The N2

[NoahTeates]

Before I get started, here is the short version of how I got here: I spent a pile of money over about five years of rebuilding a 96 Nissan 240SX in which I blew up the SR20DET one morning on the way to work, and when I finally got it back together, it was illegal in Northern Virginia where I live. At that point (Jan-Feb 09), it was probably putting somewhere around 350-375 hp to the wheels, so I set about trying to sell it where it was legal, only nobody had 3 dimes to rub together so I coudn't. Meanwhile, I've really come to enjoy the E36 M3 I drive to work every day, and had planned to build an M2 when I finally found a home for the Nissan (http://www.m2bmw.com/), having really come to enjoy BMW's free-revving NA engines.

I finally threw up my hands trying to sell the Nissan, and rather than write off my losses or take pennies on my dollars on eBay, I asked "Now what else can I think of that makes good use of a 2L four-banger?" First thought was an old 510, but those are pretty impossible to find in any kind of rust-free condition on the East Coast unless you find one completely restored, and I didn't have the heart to hack into an original specimen. Then one day whilst dreaming of an M2, a light bulb went off...

Long story short, as most of you know the Governator changed the laws in Sunny California , leaving anyone with non-stock smog gear on cars 76 and newer unable to get tags. I found a pretty well hot-rodded BMW 2002 on the cheap around Los Angeles, had it shipped cross-country to me in DC, and it's now in Baltimore undergoing the transplant. You will note that in the course of this story, I use the word "we" a lot. When I say "we," it will usually refer to "Ray and Brian," the Mad Scientists at MA-Motorsports (www.ma-motorsports.com). They made the mistake of showing me around their shop while they finished up my 240, and at the time they had an early 240Z with an RB26DETT, and 2JZGTEs stuffed into both a Z32 and a third gen RX-7--all of which looked like they were born there. "We" usually discuss what's happening on the car, but "Ray and Brian" are actually underneath it making the magic happen.

A "before" picture is attached. Worst discovery so far on the project: Jeremy has dibs on "Project 2020," which I think is a much cooler name than "N2." Not that 99% of pedestrians will understand either one. Here is Jeremy's thread: http://www.bmw2002faq.com/component/option,com_forum/Itemid,0/page,viewtopic/p,616897/sid,c102ff25c7d86363f1a51d02e078d668/ Thanks to Jeremy for 1) shooting me straight about how much work this would be and 2) not talking me out of it. The knives came out in March, and as you can see in the attached picture, the immediate problem areas are expertly marked and numbered for your convenience.

Problem 1 - The old-school steering box & associated linkages all stick up where the turbo will hang off the SR20. We'll be solving that problem with a manual rack & pinion from an early E21 (320i). True story: the only place I could find a good alloy linkage to replace the stocker (cast iron with a rag joint) was in Oz. Should be arriving in a week or two.

Problem 2 - Obviously the battery moves to the trunk. I've seen several outfits that sell rear strut tower braces that have built-in battery cradles, and will have the guys at MA riff off of the design of one of those. Then again, my rear strut brace may be a straight section of 2" tube welded between the strut towers. Either way, should be strong enough to support enough CCAs to turn an SR20.

Problem 3 - The brake booster is actually tied pretty closely to #4, which you can't see in this picture, as we'll solve them together. Stock configuration runs a pedal box that dimples out of the floor board into the engine bay, about where the bellmouth would mate to the exhaust system. Thanks to Jeremy's pioneering work on Project 2020, we know to fix this by installing a Wilwood pedal box, reverse-hanging under the dash. With 3 master cylinders (front brakes, rear brakes, clutch) and the right lever ratio on the pedals, we'll completely eliminate the booster and go manual. Here is the current thinking: http://www.wilwood.com/Products/005-PedalAssemblies/003-RSMP/rsmtmc/index.asp

Next up, we massage the trans tunnel a bit to take the SR gearbox. There's a pretty good chance it will need some love from the BFH, and possibly even a little trimming of the firewall and new pieces welded in, but we won't know til we get the engine mocked up in the bay--which will happen once issues 1-4 are resolved.

Stay tuned. Once we get it in there, we'll be answering questions like what radiator (hoping to avoid a custom Griffin--as my wife often reminds me, we're still somwhat budget minded), how to fab & mount an intercooler, etc.

Best,

Noah

[NoahTeates]

As expected, the worst part of the job so far has been the steering, but not for the reasons we expected. InstructorBill provided this excellent illustration of how to install an E21 rack in a 2002, which got us started:

http://www.bmw2002faq.com/component/option,com_forum/Itemid,57/page,viewtopic/t,309896/highlight,rack+steering+pedal/

The problem we had was the way the lower control arm mounts to the back of the cradle--this keeps the rack both up and behind the forward cross member. Fine if you're putting back an M10, which has a modest-sized transmission behind it, but mounting the SR so the bellhousing cleared this assembly put the motor too high--which meant that to clear the firewall, it had to go too far forward. Something had to be done. Thankfully, Ray and Brian were on the case. Attached is a photo of the old pieces after we first mocked up the rack like InstructorBill's.

