Grassroots Motorsports: The Hardcore Sports Car Magazine

The rubber spring pads are easy to remove, but doing so requires disconnecting the damper and the anti-roll bar mount while the car is in the air.

We pulled the top and bottom spring pad from the left side only, giving our car a bit more right-side bias as indicated on the corner weighting scales.

All Thugnificent Chromepocalypse brand wheels–well, the one, anyway–are carefully prepared by master wheel artisans in our surgically clean rapid prototyping facility.

Our state-of-the-art welding robots apply precision welds to ensure that the decorative enhancements are one with the wheel.

Naturally, the Thugnificent Chromepocalypse wheel is balanced in conjunction with our patented Looksaboutright process. This ensures wobble-free rolling at idle and perhaps beyond.

With European-style speed bolts secured to the decorative outer fascia elements, the Thugnificent Chromepocalypse wheel is sent to our incomparable chrome plating facility, where master chrome artisans apply several coats of gangstah-quality bling.

Oh, snap! Snap indeed, Johnny, that’s one glorious Thugnificent Chromepocalypse wheel. Now none will question that we’ve got some junk in our trunk.

We were shocked to find that the Thugnificent Chromepocalypse wheel and tire combo added exactly 50 pounds to the car’s overall weight. That’s the price to pay for a stylish spare, it seems. Oh well.

Our season debut with the Spec E30 is less than a week away, so we needed to address our weight issue. Specifically, our car is very light, and we needed to add some ballast to ensure that we’d still be over the class minimum of 2750 pounds with driver after we’ve burned up some fuel. When we weighed the car with a full gas tank, we only had 4 pounds of leeway; that’s less than a gallon of gas.

We were also a bit discouraged by the rear corner weights of our car; the left rear was 100 pounds heavier than the right rear. Fellow Spec E30 racer Rob Keehner saw our forum thread at spece30.com and suggested we play with the spring pads to get a slightly more favorable distribution.

To review, before touching the pads, we had corner weights (in pounds) of:
LF 729 - RF 743
LR 691 - RR 591

We pulled the top and bottom spring pads from the left rear spring perches and weighed the car again. Sure enough, we saw an improvement:

LF 753 - RF 718
LR 668 - RR 615

The time had come to address our low curb weight. In the interest of playing legal, we consulted the Spec E30 rule book.

“9.2.2. A car found to be underweight after a qualifying session shall (3.1) have securely mounted ballast installed in the passenger compartment to meet the minimum weight requirement without exceeding the maximum ballast weight allowed. Alternatively, a spare tire may (3.1) be placed in the spare tire well and appropriately secured. The car shall (3.1) start at the back of the grid for the race if it meets the minimum weight requirement.”

We knew that our salvation lay in the spare tire wording. There are many kinds of spares in the world, and rather than settle for the relatively lightweight aluminum spare that wasn’t doing us enough good, we decided to create the Thugnificent Chromepocalypse: the ultimate spare. Nowhere in the rules does it say that the spare can’t have a little bit of style.

Each Chromepocalypse wheel is made from the finest raw materials. We went to a junkyard and found the heaviest steel 4x100 14-inch wheel and tire combo we could (about $20). The plain face of the wheel simply would not do, so we went to our local decorative supplier (the Wal-Mart fitness section) and found some metallic discs that would echo the wheels’ round theme even as they redefined its aesthetic. Wheels within wheels, people.

Our master artisan technician (Tech Editor Per) carefully prepared the Chromepocalypse with the deft touch of an enraged gorilla, and then sent the wheel to the welding department (Tech Editor Per) for the careful attachment of the decorative elements. Not to be outdone by those fancy European wheel companies, we gave the wheel a quartet of Grade 5 bolts to ensure that the decorative elements are doubly resistant to the advances of jealous thieves who covet thy neighbor’s bling.

Finally, the Chromepocalypse was sent to our chroming facility to receive its angelic outer coating. Carefully hand-lettered chrome decals were then affixed to the wheel, leaving no doubt that the end result is, in fact, the Thugnificent Chromepocalypse.

With the Chromepocalypse in place, our weight is looking much better at 2804 pounds with a full tank of gas. Corner weights to come shortly.

