N52 Swap Discussion

[MWC]

I finished my build and it's running. I took the car to the dyno and had some disappointing results. The car made 220 whp on a Dynojet reving out to 7700 rpm.

I am trying to understand how the E30 is making almost 270. The only difference is I have the Active Alibabawerks headers into an adapted E36 midpipe and catback instead of S54 headers. I don't see how that could be worth 50whp though.

I am running a DCT which consumes around 5-10 whp, and I do have a few issues to work out, but I'm wondering what else could be going on here. My S52 made 220 whp too...

Is this E30 somehow a unicorn? I have not been able to find another N52 dyno with bolt-ons anywhere else that comes close to 268 whp. I am by no means suggesting it's fraudulent etc. I am trying to figure out what I may be missing. I'm trying to get as much as I can out of this thing.

[LukeJ]

I would suspect those headers aren't measuring up to the S54 headers.

First off, not equal length. Secondly, the tube diameter is smaller, so more restriction.

Another thing you mentioned the E36 mid pipe. Are the pipes larger than 2"? Bigger pipes may actually be robbing power if the exhaust is losing too much velocity.

My swap dynoed at 248whp at 6700rpm or so. I built equal length headers, but my tube diameter is slightly bigger than the "optimized" S54 diameter. So my exhaust gasses are moving a little slower, everything else being equal. Also, my exhaust is a true dual exhaust until after the twin cats where they join the resonator. Not sure if not having a crossover pre-cat is hurting or helping.

Hoveringuy's N52'd E30 (268whp) is using the S54 headers, and his exhaust comes together after a couple feet to a single pipe with no catalytic convertors. So very unrestrictive.

EDIT: I just went out and took some measurements of the Ebay AA headers and the S54 headers. The S54 header runner tube inside diameter is 1.48". The Ebay AA headers, 1.38" ID. And as mentioned before, the tube lengths of the 1st and 3rd runners are way off, with the 1st being almost twice as long as the 3rd. So you're not getting the extra boost of having somewhat equal exhaust pulses.

[hubcapboy]

(blows dust off keyboard)

I don't know much of anything, and I've never dyno'd anything. My only goal is to beat the ~90hp coming out of my old eta. The only guess I might have about power levels goes back to the write-up that got me interested in this engine in the first place (too big to attach to this forum, but still available where I found it here: https://www.bimmerfest.com/attachmen...c-pdf.1046925/

BMW did a ton of optimization on this engine that might be getting left behind when you treat it as bare metal. How to reproduce it all as a starting point and build from there? No idea. Cue Nando to cut in and tell me that he knows everything it does and there's no magic and I just believe in witchcraft.

[hoveringuy]

I have forwarded the PipeMax calcs that digger ran for me and I followed the primary/secondary diameters and lengths perfectly, plus a Burns merge and mandrel bent turns.
It seems to work, but I also think more dyno time to optimize valve timing, ignition timing and A/F would pick-up power for you
LukeJ and I have the same tunes

[sweet3]

I'm happy to see you offering this! What's the Can bus emulator?

It simulates the CAN signals which would be missing because of the swap. The emulator helps remove several unnecessary engine codes that would show up and put it in limp mode. It allows the engine to actually run normally.

[digger]

i don't know the dynos in question but there probably isn't 50whp peak in an exhaust unless its plugged. Can be huge differences in low end and midrange but usually not top end. There is also the different dynos being like a different measuring stick

[MWC]

When compensating for the DCT the difference is more like 35-40 whp and there are a few other things I need to optimize like the fuel injector tuning and vanos tuning.

I picked up another N52 this past weekend that I'm going to build up out of the car and swap in before spring. On this one I'm going to definitely switch to S54 headers and try and get the merge correct as well.

LukeJ is right about the AA headers, they aren't even close to equal length and my current merge is a horrendous hackjob we threw together with the existing S52 exhaust to get the car working.

[LukeJ]

It simulates the CAN signals which would be missing because of the swap. The emulator helps remove several unnecessary engine codes that would show up and put it in limp mode. It allows the engine to actually run normally.

Do you sell the emulator alone?

Would it help with the A/C issue, with regards to the DME not picking up the rpms at idle when the A/C compressor is activated?

