cpbeasley

I'd like to clarify something for starters.
Per an older thread (for all you with your 'STFF' macro'ed), my c350 6 spd apparently has a 2.82 final gear ratio. The SLK350 apparently has a 3.27. This all sound right?

The lackluster take-off that Karo & I experience must surely be due to the belly flopping 2.82 gear ratio?
I wonder how much quicker the SLK is off the line as a result of its slightly lower 3.27 ratio? (yes assuming all other things equal for the hell of it)
Gas mileage is nice and all, but I wasn't afraid to put 4.10s in my old LS1 car (yes I realise different gearing in the T56 and maybe a slightly different motor, so why not have some fun and put a set of 3.67s, or something else in b/w?

Yes, 1st gear is gone in an instant as it is, but that's also what a push of the clutch and second is for... as I'd like to consider taking advantage of the freedom the 6 spd grants to the ability to alter rear gears.

Aside from the drivability aspect, any comments on such an endeavour?

The 4.10s was quite possibly the funnest mod I did to the old Camaro aside from the bumpstick. I went from 3.23 to 4.10 in that setting. My RPMs went up a bit at given speeds, but nothing to cry about. The torque on the other hand... whoa nelly.

So, any opinions thoughts?

W203E35

Wait so you feel the lack of POW off the line as well? Damn 2.82 is weak sauce. I thought we had 3.27??

cpbeasley

search forum for c350 final gear ratio
it brings up a thread titled something like '05 vs 06'
he traded his 05 c320 in for an 06 c350. in fact, he ordered the c350 with a 6 spd. the info is all there. 2.82 for c350 6 spd but the slk350 got the 3.27 (why?) - and he was almost sure was the same for the 7G as well (but by the sounds of it, we both suffer from the 2.82 because yes, my launch sucks... 2nd, 3rd gear and beyond accumulate like a freight train)

yes, 2.82 = weak, weak saucey sauce
which now that it's been said, doesnt it make sense re: our flat face take off???

cpbeasley

me thinks 3.67 FTW

Glyn M Ruck

That long axle ratio is for low rpm cruising, economy etc. For sure it will blunt launch! These cars are set up as high speed Autobahn cruisers.

OneOfaKindTrini

Can you chirp the tires from first to second.. Yes im home today OMW to the auction

cpbeasley

Yes I can chirp second, but nonetheless, 2.82 is sooooo tall.

Glyn, good point re: the autobahn cruising.

The search for a 3.67 rear end begins.
To anyone still reading this, should the 3.67 rear end out of a c240 be direct bolt-in replacement?

Glyn M Ruck

C240 & 320 axle mounts are identical so I imagine C350 will be the same.

MiKeSSw203

It should bolt in. I still have my 3.67 collecting dust that I still haven't installed. Was debating on using that or trying to source the MB parts to build a 3.92 or convert to bolt up axles vs slide in to be able to swap various pumpkins easily. I'll probably put the 3.67 when I get my next service done at Hyevon Motors.

TemjinX2

A different gear ratio will cause a esp error unless you plan on driving with no abs or esp.

cpbeasley

this is the first i've heard of this.
why would this happen?
in another thread a fella did it to his c230k 6 spd with no issue other than flakey cruise control

i have 6 spd so no tcu worry and will have it tuned if necessary to eliminate any error in the ecu.

TemjinX2

esp goes off the gear ratios off your tranny and rear diff. Might be different on a manual. You can give it a shot.

cpbeasley

Oh, I will.

Glyn M Ruck

Can all be set up with Star for the new ratio.

91RS

You will have to get the new ratio set or your speedometer will be way off (also causing your odometer to be off).

cpbeasley

JJ from OE Tuning said that there was no programming necessary for different gears in my 6 spd car... is he wrong?

W203E35

As Glyn mentioned you can select different gear ratios in DAS/SDS.

mleskovar

2.82 to 3.27 is a significant change. If my math is right it would take a 135 mph top end to 113 mph but you'd probably get there in a 1/4 mile

e1000

With this change, you will be slower to 60mph, but maybe a hair faster through the 1/4 mile. If you really want to go forward with this, just drive around without shifting to 6th, it's almost the same thing.

Although you may feel like your car is faster, the resultant performance difference will be negligible.

This will change your theoretical maximum top speed (max revs in 6th gear) from 198.4mph down to 171.1mph.

FrankW

this reminds me of my friend's e36 M3 which he did a auto-to-manual swap and kept the auto rear diff. makes one heck of a fun car, but runs out on the top pretty quick. he didn't have issue with his car, but then again this was a 98 e36 M3 sedan.

the SLK has the 3.27 diff because it's meant to be marketed as a sports car. plus it has a different M272 E35.

cpbeasley

I've lowered the gear ratio on nearly almost every car I've owned. 3.23 to 4.10 in my 02 LS1 F-body was worth every penny.
When options are as limited as they are, and existing options are expensive... I'll take this mod anyday.

Glyn M Ruck

Lower ratios & being able to rev out in every gear is always a winner. This is one of the few times I will challenge e1000's theory.

The only thing that might scuttle my point of view is the Benz MT's ability to accept snap changes.

cpbeasley

finally some encouraging words!

Waiting on a call back from the european rear differential "pumpkin" man to place my order for the 3.67 out of an 02 c240 for hopefully approx ~$300. Found a local installer, a performance shop, willing to do the swap for $350. Also just got off the phone with Jeremy @ OE. He has a hunch that the ratio change in Star Developer isn't a necessity, but is checking on it for me in the meantime. @ time of the install, ECU will be headed off to see Jeremy for the tune and mod for the new ratio if needed. Looks like this is all coming together nicely.

It's probabl a few weeks away from being completed, but stay tuned! The first mbworld w203 c350 w/ lower final gearing is on the way!

TruTaing

this is interesting

e1000

haha, one of the few people I can have a constructive conversation on a technical level with. Glyn I'll PM you my thoughts.

EDIT: Glyn your PM box is full!!!!!!!!!!!!!!