14 years - 1991 325ix, Stroker/5-Speed (N52 swap?)

[stonea]

I've spent nights thinking about it and never thought about using the RWD hub .___. That simplifies it a lot. Thanks for the insight!

[nando]

why are the rears impossible?

the only real difference is the hubs. it would be easy enough to use a RWD hub and BBK in the rear. The main reason there's a difference at all is because the hub sticks out a bit more, all you really need is a spacer to fix that.

but, I'm not really thinking much about that at the moment. the reality is, the car is going to weigh slightly less than it does now. The brakes I have are more than adequate - as long as I don't have to switch to a manual setup or a tiny little booster. :p

the biggest benefit IMO to a BBK is cheaper consumables and less weight. The car can't stop any faster than the tires can grip.

[stonea]

You mentioned a bbk down the line, any ideas on that? I looked into it and the fronts are obviously easy, but there rears are impossible. The only thing I could think of is a 2 piece rotor.

[nando]

Yes it will.

I have an custom ix getrag with a 24v bellhousing, but the only difference is the extra 10 degrees of rotation to the passenger side. if you don't have an ix, then use the 6 speed that comes with the engine.

[Bimmer_man]

I'm not sure if this has been brought up but, I'm curious will the n52 engine mate to the e30 getrag? I'm guessing no but had to ask .

[nando]

I can probably borrow one for some stuff. The main thing i want to weld is the engine mount brackets to the frame rails.

[Kershaw]

Time to buy one. Basically mandatory for your level of modding. Nice progress.

A welder will be the second purchase if my garage ever gets started. A lift the first, lol.

[nando]

yeah, the alignment is looking pretty good.. I didn't have it sitting in the right place last night (it was late, I moved it before taking the picture by accident). But the two holes around the passenger side shaft line up pretty much perfectly:





Picture makes it seem more out of alignment than reality. I measured 10" from the center of the shaft to the mating face of the block on the stock ix pan. On the N52 pan with the two bolts holding it down (I only had to ream them out a little to fit the larger aluminum bolts), I'm measuring 10 1/2". I'm pretty sure I can deal with 1/2" just by positioning the engine back a little bit. Actually I think this will help me because it looked really tight between the front of the engine and the radiator.

I'm thinking the AWD N52 oil pan isn't that great of a place to start. The RWD pan looks a lot simpler, less cutting is required. When I pull it I will know for sure - here's the AWD pan for reference:



BTW, the old iron blocks are so ridiculously heavy in comparison to the new aluminum/magnesium designs. The S52 block has to be around 90lbs - I should weigh it on the bathroom scale. Pretty sure the N52 block is around 50lbs. The M20 isn't much lighter than the S52 either..



The angle isn't quite right of course (what is it, 20 degrees vs 30 degrees?) but I have a plan for that. I have to mock it up with the diff/trans/transfercase anyway. I'll have to see if I can make some sort of jig like nomansland92 did - naturally, I don't own a welder..

[nando]

I lent out my spare ix oil pan to nomansland92 - he's basically doing the opposite thing as me. In return I got the cut out portion of his ix pan. It's actually really helpful - I realized that 2 of the holes on the passenger side actually line up with the holes in the block, and it's almost in the perfect spot! So it's totally doable.



At some point I'll start cutting into a pan. I've got an AWD N52 pan, and a RWD pan. Not sure what will be easier to start from at this point, but at least I have a pretty good feel for where to line this sucker up.

actually the only thing I'm missing to make a complete mock up is a front diff. I know somebody said they had a broken one I could borrow but I can't remember who that was..

[nando]

I borrowed a stand from my stepdad - eventually, I'll need a hoist though. Trying to avoid having one take up space in my garage until I need it though lol.

experimented a bit with cam timing. I should be able to retard the intake cam 10 degrees - that would give 60-130 degrees of intake cam adjustment (S54 is 70-130 degrees in comparison). That should allow the extension of the power band a bit higher up, even with the stock cam.

[wazzu70]

Too bad I dont check the forums much anymore. I have a cherry picker and an engine stand I would have lent to you. Let me know if you need to borrow the engine hoist at some point.

Love the N52 route you are taking!

[nando]

oh yeah, after 4 years I realized the title of this thread was "1990 325ix". err, the car is a 1991 model year.. it was produced in 10/1990, but it's not a '90 ix. :p

this car is almost 26 years old now too. crazy!

[nando]

yeah, I've looked at all of that and I don't really like any of the solutions. the 3 MC Tilton setups are nice, but $$$$. Hydroboost is a bunch of extra weight and complication. One of the reasons I settled on a custom intake (aside from not really needing any throttle on the N52), is because I should be able to make it clear the stock booster. I still want to do a BBK down the line, but I really don't think I want to sacrifice the brakes. Eventually I will do a BBK, but I still want to retain the stock booster as much as possible.

I think it would be easier in the end, to custom make a filter housing relocation plate - it would basically be a flat piece of aluminum with the gasket profile machined in and ports for a standard filter housing. of course, I much prefer a stock BMW filter housing, it's just much easier to change the oil with. I think I will do my best to make everything fit within the packaging constraints that I have. I think it will most likely mean I will need a different ix strut bar too.

The S54 plenum was really just an idea - it does give me a good feel for the fitment of what I have planned though. I don't think the S54 housing will be worth it, realistically even with a custom plenum and the ITG filter housing, it will still cost less than a used 3 stage N52 manifold and new DISA valves (which I'm almost certain will not fit regardless). For what I would have to do to make the S54 plenum work, it would be both more complicated and expensive.

also down the line, the stage 2 plan is to include the E46 MK60 DSC unit, sensors, etc. Should be a big upgrade over even the IX ABS - but it requires some work to the MC, since it needs pressure sensors and a bunch of other stuff.

[iXguido]

What about using the sikky hydro booster setup that everyone is using with their ls swaps these days?

[nando]

Just for fun...



the holy grail for me, always has been and always will be, the E46 M3 CSL carbon airbox. glad I was able to pick this up for mock up - it would be relatively simple to adapt to the N52, but it would probably be too long - I'm not sure it would clear my brake booster. I also think the trumpets are about 3" too long (the N52 head is deceptive, since it has no throttles the ports on the head are significantly longer than a "normal" head - probably 4-5" longer).

The trumpets are pretty huge - but they taper it down to ~49mm. I had been planning 48mm trumpets. Wondering if I should go a little smaller to keep up the velocity. 48mm just seemed to line up better with the transition to the oval ports.

One thing this does illustrate is a problem that I realized when thinking of my custom trumpets with the ITG filter setup - the oil filter housing is seriously in the way. I can make something that clears it, but then I lose brake booster clearance.. I think it's doable just a little more difficult.

Also going to look a bit at the clearance inside the airbox - there was some discussion on whether it was a good idea to notch the airbox around cylinder 6 so the stock booster would clear. I'm going to have to say, that looks like a pretty bad idea - it's already tight back there. there are minimum clearances you want around an air horn, and the stock M3 box looks like it's pretty much at minimum already..