EDIT:
Corner weights with the Chromepocalypse in place and a full tank of gas (minus maybe 6 minutes running time worth of fuel):
LF 746 - RF 718
LR 700 - RR 640
TOTAL 2804

In a perfect world, we’d add our missing 100 pounds to the right rear corner.

We’ve done a lot of work to the BMW Spec E30 project lately, including some pretty dramatic weight-changing things like removing the heavy stock exhaust and replacing it with the very light spec system. It was time to put the car on our Longacre corner-weight scales and see how it measured up.

The rules state that our car must weigh a minimum of 2750 pounds with the driver in place. Our fuel tank was much closer to full that it was to empty, so rather than try to drain it out we topped it off to the brim. Knowing that street gasoline weighs approximately 6.2 pounds per gallon, our 16.5-gallon BM1B-style fuel tank gives us an approximate fuel weight of 100 pounds.

If you can’t read the numbers in the photo, the totals were:

LF: 729 RF: 743
LR: 691 RR: 591
TOTAL: 2754 lbs.

This means that even with a nearly overflowing fuel tank and our driver in place, we’re just four skinny pounds over the MINIMUM weight. Looks like we’re going to have to add some ballast.

This blew our mind a little bit, as the car was weighed with a spare wheel/tire and carpet in the trunk as well as fully operational all-glass power windows still in the doors. Our driver weighs about 175 pounds in regular clothing, probably closer to 180 with a helmet and driving gear on.

The passenger footwell was less than spiffy.

We rerouted some wires, cleaned it all up and touched up the rusty bits.

Our neighborhood AutoZone had a great deal on a case of Valvoline VR1 Racing Oil.

It’s got what engines crave.

We used a spring punch to mark our drilling location for the hood latches.

Steel rivets should keep the latch mounts firmly in place.

The new latches keep the hood most of the way closed, even when the factory latch is disengaged.

We swapped out our impromptu washers for some Factory 3 Performance tie-down hooks.

Factory 3 Performance also makes this cool oil pan guard. Step one is to measure and mark.

We carefully bent the panel using our bench vise. For the big section, we used the edge of our workbench and had Ashley stand on a big piece of wood to work as a human vise.

Now Per’s not the only one with cool skidplates on his cars.

It’s not quite as structural as the ones for rally use, but it should defend the fragile pan from the occasional curb.

It amuses us that the shiniest part of our entire car is underneath everything.

Our first race of the 2008 season is just a few weeks away at Roebling Road, so we spent some time during the past couple of weekends making a few minor upgrades and doing some routine maintenance.

Step one was some simple housekeeping. The passenger footwell was something of a mess, with various wires crossing the floor and some surface rust rearing its head. We went crazy with the zip-ties, rerouting several wire clusters so they’re permanently out of sight. Then we cleaned up the rusty bits and performed a tactical strike with Rust-Oleum and then a coat of some generic metallic gray we had from our Volvo wagon days.

A new season is also a great time to do some minor maintenance. We checked the fluid levels and changed the oil and oil filter. Last season we ran Castrol GTX High Mileage, but when we went to the local AutoZone for some new dino sauce they had a killer deal on Valvoline VR1 Racing Oil; $12 off a case of 12. The total for 12 quarts was just 26 bucks. We’re not sure if we’ll see any benefit from the supposedly Extreme Race Level Protection, but it can’t hurt.

With the spring cleaning out of the way, it was time to perform some minor upgrades. First up was a set of hood latches. Last year, we had a qualifying session ruined when the hood popped up on our warm-up lap. A dose of spray lubricant seemed to remedy the hesitant factory catch mechanism, but a set of external latches are further insurance against stupid pit stops. Per was installing a set of rubber latches on his Saab, and when he placed the order at Speedway Motors he was kind enough to grab a second pair for the BMW. They’re just $5.99 for a set of two.

After eyeballing a good location, we marked the location of the intended holes and then broke out the spring punch to mark our drilling spots. Some steel rivets with washers ought to keep everything snugly in place. With the latches mounted, we pulled the hood release and were pleased to see that instead of jumping forward half a foot in the air, the hood nudged up about an inch at its highest point and was securely retained.

