<![CDATA[1987 325e Power options?]]>I recently purchased a 1987 bmw 325e for 1400 dollars. It is primarily rust free, everything works except the rear defroster and the window washer pump.

I'm currently running into a dilemma however...

I wan't to make it fast! No, not 200hp at the crank! I want to atleast be at 350whp with my primary goal being around 400whp.

I have the m20b27 motor (2.7liter m20) which is a very torquey motor however it only puts down around 130hp. My motor also happens to have 280k miles on it.

So heres where I have two options.

for my power goals I would need to:

A.

swap a m20 325i head (This head has ALOT more flow) onto my existing m20b27 block and then boost it.

(I would have to use m20 325i electronics to do the swap. aswell as throttle body and some other misc parts). According to forums I can safely run atleast 15psi off a hx35 or hx1c on the motor with the ONLY modifications being a new (stock) headgasket and ARP headstuds. Keep in mind that this would be done on a block that already has 280k on it. My compression after swapping the 325i head onto the m20 would be 8.5:1 which is perfect for boost. My displacement would also stay at a healthy 2.7 liters.

B.

swap an m5x or S5x and boost it.

I would most likely buy the motor and while its out I would "update" it and install things that will be harder to get at later on.

Apparently this swap is easier to do on 88+ E30s due to the fact that it requires some 88+ parts.

The most intimidating part for me doing this swap would be wiring. I know the m50's are also easier to swap due to the fact that they are OBD1. However the issue with the m50 is that they only come in a 2.5 liter. I am hoping for atleast a 2.8l so i can run less boost and have the same effect with increased reliability (less stress on the engine).

The problem with the s5x is that they are expensive (correct me if i'm wrong?), So at this point I am thinking that the m52b28 would be the best option however I will have to convert from OBDII to OBDI

I've never done this swap before and unless a forum member can guide me along the way and help out (possibly? I give free food?) it seems like I will be in uncharted territory as soon as I take the m20 out. granted there are a lot of forums but I have never actually swapped an engine or done the required electronics. Only worked on engines in the bay (Headgaskets etc).

For both options I would be reusing my Getrag G260 trans (Pretty bulletproof even at 400hp)

What do you think is the better option? and what am I leaving out?

]]>https://wibimmers.com/topic/2256/1987-325e-power-optionsRSS for NodeWed, 16 Sep 2026 04:49:48 GMTSat, 28 Dec 2013 02:04:33 GMT60<![CDATA[Reply to 1987 325e Power options? on Tue, 31 Dec 2013 16:31:16 GMT]]>It looks like I will be going 2.7i!

Check out my build in progress here: http://www.wibimmers.com/board/index.php?/topic/2261-1987-325e-eventually-boost27i-m20/

/threadclose :)

]]>https://wibimmers.com/post/33596https://wibimmers.com/post/33596Tue, 31 Dec 2013 16:31:16 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 21:32:08 GMT]]>Todd is a great guy/contact to have in this community and if you're boosting you should talk to him.  He helped me out boat loads throughout my build.

Spring is coming!  Is this boosted yet?!?

]]>https://wibimmers.com/post/33569https://wibimmers.com/post/33569Mon, 30 Dec 2013 21:32:08 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 20:51:42 GMT]]>

Snap ( I ❤ M50) said:

$4000 budget should do it. 

I had the pleasure to meet Todd from TDC a little over a week ago and I expressed my interest in turbos. The above cost is exactly what Todd said it would cost with engine, suspension and drive train related items that would need to be replaced/upgraded to handle the boost. It's not a poor man's hobby but sure is a fun one!

]]>https://wibimmers.com/post/33566https://wibimmers.com/post/33566Mon, 30 Dec 2013 20:51:42 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 18:59:34 GMT]]>$4000 budget should do it.

