or How to Build a Crappy Race Car out of a $200 BMW and an LM7
With all of the V8 swapped oddballs we like to feature here on DT, we had to eventually start practicing what we preach. This build was over 3 years in the making, and we finally ran it this October in its maiden 24 Hours of Lemons endurance race at Buttonwillow Raceway Park in California’s dusty Central Valley. Time to share!
The story started in 2012 with the first incarnation of our newest build for the 24 Hours of Lemons. It was a 1993 BMW 325i (E36) 4-door that old friend Dan (Listener Dan of DT Radio fame) had bought back in Michigan about 10 years earlier. Needless to say, there was rust. At the time, there weren’t any other E36s in Lemons that we knew of, so we figured the rust would help our cause in convincing the judges this was a $500 car. In California you’d be hard pressed to find someone to pay $250 for this thing except as a parts car.
We caged it, did some brake, wheel, and tire upgrades, and turned it into the Brougham d’Bavaria at Judge Phil’s behest. In order to race an E36 in Lemons with zero penalty laps, we had to get weird with the theme. He told us to imagine if BMW had decided to market the 3-series to octogenarian retired dentists in Phoenix, and bedeck the car accordingly. We installed chrome, a huge grille, opera lights, and a padded white vinyl landau top.
We ran the full 24 hour race at Buttonwillow in June 2012, followed by the Arse Freeze at Chuckwalla the same year [race report here]. At Buttonwillow we had fun, but the original motor mounts and trans mounts all failed and the drivetrain tried to jump ship. We fixed this with a few new mounts and a track-fabricated center bearing support for the driveshaft since the original had been destroyed when the driveshaft slipped out of the forward moving transmission.
The original M50 engine was plagued with water consumption and overheating issues. The rest of the car felt great, except when Jay told us to fix the rust by welding in fresh CA sheetmetal in the trunk / bumper support area. I did so, but not well enough, and at Chuckwalla we were told this was the last race it would be allowed in. That was a fun track; the engine kept up its overheating behavior and we lost a left rear wheel while I was driving, due to old, busted, overtorqued lug bolts. They were aftermarket “chromies for the homies” and we replaced them with studs afterwards.
The rest of the team prodded Dan and discovered that the M50 had been previously seized when he had used the car for a stunt driving TV show that he won, which was supposed to air on the Speed Channel but never did (ostensibly due to the Fox buyout of the network, or some other showbiz malarkey). Seized! That explained the engine’s ill behavior along with the low compression and leakdown numbers we measured. So we looked at the options at this point. The sane thing would’ve been to source a junkyard fresh replacement and keep running. But the prospect of fixing all that rust was daunting and de-motivating, to put it mildly.
Our enthusiasm was rekindled in 2013 when we decided to V8 swap it for “less than it would cost to rebuild the BMW engine” or so we convinced ourselves. Motivation of choice was the GM LM7, the most common, cheapest, iron block 5.3L version of the Gen III small block. Go ahead and call it an LS if you want to, but it’s more agricultural than that. We sourced one via a wrecked 2004 Suburban 1500 which got parted out. We saved the engine with all accessories, the drive-by-wire throttle assembly and controller, intake snorkus, and exhaust manifolds with part of the pipes. Internals were, and remain, all stock.
Looking into transmissions, it became apparent that everybody’s favorite swap choice, the T56 6-speed, would be cost prohibitive and not in the “spirit of Lemons.” The cheapest I could find a trashed example was around $1700 so that was off the table. The T5 World Class can be OK in Lemons, or so I’d heard, but we came across a Super T-10 from a 1978 big-block Firebird and decided to go with it. This is a 4-speed with external shift linkage. Descended from the Muncie. This one looked decent but was in unknown condition. We discovered through LS forums that a big block Chevy bellhousing and a 2006 Chevy 1500 4.8L flywheel would make the whole assembly work together. The flywheel was $60 brand new, and I honestly forget where we got the bellhousing at this point. Oil pan was sourced from a 4th-gen Camaro.
We sold the M50 and original transmission, and didn’t look back.
Motor mounts were pretty straightforward – made from some poly bushings from an old unknown suspension kit, plus scrap sheet and tubing we found in the shop. I welded mounts to the E36 crossmember to accept the bushings, tacked a piece of tubing to the bushing carrier tube, then slid a larger diameter tube over it. That larger tube was tacked to a rectangular plate that bolts into the stock motor mount bosses on the block. We slid the engine/trans around in the car, measured four or five times, then tacked the telescoping tubes together to finalize the location. It ended up cocked a bit with the tail towards the passenger side but this ended up helping with shift linkage clearance. The E36 diff input shaft is offset towards that side too so I’ll claim that I totally meant to do that.