Regular readers will recall that we had an issue a while back with our tie-down chains pulling the Bilstein damper free of its lower mounting point. Our initial fix was to install a large washer at the end of the mounting bolt to prevent the damper from running away again, but Factory 3 Performance has an even better solution. They offer a simple tie-down loop that will both keep the damper in place and give us a dedicated mounting point for tying the car to the trailer. The loops cost $16.99 for the pair.

Factory 3 Performance also has a nifty Oil Pan Protector. On an E30 BMW, the oil pan is the lowest point in the front of the car. A few racers have found out the hard way that, given the opportunity, the curbing at some tracks loves to demolish this somewhat fragile piece. The Factory 3 steel panel costs $39.50 and works like a skidplate to protect this vital low-hanging part. The part ships totally flat, so it requires some simple measuring and a bit of bending, but we got ours measured up and mounted in about 45 minutes. The bolts and speed nuts required for mounting are included with the kit.

Hopefully that means we’re about ready for our race season. We’re going to put the car on our corner-weighing scales and make sure we’re still legal, since the exhaust swap shed a bunch of pounds. Look for us at Roebling in May.

Judging the cut location for the downpipe was easy with the the Spec E30 exhaust next to it; we used the hanging bolt location as our index.

A large fiberglass cutting wheel made short work of the downpipe tubes; you can see the first cuts at the bottom. We did have to use a reciprocating saw to get the remaining metal that the cutting wheel couldn’t reach.

We used a Dremel with a sanding drum to give the tubes a bit of taper at the lip. Then we rubbed some motor oil around the edge to help the downpipe tubes slip into the Spec E30 exhaust flange.

With some help from a bench vise, we were able to line up the downpipe tubes with the Spec E30 exhaust flanges and slide the assembly together. We then snugged down the clamps that were provided with the exhaust.

We’re eager to hook up our Innovate Motorsports wideband air/fuel gauge, so Tech Editor Per gave his welder a bit of a break from the Saab 99 to help us attach the O2 sensor bung.

The bung has a small plug for when the O2 sensor isn’t plugged in, but we’ll get that installed before we take it to the dyno.

Our friend Rennie at Redline BMW came through for us with a replacement downpipe, so we were able to finish up the Spec E30 exhaust install this weekend. The trickiest part of the operation was fitting the two downpipe tubes into the Spec E30 exhaust’s flanges. In a nutshell, we figured out where to cut the tubes, used a fiberglass cutting wheel to slice through the metal without deforming it, Dremeled away some material from the outer edge to make fitment easier, and then slid the downpipe tubes into the exhaust flanges with a dash of good ol’ 5W30 motor oil to facilitate things.

Once we had the BMW downpipe securely fastened to the first of the three parts of the Spec E30 exhaust, we mocked up the fit and then took the pipe assembly over to Per so he could weld in an O2 bung for our upcoming Innovate Motorsports air/fuel monitor installation.

Bolting the downpipe to the exhaust headers is a bit of a pain; we used plenty of weird extensions, angle drivers, air-driven impact wrenches and manual gear wrenches in the process. The middle and rear segments slipped together with ease by comparison. Ours is a very early version of the exhaust, so it only had one rear hanger for the rubber doughnuts in the back. Apparently the newer versions use dual hangers and forgo the middle-section hanger, so we might weld on a bar of steel to mimic the newer style.

The gaskets were all but disintegrated where the downpipe mates to the exhaust manifolds.

Once the downpipe was free of the manifold, we found a crack at the top of the accordion section. It was easy to wiggle the tube at this fracture.

One of the flanges at the top of the downpipe was cracked all the way around, allowing it to be removed from the tube with ease. It’s not supposed to come off at all.

The spec exhaust comes in three major pieces with all the clamping hardware necessary to mount it up.

A simple two-into-one section combines the two header streams into a single large-diameter flow.

There’s been a lot of buzz going on at the Spec E30 forums for the past few months about a change in the exhaust rules.