We tried pulling the spacer out of the cradle and bolting it there, but nothing fit right anymore, and frankly, this was not the point to start backyard engineering. The final solution was much more elegant: custom new control arms. The end that mounts the base of the strut and steering arm stayed, but everything from there in is custom, ending with a heim joint sitting in custom spacers inside the cradle mounts. Stock geometry is maintained, and we've added a point of adjustment to tune in the suspension when it's all done. A photo of the new control arms is also attached.

When we bolted it all back up with urethane bushings, and the rack went down and forward--which means the engine went down and back. Mission accomplished. See attached picture of the new pieces installed in the cradle and the new mount point for the rack.

Now that the rack is in the bay, the next step was connecting it to the column. I bought an E21 column from the guy who sold me the rack, but we ended up not needing it. The original cast linkages and rag joint were obviously not up to par, so they were replaced with cast aluminum linkages (bought it on eBay from some guy in Greece--who'd have thought?) and a solid Al plate where the rag joint used to live. Note in the attached pic how it just barely clears the old oil return line (it's got a stainless hose clamp on it), which will end up replaced with an angled fitting and a new line after the new manifold is welded up.

There's no resistance to it yet of course, but the steering wheel feels rock solid, no play anywhere. Next step: cut down the steering arms on the base of each strut to keep the steering ratio nice and tight. As MA mods spindles for a lot of their track cars, they'll have that done before breakfast.

And now that things are where they need to be, we fabbed up a new rear cross member to hold it all in place. Very nice work, also pictured below.

More to come...

[NoahTeates]

After initial discussions about fitting the S14 air-con pieces that ended up with us all agreeing that it would have to bolt up where the turbo will go, we decided that cooling needs were three: radiator, oil cooler, and intercooler. Attached is a photo of the clearance we have in the front of the bay.

After a quick show of hands, we elected to make more room. Next move is to take a cutting wheel along those red lines, pull the sheet metal out, and fab up something tubular that will replace the load-bearing pieces of it and bolt to two plates behind the headlights. From there, it's a lot of measuring, and a call to Griffin for a custom radiator and intercooler. Ray and Brian talked about actually replacing the grills on the front of the car with intercooler cores, which would have been very clever, but I kind of like the unbroken horizontals of the stock grills. For now, the plan is a traditional stack of heat exchangers in the nose.

We're also considering opening up some of the metal under the grills. I think if we needed some more airflow, we could cut in some vents, and as long as they were cut in clean, rolled, and covered in mesh painted body color, we could probably get away with it. The two red lines above the air dam, between the rally lights, are 2 possible candidates. As the attached pic illustrates, most aftemarket air dams for the 2002 cover a good bit of the stock metal, which means we could theoretically make room for a larger core if we're careful. And before you ask, that air dam is a one-off design--tell anyone who asks you where you found it to go pound sand.

Another item on our checklist: pull the rat's nest of wiring that's moved into the bay over the years and start fresh. Apparently the stereo system and driving lights were wired by vandals. Stay tuned: Ray is still leaning on me to ditch the stock ECU and swap my GT25R for a T28 from an S15, which he swears he can tune to hit my target of 300-350 rwhp with the linear delivery of a naturally aspirated motor. We'll see if he talks me out of that last 50-100 hp. Wonder how much a plug-n-play ViPec for a red-top SR would cost me...?

[dhs]

always love seeing mods and thinking to complete them. that said, I strongly suggest you look into ackerman steering and what effect your placement of the steering rack is going to have. You may be able to find a liveable compromise but from what I see in the pics you are asking for trouble as is.

[NoahTeates]

Thanks for your note, I appreciate the advice. I'm afraid I don't follow though: what kind of trouble am I asking for?

I'm not familiar with Ackerman--are they a shop or a product vendor?

Best,

Noah

[Colin]

Thanks for your note, I appreciate the advice. I'm afraid I don't follow though: what kind of trouble am I asking for?

I'm not familiar with Ackerman--are they a shop or a product vendor?

Best,

Noah

http://www.auto-ware.com/setup/ack_rac.htm

[dhs]

There are sources of info on the web but honestly I did not find a good one with illustrations, this can be a confusing topic.

For your needs, I would explain it as having to do with the relation between the angle of the steering arms to each other to where the steering rack is placed in between them. You might expect the steering arms to turn at the same angle as you turn the wheel. This is not the case for most vehicles. If the outerwheel is turning at a lesser angle than the inner wheel, you have Ackerman steering if the outer wheel is turning at a sharper angle than you have anti- or reverse Ackerman. The angle of the steering arms at a neutral position (toe-in toe out) and the placement of the steering rack add up to what sort of results you can expect.

