Are there reasons to buy a swapped S52 vs an S54?

[Earendil]

"Back in the day" S54 swaps were rare, and I thought that an S52 in an E30 would be plenty of umph.

Now S54 swaps are more common, and I track a lightweight E30 with a very strong M20. This leads me to think that a really clean DDable S52 swapped car wouldn't feel all that fast.

So here is the question. If you had the money for an S54 swapped car, are there any reasons to go with an S52 swapped car instead? I'll provide some potential (but perhaps not true) reasons as examples of things I'm thinking of:

• The S54 is more fragile
• The S54 is more expensive to maintain
• S54 swaps are inherently more frankeinstein
• S54 swaps are harder to trouble shoot
• S54 swapped cars can't put the power to the ground without X, Y and Z.
• If you want more than S52, then go with X engine not an S54.

So, what should the considerations be?

Also, I realize the forum has a wealth of information on this sort of topic, but I find that most of it is

• Centered around considerations specific to doing the swap yourself
• Incredibly detailed, and not written in a way that makes comparisons easy.

I'm looking for big picture stuff here, things that a post-swap buyer might care about.

Thanks!

[TobyB]

Ok, making shit up here:

There's a lot more shit on an S54.

The S54 expects (and won't run without) a lot more inputs that the E30 doesn't generate.
And repairing that stuff out of context (i.e. without the vin) of the original car gets really hard. As does finding someone who will work on it that way.

t

[Best_name_available]

Personally, I've heard that the S52 is a lot stronger and better for F.I compared to the more "fragile" S54

[ak-]

Dat der rod bearings.

[E30335i]

been in both. Worth the extra cash.

[berlow94]

Capabilities are far greater with the S54. The S52 is a glorified street engine (basically an M50). The S54 is a detuned race engine. If done properly, the S54 will make more than 100 hp to the wheels than the S52 in the same car. With that being said, you really need to spend the time and money to do an S54 swap right. Your best bet will be a standalone ecu so you have full control over all engine parameters and much more reliable running than a stock ecu. (Please don't get some half ass system like mega squirt which will never be able to run a dual vanos motor properly).
Happy to help you with a EMS for the swap if you shoot me a PM.

Lastly, being the owner of a full race blueprinted S52 E30 track car, I must warn you that you will need to do ALOT to the car to make it stable enough to really push it on the track. I dynoed close to 300 to the wheels in my car. I'm also the first to admit that the power is the biggest thing that's holding me back from really pushing my car. These are momentum cars, they dont need that much power to be fast. After a certain point all your doing is making more noise and breaking shit quicker.


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[Earendil]

Thanks for the input guys, keep it coming! :)

Lastly, being the owner of a full race blueprinted S52 E30 track car, I must warn you that you will need to do ALOT to the car to make it stable enough to really push it on the track. I dynoed close to 300 to the wheels in my car. I'm also the first to admit that the power is the biggest thing that's holding me back from really pushing my car. These are momentum cars, they dont need that much power to be fast. After a certain point all your doing is making more noise and breaking shit quicker.

I have a track prepped E30 that I'm not getting rid of. I have a 328i E46 that I have no love for. In the next year I'm thinking of ditching the 328i and either getting an E46 M3 or a well put together and clean E30 S54. All of my previous dreaming had been about the S52, but it seems like an S54 is within the realm of possibility, and might even be reasonable.

[ST1G]

s54 has ITBs.




/Thread.

[nando]

Ok, making shit up here:

There's a lot more shit on an S54.

The S54 expects (and won't run without) a lot more inputs that the E30 doesn't generate.
And repairing that stuff out of context (i.e. without the vin) of the original car gets really hard. As does finding someone who will work on it that way.

t

huh? that's news to me and the couple dozen S54 swap tunes I've done, and the hundreds of other people who have done the same. There's nothing you need the VIN for to repair the motor..

Capabilities are far greater with the S54. The S52 is a glorified street engine (basically an M50). The S54 is a detuned race engine. If done properly, the S54 will make more than 100 hp to the wheels than the S52 in the same car. With that being said, you really need to spend the time and money to do an S54 swap right. Your best bet will be a standalone ecu so you have full control over all engine parameters and much more reliable running than a stock ecu. (Please don't get some half ass system like mega squirt which will never be able to run a dual vanos motor properly).
Happy to help you with a EMS for the swap if you shoot me a PM.

