How slow is a 3.64?

[Quaser]

Hi Guys

Just a quick question about lsd's - how much slower is a 3.64 compared to a 3.73 or 3.91?

im talking 0-60 and 0-100 times here.

would you really notice it?

Thanks

Q

[Kos]

on a 325i sport with a manual box you will be fine, it will allow you to hit 60 mph in 2nd gear

i prefered my tech 1's with a 3.64 compared to a 3.91 which i fitted

[Quaser]

2.7 convertible - currently has a 3.73 open diff on it

[Kos]

has it got a manual sport box ??

[Quaser]

yep

[Kos]

the 3.91 will be nice and buzzy, but you will be looking for 6th on the motorway at times!!!

i personally like a 3.64 holds it in gear for longer and it make use of the extra power and torque you have

[Geoff]

I had a 3.64 on my old H26. To behonest i would have wanted a 3.91 for better acceleration, but once your one the motorway is a demon cruiser. Saw the far side of 150mph on the clock at just about 6200, it rev'd to 6900 but couldnt really get it to go much faster.

My firends C2 has a 4.1 on, now that makes for quick acceleration. Still do 135 no probs.

I would have thought a 3.64 might be cheaper too?? Ask HartgeH27 or Iain for some prices. He may have one going.

[Quaser]

thats what im wondering - how much slower is a 3.64 compared to a 3.91?

I have a 3.64 diff at home - just wondering whether to fit it or not!

[Kos]

fit it, you wont regret it

[Quaser]

ok - which oil do i need to put in there?

[Kos]

dont know which one is recomonded , pm the oilman

i always use castrol

[M5pilot]

Kos,

Q has a very very heavy cabriolet. Even with it's quite powerful 2.7 it feels as though it needs shorter gearing. The car is only just quicker than a 325i sport due to the weight.

Cab's and tourings came with a shorter final drive from factory to make up for the extra weight they carry.

I've driven the car quite a bit already and it just doesn't want to pick up speed in 2nd. Already does just past 60 in 2nd indicated.

My personal opinion - go 3.91:1 and enjoy the acceleration! Who needs to go fast in a cab on the motorway anyway. It's noisy as hell @ anything over 80mph.

Geoff, your friends car has a 3.91:1 LSD - he cruises at 100mph doing roughly 4250rpm in 5th gear which equates to a 3.91:1 final drive.

Sal

[stevetigger]

Im happy with my 3.64 but I need to change it to LSD

And its noisy as hell over a ton! Car that is not Diff

I can cruise at 70@3300rpm

[Ziggy]

Got to agree with Sal here - I prefer my cab with the 3.91 rather than the 3.64 (aside from the obvious due to it being an LSD!). & it's still fine on the motorway... didn't even notice any difference on economy; I fitted the cruise at the same time!

I'd get a 3.91 & sell the 3.64 - shouldn't be any difference in price...

[Geoff]

Sal, Gareths car is (im told) an old press car and it came with a few different additions like the 4.1 as a mod?? Not sure but thats what Gareth says.

Oh F~@k it go 3.91 and tell all and sundry how quick it is!

[MikeeMiracle]

how much slower is a 3.64 compared to a 3.73 or 3.91?

im talking 0-60 and 0-100 times here.

would you really notice it?

Hell yeah you would notice it. I thought I was getting a 3.91 installed at the weekend for my iS but it turns out it was a 3.64 I have had fitted. The car came with a 4.1 open diff as standard. I recon im at least a good second slower to 60mph which im not happy about. Really wanna swap it for a 3.91 to get my acceleration back.

[Quaser]

Steve - mine does 70mph @ 2750rpm???

[Demlotcrew]

Well i have gone through four diffs so far. (not because they broke)

3.46 > 3.33 > 3.25 and the last one is a 3.15 and each time i went up the car didnt seem to slow down at all if anything it got faster!

Andrew

[M5pilot]

I can definately say Demlots car goes like a bullet now, I can't see any 2.7 other than Player6's beating it.

However your S14 has a totally different powerband to an M20. M20's just get slow with long diffs. M3's can really use the taller gearing upto a certain point to their advantage.

3.91 Mr A1 Quas! You won't regret it.

Or wait until it gets it's final map done and then see how it goes. We know it's not putting down anywhere near as much power as it should right now.

Sal

[Demlotcrew]

Thanks sal!

I have got word of a New MAXX system coming out.

Ignition and fueling (plus a whole load of other features)

[stevetigger]

Steve - mine does 70mph @ 2750rpm???

I have an M50 with direct 1.1 5th gear!

[M5pilot]

Thanks sal!

I have got word of a New MAXX system coming out.

Ignition and fueling (plus a whole load of other features)

They should make a 6Cyl version aswell.

Sal

[Quaser]

Dude - tell me more!!!

Sounds like an interesting comprimise!!!

Where can i get the clutch pack from?
Q

[Ziggy]

Andy, how difficult is it to swap a LSD unit (from an e30 diff) into another diff? Mine's got a whiney input shaft bearing... don't know if it'd be easier to just change that?!

Ta

[Demlotcrew]

It really is not that easy to swap parts about from diff to diff!

Ziggy doing any bearing on a diff is really hard work! You need a good press, then a monster of a vice and a very large breaker bar!

You are looking at around £80 for parts.

Andrew

[Ziggy]

Bugger. Guess I'll live with it for a bit longer, then cut my losses & stick the b****** on eBay. Thanks anyway!