N52 Swap Discussion

[nando]

maybe from a 1 series?

[hoveringuy]

I'm looking into this as well. Could also be a good solution.


Does anyone know which model had the smallest alternator on an N52?

Ooh. good question.

I know mine came off a 328i and even it's 180A. I would love a smaller, svelte, 115A unit like the e36 had, but with the CAN voltage regulator I don't know how easy it would be to mix and match.

[MWC]

prius, MR2, RX8 power steering EPS pump maybe?

I'm looking into this as well. Could also be a good solution.


Does anyone know which model had the smallest alternator on an N52?

[2.5-12]

prius, MR2, RX8 power steering EPS pump maybe?

[hoveringuy]

This is going into a racecar so I am definitely going to be cooking that baby with gas lol.

So the whole Cayman pump assembly will swap onto an N52, or you can swap the regulator from pump to pump?

Going back through the thread I realize I may have mixed up 135mm and 135 bar in a few places. The pulley you had made is 135mm, which matches most e36 pulleys. What was the diameter of the pulley off the Cayman pump? Was it 135mm as well?

Yes, I was cooking my PS fluid and temps were in the 285 neighborhood as I recall, and that's in Seattle! A cooler would have obviously helped but I'd rather address the temperature at the source. I like not having extra plumbing and crap to leak.

I don't remember if the Cayman pulley was a different diameter because I wasn't going to use it, but the offset was different. They're cheap on ebay! The regulator looks slightly different but they're interchangeable. The pumps are all a Luk-30 with differences in the pulley offset. I looked at swapping the e90 shaft into the Cayman pump to keep the same offset but it wasn't very easy to do.

[MWC]

Unless you plan to use an intake manifold other than the 3-stage (N54 or ITBS) then you probably don't need to worry about the PS pump overheating because the engine won't make power past the stock redline of 6900rpm anyway.

It matters if you plan to bump up the power band to peak at 7500rpm or higher though.

Agreed, I'm going to rev it to at least 7500 rpm though, probably higher just to see what happens. I'll start with the N54 manifold but am excited to see what happens with the S54 stuff if that goes anywhere.

If hoveringuy was overheating his PS in an E30 I will for sure do the same with a slightly heavier car and Hoosiers.

[nando]

Unless you plan to use an intake manifold other than the 3-stage (N54 or ITBS) then you probably don't need to worry about the PS pump overheating because the engine won't make power past the stock redline of 6900rpm anyway.

It matters if you plan to bump up the power band to peak at 7500rpm or higher though.

[MWC]

The Cayman uses a different pulley offset, I forget how much and which way, but yeah. The Cayman regulator dropped into the stock N52 pump will also go a long way towards reducing heat but the larger pulley helps a lot, too. If you're not tracking it you may not need to worry about it.

This is going into a racecar so I am definitely going to be cooking that baby with gas lol.

So the whole Cayman pump assembly will swap onto an N52, or you can swap the regulator from pump to pump?

Going back through the thread I realize I may have mixed up 135mm and 135 bar in a few places. The pulley you had made is 135mm, which matches most e36 pulleys. What was the diameter of the pulley off the Cayman pump? Was it 135mm as well?

[hoveringuy]

Sorry to get off topic for a second, but I have a question about the power steering pump solution.

I don't really have access to someone who can make me a custom pulley. Can I simply buy a PS pump from a Cayman and space the pulley out 10mm? Is it the right diameter? and it will bolt right onto an N52?

Thanks!

The Cayman uses a different pulley offset, I forget how much and which way, but yeah. The Cayman regulator dropped into the stock N52 pump will also go a long way towards reducing heat but the larger pulley helps a lot, too. If you're not tracking it you may not need to worry about it.

[MWC]

Sorry to get off topic for a second, but I have a question about the power steering pump solution.

I don't really have access to someone who can make me a custom pulley. Can I simply buy a PS pump from a Cayman and space the pulley out 10mm? Is it the right diameter? and it will bolt right onto an N52?

Thanks!

[MWC]

There was no benefit to a donor car for me so I just got the motor, but one of the reasons I went with an N52 and moved away from an S52 is how affordable all of the accessories etc. There are just 100s of alternators, starters, PS pumps etc. on ebay. I got each of those items for under 50 dollars each. Contrast that with an S52 where an original E36 PS pump is like 250 now which is just insane.

[hoveringuy]

Super weird revelation today, and relevant to the "do I buy an engine or a donor" conversation. If you buy an engine from a junkyard, you won't get cats (as far as I can tell, unless you call before they pull the engine) which means that you probably won't get O2 sensors either. Weirdly, there are two vastly different lengths of lead for the pre-cat O2 sensors. Like, at least a foot different.

I didn't get cats, but they just unscrewed the sensors and I got the longer ones.

[hubcapboy]

Super weird revelation today, and relevant to the "do I buy an engine or a donor" conversation. If you buy an engine from a junkyard, you won't get cats (as far as I can tell, unless you call before they pull the engine) which means that you probably won't get O2 sensors either. Weirdly, there are two vastly different lengths of lead for the pre-cat O2 sensors. Like, at least a foot different.

[ralle30]

That's great news and thanks for the pointers!

I do have the space *and permission* to do a part out if that's the best path ... it was pretty much the plan for a M5x swap since you get more out of it.

That said - I suck at selling stuff. I have an ever-growing selection of "stuff" that needs to be sold off. This affliction is not specific to the car ...

[hubcapboy]

ralle30 The good news is I haven't delivered anything to any of the guinea pigs, so I'll put you on my informal list. Being local is a huge benefit there. If you've got space, you might want to reach out to Habla on here (he commented on post #497... looks like my tag isn't working). He started with a complete car and might be able to tell you roughly what he was able to make up by parting it out. He's also on your side of the sound, but a different ferry.