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Spec E30 Debut Looms Jun 18, 2007
With the BMW Spec E30's debut at the NASA Hyperfest at Summit Point only a few days away, we're taking care of some last-minute preparation items. This past weekend we installed the fire system, a kill switch, some Goodridge brake lines and ATE Super Blue racing fluid. We also mounted up a sequential shift light, but we don't yet have it working, so look for more on that once we've got a good tach signal.
The Brockway Engineering S100 sequential shift light didn't like being hooked up directly to the coil, but we found the all-black tach signal wire going into the instrument cluster and spliced into the signal there. Seems to be working like a charm, although we've got to get it out on the road and fiddle with the shift point; we're not convinced that the E30 is sending the logical three signals per revolution to the tach, it seems to be getting to the "redline" very early. This Brockway unit is pretty sweet, and it'll help us pretend that our Spec E30 is a BMW Sauber F1 car.
If you're heading out to the HyperFest be sure to watch for us, and feel free to drop by the Paul Reed Smith tent where Gary will have the booth set up. Scott will either be by the tent or in the paddock with the BMW. Wish us luck!
Not that fast, and only a little broken Jun 27, 2007
Project Spec E30 made its debut this past weekend at the NASA Mid-Atlantic Hyperfest at Summit Point in West Virginia. Viewed as a shakedown, it was a big success. Of course, once we hit the track we’re as eager to win as anyone, and that wasn’t in the cards for us this weekend.
This was Scott’s first race weekend in a rear-wheel drive racecar, so there was a bit of a learning curve but the E30 was really very easy to drive at speed. On the few instances where the tail came out it was because we were doing something at full throttle in second gear. It never got scary, and was generally easily corrected. We had one off during qualifying on Sunday when we tried to brake a little too late going into turn one, but it was a simple agricultural excursion under full control when the corner just wasn’t going to happen for the amount of grip available.
Our first-ever session in the car, Saturday practice, resulted in a 1:36.089 fastest lap. By comparison, Vic Hall turned a 1:28.951 in his Spec E30. Yowch.
Unfortunately, we seemed to be a bit down on power, particularly compared to the front runners. We’ll need to get our car to a dyno and try some of the allowed bolt-on modifications to bring our straight line speed up to par. You can only push the gas pedal so hard before Mr. Scott reports that the engines can give no more than that, captain.
With a hair more familiarity with the car on the course, we qualified as second faster with a 1:35.088 for Saturday’s race. The brakes were holding up beautifully, and they seemed to be the only area in which we had some advantage over a few of the other cars on course.
At their full tread depth, our spec Toyos were a little less spec than the rest. Shaved tires were all the rage in the paddock for dry weather, and our attempt to save some bucks by doing the shaving ourselves the old fashioned way wasn’t helping us in the traction department. Still, it’s always nice to have an excuse in your pocket. We also installed fresh spark plugs, as our BMW still seems to enjoy fouling the plugs. We used carb cleaner to clear up the idle air control valve, a possible culprit.
In Saturday’s race, following a rather jumbled starting lineup, we did a lot of mirror watching for faster 944 Turbos and much quicker cars that got gridded behind us for the rolling start. We turned a 1:35.476 and finished 16th out of 19 cars in our class.
Because of a fluid leak, we cut the power steering belt on Sunday. In theory this would free up a few ponies, and we were down to a 1:34.712 in practice on Sunday morning. With a certain level of trust in the car, we were pushing harder in some key turns.
We found another tenth in qualifying on Sunday by really pushing our braking zones. A 1:34.608 had us 14th out of the 15 Spec E30s in the session. Pole was a 1:29.536 by Jonathan Allen. Five seconds off the leader is better than seven seconds, but it’s still a damn lot of seconds over a single lap.
In Sunday’s race, things were going well enough; we’d picked up a few spots at the start and were trying to get close enough to a fellow Spec E30 for a pass while dealing with the lapping Sports Racers and 944 SuperCups. When braking hard into Turn 5 something went awry, and when we got back on the gas we had very poor acceleration. We pulled off line and tried figuring out what was going on.
The engine seemed properly connected to the throttle, was making the right noises and seemed to have a linear throttle, but full whomp felt like about 1/10th whomp. The parking brake had not mysteriously engaged. Nothing felt or sounded broken. We just didn’t have any get up and go. As we headed for the pits, the drag got worse, requiring a downshift to second to keep momentum. Something smelled hot, so we stopped by a fire extinguisher in the pits and asked a friendly bystander to confirm that we weren’t on fire. He said the rear brakes were smoking a lot, but no flames, so we decided to head for our paddock spot.
Getting to the paddock required all the thrust that first gear could muster. The rear brakes were clamped down hard. We parked, changed out of our driver’s suit, downed some water and went to see if we could figure out what was going on. On start-up, the car behaved normally, the rear brakes were fine and we were particularly confused. Also, we seem to have a wicked transmission fluid leak, so we’ll have to get dirty figuring that one out, too.
Our fastest race lap was a 1:34.613, pretty consistent with our qualifying time. Obviously, we’ve got some work to do in the power department, and we’ll have to chase down some braking demons. It wasn’t a record-shattering debut, but the Spec E30 enjoyed a good shakedown, revealed a few problems and still drove itself on to the trailer at the end of the weekend with no visible damage.
MISSING: Some Horses from the Spec E30 Ranch Aug 30, 2007
We took Project Spec E30 down the road to the Dynojet dyno at Projekt7 on Tuesday, and our suspicion that we were down on horsepower a bit at the HyperFest was confirmed.
From what we’ve seen, most healthy Spec E30s make in the low to mid 150-horsepower range, and those on the low end find themselves in the mid 140s. Our baseline was 134-135 horsepower, and after switching out the stock MAF and filter box with a different MAF and an aftermarket cone filter, we saw a peak of 136 horses.
The tailpipe sniffer told the real story, as our car is going Bill Gates rich at 5000 rpm. The car is leaving for the NASA Championships soon, so we’re going to do some last-minute diagnosing with Rennie Bryant of Redline BMW on Saturday in the hopes of getting the most out of the car at Mid-Ohio.
Playing Doctor Nov 14, 2007
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.
Fuel Tank Frenzy Nov 20, 2007
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.