Porsche Custom Tune Baseline

Finally finished base-lining the Porsche today. We lost a month of preparation due to the accident repairs, but finally finished all of the tasks necessary to establish a baseline and get the car out onto the track next week. We even managed to fix the broken vanity mirror on the passenger side visor. The last step in the process was completed this week when we took the car down to Behe Performance to get it on the Dyno. Since we are starting to run out of time before the next trackday, we had them finish the remaining maintenance tasks and put the car on the Dyno to see what we have to work with. They inspected the suspension (nice to get a second opinion after any repairs), flushed the brakes, changed the transmission oil, and aligned the car as well.

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The initial results were a bit disappointing. The initial runs on the Dyno showed only 221 hp at the wheels and 207 ft lbs of torque; peak torque band was pretty narrow. After Behe worked his magic, however, horsepower is up to 236.9 and torque up to 217 ft lbs. More importantly, the peak torque band is wider, with more than 205 ft lbs from 4400 to 5600 RPMs as opposed to only 4700-5300 before the tune. The 2000 Carrera had 300 bhp when it left the factory. If you figure a 15% drivetrain loss, that amounted to about 255 hp at the wheels. Considering that this is a twelve year-old car with 68,000 miles that means it’s down about 8% from new. That’s probably not too bad, especially considering the nature of dyno testing where weather conditions and fuel quality can impact results.

More Power Cap’n

The local BMW club arranged a Dyno day down at York Auto which is just down the street from GeorgeCo world headquarters. Now that the GeorgeCo E30 has a fresh coat of paint, we figured it was time to dial up some power. Since good tuning starts with a good baseline, we backed the E30 on to the Dyno and made a couple of pulls to see what we had. The GeorgeCo E30 left the factory in Regensberg 22 years ago with about 170 hp at the crank. Assuming a 15% driveline loss, that should translate into about 144 hp at the wheels. Given that this engine has over 230K miles and very little modification, we were hoping to get 135 hp on the dyno. The only mods are a cold air intake (which really doesn’t help the E30 but looks good); a header; and a “performance” chip from a reputable supplier who shall remain nameless.

After a couple of runs to calibrate the Dyno, the results came in at only 125 hp. That’s a 14% loss from new and a bit disappointing. It turns out the air/fuel ratio (AFR) was way out of tolerance. In naturally aspirated engines powered, maximum power is frequently reached at AFRs ranging from 12.5 – 13.3:1 or lambda of 0.850 – 0.901. The AFR runs rich to 5000 RPM then lean to redline. The risk in running too rich is that the combustion chamber is washed by the excess gasoline, effectively cooling the burn (reducing efficiency) but also washing away the lubrication protecting the cylinder walls. As it leans out, it could damage the engine because of pre-detonation.

What’s the solution? The WAR Chip by Miller Peformance. WAR stands for Write and Remap. It is an infinitely rewritable chip solution for ECU tuning. It can be tuned from a laptop PC via USB and can store 4 separate tunes that can be switched on the fly without a laptop. We installed the chip following the simple instructions that were included and turned the car over to York Auto to dial in the AFR and put it back on the dyno. Initial results were promising with the preloaded tune from Miller Performance getting up to 135 whp out of the box.

Then when we broke the intake rocker on #6 cylinder and put a halt to progress. Since we have to take the timing belt and cam gear off to get to the rocker, it’s going to be a while before the GeorgeCo E30 is back on the track.

518hp MINI

I recently lost my cell phone which turned into an opportunity to get an iPhone. There are a couple of interesting automotive apps available for iPhone so I thought I’d test a couple of them.┬áThe image above shows the Dyno results for the MINI using an app called Dynolicious. It shows a 12.82 second quarter-mile at 137.4 MPH and a peak horsepower of 518 HP. In third gear. On a public street…. OK, so maybe the calibration was off a bit. My second run after calibration showed 229 HP, but I didn’t capture the image. I think that’s still about 10% too high, but more realistic given the previous Dyno results at 197 HP.

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The second image shows the results for the BMW — Even though it still says MINI — which I suspect are more accurate. I’m really most interested in initial acceleration so the chart really tapers off as soon as I get into third gear. I was trying to compare the BMW to the MINI to see which is quicker off the line for autocross. I decided to try a second app as well called PocketDyno+ which I thought was a bit easier to use and set-up than Dynolicious, but doesn’t produce the really cool charts you see above. The results were interesting.

The MINI has about 25% more HP than the BMW; weighs about 200 lbs less, and is almost half a second faster covering 1/8 mi; but in the first 60 ft — which is what really counts in autocross — the BMW is faster by .15 seconds. Both cars are running the same Falken ZE 912 tires and the test was conducted on the same stretch of road under the same conditions. I suspect the effect of the weight transfer on the FWD MINI negates the superior power and torque available until the cars starts moving, and then it plays less of a role in straight-line acceleration.

Dyno Day

I went in to Behe Performance for a track-day inspection. I got that, but I also got a couple of surprises — one pleasant and one expensive. I knew my car was leaking oil. You could see it dripping at the drain plug. But it turns out the pan seal was going bad and the drain plug was almost stripped. In the photo you can see how two of six threads are already gone. So rather than losing all of my oil on the track at Summit Point this weekend, I went ahead and had the pan replaced. (Note: And that’s the point I started changing my own oil.) That’s the expensive part. Now the pleasant part.

494279862_97f6554d67_bBehe has a new Dynapack dyno. John suggested we should hook my car up to the dyno to see what potential there might be for doing some dyno tuning. From the factory, my car came with 163 horsepower (at the crank) and 155 ft-lb of torque. If you assume a 10% drive-line loss in horsepower, that should translate to about 148 hp at the wheels. I have done the typical bolt-on mods of pulley, intake, exhaust, hotter coil, cooler plugs, and uprated plug wires. On the engine management side, I also have a canned tune from MTH. We were expecting something around 180 to 185 hp.

Much to my surprise (and I think John’s as well) it was pulling 188.8 hp at 6900 RPM. Max torque was 165.9 ft-lb at 4250 RPM. Considering those numbers were at the wheels, that’s about 207 hp and 188 ft-lb of torque at the crank. Chart below. Not bad when you consider the cost of those mods adds up to only about $1,500.

As for DMH, John also had their Cooper S test car which he let me drive. This beast has a re-worked head and cam as well as extensive tuning from John. It’s pulling over 240 hp at the wheels and a max of 190 ft-lb of torque. It revs all the way up to 8,000 RPM. When I was driving it, John kept telling me to stick my foot in it and stop driving like a granny because I was shifting short at 7,200 RPM. It was almost too much power for a street car, but I can only imagine what it must be like on the track. It was quite impressive.

I’ll go back to get some more dyno-tuning in the future. I’m not sure John can get much more horsepower out (short of raising the rev limiter some more), but he thinks he can get me 170 ft-lb of torque at the top end (6900 RPM is only 143 ft-lb now.)

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