The rust in the car was enough to discourage us once again. I had no interest in doing that much welding to make a franken-bimmer that would be of questionable safety even after all the labor. This was in 2013. Then we adopted a Kawasaki motorcycle powered MR2 which distracted us for over a year, but that’s a different story.
At some point we started talking about how much nicer it would be to start with a fresh shell now that E36s are basically free. No point in running a worthless rusty one any longer, and The Lamm said he wouldn’t count any chassis repairs against our $500 total. A roached out, engineless, but CA-native rust free 325i popped up on craigslist for $200 so we went to get it the same day. The old chassis got stripped down and cut up into little pieces. We ended up using very little from this new car other than the shell itself, hood, trunk lid, and bumpers. The subframes, suspension, brakes, engine, trans, fuel tank, doors, and everything else was swapped over from the old car. This lit the fire under the project again.
The new shell was stripped down and cleaned, then the interior and engine bay got painted with Rustoleum gray to get more ambient light and make it easier to see dropped bolts and oil leaks.
For exhaust we experimented with the stock GM truck manifolds pointed up and forward which was a no-go. They wouldn’t fit the traditional way either, not even close. Neither would GTO cast iron manifolds which we borrowed for a fit try. So we ended up getting some pure Chinesium ebay manifolds and used part of a Jegs circle track header kit to make our own headers. Passenger side was straightforward; driver side was not. It had to snake around the E36 steering column which was not designed with exhaust in mind. The collectors are super cheesy stamped pieces. Flanges are about as flat as Katy Perry (which is to say, not very). We made a y-pipe with scrap from around the shop and then adapted that into the remainder of the original 3” exhaust system with Flowmaster which we ran on the old car.
Engine management is just the stock Suburban ECU with the vehicle anti-theft system (VATS) disabled, and auto trans shift business removed. Thanks to EFI University for their help with that. The wiring harness was painstakingly pared down by Dan into something that both laid nicely in our engine bay and interfaced as simply as possible with the rest of the car. I think there are only 4 wires that get connected from the ECU into our homemade chassis harness to make it run. The GM ECU lives in the stock E36 “DME” cave without a care in the world. We kept all of the original LM7 truck accessories except AC of course.
Intake was accomplished by sawing the Helmholtz resonators off of the Suburban snorkus, fiberglassing over the open holes, and cleaning out our old crumply K&N. We used the stock MAF at the end of the snork.
Originally the E36 ABS pump lived under the brake master cylinder, in the area now closely occupied by the driver’s side exhaust header. I had to relocate the pump to the upper inner fender area to get it far enough away from the exhaust, which was accomplished by carefully un-bending and re-bending stock hard lines, plus one or two adapters, and some custom fabbed bracketry.
Our buddies Alex & Karl Buchka took a break from building Volvo 240s and helped out by makingde a steel driveshaft using common 1310 yokes and an adapter to the BMW differential. I took our Hurst bent shift lever with T-handle and cut the bend out of the center section, then welded together for a straight shorter shifter.
The cooling system consists of our old E36 radiator, plumbed into the Suburban system as simply as possible, with a homebrew adapter fabricated to get the long upper hose to bend 90 degrees into the rad. The stock Suburban surge tank / pressurized coolant bottle now lives in the back corner of the engine bay where the non-battery tray was. Battery lives in the passenger footwell.
Bodywork was necessary to clear the truck intake manifold and accessories, but also helped with the theme. On the old car we ran a Lincoln Continental MkIV grille which weighed about 80 lbs, and was not well integrated into the body. This time I hit up the junkyard for a Chrysler New Yorker Fifth Avenue grille and headlight surrounds. There was one such car in the Wilmington Heptapus yard and it gladly donated parts. I sliced the E36 hood right at the stock bump-up bends, and bent the center section up to meet the top of the new grille. The open gaps were filled with easily formable 3003 aluminum sheet held on with many rivets. The same sheet was used for closing off holes in the front of the car, and ducting the radiator. Alex Vendler, he of the Geo Metro Gnome signed on to arrive-and-drive around this time. He built the front ducting, plywood splitter, and made us a great new surfboard…I mean wing…using Styrofoam, plywood, fiberglass, and some scrap metal for end plates and supports.
With about ten weeks before the Buttonwillow race we turned up the wick to get this thing finished. The new car was a bare shell at that point. Eight weeks later we had a running car, and one week after that we tested it at Big Willow, with another seven whole days before the race to fix any issues. Apart from some loose wiring causing a short and blown fuse, and then some diff overheating which blew gear oil out of the vent and all over the car, it went swimmingly. We were on ancient 235 RT615s for the test day but went with a fresher set of RT615Ks for the race.
