4.45 or 4.27 Diff in An IS

[Alex]

My winey diff could do with changing to a quieter one, and was thinking changing to a shorter one to make it quicker

has anyone got any experiance with either a 4.27 or 4.45 diff

also does anyone know what revs it would be doing at 70mph in 5th with both diffs


i mainly do town driving and maby once or twice a month do a couple hour drive down/up the motorway

Thanks

[Kedge]

I know Dan318iS had a 4.27 LSD in his and i think i found it fine on motorways, went Le Mans with him the other year and he had no complaints and a few weeks later he drove it down to the south of France and reported some pretty good MPG. I seem to remeber him saying it had a similar affect to how the car drove to my JBR flywheel.

Not sure what a 4.45 would be like but i have a nice quiet one on ebay at them moment .

[DHFiS]

With the 4.27 diff you will have 3400rpm at 70 and with the 4.45 3500rpm.

With the std 4.10 ratio 70 mph is at 3250

[Alex]

I know Dan318iS had a 4.27 LSD in his and i think i found it fine on motorways, went Le Mans with him the other year and he had no complaints and a few weeks later he drove it down to the south of France and reported some pretty good MPG. I seem to remeber him saying it had a similar affect to how the car drove to my JBR flywheel.

Not sure what a 4.45 would be like but i have a nice quiet one on ebay at them moment .

i belive it was you i asked a question about shipping last night

[Alex]

With the 4.27 diff you will have 3400rpm at 70 and with the 4.45 3500rpm.

With the std 4.10 ratio 70 mph is at 3250

Is that it, i think i will go 4.45 then

i was thinking 4000 -4500 rpm at 70mph

[Bob_S]

4.27's work well on an is, they make them more interesting

[Alex]

a 4.45 may make it more interesting

[Bob_S]

a 4.45 may make it more interesting

no, it just makes the gears really short and boring.

[Alex]

but the power band is high up in the revs on these turds

or would i get sick of changing gear

[capri_rob]

Alex a couple more cylinders would make it more interesting

Oh come on it was only a matter of time

[Alex]

Alex a couple more cylinders would make it more interesting

Oh come on it was only a matter of time

i 100% agree but the next engine up a 320i will cost an extra £500 to insure

[Alex]

i'am debating an engine conversion next year

[capri_rob]

Alex a couple more cylinders would make it more interesting

Oh come on it was only a matter of time

i 100% agree but the next engine up a 320i will cost an extra £500 to insure

Ouch !!!

Was only pulling your leg fella

[capri_rob]

How much No Claims discount do you have now ?

[Alex]

Alex a couple more cylinders would make it more interesting

Oh come on it was only a matter of time

i 100% agree but the next engine up a 320i will cost an extra £500 to insure

Ouch !!!

Was only pulling your leg fella

your rite though

[Alex]

How much No Claims discount do you have now ?

1 year will get 2 year in feb 2010

[ImysE30]

Just save up and get a proper engine next year

[capri_rob]

I think 2 Years claim free should see you with quite a drop in premiums - IIRC I went from a 1.3 Astra L to a 1.8 Cavalier SRi just after I had 2 Years NCB for about the same insurance cost

[Alex]

[Kedge]

I know Dan318iS had a 4.27 LSD in his and i think i found it fine on motorways, went Le Mans with him the other year and he had no complaints and a few weeks later he drove it down to the south of France and reported some pretty good MPG. I seem to remeber him saying it had a similar affect to how the car drove to my JBR flywheel.

Not sure what a 4.45 would be like but i have a nice quiet one on ebay at them moment .

i belive it was you i asked a question about shipping last night

Arh i see, was wondering that, does that mean you want it then?

[Alex]

will let you know

not sure if i want a 4.45 or 4.27 still

[Omi]

4.10 is fine, motorway miles will be hatefull with a shorter final drive and the diff will be completely useless if you did an engine swap later.

3.91 is cheaper and easier to come by if you want a slipper, and a few extra ponies from a chip and BBTB will make the steeper ratio disappear completely.

[GrindCulture]

4.27 isn't too bad on motorways to be honest. I think 4.45 would get very annoying very quickly. A 4.27 diff in my touring feels a little nippier than my old saloon with a 4.10, so a 4.27ed saloon should be pretty good really.

And I feel your pain with this insurance malarky, although now I can insure a 6 pot, I just don't have the cash to get one

[Nay]

Living in jersey and our great little windy roads, I want a short ratio LSD for my 325i. We have a top speed of 40mph <<pause for the laughs>> (not to say everyone sticks by that) but its all about handling and acceleration over here as theres nowhere to have a really good run *safely* unless you find your way into the car club and enter the rare sprints and hill climbs etc.

What I want to know is I've heard 4.10 LSDs are ok, but will the higher ones like Alex mentioned be chewed to pieces by a powerful M20B25? Will they cope at all? I mean even a 3.91 or preferably 4.10 would be great, but going into the higher ratios will be more suited for my humble little home rock.

[Alex]

3.91 is cheaper and easier to come by if you want a slipper, and a few extra ponies from a chip and BBTB will make the steeper ratio disappear completely.

i'am thinking that with a 3.91 a bbtb and chip will be wasted, though

think i will play it safe and go for 4.27 rather than the 4.45

Grindculture- how much quicker is it, just a bit nippier or noticably quicker??? what do you prefer????

[mt1104]

I thought 4.27s were very very rare to find though, or is that just LSD versions?

[Alex]

LSD version will be, all 316i tourings have them

actually there is a 316i touring parked outside my house

[stonesie]

Theres one sat on my garage floor too

[mt1104]

lol, hmm, how quiet of a worker are you , some chavs managed to remove my friends turbo recirculation valve from his impreza one night without him waking up.

[GrindCulture]

Grindculture- how much quicker is it, just a bit nippier or noticably quicker??? what do you prefer????

It's only a little more noticeable in my car as I'm lugging the extra weight of a big boot around with me. Off the mark I'd say it was a little slower (due to the weight and the lack of torque ) but once it's up and revving it's more perky. I'd say a 4.27 in a 2door would be a noticeable improvement.

[GrindCulture]

all 316i tourings have them

All 4 pot tourings have 4.27s if manual, 4.45s if auto.

[mt1104]

so only available in small cases?

[GrindCulture]

Yup

[Alex]

all 316i tourings have them

All 4 pot tourings have 4.27s if manual, 4.45s if auto.

i thought the 318i had a 4.10 even the tourings

[robbo86]

I have 4.45 in mine as that was what was with the car when I did the conversion and want to get a 4.10 ASAP. To be honest 4.45 is just annoyingly short.