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-   -   How much do these items improve 0-60 acceleration times? (http://forum.e46fanatics.com/showthread.php?t=645464)

SpeedDemon 02-03-2009 01:35 AM

How much do these items improve 0-60 acceleration times?
 
I'm wondering how much these two mods make the car faster in 0-60...

If the ZHP could originally do 0-60 in 5.6 seconds then how much faster do the following items make the car do a 0-60 sprint?

1. LSD
2. 3.46 FD from a 3.07
3. Stickier tires

Thanks!

tchavis1989 02-03-2009 11:49 AM

they'd shave a couple points of a second off that 5.6 0-60 time and you can buy a 3.46 lsd ...

regards,
tyler

SpeedDemon 02-03-2009 03:22 PM

I have a 3.46 LSD with some of the stickiest street tires around ;)

It's just that it's winter time (cold) and there's nowhere that I can accurately measure my 0-60 this time of year so I'm wondering what people's experience is with these mods? I mean would it shave off .2? .1? .3?

SeanC 02-03-2009 03:25 PM

3.46 diff would actually decrease your 0-60 time, because you cannot achieve 60mph without shifting to the 3rd with the 3.46 diff... It would improve 1/4 mile numbers though.

LSD doesn't have any effect on linear acceleration.

Stickier tires would help a great deal, since at the time of take off, friction is the dominant force to get your car going rather than its horse power or differential.

bimmerboi19 02-03-2009 05:55 PM

if you got a 3.38 diff that would help your 0-60 b/c you would hit 60 at the top of 2nd gear.

JJR4884 02-03-2009 05:59 PM

Quote:

Originally Posted by cngzsn (Post 9344573)
LSD doesn't have any effect on linear acceleration.

accelerating you are correct, however LSD would jump off the line a little quicker due to the face that power is going equally to both wheels, rather than one....

SeanC 02-03-2009 06:54 PM

Quote:

Originally Posted by JJR4884 (Post 9345453)
accelerating you are correct, however LSD would jump off the line a little quicker due to the face that power is going equally to both wheels, rather than one....

Lsd never distributes the power equally to both wheels. There is a certain amount of "locking" while taking a curve, so that the outer wheel gets "some" of that power, as well as the inner one. While accelerating on a straight line, it doesn't matter if you have an lsd or an open diff.

SpeedDemon 02-03-2009 10:39 PM

It seems like an LSD would have to help off the line. Of course you are still going to slip a wheel, but wheel slip won't be as detrimental as it would be with a Open Diff. Wheel slip with an LSD will cause the other wheel to get the rest of the torque. It seems like this would be especially true with an LSD like my Torsen (Quaife) that is auto-torque-biasing (ATB) all the time.

Yes, a ZHP does have a 6800RPM redline, but the rev limiter doesn't kick in until just after 7000 RPM. A ZHP or any E46 that has a flashed ECU can hit 7000 RPM in 2nd and bounce off the rev limiter at which point it would be doing 60.25 MPH with a 3.46 final drive. Check out the calculation I did over on my330i.com:

http://dl.getdropbox.com/u/38192/gearing.png

jsonli 02-09-2009 12:00 AM

LSD does little for us in this regard since we're aren't getting that much wheelspin. Same with tires, if you aren't getting much wheelspin now, I can't see better tires helping.

Getting a good launch is probably the xfactor.

johnnyg 02-09-2009 12:30 AM

ZHP 5.6 to 60 is a little ambitious. That number is more than a half second quicker than my 330 CI AT and within .5 of my 08 G37S all while giving up nearly 100 hp to the G. These threads are interesting but wildly inaccurate, fun to discuss though. Cheers!

SpeedDemon 02-09-2009 03:07 AM

0-60 in 5.6 has been achieved by multiple magazines.

Your Steptronic slows the car down by at least a whole second and the only reason that it comes close to the manual time is due to it having the shorter 3.46 gearing vs. the manuals 2.93 or 3.07 in a ZHP.

You G37S is heavy and the horsepower means nothing if it isn't developed at the right points in the power curve.

SeanC 02-09-2009 09:25 AM

Quote:

Originally Posted by johnnyg (Post 9375229)
ZHP 5.6 to 60 is a little ambitious. That number is more than a half second quicker than my 330 CI AT and within .5 of my 08 G37S all while giving up nearly 100 hp to the G. These threads are interesting but wildly inaccurate, fun to discuss though. Cheers!

FYI, 0-60 was done in 5.4 seconds and 1/4 mile in 14 seconds flat by KrisL, on a %100 stock ZHP... When in doubt, use the search button.

SpeedDemon 02-09-2009 09:15 PM

Quote:

Originally Posted by cngzsn (Post 9376356)
FYI, 0-60 was done in 5.4 seconds and 1/4 mile in 14 seconds flat by KrisL, on a %100 stock ZHP... When in doubt, use the search button.

Any idea what his launch techniques were?

SpeedDemon 02-09-2009 09:23 PM

Quote:

Originally Posted by jsonli (Post 9375060)
LSD does little for us in this regard since we're aren't getting that much wheelspin. Same with tires, if you aren't getting much wheelspin now, I can't see better tires helping.

Getting a good launch is probably the xfactor.

Just wanted to add that I found it pretty easy to spin the wheels with the original tires.

SeanC 02-09-2009 09:40 PM

Quote:

Originally Posted by SpeedDemon (Post 9380298)
Any idea what his launch techniques were?

Launch at around 2700 rpm and shift as fast as you can. That was it IIRC... No DSC of course.

TxZHP04 02-09-2009 10:05 PM

Quote:

Originally Posted by SpeedDemon (Post 9375778)
0-60 in 5.6 has been achieved by multiple magazines.

FWIW, the C&D video review of the ZHP coupe indicated their 5.6 sec was an estimated value.

Quote:

Originally Posted by cngzsn (Post 9376356)
FYI, 0-60 was done in 5.4 seconds and 1/4 mile in 14 seconds flat by KrisL, on a %100 stock ZHP.

Those were GTech Pro numbers, which I believe factors in a 1 ft rollout. You can add roughly 2 - 3 tenths for a standing start. And of course, you can always debate the accuracy of the GTech. :)

SeanC 02-09-2009 10:36 PM

^ I am sure those issues were debated in the past without any consensus, but I think 5.6 should be consistently doable :)

TxZHP04 02-10-2009 07:37 AM

Quote:

Originally Posted by cngzsn (Post 9380917)
^ I am sure those issues were debated in the past without any consensus, but I think 5.6 should be consistently doable :)

IIRC, KrisL only got below 6 sec on 1 out of 3 attempts. I know we're all pro drivers but 5.6 is a wee bit optimistic for most people. While it's not impossible, it would certainly be easier to achieve consistently in a car with more torque that would make nailing the perfect launch a little less critical.


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