Like any rule change that involves a spec part, the announcement of a mandatory spec exhaust system caught some racers at the worst possible time; imagine torquing down the last bolt on your fancy new exhaust and then finding out it’s been rendered obsolete by the rules. For others, the announcement brought relief; nobody will be able to spend huge money on a fancy system to gain a slight competitive advantage over their more thrifty neighbors.

We got the impression that the series organizers wished they’d written a spec exhaust into the rules from day one. Until we get a spec time machine, however, that’s not going to happen. The moral of the story is that starting in June, all NASA Spec E30s will be on the same exhaust. The rule is included at the bottom of this post.

Fortunately for us, our BMW 325is was still on its stock exhaust, and we were eager to get rid of it. In fact, knowing that we’d have to make the change to a new exhaust anyway, we chopped that sucker in half to facilitate the fuel tank change while still keeping the car drivable.

The new system costs $175 plus shipping from the mandatory supplier, Paul Poore. Expect to spend about $200 after shipping. It’s not a pretty exhaust by today’s chrome-tastic standards, but the unit is mandrel bent and made in the U.S.A. Kudos to the NASA organizers for keeping the price very reasonable.

We’ve heard an exhaust leak in our BMW since we bought it, so before mounting up the new part, we decided to take the downpipe out and give it a good look. We were hoping that we’d just need to replace the triangular gaskets that seal the downpipe flanges to the exhaust manifolds, but once we got the downpipe on the ground we saw that the situation was dire.

The gaskets were toast, sure, but one of the flanges was completely broken off the tube. Plus, there was a crack on the aft downpipe where it mates to its accordion section. We’re in a holding pattern on the install while we source a replacement downpipe.

We also stepped on the scale to weigh each system. Our OEM exhaust (with a bypass already in place of the catalytic converter) weighed 53.4 pounds. The spec system weighs just 21.8 pounds, a 31.6-pound savings. We may need to add some ballast after all.

We’ll post the installation photos once we source a new downpipe.

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9.3.4. Exhaust System
9.3.4.1. Any Spec E30 racecar towed to any competition event shall use a spec exhaust.
9.3.4.1.1. The spec exhaust system must be purchased from the Spec E30 approved
supplier (Paul Poore pepco2@verizon.net) and may not be modified in any way. The
following parts must be used and assembled as designed by the manufacturer.
1- PPS30101 Forward Section with Collector
2- PPS30102 Middle Section
3- PPS30103 Muffler/Tailpipe Assembly
4- PPS30104 49.5 mm Clamp (2 req. - optional)
5- PPS30105 59.5 mm Clamp (2 req. - optional)
9.3.4.1.2. The spec exhaust system components must be either welded or clamped
together after all slip joints are fully seated.
9.3.4.1.3. The spec exhaust will be available after January 21, 2008 and is required on June
1, 2008.
9.3.4.2. Any Spec E30 car that is driven on public highways, to a competition event, must use
either the Spec E30 spec exhaust or a fully functioning OEM or OEM equivalent exhaust
system that may not be modified in any way.
9.3.4.3 Original factory installed exhaust heat shields may be removed.

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This isn’t the kind of thing you like to see the week before you make the tow up to the big race.

The chains were pulling on the Bilsteins at a slight angle on the trailer, and it was enough to pull the damper body free of its large bushing.

A big metal washer should prevent any future pullouts.

Pristine new Vorshlag Motorsports engine mounts will keep the engine firmly in place.

Our repaired brakes seem to be working properly, and the engine runs much better with the new gas tank.

Hey, with the brakes no longer binding up, we’ve got enough power to kick the tail out. Whee!

A completely reworked brake system and a new fuel tank leave us with what should be a fully operational BMW Spec E30 race car. The only way to find out for sure, however, is to go drive the thing.

While we were going through the list of things we’ve done to the car since the last in-magazine update (look for the next installment in the April 2008 issue), we recalled a few other fixes that have taken place.

First up was the replacement of the completely fried engine mounts with some more rigid Vorshlag Motorsports units. These aluminum and nylon mounts cost $159 for a set of two from Vorshlag.com and installed easily. Having a friend handy to work the jack or engine hoist while you tighten up the four bolts helps, though.

