Another N52 swap attempt!

[Striker01]

Too cold to spend much time in the garage but made a little progress.

Decided to go with the Valeo single mass flywheel and clutch kit.



Found a clutch slave cylinder that I think will work and mates to the E30 clutch line.



Compared to the E90 one.



Had to trim the transmission just bit to get it to sit flush.





Unfortunately I won't know if it actually works for a while but I'll update this if I have any issues once I get it running. This slave cylinder does work!

Other than that, headers are done and off for ceramic coating. Got the alternator, tensioner, and power steering pump mounted back on the engine.

Running out of stuff before I actually have to finish the engine bay prep and tackle wiring.

[E30budget]

This is where I get fuzzy on the cost/benefit tradeoffs. I had always kinda thought that Valvetronic was individual TB's because each valve is its own throttle based on lift, so I don't understand how locking-out the Valvetronic (forcing full-lift at all times, like it does when it's in limp mode..) and replacing with ITBs makes more power.

Plus, low valve lift makes better power at lower rpms and I LOVE how this motor makes gobs of torque down low.

That is one way to think of it. Think of it like this, Both intake/tuning options make more power over stock manifold. However, the ITB option is safer. While yes I want to drive this car hard and fast at times, I also want as much seat time as possible and to not ever be stranded. I do think running with no TB gives you the potential for more power with a well designed intake manifold. But the risk of the valvetronic motor failing doesnt justify it for me for what I want to use the car for.

I actually was dead set on running only valvetronic with my 1M clone 128i. I made a plan to use a DOC race N54 intake manifold. I was going to remove the plenum from the runners, weld proper velocity stacks to each runner, and create a carbon plenum with 5" inlet velocity stack and bond it to the existing flange of the DOC race manifold.

Even with ITB im expecting atleast 280-300whp. My last N52 made 262whp with N54 manifold.

[hoveringuy]

My future plan is to delete valvetronic and run S54 ITB's with CSL airbox.

This is where I get fuzzy on the cost/benefit tradeoffs. I had always kinda thought that Valvetronic was individual TB's because each valve is its own throttle based on lift, so I don't understand how locking-out the Valvetronic (forcing full-lift at all times, like it does when it's in limp mode..) and replacing with ITBs makes more power.

Plus, low valve lift makes better power at lower rpms and I LOVE how this motor makes gobs of torque down low.

[E30budget]

I'd love to see that!

My motor is tuned to run well, make decent power and not have flat spots and it makes 250 whp with the DISA intake, but I know there's a lot of untapped potential including the MAF delete, MILV, or going back to the N54 intake. I haven't even touched timing.

It screamed with the N54, but the bottom-end was "meh".

Healthy numbers for sure. I made 262whp on full E85, N54 intake manifold, S65 fuel injectors, AA headers, N55 135i full magnaflow exhaust no cats, and thats it!

My future plan is to delete valvetronic and run S54 ITB's with CSL airbox. I did all of this research a few years ago so bare with me as I try to remember lol. The S54 fuel rail has a vacuum rail attached to it for the intake which will allow an easy and seamless integration with the held of the flage adapter. The other plus side is the ability to use the factory S54 throttle actuator with drive by wire. So you really just install and plumb the intake system and tune for it.

I had other plans in the past to do the opposite and KEEP valvetronic and remove all throttle bodies from the intake system. I was going to use the DOC race intake manifold, remove the aluminum plenum from the runners, and make a carbon plenum with 5" inlet to be bonded to the existing DOC race runners. The downside of this risk factor in valvetronic fails. Im not ruling this option out as I believe it will really wake up the N52, but I also plan to street drive my build and I drive my stuff hard at times, so I would like to avoid mechanical catastrophe on these LA roads lol.

my idea with the n52 and DCT is that I would be removing roughly 50lbs from the engine and gaining it back with the DCT which is behind the front suspension

[E30budget]

Not OP, but I'm in the LA/SGV area working on an N52 for my E30 also. Let's connect!

Shoot me an instagram message @halfcabbob

[projectJTv4]

Are you in SoCal? would love to see the car and pick your brain and maybe give you some ideas too perhaps. I have lots of experience pulling power from the n52 and building e30's. Im actually looking into this swap for one of my current e30 projects but to be paired with a DCT. Im in Los Angeles

Not OP, but I'm in the LA/SGV area working on an N52 for my E30 also. Let's connect!

