More acceleration Power

[{NTM}]

Hi
In two week i will put a 325i 90 engine on my 325es 86 body. After this engine swap, what is the better upgrade i have to do for have more accelaration power (i dont do top speed, i'm from quebec and the road are very scrap so, acceleration is the fun way :-)
So, does is better to buy a headers set i change my cam or change the differentiels?
What size of differentials is better to buy?
Did you have good suggestion where to buy? I have seach headers on ebay and for E30 it are very hard to find it. the best price i have find is on this web site:
https://secure7.nexternal.com/shared/StoreF...sp&CategoryID=3
Note: i dont whant to paid more that 700us$, and if some body know can i find use part just said it :-). I know that chips do big upgrade but i does'nt trust that for the moment, i prefere do old school modification


Thx a lot for your suggestion

[Aether]

I think the 3.25 manual 325is differential is the better one for accelertion.

[Conisa325]

4.10 is the way to go. The greater the ratio is the quicker your car will accelerate. The 3.25 is good for top speed, not acceleration.
'87 325is has a 3.75 lsd, and the E30 M3 has a 4.10, not much diference but enough for th M3 to leave the 325is almost 0.5 seconds behind. If you put the same diferential on ths 325is and a chip to bring the revs up to match the M3, then M3 will be left behind, if not berely matching the 325is.
Given the same power, rpm and weight ratio a 4.10 LSD will give you acceleration quicker than 3.75 and even more than 3.25.

[Conisa325]

Definitly I think 4.10 is the way to go for acceleration.

[MrM3]

why do you want headers for a stock engine?

[{NTM}]

Does is just the M3 that have 4.10:1 ratio or Z3, 328 or oder bmw have it? If yes, what can fit on my car? (M3 are very hard to find at quebec)

For the headers, i think that if i put a performance cam on my engine i need a headers for better performance.

thx for your help

[pogiboy9]

I'm guessing you don't care about gas mileage

[{NTM}]

Umm if we whant power...we have to paid the gaz....
Witch car have a 4.10:1 differential ratio other that M3?

Does i change all the differentials or juste the rear gear and seal?

Thx

[MrM3]

you just replace the differential as a unit, which isnt complicated since its just a big case your dealing with. Automatic E30 325i/is/iC came with 4.10 diffs, but not all had LS since it was a option. the 325iX had a 4.10 LSD but it uses viscous coupling which ive heard isnt very helpful for performance on a RWD car but it may still work. the later 318i/is/iC had optional 4.10 LSD's, but used a small case diff which would not work on a 6cyl car

[Conisa325]

Indeed, as MrM3 has stated, a 4.10 is the diferential on most if not all automatic E30 came with. About that not all had LS since it was a option, I'm glad to have learned it today. Thanks MrM3!

[{NTM}]

Oki Thx, i will seach a automatic differential it will be more easy, else i will put de 3.73:1.
Did you have a web page that explain all step to do to change this part?

Thx
Alex

[anxious]

I own a 1988 318i Auto running on a 4.1 diff.

I am thinking of getting a 4.1 LSD.

Can I get a 4.1 LSD off any E30 or must it have come from a 318i Auto like mine.

By the way how much would it cost?

Thanks.

[anxious]

4.1 Differential E30

I own a 1988 318i M40 auto( not sold in US).(RHD)

I want to buy a 4.1 diff(non LSD) from a 1991 318i M42.(LHD)

My question is will it fit?

Thanks.

By the way how much would a 4.1 LSD cost?

[{NTM}]

I'm not sure, i seaching the same information (525 diff.)

[toffa182]

anxious: it will fit.