]]>https://wibimmers.com/post/33563https://wibimmers.com/post/33563Mon, 30 Dec 2013 18:59:34 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 17:45:29 GMT]]>im going to assume that for the sake of making space on the pass. side, that youd want a late model cooling system/water pump/radiator etc as well

]]>https://wibimmers.com/post/33558https://wibimmers.com/post/33558Mon, 30 Dec 2013 17:45:29 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 17:11:21 GMT]]>For the i head swap you'll need everything from the i except the block, starter and radiator.

]]>https://wibimmers.com/post/33555https://wibimmers.com/post/33555Mon, 30 Dec 2013 17:11:21 GMT<![CDATA[Reply to 1987 325e Power options? on Mon, 30 Dec 2013 16:34:28 GMT]]>

Laishes said:

Pretty much!

But na, I figure 400hp in a 2700lb chassis is plenty for me :)

Welcome to light ass bmw league

]]>https://wibimmers.com/post/33550https://wibimmers.com/post/33550Mon, 30 Dec 2013 16:34:28 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 06:02:01 GMT]]>

Ramze46 said:

I'm gonna be megasquirting my e28 and running a t4 on it on the economy m20 engine and eventually swap to the normal m20 head for more flow. Until I blow it up and deem it useless then swap to ls1!!!

Thinking about keeping the m20 thus far. It's just cheaper and far more easier than other options it seems. Although if I was to boost I would run the 2.5i head on the 2.7 block

]]>https://wibimmers.com/post/33466https://wibimmers.com/post/33466Sun, 29 Dec 2013 06:02:01 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 06:00:42 GMT]]>

Snap ( I ❤ M50) said:

You sound like you want 1000hp

Pretty much!

But na, I figure 400hp in a 2700lb chassis is plenty for me :)

]]>https://wibimmers.com/post/33465https://wibimmers.com/post/33465Sun, 29 Dec 2013 06:00:42 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 05:41:03 GMT]]>

Laishes said:

can a m30b35 out-horsepower a s50/s52b30 when boosted due to the increased displacement?

All other things equal, no, 24v heads flow better. 

Its also a game of quantity of power vs quality of power.

You sound like you want 1000hp

]]>https://wibimmers.com/post/33464https://wibimmers.com/post/33464Sun, 29 Dec 2013 05:41:03 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 03:56:55 GMT]]>Also; does anyone know offhand if the "sand beige" m3 vader seats are the same color as the "sand beige" e30 interior? If I were to get a pair and swap out my front seats would they match the rear seats at all?

]]>https://wibimmers.com/post/33463https://wibimmers.com/post/33463Sun, 29 Dec 2013 03:56:55 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 03:55:34 GMT]]>can a m30b35 out-horsepower a s50/s52b30 when boosted due to the increased displacement?

]]>https://wibimmers.com/post/33462https://wibimmers.com/post/33462Sun, 29 Dec 2013 03:55:34 GMT<![CDATA[Reply to 1987 325e Power options? on Sun, 29 Dec 2013 00:59:27 GMT]]>Or go M30 + snail.  That's what a lot of them ur-op folks do.

]]>https://wibimmers.com/post/33456https://wibimmers.com/post/33456Sun, 29 Dec 2013 00:59:27 GMT<![CDATA[Reply to 1987 325e Power options? on Sat, 28 Dec 2013 15:14:35 GMT]]>I'm gonna be megasquirting my e28 and running a t4 on it on the economy m20 engine and eventually swap to the normal m20 head for more flow. Until I blow it up and deem it useless then swap to ls1!!!

]]>https://wibimmers.com/post/33448https://wibimmers.com/post/33448Sat, 28 Dec 2013 15:14:35 GMT<![CDATA[Reply to 1987 325e Power options? on Sat, 28 Dec 2013 03:17:41 GMT]]>I think the popular answer would be M50 + turbo but I think the lowest cost route to 400hp would be an M20 + turbo

]]>https://wibimmers.com/post/33439https://wibimmers.com/post/33439Sat, 28 Dec 2013 03:17:41 GMT