[hoveringuy]

I have lots of experience pulling power from the n52 and building e30's. Im actually looking into this swap for one of my current e30 projects but to be paired with a DCT. Im in Los Angeles

I'd love to see that!

My motor is tuned to run well, make decent power and not have flat spots and it makes 250 whp with the DISA intake, but I know there's a lot of untapped potential including the MAF delete, MILV, or going back to the N54 intake. I haven't even touched timing.

It screamed with the N54, but the bottom-end was "meh".

[E30budget]

No, I'm in Tulsa, Oklahoma. Be nice if there were other E30s around here, I've only seen a couple.

Aw bummer, less crazy people there though. I too am from a smaller area than LA and we had a few E30 owners in the area but not like here. Sub'd to this thread, keep it coming!

[Striker01]

Are you in SoCal? would love to see the car and pick your brain and maybe give you some ideas too perhaps. I have lots of experience pulling power from the n52 and building e30's. Im actually looking into this swap for one of my current e30 projects but to be paired with a DCT. Im in Los Angeles

No, I'm in Tulsa, Oklahoma. Be nice if there were other E30s around here, I've only seen a couple.

[E30budget]

Are you in SoCal? would love to see the car and pick your brain and maybe give you some ideas too perhaps. I have lots of experience pulling power from the n52 and building e30's. Im actually looking into this swap for one of my current e30 projects but to be paired with a DCT. Im in Los Angeles

[Striker01]

Progress has been slow lately, busy time of year and temps aren't very garage friendly. I did get the fuel pump sorted, I hope.

I went with the Walbro GSS340, I chose it over the GSS342 because the sock matches the stock E30 one better and can be oriented in any direction.

I had an old fuel pump assembly that I modified for the new pump. I used thin walled 1 1/4 pipe, cut in half and spread slightly to fit the pump, and a small piece of sheet metal to hold the bottom in place.



Prepped and coated with POR-15 fuel tank sealer. With the lip on the bottom of the bracket and hose connected it sits in the bracket nicely.




This pump has a smaller diameter than the stock one and with the sock it just slides into the tank.

[Striker01]

Comparison of AKG and Revshift mounts here, starting with post #20: https://www.r3vlimited.com/board/for...-z4-arms/page2

[Striker01]

wow, I just used the AKG mounts because that's what someone locally had, I thought all DOHC mounts were the same. I would love to see a side by side comparison between what you have and the AKG ones!

I'll get a picture when the AKG ones arrive.

[hoveringuy]

I'll just chalk this one up as a rookie mistake and use the mounts that have already been proven.

wow, I just used the AKG mounts because that's what someone locally had, I thought all DOHC mounts were the same. I would love to see a side by side comparison between what you have and the AKG ones!

[Striker01]

Last night I checked my engine position after wondering why my oil filter housing is so high and I couldn't get the N52 intake on with the Bosch booster. I made the mistake of assuming any DOHC e30 engine mounts would place the engine in the correct position. I don't believe that is the case. With the revshift 24v mounts my engine sits about 1/2" higher than what hoveringuy's does and the crank is about an inch closer to the driver side frame rail, not even close to center.

Unless I overlooked something else, trying to save a few bucks over the AKG mounts that work is going to cost me more time and money in the long run.

FYI-AKG poly mounts are about 6 weeks out right now so I have the aluminum ones on the way to finish fabbing up exhaust. I spoke to AKG and they confirmed that the aluminum and poly have the same engine arm to subframe geometry.

Here are poor pictures of the crank in relation to each frame rail.



I switched the left mount to the right side and vise-versa. Here is the result, too far to the other side.




Here is one of how the transmission sits on its mount with the mounts swapped to the wrong side.



Both engine mount positions took quite a bit of pulling left or right to get the transmission crossmember to lift up onto its studs.

I could try switching the mounts back to the correct sides and rotating them so the guide pin goes through the hole and the stud goes through the slot on the subframe but that I'm not willing to go that route because it will make it way too difficult to tighten the mount nuts with subframe reinforcements.

I'll just chalk this one up as a rookie mistake and use the mounts that have already been proven.