Lastly, being the owner of a full race blueprinted S52 E30 track car, I must warn you that you will need to do ALOT to the car to make it stable enough to really push it on the track. I dynoed close to 300 to the wheels in my car. I'm also the first to admit that the power is the biggest thing that's holding me back from really pushing my car. These are momentum cars, they dont need that much power to be fast. After a certain point all your doing is making more noise and breaking shit quicker.


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any standalone worth it's salt is going to cost about $10,000. Then, you get to tune it from scratch, which most people neglect to account for, and dyno time isn't free. Then, once you get the power tuned, you get to dick around endlessly trying to get your cold starts, idle, and fuel economy right. For what it's worth, Megasquirt could control the double vanos just fine.

Or, you could just have the stock computer tuned, which is inexpensive. It's not like you need to be fiddling with the tune all the time. as far as more reliable - I really doubt that. BMW/Siemens spend millions on R&D and have a lot invested into things like redundancy and safety, not to mention diagnostics. Cold starts, idle, and driveability will always be perfect because it's the stock computer and it's already tuned correctly.

[Earendil]

any standalone worth it's salt is going to cost about $10,000. Then, you get to tune it from scratch, which most people neglect to account for, and dyno time isn't free. Then, once you get the power tuned, you get to dick around endlessly trying to get your cold starts, idle, and fuel economy right. For what it's worth, Megasquirt could control the double vanos just fine.

Or, you could just have the stock computer tuned, which is inexpensive. It's not like you need to be fiddling with the tune all the time. as far as more reliable - I really doubt that. BMW/Siemens spend millions on R&D and have a lot invested into things like redundancy and safety, not to mention diagnostics. Cold starts, idle, and driveability will always be perfect because it's the stock computer and it's already tuned correctly.

Okay, so I'm sidetracking my own thread a tiny bit, but what exactly needs to be tuned if you keep the S54 stock? Is there an inherent loss of power when moving the S54 into the E30 without having a custom tune (be that mega squirt or standalone) ?

[berlow94]

Wrong.
Even a full Bosch Motorsport system will run you less than $8k. A EMS from Emtron or Vipec (Link) will run you less then $3k. It's not solely redundancy or reliability you buying. Factory ECU's processors are primarily running the engine based on emissions. What your buying with a standalone is the ability to to have full control over how your engine runs.
I spent $3k total buying my ecu (Vipec) getting it installed and having it fully calibrated and tuned. After 1 year I have found zero bugs, make ALOT more power, get better gas mileage, and my engine even runs cooler.

Again, not emissions based fueling...
Not to mention almost 20 year newer electronics.


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[FredK]

Okay, so I'm sidetracking my own thread a tiny bit, but what exactly needs to be tuned if you keep the S54 stock? Is there an inherent loss of power when moving the S54 into the E30 without having a custom tune (be that mega squirt or standalone) ?

There is no inherent loss in power. I have seen some nasty torque dips down low that were mostly tuned out. I believe at the very least some of it was because the post-collector merge was placed too far forward.

There is nothing intrinsic to running an MSS54 with a few things deleted that will cause power loss. There is a guy on R3v with an Epic Race tune MSS54 that pulled 340 whp or so, with nothing more than +1mm ITBs, stock plenum, and some sort of headers.

[nando]

Wrong.
Even a full Bosch Motorsport system will run you less than $8k. A EMS from Emtron or Vipec (Link) will run you less then $3k. It's not solely redundancy or reliability you buying. Factory ECU's processors are primarily running the engine based on emissions. What your buying with a standalone is the ability to to have full control over how your engine runs.
I spent $3k total buying my ecu (Vipec) getting it installed and having it fully calibrated and tuned. After 1 year I have found zero bugs, make ALOT more power, get better gas mileage, and my engine even runs cooler.

Again, not emissions based fueling...
Not to mention almost 20 year newer electronics.


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that's just a matter of tuning. you still probably spent 2-3x as much as it would have cost to make the same power as a factory computer with a good tune could do. There's nothing preventing the stock DME from making as much power as an aftermarket one.

do you daily drive it or is it strictly a race car?

[Earendil]

So what I'm hearing here is that there isn't anything inherently worse with the S54, besides the price tag. It also sounds like it might be harder to get a mechanic to work on it?

How about working on the S54 vs the S52. If I'm a Software Engineer that can tear down and rebuild an M20 head, should the S54 be well within the scope of diagnosis and repairable in my own garage?

[nando]

I don't know why it would be hard to get a mechanic to work on it. they made a ton of them in the E46 and Z4. Any BMW shop should be able to do basic maintenance to it and most repairs.

There's nothing magic about the S54 - it's not like the dark art of working on an S38, or finding parts for a euro S50.