I'm curious about what codes would be thrown that would put it in limp mode? The only time my engine 'went limp' was when my fuel pressure was not enough. I forget which code that was.

[hoveringuy]

It simulates the CAN signals which would be missing because of the swap. The emulator helps remove several unnecessary engine codes that would show up and put it in limp mode. It allows the engine to actually run normally.

yeah, I don't have one and I'm not in limp mode. My only codes are benign ones like EWS not present. I think I have 2 or 3 background error codes that are meaningless but don't effect anything.

[Cdmef]

I’ve had my eye on the Russian drlavr supersprint replica headers, real ones are a hard sell on value for me. They look to at least be very close to equal length, has anyone run them or genuine supersprints? The 3rd bends out quite far which makes me a bit worried about tower clearance

*actually now I think about it that bend is probably not an issue

[DEV0 E30]

=== N52 Swap Skidplates ===

Once things are further along on my swap I'm going to be really looking at all options.

Some of these N52 swap oil pans are steel, some are aluminum.

Regardless --- with them being basically one offs, looking at ways to protect mine.

========================

@hoveringuy - Has tested the strength of his steel pan on track, and thankfully it's taken a beating and hasn't complained at all.

Since most of these pans are sitting higher or equal with the subframe, many will opt to not worry about this.

========================

It was only due to bad luck and my own doing that I've killed one e30 oil pan some 15ish years ago (E34 oil pan in E30M50).

After that and on other E30s I ran or acquired different skid plates, like the aluminum bent plates. Even had the OEM steel one special ordered, ended up selling that to a friend.

BUT - Since the roads are unpredictable, and since the pan that is going into this car will be custom, I'm thinking protection sooner rather than later is likely the route I'll go.

========================

Right now, leaning towards one of the more overbuilt that is on the market or having a copy/similar skidplate made.

If some locals express interest, a local fabricator may be approached to make a few copies of this with differing heights for different pans.

Another member here (@dylhaus) doing a 24v swap into his iX proposed this idea, so I told him to keep me posted on any of that.

If this doesn't pan out, I have no problem getting one from HIK directly.

========================

HIK Fabrication Skidplates

The current one I really like is the HIK Skidplate, that can be made for m20 or 24v cars already.

Now, some may not be jazzed about welding (required) on the bar to the front (directly to front frame rails, underneath behind core support) but I think it's a worthwhile thing to protect the underside of the front of the car. Maybe even strengthens this area.

Description:

The HIK Fabrication skid plate for E30 325e/325i (M20 engine) is the strongest and most rugged design we have seen. Numerous online testimonials back up the stout design for this piece and it was the only skid plate we wanted to offer for sale. It's also SpecE30 legal!

What makes this E30 skid plate so robust is the reinforcement bar that is welded to the frame rails. Other designs that are bolted to the subframe or core support and offer minimal protection. They are likely to flex and fold during a severe impact, cracking your oil pan. The HIK skid plate has much greater strength thanks to the reinforcing bar so that most* impacts will not ruin your race.

This kit requires welding brackets to your frame rails. The bar is then bolted to the brackets with supplied hardware. This allows the bar to be removed for normal service. Instructions are included.

* - nothing is indestructible. If you hit something that bends or breaks this steel tube you've already exceeded the protection any skid plate will provide.

M20 Version: https://www.bimmerworld.com/HIK-Fabr...-325i-M20.html

M/S5X Version: https://www.bimmerworld.com/HIK-Fabr...e-E30-M50.html

iX Version: https://hikfabrication.com/product/ix-skid-plate/

HIK Fabrication Website: https://hikfabrication.com/


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Pictures









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If there is any progress on having custom ones made --- I'll make a new thread, but this is just putting ideas to paper for now.

[projectJTv4]

I think this may be uncharted territory, but has anyone retained all emissions related accessories and the OBD port functionality?

Being in California, this is important so that I can legalize the swap.


Sent from my iPhone using Tapatalk

[hoveringuy]

I think this may be uncharted territory, but has anyone retained all emissions related accessories and the OBD port functionality?

Being in California, this is important so that I can legalize the swap.


