*alpha + (Mwheel+Mcar)*r*alpha(NOT a(linear acceleration)). The torque is only equal to M*a*r when the system is not translating and rotating. This is the error in his approach.

So, what is I(system load)? I checked out my mechanics of materials book, the

I(system load)=I(rotating mass) + M*rwheel = Mwheel*rgyration^2 + (mcar+mwheel)*rwheel, or, if we're going to say that the radius of gyration is the radius of the wheel,

I sys = mr^2 + m*r

an increase in mass of (x) amount will yield an increase in the inertia of the system of
x*(r^2 +r). In other words, the amount of which adding mass to the wheels will depend upon what the radius of gyration and the radius of the car is. For example, if we add mass to a wheel where the radius of gyration were theoretically zero compared to a wheel with a positive radius of gyration, the change in system load should only be based upon the change in mass of the linear system in the case where the radius of gyration is zero. According to whomever wrote that article, that would not be the case, it would be double the effect no matter what the radius of gyration, and that simply isn't so.

Now, all that aside, plus sizing the wheels moves more dense material (steel) towards the outside of the wheels, increasing the radius of gyration (not the radius of the wheel as whoever wrote that article oversimplified). If the radius of gyration increases, the inertial load of the wheel will increase, despite the overall diameter bieng unchanged.

If this seems confusing, its because it is. I might be wrong too. But I don't think so.

[niall]

i still stand by what i said , and that is

that dead weight like an extra passenger or more fuel,
or overall wheel diametre will be more influencial than
outboard wheel mass.

im surprised nobody has mentioned altitude yet
that would also probably affect your times by 1%
or someting stupid like that

[Jose]

well, duh?! Of course weight makes more difference, you don' t have to be mister sience for that !!! What we tried to point out is that the difference is there. Nobody said that the difference would between rim and tire size would be bigger than weightloss. There are many factors having influence on the acceleration of a car, weight, tire/rim size, spoilers, climate, air humidity, clutch wear,rear end diff,gearbox, etc, etc. It' s too many to list. I think we all got out context from Kyle's question when we started on rim sizes and other stuff . On the other hand, the tone of some messages in this thread, is not the tone we should use to each other as we are all BMW lovers, and that' s what it boils down to at the end of the line.

[niall]

Of course weight makes more difference

thats what i have been trying to say
good to see an end to this debate :)

[kyleN20]

right directly befor 600 rpm, or redline, i hit 60, though the say i ought to go to 65, which would mean i would need another shift. but for my speedo's 60 mph, i only need 2 gears

[JD525IA]

?


this outboard wheel mass is bull ****, i cant belive some of you guys actually
belive it, the difference it would make would be about the same as the driver
having eaten an extra burger at lunch time

the advice you guys should be giving to people doing 0-60 runs if your
so concerned about weight would be to take the spare wheel out and
run the car with only two gallons in the tank.

[niall]

nobody likes an ******* mate so dont be one,

does the length of time i have been a member
of this board really make my opinion further
from the truth.

get a life mate, this isnt about number of posts or membership
times

[Paul in NZ]

Niall sometimes a litle diplomacy doesnt go amiss either mate.

[Rory535i]

i think this thread should be swept under the carpet! causing too many bad vibes! where is the love!?! lol

[niall]

Niall sometimes a litle diplomacy doesnt go amiss either mate.
ill take that comment,
just get frustrated easily

[SRR2]

There you go again... confusing a perfectly good emotional argument with facts.

For those who still don't get it, the principle of superposition can help in understanding what's going on. Superposition says that you can isolate the translational and rotational properties of the wheel assembly. Specifically, think about a) the force necessary to accelerate the mass of the wheel (without regard to rotation) from rest to some speed. This is the same as accelerating any other dead weight in the car. And b) think about the force (or power if you prefer) to spin the wheel up from rest to 1000 (or whatever) RPM at the end of the acceleration run. Then add the two. That's all there is to it. To get a handle on the power to spin the wheel, think about a wheel balancer and how fast it spins up a wheel. The motors in those are less than 1hp and you can see that it doesn't take long at all to hit a couple of hundred RPM. No different with the car, so it should be easy to get an intuitive handle on the net power going into the wheels. This, BTW, is how the guy on the Audi board comes up with the 2X weight estimate. It's right on target.

[niall]

To get a handle on the power to spin the wheel, think about a wheel balancer and how fast it spins up a wheel. The motors in those are less than 1hp and you can see that it doesn't take long at all to hit a couple of hundred RPM. No different with the car,

that is a really good point