Best diff for acceleration

[e30-320i]

what would be a good ratio diff to get better acceleration from my 320i i'm not really after a LSD at the moment as i dont have the power or the balls for drifting(yet) i just want it to get up to speed a bit quicker.i'm not sure what ratio i got at the moment as i've not had a look but what should i expect to pay for a standard diff second hand.

[Demlotcrew]

Im sure you got a 4.10 right now. SO you can use one from a 316i auto which is 4.26. But its not really worth the effort.

Andrew

[E30BeemerLad]

can't help on the ratio front i'm afraid but a non-lsd diff should be about Ԛ£50, trouble is the ratios you need may only be lsd equipped diffs, which puts you into Ԛ£250 region for a good'un

[Brianmoooore]

BMW already geared the things with a diff for max acceleration. THat's why they're so thirsty.
This engine just doesn't have the power. Nothing 500cc won't put right.

[Simon]

BMW already geared the things with a diff for max acceleration. THat's why they're so thirsty.
This engine just doesn't have the power. Nothing 500cc won't put right.

Got to agree though, I've recently acquired another 325i sport, and got used to driving both (320i and 325i) back to back again, I was driving the sport home the other night up the motorway doing a nice 80mph, the motorway from my work is quite steep, in 5th, from 80mph to 120 was totally effortless and didn't take long, I tried the same thing in the touring the day after, and it was a no go, it hardly budged from 80mph, the only thing that moved was the 'swingometer'! Apologies to the '731' crew, but I can't wait to ditch the 2.0 and get something better in there!

[chief]

didn't realise a 4.26 existed
would this fit my 325i se and what would one cost
anyone know
thanks

[Gwynleym10]

didn't realise a 4.26 existed
would this fit my 325i se and what would one cost

It will cost a sh!t load in petrol if you ever go above 65mph thats what!

First gear would also b useless

[320Touring]

didn't realise a 4.26 existed
would this fit my 325i se and what would one cost

It will cost a sh!t load in petrol if you ever go above 65mph thats what!

First gear would also b useless

not to mention that the diff is probably small case and possibly less strong (ask andy_magic about a 2.7 and a 4.10 smallcase )

3.9ish diff out of a 325i would give similar accel to current diff and strength of largecase.

To increase accel, lose weight wherever you can-eg-all the crap in the boot!

a 325i Throttle body also appears to be beneficial on the m20b20 so give that a bash too-get one from a scrappy for Ԛ£20

[HartgeH27]

Tried a few combinations:

3:64 not bad good cruising

3:73 BETTER

3:91 best ratio I think, for acceleration and economy/comfort/cruising

4:10 harsh and wickedly bad economy

Above those ratios I have no experience,

Iain

[Andy_magic]

(ask andy_magic about a 2.7 and a 4.10 smallcase )

I'm still running a 4.1:1 small case diff with the 2.7 out of necessity as I'm skint, great acceleration but theres always a nagging feeling that I'll send the planet gears of the diff into a different orbit if I stamp it in 1st and 2nd.

I would fit a 325i TB, AFM and a zone chip, should make a nice difference, loose as much weight from the car as you can too. It shoul perk your car up nicely.

[Brianmoooore]

(ask andy_magic about a 2.7 and a 4.10 smallcase )

I'm still running a 4.1:1 small case diff with the 2.7 out of necessity as I'm skint, great acceleration but theres always a nagging feeling that I'll send the planet gears of the diff into a different orbit if I stamp it in 1st and 2nd.

I would fit a 325i TB, AFM and a zone chip, should make a nice difference, loose as much weight from the car as you can too. It shoul perk your car up nicely.

If you changed the diff for something a bit more suitable, it wouldn't drink as much, and you wouldn't be quite so skint!

[320Touring]

(ask andy_magic about a 2.7 and a 4.10 smallcase )

I'm still running a 4.1:1 small case diff with the 2.7 out of necessity as I'm skint, great acceleration but theres always a nagging feeling that I'll send the planet gears of the diff into a different orbit if I stamp it in 1st and 2nd.