Sent from my iPhone using Tapatalk

OBD port is easy, and it's almost an essential element of the swap. It lets you troubleshoot and test EVERYTHING!

Not sure about emissions, although Luke is running catalytic converters, just not the ones original to the N52.

[LukeJ]

My E30 originally had an O2 sensor, catalytic convertor, charcoal canister, and PCV. I think some had a smog pump? But my car didn't.

My swap retains all of those components. I didn't remove anything from the N52 except the rear O2 sensor pair. If it is an issue, you'll have to construct an exhaust that will fit a couple more O2 sensors after the cat(s).

I would think that if you do a good job and tidy everything up with the above mentioned stuff all plugged in and the motor is running good..... The tail pipe emissions should be no problem for a 30+ year old car and the standards they are held to.

I mounted my OBD under the steering wheel on the kick panel. In hindsight, it should be in or near the glove box so the cable doesn't have to reach across everything if you want to place the laptop on the passenger seat.

When I went to get the car tested.... I just presented it as a 1988 car. They hooked up the sniffer and ran it on a dyno, driving it though the gears. After that, they looked at everything under the hood and under the car. Didn't say anything about what obviously didn't belong. I passed because of the emissions and I had everything they were looking for on the checklist. Not sure if it would have turned out the same if I had pointed out the OBD port and suggested they hook it up. But 1988 cars don't have an OBD port..... ;-)

[projectJTv4]

OBD port is easy, and it's almost an essential element of the swap. It lets you troubleshoot and test EVERYTHING!

That's good to know. I must have missed it somehow if it was mentioned here. I spent most of my morning reading through all 53 pages / 791 posts on this thread. I've tried numerous times before to read through all of it but never did until today. Now that I have an N52 sitting in my garage, I'm a bit more motivated to read thoroughly. There's a few posts specific to wiring, but it was mentioned it was trivial in comparison to mocking up the oil pan and arms.

My E30 originally had an O2 sensor, catalytic convertor, charcoal canister, and PCV. I think some had a smog pump? But my car didn't.

My swap retains all of those components. I didn't remove anything from the N52 except the rear O2 sensor pair. If it is an issue, you'll have to construct an exhaust that will fit a couple more O2 sensors after the cat(s).

I would think that if you do a good job and tidy everything up with the above mentioned stuff all plugged in and the motor is running good..... The tail pipe emissions should be no problem for a 30+ year old car and the standards they are held to.

I mounted my OBD under the steering wheel on the kick panel. In hindsight, it should be in or near the glove box so the cable doesn't have to reach across everything if you want to place the laptop on the passenger seat.

When I went to get the car tested.... I just presented it as a 1988 car. They hooked up the sniffer and ran it on a dyno, driving it though the gears. After that, they looked at everything under the hood and under the car. Didn't say anything about what obviously didn't belong. I passed because of the emissions and I had everything they were looking for on the checklist. Not sure if it would have turned out the same if I had pointed out the OBD port and suggested they hook it up. But 1988 cars don't have an OBD port..... ;-)

LOL that would be hilarious if that happened here. Typically for engine swaps in California they can either be dirty smogged or legitimately done through a BAR Referee. From what I read, they go through your swap with a fine tooth comb, looking for anything out of place, non-OEM, aftermarket, non CARB approved items. All emissions related equipment must be fully functional.

On top of the emissions portion, they require that the DME be verified by a BMW dealership to confirm nothing has been altered. I'm reading some will waive the EWS delete, as they understand it is not emissions related. This is copy from another thread on here: "I received your letter and forwarded it to BAR. They requested that the info be put on a dealer invoice. They want verification that the PCM is for a 1999 BMW M3 CA cert. The BAR would like the dealer to list the Calibration ID (CAL ID) and Calibration verification number (CVN) as well."

Full discussion of here on another thread. I posted the question a few months ago regarding getting a swapped N52/4/5 BAR'd, but no one responded. I'm assuming no one on here has done so yet?

I'm opting to do it correctly, as this would be my daily driver.

This is also my first engine swap, so I have plenty to learn here. I'm grateful for this platform and all that have contributed to the discussion, it's really given me a lot of confidence to try something new.