E36 323i / 325i
Discussion
I'm looking at a 323i as a run-around while I look for a new car proper.
The 323i has 170bhp, the 325i has 192bhp, but they're the same engine size.
I seem to recall reading it was an artificial limit put in place by BMW to put more distance between the 323i and the 328i. Is there any way to liberate the missing ponies, or is it more complicated than that?
The 323i has 170bhp, the 325i has 192bhp, but they're the same engine size.
I seem to recall reading it was an artificial limit put in place by BMW to put more distance between the 323i and the 328i. Is there any way to liberate the missing ponies, or is it more complicated than that?
clonmult said:
Not sure theres any way of doing that, although I'd say that the 325i is probably a better bet, I believe its a little better on fuel?
The 328i is no worse on fuel as far as I can tell. But a hefty slice more torquey, even if its restricted power wise.The 328i was strangled to get the power under the German Tax laws - where anything over 194bhp got stung.
As a consequence, the freer breathing inlet manifold from a 325i, plus throttle body, add a touch of air filterness and some live remapping, and bingo, say hello to an easy 230/240 bhp.
Even with a upgrade filter and remap, the 328i seems healthier.
I can't remember the specifics for restricting the 323i, but I think the 325i is as it should be.
neil_bolton said:
dan101smith said:
When is the cutoff for the Nikasil issues? What should have been done for this, a recall?
Late 98 I think. Mines a mid 97, and had a new short engine at 63k miles as a result.If a car is post Feb '98 you're going to have to check yourself so find out what to look at on the block to identify whether its been upgraded or not.
Its a while since I've driven a 323 but I don't remember it feeling any slower than a 325, possibly torqier as well, best bet is to try them both.......
And then by a 328!
325i was produced from 1991 up to 1995, the engine came in two versions. The earliest ones have engine code M50B25 and do not have VANOS variable valve timing on the intake camshaft. The later version was the M50B25TU (Technical Update) with VANOS on the intake camshaft. Both engines have cast iron blocks with alloy cylinder heads.
In 1995 BMW switched production to an engine with the same architecture but used an all alloy block with nikasil cylinder bore liners on the earlier engines and after a certain point in 1998 steel liners. All M52 engines have VANOS on the intake camshaft.
The engine size of the top model also went up from the previous 2.5 to 2.8 litres. A 2.5 litre engine was kept in the range, however to diferentiate it from the 328i it was designated the 323i. Engine codes are M52B28 and M52B25 respectively. The alloy M52 blocks are slightly lighter than the iron blocks of the M50.
Performance wise the 325i has 191 bhp, wheras the 328i and 323i have 192 bhp and 170 bhp. The power difference between the 325i and 323i comes from the difference in intake manifold design. The diameter of the intake runners on the M52 are smaller. This restrics top end power, however does provide more low end torque. By fitting a M50 manifold you can get back the top end power at the expense of some of the lower end torque. It is not universaly agreed weather it actualy makes the car quicker overall without other modifications.
The alloy M52 blocks needed a coating to prevent bore wear, BMW chose nikasil (nikel silicon alloy) on the early engines. Some engines suffered problems with this, as the fuel at some petrol stations at the time had fuel that contained a relatively high sulpher content. This reacts with the nikasil lining causing the cylinder bore to eventualy wear and cause compression loss. As the bores can not be recoated the entire block needs to be replaced which was done on quite a few cars under warrenty.
Not all cars suffered the problem though and there are still plenty of cars (including mine) running on their original engines with no problem at all. The chances of nikasil problems now are small as everywhere now has low sulpher fuel. Beware that the problems can take a long time to develop though, so the only way to rule out that the damage hasn't already been done is a compression test.
For more info go to http://www.e36coupe.com and join the forum.
In 1995 BMW switched production to an engine with the same architecture but used an all alloy block with nikasil cylinder bore liners on the earlier engines and after a certain point in 1998 steel liners. All M52 engines have VANOS on the intake camshaft.
The engine size of the top model also went up from the previous 2.5 to 2.8 litres. A 2.5 litre engine was kept in the range, however to diferentiate it from the 328i it was designated the 323i. Engine codes are M52B28 and M52B25 respectively. The alloy M52 blocks are slightly lighter than the iron blocks of the M50.
Performance wise the 325i has 191 bhp, wheras the 328i and 323i have 192 bhp and 170 bhp. The power difference between the 325i and 323i comes from the difference in intake manifold design. The diameter of the intake runners on the M52 are smaller. This restrics top end power, however does provide more low end torque. By fitting a M50 manifold you can get back the top end power at the expense of some of the lower end torque. It is not universaly agreed weather it actualy makes the car quicker overall without other modifications.
The alloy M52 blocks needed a coating to prevent bore wear, BMW chose nikasil (nikel silicon alloy) on the early engines. Some engines suffered problems with this, as the fuel at some petrol stations at the time had fuel that contained a relatively high sulpher content. This reacts with the nikasil lining causing the cylinder bore to eventualy wear and cause compression loss. As the bores can not be recoated the entire block needs to be replaced which was done on quite a few cars under warrenty.
Not all cars suffered the problem though and there are still plenty of cars (including mine) running on their original engines with no problem at all. The chances of nikasil problems now are small as everywhere now has low sulpher fuel. Beware that the problems can take a long time to develop though, so the only way to rule out that the damage hasn't already been done is a compression test.
For more info go to http://www.e36coupe.com and join the forum.
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