Another snag we had almost forgotten about was the discovery that one of our Bilstein dampers had pulled completely off its lower mount bushing while on the trailer. We’ve been using chains to keep the back end of the car from misbehaving while in tow, and the slight inward pull was enough to wiggle the damper tube free. A trip to the hardware store gave us a pair of big washers that should fix the problem.

We’re happy to report that the long list of repairs seems to have done the trick. The car performed better than ever at our Ocala test track. After a lot of brake bleeding (with lots of help from Margie in the pedal pumping department) we’ve got a firm brake pedal and no signs of rear brake drag. The engine even ran well, and it sounded wicked with a cutoff exhaust.

Soon we’ll be bedding in a fresh set of Carbotech brake pads and bolting up the new, just-released spec exhaust system. We’re looking forward to doing more racing than troubleshooting in 2008.

AutoZone sells various lengths of replacement stainless steel hard line with brass inverted flare union fittings for just a few bucks each. We picked up two lengths so we had enough fitting hardware to perform a splice.

After cutting the stock brake line with a line cutter, we used a flare tool to give the line the proper shape for the inverted flare union fitting. Don’t forget to slide the flare union collar on the line before you flare it out, or you’ll be cutting again and starting over.

The stock brake line was pinched, but we were able to blow through it, so it might not have been the source of the problem. Still, removing it puts one less variable in the mix.

Connecting the OEM line to our aftermarket splice was simply a matter of tightening four flare union fittings.

We curved the replacement line so it follows nearly the same path as the segment it replaced.

We used an old car wash bottle and some of the same clear hose we use to bleed our brakes to siphon the brake fluid out of the master cylinder reservoir. This kept the spillage to a minimum when we removed the reservoir.

We found this Girling master cylinder at the local junkyard on a BMW 318is. It looked to be in better shape than our car’s master cylinder, it was easy to remove at the junkyard, and it cost just $6.

Just like we did with the fuel lines, we marked the brake lines going into the ABS unit with easy-to-read tape flags so we don’t get confused and cross anything up. The unique shape of the OEM lines would make messing up difficult, but backup plans are good.

Using a Torx-head socket we removed the ABS’s plastic shield, then we unplugged the big electrical connector and undid the brake lines. The big plug took some tugging, but it slides off vertically (don’t forget to remove the cable collar at its base first).

With the ABS pump and master cylinder replaced, we filled the reservoir with Motul RBF 600 brake fluid in the hopes that some of it would drain into the system while we swapped out the rear brake calipers.

Can you point to the old caliper? Now point to the remanufactured caliper. Hint: the really gross one is the old one.

Our refurbished rear calipers are so shiny they look almost out of place on the old rotors.

We used a Harbor Freight hand pump to get the bleeding process started; once the master cylinder had filled up, it was pushing fluid on its own and we were able to bleed the lines normally.

With our fuel delivery issue sorted out, the next big ugly box on our to-do list was the brakes. Specifically, we needed to eliminate the BMW’s tendency to apply increasingly severe rear brake line pressure to both rear wheels all by itself until the car could barely accelerate, even in first gear.

After experiencing the problem in competition and re-creating it under test conditions, we had a pretty good idea of what was going wrong. The rear brake line (it’s a single hydraulic line until it splits in two near the rear differential) was for some reason unable to release pressure, causing the rear pads to drag on the rotors. This manifested itself physically by making it feel like the parking brake was partly engaged, as the rear of the car would dip under acceleration from a stop and more gas than usually was necessary to get underway.

If we tried to drive through the problem, the pads would continue to drag, heating everything up. As the calipers and lines heated up, the fluid inside them expanded, increasing the pressure. When things were at their worst, the car would barely move. With enough momentum we could drive through the problem to a certain extent, but this had pretty catastrophic consequences for the poor rear brake pads as they were pushed well beyond their temperature limits.

Finding the source of the problem was the real trick. Essentially, it could be any one of the four major components that make up the brake system. Originally there could have been five sources, but we already removed our rear brake line pressure regulator at the NASA Championships, so all that’s left of our brake system is the master cylinder, the lines themselves, the ABS unit and the rear brake calipers.

