What prop shaft for m3 evo into e30 conversion?

[e92mirro]

Hi and thanks to all who replied to my prev post about 5 stud conversion for my project that all went in loverly and now the wheel sit's alot better in the arch.
On to my next problem what prop to use? my mate at bmw spares in charring kent recons that a z3 2.8 prop will do the job as the box is the same and the z3 has alot incommon with the e30 running gear but said to check with the great people of e30 zone 1st.
So any help you guy can give will be well apriciated.
Cheers dudes

[Ant]

E36 328 manual prop should fit straight on, needs an E30 centre bearing carrier fitting(backwards) otherwise on she'll pop.

Ian knows this

what diff you running ?

[glenn]

if it's got the evo six speed box, the e36 328 wont fit.
the 328 prop is ok with the 5 speed box

[e92mirro]

I have a 5 speed from Ian at bmw spare's outa 328, he say's they are the same box or as close as, so it looks like the prop from a e36 328 is what i need.

Will i need a different doughnut/coupling to fit them up or will original do?

As regards to the center bearing dose it need to be a 325 or e30 m3? Is it just a case of reversing the braket or dose the bearing its self have to be backwards?

I havent brought a diff yet or looked into ratios but if any one know's what would be the best to use that would be great.

cheers guys

[e92mirro]

off to get my engine today not sure what diff to ratio it gonna need with a 328 box. anyone got a idea?

[Taylor325i]

off to get my engine today not sure what diff to ratio it gonna need with a 328 box. anyone got a idea?

3.15 ratio - Z3M or E30 M3


Taylor.

[e92mirro]

cheers dude picking up box monday will see if Ian at bmw spares has got a diff aswell.

[RoadHazard]

Normally, you use the E30 M3 guibo. But I believe it can be replaced with something else.

Same center bearing on both E30's.
You can use E30 M3 prop. If you use 328 prop, you need the center bearing from E30 but use dust cap and seal from E36 and install everything just like on E36.
You'll see what I mean when you're there.

[UweM3]

off to get my engine today not sure what diff to ratio it gonna need with a 328 box. anyone got a idea?

3.15 ratio - Z3M or E30 M3



Taylor.

E30 M3 = 3.25
Only EVO2 or EVO3 was 3.15 and therefore very hard to find.

[GermanGorilla]

Hi,

Couple of small points.

Use either a E36 m3 Evo or a
E46 M3 Propshaft Guibo as
they take far more stick than
an E30 M3 one.
Reason being they are thicker and
you can adjust the prop to suit.

The E30 M3 has 2 different centre
bearings, one is wider than the other
and turning them around does not
sort the problem as they are not
truly centered.

Do not understand why when using
the 5 speed box, that the 3.25 diff
is the one of choice ?

5 speed and 6 speed have more or less
identical ratios, other that 6th Gear is
0.83, ie a sort of overdrive.

E46 M3 Uses the same box ratios and runs
a 3.6 CW/p, on 18/19'' wheels so with
O/A diam being 630mm +/- then why would
you want to run anything that would in
effect decrease acceleratrion for a
greater top speed ?

17'' Wheels ie 585/600mm O/D brings
it back but nothing like the CW/p.
I would have thought that
3.45 CW/p at a min would be used unless doing
mostly motorway driving.

I ran my S50 B32 E30 M3 on a 3.73 with 6 speed
and found first a tad short, but it was spot on
through the box with a SSK.

A 3.25 or 3.15 would push the gear ratio v
road speed v RPM very long for a road
car, which I would have thought was not
the objective of such a conversion.

Still each to his own.

Regards,

The Gorilla.

[e92mirro]

Thank for taking the time to respond to my post.
What i am trying to achieve is acceleration with a max speed af around 140mph as the intended use is for the track so what diff i fit is important.
What info i am going to need is the output figures for the 5 speed e36 m3 box so i can work out the diff ratio i am going to need with the wheels and tyer's im using
cheers
guy

[DanThe]

205/50/15 with a 3.25 diff will give a slower road speed than 255/40/18 tyres and a 3.6 diff = greater acceleration

This is why the 3.25 diff is the one to use

[e92mirro]

I am running 225/40/17 because of the brakes im using, i thought a ratio of around 3.9 would do the job but was going to let the computer program at work calculate the ratio.
It works by entering the the roling radius of the wheel, the output ratio of the box and aprox top speed. It will then give you the diff ratio you need and the top speed in each gear

[DanThe]

Well then you will need a 3.45 diff to keep the same ratios as the E46 M3

For a track car though 3.64 would be good

[RoadHazard]

Don't 5-speed E36 M3 also come with 3.15?

[GermanGorilla]

Hi,

E92 Mirror, assuming 7250-7500 rpm in each
gear then a 3.73 is what you require.

A 3.64 will also work, but for a
top speed of around 140/145 mph
in 5th direct 1.0, with 600mm
O/D wheel /Tyre then a
3.73 is very good.

@7750 rpm with 600mm O/D Wheel/Tyre with 3.73 Diff

1st = 34.3
2nd = 57.3
3rd = 87.3
4th = 118.8
5th = 145.03

Hope that helps.

Regards,

The Gorilla.

[jmc330i]

Don't 5-speed E36 M3 also come with 3.15?

Yes.

As for what diff for a conversion, it depends what the car will be used for - I havent seen any mention of what the OPs car is to be used for.

Mine is an everyday road car so Im using a 3.15 with the 5spd and TBH, for motorway driving Id prefer maybe a 2.93. Its sits just below 3k rpm at 70mph in 5th (this is with 205/55/15s, which have a rolling diameter a little smaller than the E36 M3 235/40/17s). This may change when I swap to 16"s.

3k rpm at 70mph is more than enough for me. Theres no way Id want a shorter ratio diff, but I do know a few people who swear by 3.64s on S50 5spd track cars.

[Jhonno]

I am running a 3.25i slipper, and couldn't imagine running shorter.. It is nicely spaced through the gears that you don't have to keep rowing the box.

OP.. So far all the questions you've asked are very basic. A small amount of investigation would have revealed, and saved your questions for the more difficult bits..

[GermanGorilla]

Hi,

I think E92 Mirro clearly stated it was for
Track Use.

''Thank for taking the time to respond to my post.
What i am trying to achieve is acceleration with a max speed af around 140mph as the intended use is for the track so what diff i fit is important.
What info i am going to need is the output figures for the 5 speed e36 m3 box so i can work out the diff ratio i am going to need with the wheels and tyer's im using
cheers .''


Should have gone to Spec Savers.

Regards,

The Gorilla.

[jmc330i]

Hi,

I think E92 Mirro clearly stated it was for
Track Use.

Yup, just seen that. Missed it first time around, but then that first mention of a track car was after your post of not understanding why people opt for the 3.25 or longer ratio - which is what I was replying to. For a road car, a 3.15 or 3.25 will be fine, meaning you wont have to rev the thing to death when on the motorway or dual carriageway etc.
I still think a 2.93 would be ideal for an everyday car (especially on 205/55/15s) as the S50 has enough torque/power to pull the longer ratio.

As I clearly said above though, I know a few people who swear by 3.64s for a track orientated car.

[e92mirro]

cheers gorilla for your info and for taking the time to post it

Some of my questions maybe basic but i am a bodywork man trying to do this coversion for the 1st time so i need all the help i can get!!lol

Cheers guys for your posts
mirro

[UweM3]

I am going to 3:25 on my track only car. I want to keep the revs down. And I want some serious top speed
over Schwedenkreuz