m20b25 turbo or S50b32 swap

[Game101]

Hey guys.
I have been readng this forum for 2, 3 ears now, mostly as a visitor, havent posted until now. So I have a e30 325i m20b25 for a couple of years now, it s going under a smooth process of restoration. I am almost done with the exterior and interior, I did most of the work myself. I will post pics of the car later, probably I will make a topic in the project builds section.
So I have something on my mind for a while and I cant seem to decide yet. I am between making my m20b25 turbo or swapping with a s50b32. I have found a complete PnP S50B32 swap, for around 4600 dollars. Engine is in good condition, it was taken care of.

My budget for engine build goes around that sum, let s say a nice even 5000$. Should I go on the path for turboing the m20b25 or the swap. Also I have been considering ITBs on the m20b25, and some other mods to get it around 190 hp.
I am not looking for enormous power, even if I go the turbo way, I would go with a small turbo that spools fast.
When I say enormous I mean more than 400 hp.

Thanks.

[roguetoaster]

Since you get the European specification S50 I'd skip turbocharging the M20. The S50 should be more reliable, a better fit in the engine bay (if the ITBs clear things), and as, if not more powerful than a small turbo M20.

[YosemiteSam]

Yeah, personally I'd go S50B32 for improved reliability and I've just never been a huge fan of M20 turbos.

[Game101]

On a side note, is the price fair/ok for the s50b32 swap? I haven t found a complete bolt on swap for sale to compare.

[roguetoaster]

If it were in the US it wouldn't even be a question of fair price or not as we never got that engine in a US spec car. Of course as the buyer you are the only one who can determine if a PnP setup at that price is fair/works for you, and when doing so just consider the price/time cost of the other components.

[Shangsta]

To answer your question if that is a complete swap then its a steal

[redsubdivisions]

I've done this in previous threads and I'll do it again: I'm going to play devil's advocate here and say M20 turbo.

Why? Everyone is dumping their M20's for next to nothing in favor of the M5x/S5x setups, which have began to command some premiums over the last few years. It's not going to get any cheaper. If my M20 turbo blows up tomorrow, I honestly wouldn't be mad or upset. I would just scour the ads and CL for another M20, freshen it up for relatively low money, and boost that one. Repeat as necessary.

July will be 3 years since my M20 has been fitted with a Holset and I can tell you it is the most fun I've had with this car. Not once have I had to open the engine back up and when I do, I'm confident I won't see anything out of the ordinary. Sure, the turbo spools late, but the look on people's faces when I rip past them in an otherwise stock looking car is priceless. Especially the domestic crowd. They normally are the most surprised.

And the total cost was well under an S5x/M5x swap. Now keep in mind that is my personal experience. I took my time and did things the right way instead of rigging shit up. Do it right the first time or do it twice (and pay twice!). M20's catch a lot of shit but not once has it let me down.

And if you're creative, you can still keep your AC and PS and make it a daily driven fun car (when need be) as I have.

[rturbo 930]

And if you're creative, you can still keep your AC and PS and make it a daily driven fun car (when need be) as I have.

How did you mount your intercooler while keeping AC? My dad has taken over for my old E30, and wants to do exactly that. PM me if you want.

[redsubdivisions]

How did you mount your intercooler while keeping AC? My dad has taken over for my old E30, and wants to do exactly that. PM me if you want.

Check out my build thread from a long time ago:

http://www.r3vlimited.com/board/showpost.php?p=3978497&postcount=29

That particular post shows what type of intercooler I used. I trimmed the headlight bezels enough to fit the piping. Don't worry, it won't affect the mounting, they will bolt right back up. You will have to remove your condenser fan, though. I am running a clutch fan, so that helps a little bit as far as some airflow. It works better when cruising around compared to sitting at idle (as most of E30's are).

[MrBurgundy]

Be hip like a hipster and turbo your m20 instead of swapping it like most others looking for more power.

[ba114]

How did you mount your intercooler while keeping AC? My dad has taken over for my old E30, and wants to do exactly that. PM me if you want.

http://www.r3vlimited.com/board/showpost.php?p=4736817&postcount=100

[rturbo 930]

Check out my build thread from a long time ago:

http://www.r3vlimited.com/board/showpost.php?p=3978497&postcount=29

That particular post shows what type of intercooler I used. I trimmed the headlight bezels enough to fit the piping. Don't worry, it won't affect the mounting, they will bolt right back up. You will have to remove your condenser fan, though. I am running a clutch fan, so that helps a little bit as far as some airflow. It works better when cruising around compared to sitting at idle (as most of E30's are).

http://www.r3vlimited.com/board/show...&postcount=100

Thanks guys. Will reference those when we get to that point.

[redsubdivisions]

Be hip like a hipster and turbo your m20 instead of swapping it like most others looking for more power.

I'm honestly not sure if you're being sarcastic or being serious.