Our rear brake calipers were gross, but we’d given them a field refurbishing at the NASA Championships and the pins slid and the piston compressed as they should. Also, the problem seemed symmetrical, so we felt it was unlikely that the rear calipers were simultaneously responsible. Still, our calipers were rusty and gross, so we got a set of refurbished calipers from Redline BMW for $65 each. One variable down.

Next we pondered the brake lines themselves. We found a dinged-in section of line when we were replacing our fuel tank. In our testing we determined that disconnecting the brake line fitting at the ABS pump relieved the pressure on the rear brakes and allowed the car to roll, so logic dictates that the problem was at the ABS pump or upstream of that, but we still didn’t like the idea of a crimped line, even if it was allowing fluid to flow freely. We picked up some replacement steel line at AutoZone. That’s another variable checked off.

Next on our potential list of culprits is the ABS unit. The first time we experienced the problem was at Summit Point just after some particularly heavy braking going into Turn 5. We were very likely engaging the ABS, and when we went to get back on the gas the tail end was locked up so hard we barely made it back into the pits at full throttle in second gear.

The factory service manual warns against tinkering with the ABS unit, but it didn’t really say anything about replacing it. Rennie at the aforementioned Redline BMW had an old 325i pump in his possession, so we figured making the swap was worth the trouble. There’s no guarantee that the new used pump is any better than our used used pump, but we’ll cross our fingers as this is the component we suspect the most.

The last potential culprit is the brake master cylinder. This little doodad goes for about $150 at the online retailers, so we were going to skip it on this first round. All that changed when we saw an engineless BMW 318is at the local junkyard with a fairly new looking Girling master cylinder. we ran home, grabbed our flare wrenches and sockets, and about 15 minutes and $6 later we had a replacement master cylinder. It even cleaned up prettier than our stock unit.

Short of replacing all the lines and buying a brand-new ABS unit, we’ve attacked this problem on all fronts with this recent bout of work. We though about doing things part-by-part in an effort to pin down the exact culprit, but bleeding brakes more than once seems like a hassle when you’re dealing with $6 used parts. Frankly, we don’t care if it was the ABS pump or the master cylinder as long as the new parts have fixed the problem.

Our first eBay purchase was for the wrong part; if you’ve got a pre-1987 BMW 325is, you want the BM1A gas tank with the nubs on the bottom near the driveshaft. The BM1A also has dual hard lines on the top. We’ve got a 1989, so we sent this BM1A back and ordered a BM1B fuel tank.

The BM1B has no connecting nubs near the driveshaft, and just one hard line up top. It’s also a couple of gallons bigger than the BM1A.

Even after draining the tank most of the way, it’s good to have a gas container handy to hold the runoff from connections, like the filter.

Label each line and hose. You’ll be really glad you did when it comes time to connect everything back up. When in doubt, be descriptive; for this mess of connectors, we used TO FILTER, FROM FILTER, UP THROUGH TANK and TO LOWER TANK NUB and it saved us lots of headaches later.

It’s also wise to take pictures of stuff to help you get it back together again. This is the top of the in-tank fuel pump. We ended up labeling these lines, too.

For 2008 we’ll need a soon-to-be-released spec exhaust anyway, so we got lazy and just Sawzalled the old one downstream of the O2 sensor so the car is still drivable in the meantime. Oddly enough, after we cut the twin pipes, a short length of pipe between our cut and the catalytic crossover replacement simply fell out. It didn’t look like it had ever been welded into place. The 2.5-liter straight six sounds like a proper race car sans muffler.

With the driveshaft and exhaust out of the way we were able to undo the five bolts that hold the fuel tank in place. If you’re using jackstands, make sure they’re towards the back edge of the jack point or the tank won’t be able to fall.

We gently negotiated the new fuel tank into place. Mercifully, all the pre-drilled mounting holes were pretty accurate; we had to do some nudging to get the final two bolts in their holes, but no re-drilling was necessary. Not bad for a cheap eBay find!