Before the race we Lincoln Locked (welded) an old open diff center section and swapped that in. All of the ancillary systems got hooked up. We applied vinyl numbers and decals cut on the Buchkanator5000; thanks Karl! The car got loaded into BIRT, our box truck, for the short drive on Thursday night.
The Butt Turrible race started well, with some practice laps from Mr. Vendler on Friday. We didn’t have too much to change at that point. The oil pressure gauge started flaking out. It became apparent that our stock fuel tank didn’t like accepting 5-gallon swigs very quickly. We passed tech with no issues. Judge Eric Rood didn’t take kindly on our “pressing the easy button” with an “LS1” swap but I attempted to make our case for the home-brew-ness of the swap and the fact that this is a cast iron 5.3 with a late ‘70s 4-speed behind it. We didn’t put much effort into finishing the theme or documenting the build costs, so we were handed 15 penalty laps. Firm but fair I guess. We weren’t expecting zero with a car like this, but we did stay within the spirit of the BS guidelines. Almost everything we used for the swap was either taken from the Suburban, taken from the E36, or fabricated in our shop in Compton.
First day of the race started very well. Team founder Nathan took the wheel and turned 43 clean laps to get us up as high as 5th place (not including penalty laps). We started from 122nd including the penalty laps. I got in the car and had to slowly familiarize myself with this power to weight ratio. I ended up letting many people go by as I got a feel for braking points and negotiating traffic better. I had some sort of heat stroke or gasoline fume issue even though our cool suit system was working, but I did manage to spill fuel on my driving gloves just prior to getting in the car. Luckily there was no upchuck in the helmet. I pulled in after 30 laps. Dan took the wheel and turned a very clean 31, followed by Mr. Vendler with 34 more, and Nathan again with 31 more to finish the day.
There was some steering shimmy from the front end under braking, later diagnosed as a huge crack in one of the front brake rotors due to a casting defect. In addition the old diff case had finally let go of its input shaft bearing and started puking gear oil from the front. This stuff was on the list for in-paddock repairs. Overnight we had great tacos from the Finding Tacos team (thanks guys!) and with our friends at Eyesore Racing pitted next door, celebrating the 40th Raceversary of their ghettocharged Miata, we indulged in some of their delicious chocolate cake and Maker’s Mark. It was a great time. We also got to hang out with Team Super Troop and the Nyancar guys as well, and interview them for the DT Radio show, so that was awesome.
After much consultation with Dave Coleman and kibitzing amongst ourselves we swapped the welded diff into another spare case and buttoned up the rear, while Vendler helped change out the steering rack for another unknown condition used one. We found only 3 of the 8 motor mount bolts remained in the block, so scrounged up 5 more and applied red Loctite to all of them.
Sunday went well in the beginning. I took first stint and got into some sort of “zone” and felt more connected with the car. I was our slowest driver but I was keeping my cool and turning laps. I found the limit of adhesion in the sweeper turn and spun after lifting off throttle a bit too much – sorry to Anton who was in the Crown Vic that I was attempting to pass. It was our only black flag, no penalties. No contact with any other car during the weekend either. I hope we were good track mates with everyone else.
Dan got in the car for Sunday stint #2 and things quickly degenerated from there. The GM power steering pump bearings wore quickly, not surprising since the pump had been making noise since the first test day. This boiled the fluid and blew the reservoir cap. The serpentine belt got chucked, water pump stopped spinning, and thus the engine overheated and went into limp mode. Dan pulled in and began work on sourcing a new pump and belts. We were off track for quite a while fixing this. The old pump pulley had to be extracted and pressed onto the new pump, and although we aligned the shaft vs. pulley depth the same, the new shaft turned out to be longer causing our pulley to be spaced out too far. The engine immediately chucked the new belt with Alex driving. He pulled in and we pressed the pulley on further and installed another fresh belt, which worked. The cooling system hadn’t been fully bled again so there was another stop for a top-off. Alex turned our fastest lap of the weekend as his final lap, #255, which turned out to be a 2:08.9. This was good enough for 3rd fastest lap of the race, with Eyesore taking fast lap honors.
I was happy with the results for the first real test of the new car in an endurance racing setting. The Bavarian Brougham v2.0 was given a mostly hearty welcome by the Lemons crowd and we kept our noses clean. Most of my family made it to the race. It was my mom’s first Lemons race and my dad’s 4th or 5th. As a team we have complied a list of improvements to make but are excited to get back out there. Thanks to everyone who helped or hung out with us.
All of the Daily Turismo project cars can be found here in…the Project Cars section. Fascinating.