Diff 3.64 vs. 4.10

[alexk]

This info is from Manos. He lives in Crete in Greece and has an M3 that is fully changed to CSL specs (all carbon bits etc).
I think he is member also here but doesn't post. He tracks the CSL so he is a capable driver.
I would like to thank him for the info.

The tests are in the same place, same temperature and weather.
With red is diff 3.64 and blue 4.10.
With the 4.10, the car also has SS race cats, and SS lightweight race backbox.

0-100 km/h 1.3 sec difference (3.64 faster)


The car is spinning a lot with the 4.10

0-160 km/h 0.7 sec difference (3.64 faster)
With the 3.64 you have 2 gear shifts and with the 4.10 3 gear shifts.




0-200 km/h 2 secs difference (3.64 faster)



100-200km/h 1.4 secs difference (3.64 faster)




80-110 km/h only here 4.10 is faster




0-400 m 0.5 secs difference (3.64 faster)

[_Nathan_]

Redo the graphs to eliminate wheelspin...

From a standstill the 4.1 version hardly moves for a while, then look at the 1-2 gearchange and how long there is no acceleration, wheelspin again.

[shane@mbtech]

Maybe the ss cats caused a slight loss in power????

[alexk]

Originally Posted by lawsy

Maybe the ss cats caused a slight loss in power????

I wouldn't be surprised.

[XKaLiBaR]

Too much wheel spin, for a realistic test. He needs to learn how to drive, or get better tyres.

[alexk]

Originally Posted by XKaLiBaR

Too much wheel spin, for a realistic test. He needs to learn how to drive, or get better tyres.

Comments like these are not necessary

He is running cups and he definitely knows how to drive.
If the road does not have 'dragster strip glue', that's another story.

[The Gorilla]

Hi,

These Graphs do not show the engine 'Rev' Drop
on each gear change.

They are just acceleration Graphs.

Once you factor in the Rev drop for each
gear change, and the fact that a 4.1 diff will
be using more engine revs for the same car speed
as a 3.64 in the same gear, then unless you can hit
8250 rpm in every gear, and only incur a rev drop
on each gear change of say 1750 rpm, which
would keep the S54 at around 6500rpm so right up on the std Cams,
then a 4.1 diff will give slightly better acceleration upto a
given point.

Higher lift Cams would push the window a little higher with
the Rev drop in each gear becoming even more critical.

I would guess that on just straight line acceleration,
at around 115 / 120 mph then
things would start to even out and from there on up
the 3.64 may start to have a slight edge.

Go onto most Tracks though and the 4.1 car will be quicker than
the 3.64.

Regards,

The Gorilla.

[DuncanR]

So .. Shimmy.. you leaving yours in .. or taking it out?... or was it really in at all ??

[XKaLiBaR]

Originally Posted by alexk

Comments like these are not necessary

He is running cups and he definitely knows how to drive.
If the road does not have 'dragster strip glue', that's another story.

So you think wheelspinning off the line for half a second is a fair test, whilst the comparison graph he has zero wheelspin.

[Dan]

Originally Posted by XKaLiBaR

So you think wheelspinning off the line for half a second is a fair test, whilst the comparison graph he has zero wheelspin.

Take it with a pinch of salt mate, Alex is just trying to post some information up for god sake, we can't all be as technically sound as you are in your tests, ala the 'remap' thread, lining up next to your mate before and after mapping, no variables there is there!

Snipping at people might be acceptable on Cutters but for genuine CSL owners we like to get on thanks!