While we were at it, we installed a new fuel pump and a new filter. Here’s the pump/fuel gauge sensor assembly. Don’t forget to lubricate the O-ring with gas before you install a new fuel pump, and it’s worth noting that the reason this is a two-part assembly is that the pump won’t go into the tank with the fuel gauge sensor in place. You gotta do ‘em one at a time.

With everything bolted up and tightened down, we poured a couple of gallons in, crossed our fingers and fired it up. Finally, some positive progress, as the fuel pressure at idle is where it should be instead of at 90 psi.

While were were down there, and getting intimate with the various fuel and brake lines, we noticed that our rear brake line has a small pinched area that could very well be the cause of our rear brake locking symptoms. Rather than going right for the ABS pump, it looks like our next logical step is to cut out this part of the line and splice in a healthy section.

If you remember from our recent Ocala test, our car’s perpetual rich-run condition seemed to be related to a clogged or restricted fuel return line. We were seeing 90 psi of fuel pressure at idle, as the fuel coming from the pump had nowhere to go once it was done feeding the fuel rail. It wasn’t the fault of the fuel pressure regulator (we replaced that), and the line was found to be clear as far back as the entry point to the fuel tank. That meant that the line was messed up somewhere inside the fuel tank. Unfortunately, that meant it was time to take the tank out.

Our two options were to remove our stock fuel tank and get it cleaned or to buy a new tank. Cleaning the OEM tank seemed to be the cheapest way to go, but our tank also had some dents in the bottom, and without cutting it open there was no way to tell if the line was clogged with goo or physically crimped. Cleaning might not have fixed anything. Most of the replacement tanks we found online were going for more than $300, with OEMs listed closer to $500.

That’s when eBay came to the rescue. It took a bit of digging, since searches like “BMW 325 fuel tank” didn’t work, but when we got specific and searched for “BMW 325is gas tank” a shop called The Radiator Connection popped up. They had both the early BM1A and later BM1B tanks listed, the former for $100 and the latter for $130 (plus about $40 shipping in each case). Naturally we were skeptical of the low price, but the seller had more than 17,000 transactions and a 100 percent positive rating, so we figured it was worth the gamble.

A miss-read on our part led us to first order a BM1A tank, which is for the earliest 325is models. We actually needed a BM1B, so we returned the earlier model tank after taking some pictures for posterity. In both cases we had tracking numbers for the packages within 30 minutes of placing the Buy It Now bid on eBay. We added our own positive ranking to the seller’s 100 percent streak.

The eBay tank was a dimensional match for the OEM one, although it lacked the small plug at the bottom of the passenger’s side that can be used to drain the tank. For what it’s worth, our OEM tank’s plug was completely frozen in place anyway. We drained most of the fuel by MacGyvering up an extra long hose off the fuel return nipple on the fuel pressure regulator running it into the fuel tank of one of our other cars. (If you do attempt this, refrain from smoking, please).

Replacing a gas tank is a messy chore, as it requires the removal of the exhaust as well as the driveshaft. Also, get used to smelling like gasoline, as it’s nigh impossible to completely prevent spills as you disconnect the many lines carrying fuel hither and thither. Label lines and hoses as you go, and take the opportunity to replace any worn looking hoses with new replacements. Just make sure that you use fuel injection hose for the pressurized lines; we bought two feet of the stuff (about $10 at Pep Boys) and that was plenty for the three or four hoses we replaced. Since the OEM hose clamps are of the cheap single-use variety, buy a bunch of stainless screw-type hose clamps as well and replace as you go.

Our impromptu brass T-fitting allowed us to get a fuel pressure reading.

The fuel pressure gauge indicates an insanely high amount of fuel pressure at idle.

We replaced the fuel pressure reuglator, but it did not do anything to fix the problem.

We ran hot laps at Ocala in an effort to get the brakes to seize up; it took a while, but finally the butt end of the car was dragging as it has been in competition.

The rear calipers are far from pretty, but they’re not mechanically hindered, so the problem was elsewhere.

Redline BMW’s Rennie Bryant was very helpful in tracking down our BMW’s demons.

With a number of weird symptoms popping up regularly, it was time to spend a day playing doctor with our Spec E30. The rear brakes are seizing up symmetrically, the car runs rich nearly all the time, and we’re still down on power. Plus the fuel pump started making weird noises at the end of the NASA Championship race and power delivery went all wonky late in that same race.