I would fit a 325i TB, AFM and a zone chip, should make a nice difference, loose as much weight from the car as you can too. It shoul perk your car up nicely.

If you changed the diff for something a bit more suitable, it wouldn't drink as much, and you wouldn't be quite so skint!

good point brian but i think it'll do 35mpg on a run if he behaves, just that he cant resist the 2.7 rush

[Andy_magic]

If you changed the diff for something a bit more suitable, it wouldn't drink as much, and you wouldn't be quite so skint!

A budding basil brush

It's actually pretty good on fuel, I don't drive it too fast as the noisy rear wheel bearings help me keep the speed down.

I did manage to get the consumption down to a nasty 120 miles to 20 quid the other day had fun doing it though!

[JOSEMI]

Simon

Apologies to the '731' crew, but I can't wait to ditch the 2.0 and get something better in there!

Wow ! what's wrong with the 2.0 ??????? I can kick ass with mine

[Andy_magic]

Wow ! what's wrong with the 2.0 ??????? I can kick ass with mine

You'll really wish you didn't ask that.

The replies will read something along the lines of:

Crap fuel consumption and gutless and the only thing going for them is the sound of the engine.

I love mine though, even before the implant I loved it.

[JOSEMI]

18 years old 115k and 120 mph no shakes at all !
and excellent sound as you said

[liam012]

sorry to hijack but have you kept a close eye on mpg andy? like when you're good when youre bad etc?!

[Andy_magic]

I think the worst I've seen was 22 and the best is 35.5mpg.

I normally get about 30 and thats a mixture of urban and motorway 80mph driving, with the odd blitz here and there.

[Andy_magic]

JOSEMI:

I can't see wha question you were asking (he asked me in another thread)

Like I say, I like 320i's.

Apparently the 320i gives the same fue consumption as a 325i with less power.

I personally prefer the 320i as every 325i I've seen for reasonable money has been an abused shed thats had the life rung out of it.

You can pick up a 320i in nice condition thats been looked after muc easier,I guess its something to do with everyone wanting the 325i.

The 320i motor does suffer with a lack of torque, but makes up for it by revving nicely due to the really short stroke of the engine. Fuel consumption does suffer though as a result.

I have taken steps to improve the torque on my car and it's much easier to drive and the fuel consumption has improved too, even with the 4.1:1 diff still in there.

I wasn't slagging off 320i's

[Cloggy Saint]

I have taken steps to improve the torque on my car and it's much easier to drive and the fuel consumption has improved too, even with the 4.1:1 diff still in there.

I wasn't slagging off 320i's

What steps are these? an improvement in mpg is always interesting.

[liam012]

i think datourer that one of those "steps" is dumping a eta bottom end in to the engine bay!!
maybe i'm wrong
but i don't think so....

[Cloggy Saint]

hmmm, that sounds like a bit more than a step!

[Andy_magic]

First prize goes to Liam. 2.7 ETA bottom end

Due to having loads more torque the engine doesn't labour so you end up driving about using less throttle for a given driving style. When you do stick your foot down it goes a fair bit better.

[JOSEMI]

Hi Andy,
Just found your answer mate
what did you do to yours ???
mine doesn't drink that much anyway, it has a lovely third and fourth gears (high revs as you said) which makes up for the second (usually very thirsty) and I use it a lot to save on fuel.

When I bought my car, my mate (a mechanic) gave my 320 a good whack to make sure the engine held the pressure ok. By a good whach I mean A MASSIVE SHOCK to the engine, getting as high as he could on second and making the engine scream, and woke the engine up.

These engines are strong mate, they hold what you give them, and they can be very quick !!
I like mine anyway
Jose

[Andy_magic]

Sounds good mate.

So far the only changes I have made is the 2.7 litre block with a 320i head.

Future plans include a gas flowed & ported head, 325i AFM & throttle body, Zone chip etc.