320 to 325 bits

[SUMPCRACKER]

Im converting my tourer from 320 to 325 spec and wonderd if there are any parts which are different that I dont know about.
I have the engine with loom ,ecu and oil cooler,gearbox with linkage,prop and diff.
Im thinking of the little things as well,all I can see is the plastic vent for the oil cooler in the lower pannel.
Im about to scrap my donor car so I would like to make sure I dont leave any parts on it that I need.

[Brianmoooore]

Since you are converting a touring and not a saloon, the only different bits are those that you've listed, the exhaust rear box (smaller tail pipes) and the badge on the back.
The oil cooler isn't really necessary with modern oils, and you can reduce the possibility of oil leaks and crash vulnerability, by using the 320 filter assembly.
For full 325 touring spec., you should also change to the alloy front suspension arms that the 325 shared with the M3, but the price of these will probably deter you!

[stonesie]

If you can get the 325 exhaust system it is a larger internal bore than the 320 system, it's the same on all E30 body style's and you will need a new clamp for the back of the gearbox

[SUMPCRACKER]

Ive got a sebring exhaust and a 325 front pipe, alloy lower arms? they look to be the same as the ones on my 320? price is not an issue as I have a complete donor car.

Is there a way of telling the arms apart?

I know the oil cooler is not needed but I want full spec rather than an engine swap as many seem to have.

[stonesie]

The steel arms are painted black, the alloy one's will not be painted and might appear more 'chunky' but are lighter... and about £200 each

[SUMPCRACKER]

I better get them off in the morning...oh deer.
so that is it then apart from the vin tag.
Thanks chaps..

[Brianmoooore]

It's only the touring version of the 325 that had alloy front arms, and on most, they will have long since been changed for steel ones.

[SUMPCRACKER]

No,they are still on it! and if I dont pull my finger out they will go with the shell!

[dannyboy759]

If you can get the 325 exhaust system it is a larger internal bore than the 320 system, it's the same on all E30 body style's and you will need a new clamp for the back of the gearbox

The 320 and 325 systems are the same, except like Brian said the diameter of the tail pipes on the 320 which are smaller.
If you have a 320 exhaust you dont need to change the centre section just the rear to get the correct tailpipes and all the clmaps and bits and bobs are the same.

[warner325]

hi ive got a 325i tourer which needed a bottom arm with the alloy arm got a price from bmw was £300 but my merchanic got and messured up the steal ones and they are exacatly the same but are only £50 from euro part so i had them fitted and its fine

scott

[stonesie]

If you can get the 325 exhaust system it is a larger internal bore than the 320 system, it's the same on all E30 body style's and you will need a new clamp for the back of the gearbox

The 320 and 325 systems are the same, except like Brian said the diameter of the tail pipes on the 320 which are smaller.
If you have a 320 exhaust you dont need to change the centre section just the rear to get the correct tailpipes and all the clmaps and bits and bobs are the same.

Sorry but I have to disagree there, I fitted a 2.5 system to my 2.0 (bit of future-proofing) and it is bigger, the 2.0 clamp would not fit the 2.5 front section because of the diameter difference and it has been reported on there that a 2.5 running a 2.0 system is down on power as a result.

[Brianmoooore]

The difference in the size of the main pipes is minimal, but you're right that a 2.0 back box won't fit a 2.5 front part. I found out this the hard way a few years ago, and had to resort to slitting the end of the 2.0 pipes to expand them a little.
The complete 2.0 system will fit, and a 2.5 back box will fit a 2.0 front part.

[town325i]

some 320 tourings come with the alloy lower arms mine was listed with them

[SUMPCRACKER]

Ive got all the bits on my gararge floor now, the 2.5 lower arms are alloy and the 2.0 ones are steel ,the 2.0 exhaust is the same diameter on the front part and the 2.5 centre box is smaller (maybe because its a pattern part) the 2.0 tail pipes are very small.

Ive taken Brians advice and removed the oil cooler as I agree its more of a fault liability than it is usefull.

I now have two questions,the tag on the 2.5 touring diff says 3.64- as far as I know this was never standard fitting for a 2.5 tourer- should I use it? or will it be a bit long.
Also the 2.0 gearbox was recond recently and the 2.5 one has done a lot of miles,is there much lost by using a 2.0 box? the fourth and fitth ratios are the same.

A friend of mine has a 2.5 with a 2.0 box and diff and it goes like a rocket but needs a 6th gear! (4.1 diff)

[SUMPCRACKER]

please help.

[mrLEE30]

if the box on the 320 is a getrag 240 then only 1,2 and 3 are different ratios, 4th (1.00) and 5th (0.81) are the same for both the 240 and 260 boxes. (for the record reverse is also different ratio too)

the 3.64 diff is fine for a 325 with either gearbox but standard i think is 3.74. (may need to confirm this)

using the 240 box will mean it will accelerate faster in 1,2 and 3 of course at the expense of road speed versus engine speed, but 4th and 5th are same so motorway not affected (this is where the diff choice will make most difference)

hope that helps

mrlee

[SUMPCRACKER]

Thanks for the info,I fitted the 240 box today with the 2.5 engine and a genuine clutch.
I will give the small case diff a chance and will change it when I get fed up with changing gear....

[town325i]

small case diff is not really any good with the 2.5 engine i did this for a while on my touring which had a 4.27 i think and it would be revving really high on the motorway at 70mph not any good if you dont like wasting fuel

[SUMPCRACKER]

I will change the diff but need to finish the rest of the car first,im aware the 4.1 and 4.2 diffs are a bit short.
The whole car has been almost re shelled in the last two weeks- dash,loom,suspension,brakes,interior,carpet,engine,box ect...so im a bit knackerd! the diff wil be changed when my energy returns...im cold...and hurting.

[leeparkes]

Thanks for the info,I fitted the 240 box today with the 2.5 engine and a genuine clutch.
I will give the small case diff a chance and will change it when I get fed up with changing gear....

the 4.1 diff will give 65mph @ 3000rpm,3.64 will give 75mph @ 3000rpm!
acceleration with the 4.1 diff will be like a cat thats just had its tail stamped on!
the other issue is the strength of the 4.1 (small case) ask gareth,he had one lock up!

out of interest how much did you pay for the clutch?

[SUMPCRACKER]

Ive had the clutch for a long time (about 7 years!) not sure of the value?,and I am a bit worried about the diff letting go as the last printout for the engine was 185bhp so the diff is well on edge- im OK with the diff failing but hadn't thought of it locking up...that could be interesting...

It is going to accelerate ok but I doubt it will crack a genuine 60 in second so all that gearchanging will average out the gains.

[leeparkes]

I dont know the full details but after a few hard starts at the pod the diff locked up,he does have an M30/3.5 though!
the clutch,i was just curious to know how much bmw charge for one.

[SUMPCRACKER]

Short gearing will only ruin fuel consumption on a run , around town it will help as it will be easier to pull away and there will be less open throttle needed to make progress.