We loaded the Spec E30 on the trailer and headed off to the Ocala Gran Prix track where we do much of our car testing. While we could have done most of the diagnostics in the garage, our rear brake issues only seem to materialize when the brake system is hot, so the track was necessary. Rennie Bryant of Redline BMW Performance came along with his years of BMW experience to help out.

Before we hit the track we wanted to try to figure out why the car is running so rich. We suspected the fuel pressure regulator, so we made a T-fitting out of some brass hardware in order to hook up a fuel pressure gauge and see what kind of pressure the fuel system was getting.

After we fired the car, the needle immediately jumped up to 90 psi. That’s more than double what it should have been reading at idle. Okay, so obviously we’ve got way too much fuel pressure. We swapped out the fuel pressure regulator, but that did nothing to fix the problem.

Rennie remembered a former customer who had a clogged return line in their E30, and he suspected that might be the case here. We unhooked the fuel return line and ran it into a large glass bottle so we could get a reading without the backed-up fuel return line sending the pressure to the clouds. We saw about 40 psi on the gauge with an unhindered fuel return route. After a few seconds, we also had the start of a nice Molotov Cocktail, so we killed the engine. The fuel return line carries a LOT of fuel in a short period of time, so make sure you’ve got a big enough container whenever you unplug it for testing purposes.

After unscrewing the gas cap, we used an air compressor to force air through the return line to see if we could blow the clog out. We were rewarded with air and some gas bubbling out of the tank, but the pressure still stuck at 90 psi after we hooked everything back up. The problem seemed to be somewhere in the lines of the tank itself, so we’ll have to remove and either clean or replace the entire fuel tank–Oh, joy. At least we’ve got a likely culprit, and a clogged return line would explain why the fuel pump is straining and the car is running rich as a pig. Fixing it might even free up some of our missing horsepower.

With the car put back together and running, we tried to get our brakes to seize up as they have been doing so Rennie could experience it and help figure out the problem. Naturally, the car drove just fine, with no indication of lockup; why would it want to provide tangible evidence of its malfunction with a certified mechanic around to help fix it? That would be too easy.

We tore into the rear calipers anyway to see if the culprit was mechanical. Although there was lots of nasty goo behind the caliper piston, they did seem to be moving as the factory intended. We bled the system and headed back out. A number of abusive ABS-engaging laps later we came back in, still lacking evidence of the problem. We chatted with Rennie about Murphy’s Law, sitting with the car at idle, and when we’d given up hope and lifted the clutch to take the car back to the trailer, the tail end sunk down as if the parking brake were on. Hooray! We ran for the tools and went right for the ABS unit, which Rennie suspected was to blame.

Sure enough, as soon as the hard line going from the ABS unit to the rear brake was disconnected, the pressure was relieved and the BMW rolled freely.

Hopefully, replacing the ABS unit and the gas tank will leave us with a much happier BMW.

Day two at the NASA Championships saw the first real competition of the weekend, with each group running a morning warm-up, a standard qualifying session and then the first of two qualifying races for Sunday’s championship race.

Project Spec E30 was mostly behaved during warm-up, but we were still on the pokey end of the field. The time had come to run some shaved Toyos, so our friends at Vilven Tire mounted up a set of new minimal tread-depth Toyo Proxes RA-1s before the qualifying session. We dropped 2.5 seconds from our personal best lap in the next session, so the shaved tires really do make a huge difference.

We also had a weird noise and vibration at the end of the session, so we put the car up and poked around. It didn’t take long to discover that one of the rear wheels was only barely holding on as the wheel hub splines were backing out of their threads. We re-torqued all the splines and had no issues during a caution-filled race, where we finished about 13th in class.

A few drops of rain hit the windshield in the race, but nothing more; tomorrow should be clear and cooler, great weather for racing. If you’re in the vicinity, Sunday should offer quite a show, as several classes are already showing heated competition. The massive Spec Miata field will be vying for the nearly $10,000 that’s slated to go to the winner, so we’re gonna grab some popcorn and a seat for that one.