With the placement of your rack infront of the steering arm connection with the tie rods you have created a situation of reduced and possibly reverse Ackerman. Have you tried pushing your car around with the wheels turned? low or reverse ackerman will make it very hard to do this since the tires will be fighting eachother.

[NoahTeates]

Thanks so much for explaining. I think I've found our point of confusion: the tie rods are not yet connected to the steering arms on the spindles. Both still need to be measured and cut down to restore the original steering geometry, which we'll be doing before we get the wheels back on the ground. Will that clear up your area of concern?

Thanks again,

Noah

[Guest Anonymous]

yeah that should do it.

[Guest Anonymous]

yeah that should do it.

[NoahTeates]

Thanks a lot--I was really hoping we wouldn't have to redo the steering again!

I do have a question though: the stock brakes have 4-piston calipers up front that take 2 lines in (split from a single lne upstream). I was not expecting 4-pots: does anyone know if this is stock?

I had planned to upgrade when we replace the master cylinders and lines, but don't want to toss out good parts if they're up to the task. Anyone have any thoughts as to whether these are worth keeping?

Take care,

Noah

[Lee]

Awesome build Noah. Just replied to last week's email. Sorry for the late reply.

Lee

[NoahTeates]

Thanks for the kind words Lee, and thanks a lot for the help offline in figuring out my brake situation. I'm looking forward to Massive's new full floating rotor design--my 02 will be outbraking my 96 M3.

Take care,

Noah

[NoahTeates]

Next step under the hood was locating the turbo. Initially we thought it would fit best down low on the driver’s side, but once we got everything mounted in the engine bay, it turned out there was plenty of room for a top-mount manifold. They fabricated a clean, simple log-style manifold with thick, healthy flanges, visible in the first picture below.

The downpipe is truly a work of art. Space, as we’ve discussed, was particularly tight, so we went with a 2.5” (~60mm) pipe that integrates the wastegate flow very early, and the complex curve on the tube itself perfectly navigates the remaining space without any sharp turns. It connects to the rest of the exhaust system with a V-band, and tapers out to the 3” (~75mm) diameter pipe with a perfect cone to avoid turbulence in the exhaust flow. As you can see in the pictures (next post), it fits perfectly around the new steering components.

[NoahTeates]

Note that we’re planning an intake path to the compressor that would have been tight for the ~11 inches we’d need between the Z32 Mass Air Flow sensor I was using in the Nissan and the compressor housing. This is because Ray finally talked me into a PowerFC, which he’ll use to dial everything in on the dyno once we’re done. This gives us the flexibility to replace the .86 turbine housing I had with a smaller .63 unit. The smaller turbine will spool quicker, and in a car this light, we won’t need the flat-out top end horsepower the bigger unit would have given my Nissan. That said, Ray has dialed in similar setups at ~350 hp to the rear wheels, which remains my goal.

With the turbo mounted, it was time to figure out how to mount the intercooler. We used a Griffin bar-and-plate unit that was an almost perfect fit behind the stock grills, and fabbed a clean, short custom route to both sides of it. While we trimmed a bit of the sheet metal in the nose to clear a path, there was no need to remove whole sections of it as we initially planned. The stock braces and hood mounting points left us plenty of room for everything we needed. More importantly, it gets great airflow without any modifications to the body shell, meaning it will still look bone stock to the casual observer.

We got lucky on the radiator: Griffin had a stock unit that’s a pretty good fit. As you can see in the picture of the intake, the inlet and fill neck needed to be relocated a bit, which is still in process. Expect a slim electric fan mounted as a puller between the engine and the new radiator. We’re still undecided on what to do with all the new underhood heat: the tight fits around some of the new pieces will result in a lot of thermal mass in a tight space. We’ve had some early conversations about how and where to open up that space to let it breathe: the stock hood is rust-free, but it’s got some dings right above the spot where the Weber carb used to live. Rather than try to hammer those out, it would be a perfect spot to cut a big vent above the new turbo to let some of that heat rise straight out of the engine bay. Stay tuned.

The final big improvement is the new stainless exhaust. From the V-band to the rear, there really is no usable space under the car to tuck away the pipe, so this is by far the lowest point on the vehicle. That should result in some sparks over some of the more notorious speed bumps in my neighborhood, but well worth the risk. We initially wanted a vertically stacked dual exit from the muffler, which would give us two 50mm pipes sticking out in the stock location, but space just did not allow. The 3” single outlet exits through the stock cutout in the lower valance, and terminates in a simple straight cut.

Next up: there are a few heater hoses to re-route under the hood, and the radiator needs to be stitched up. The new pipes between the air filter and the intake manifold all need to be finalized and clamped together. The brakes are coming, and the new pedal box & master cylinders are ready to be installed. Then it’s time to wire in the PowerFC and make it sing on the dyno. A final budget check will let us know whether or not we need at least a 4-point cage to keep things from twisting up when we stomp on it, but past that, we’re getting dangerously close to driveable…