Conversation Street: What it takes for a 300whp BMW e36

I'm still a ways off but I'd like to start some conversation and maybe nix a few bad ideas or add new good idea.

My baby is a 1999 BMW 318ti with an S52/ZF320 swap. I love this car and hope to have it until my or it's death. It's recently gotten paint and I'm working on how I'll be redoing the interior this summer. Now however, I've hit an issue, the S52 has begun burning oil at a rate of a quart every 500 miles. Also, as an aside, I recently bought a Jeep XJ so I have a good daily driver.

Something needs to be done. While I'm in there I would like to address my other goal. Currently the car sits at a power to weight ratio of 12.5 lbs/hp while an e90 M3 has a power to weight ratio of  8.9 lbs/bhp. Do you know where I'm going now? If my car's weight doesn't change that means I need about 337bhp to have the same power/weight ratio as an e90.

The next important topic, I'm not a fabricator. I can wire, I can plumb and I can wrench, but I am not one to be building mounts, cross-members or especially headers. That means I'll have to spend money on a kit, be it a proper swap kit or at least a transmission adapter and engine mounts. I'm still sorta cheapish so it's not like I'm just going to buy a full vorshlag kit and a crate LS3.

Engines that can be bolted to my existing ZF320 with an adapter.

1. GM LSx
2. Toyota 1/2JZ
3. Toyota 1/2/3UZ
4. Toyota 3S (a few others same pattern)
5. Nissan RB20/25/26/30
6. Nissan SR20
7. Mercedes M113
8. Volvo B200/B230
9. Mitsubishi 4g63
10. Honda K20/24
11. Mazda B6/BP

Then after that we have the kit to install a T56 which opens up any engine that bolts to a T56. I realize that the easy button from a fabrication standpoint is just toss an LSx truck engine in there and be done. I kinda like the idea of a turbo 4 for lightness and size reasons. I've also had the terrible thought of Eurotary which would be a bit more farmed out fab work or involve some custom adapters but it would be rad.

TL;DR: I'm an idiot with no fab skills and I want a 300whp BMW 318ti. Please tell me I'm stupid.

SR20 is easy to make that kind of power with.  Pretty light too.  I'd probably just as boost the S52 though.  I don't see the point of swapping in a different heavy I6.  BMW engines are nice.

Any reason why an s54 wouldn't be an option?

Also, link to m113 to zf320 adapter? 

The tried-and-true path to a 300 whp E36 used to be turbo M50/52 (or S50/52). These days, an S54 swap seems to be the most popular option.

300rwhp is easily obtainable with an S54 swap.  However, that's *really* expensive, figure $10-12k by the time you're done and that's with you doing all the labor.

The easiest and cheapest way to hit your goal is to boost the S52.  You can easily make 300rwhp with just a small supercharger, like the small Active Autowerke rotrex kit.  A non intercooled Vortech kit from VF will also make that amount of power.

Your best bet is to put together a turbo kit, using parts from TRM or CES, run around 6-7psi and make ~350rwhp.  If you have to take the S52 apart, you can build it for boost, or just reuse the stock pistons and add a thicker head gasket.  Then put 10-11psi of boost on it and make 450rwhp...

Ls?

I've not driven an SR car but I've read about the engine. I've read they have some "issues" when you modify them.

Boosting a tired old S52 seems like a great idea. I'm sure it's oil consumption will only get better. Then again, a mild refresh and boost would probably still be the cheapest option.

I've driven one S54 car and it was okay I guess. Wouldn't that bring about a bunch of computer issues? Aren't they pretty complex computers that want the whole system from the donor?

Yes, LS is the easy button. They're a bit big and heavy but the swap kit is there and it has been done plenty of times.

M113 to ZF320 adapter

The way I see it, you have two options because of you no fab skills.  Dive in head first and learn as you go.  Throw lots of money at it, and hope someday you will finish the project.  Or, start looking for a swap thats already been done.  You will spend less money than if you do it yourself, and you will be driving it straight away as opposed to possibly someday.  Life tends to get in the way of car projects.  My LS3 conversion has pretty much stalled because of lack of time to dedicate to it.  If you really want a 300 hp BMW, go find one.

I like the theory of a V8 E36 but what I found when I actually started to build one was that the driver's side of the engine bay just isn't meant to have exhaust on that side. I've seen work-arounds ranging from front dump headers to weird steering shaft solutions.  The fact that I know very little about BMWs beyond my brief experience with a 325I leads me to vote for an S54. Of course for all I know that might end up being more expensive than an LS swap. 

Rebuild the S52 that's already in there so it can take boost and add boost.It's also reversible that way so if you ever change your mind you can just take the SC/Turbo off

The E36 M3 Euro engine would do it.

So the s52 stock compression ratio is 10.5:1.  That's not THAT high for forced induction.  You can do a completely stock rebuild and run low boost.

Is this thing a street driver, autox, track toy, or what? Knowing how you want to use it will help determine what path to more power makes the most sense.

Everyone starts as not a fabricator before a certain project, come out the other side as an amateur fabricator.

It’s been a while since I’ve been in that world but I think you can throw the turner Motorsports catalog at an S52 and make almost Euro motor power which is right in that range. Cheap it is not but it should be fairly reliable and a screaming NA motor. 

K20 or k24z7. Supercharger kits put them easily in the 300whp range and you get Honda reliability. 

RossD said:

Everyone starts as not a fabricator before a certain project, come out the other side as an amateur fabricator.

True!

The answer is supercharge your engine! 


Edit: Just realized you stated that you're burning oil with the current motor. If that's the case, a 1uz is actually not a bad choice at all. Can be bought for 300-1000 depending on where you shop. Lightweight for what it is, super reliable as well.

Any motor swap will cost far more than rebuilding the current S52 and boosting it.  

You can make around 270rwhp if you build the S52 with higher compression Pistons, stiffer valve springs, schrick 276/270 cams, intake, 803 MAF, headers, track pipe and exhaust.

unless you already have everything but the pistons and cams, still cheaper to do an oem rebuild and boost the motor

Boost sure seems like the easy button here.  Those motors take boost very well.  I'm not familiar with what BMW computers can run boost and still pass emissions though.

They all can, just depends on what you tell the tuner to do.  

The car is a summer fun driver. It dyno'd at 212whp with a bone stock S52.

Somehow I'd glossed over the idea of a minor refresh and boost. I really think that's my best bet. A simple re-ring might be all this thing needs. It's not high mileage at 120k on the engine. I like the idea of high compression builds because it will drive just like stock when off boost which is nice. I've driven a 300whp DSM that was kind of a dog off boost with it's big cams and low compression.

Emissions are not an issue. My county is visual only and doesn't even care if the CEL works. I've been driving with a removed CEL bulb since I've owned the car.

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