Time | Temp(F) | RelH | Press(Hg) | Alt(ft) | DA(ft) |
9:15 - 10:00 PM | 82.7 | 38.3 | 29.45 | 172-302 | 2285 |
The real performance zealots make fun of anybody running 20-inch "Power
Eating" wheels and tires on the car. Just so I gave my car as little
advantage as possible, I'm running wheels that weigh 1.5 pounds more than HRE
P40's. (That comment should make the little mindless nazi's at SS-Post go
a little crazy.) The tires are completely track-shredded bone stock
Michelin PS2's. The rear wheels and tires weigh in at a whopping 54.5
pounds.
Car specifications as seen in the video:
Car | 2008 BMW E92 M3 |
Motor | RD Sport RS-46 "Stroker" motor |
Supercharger | ESS VT2-46 |
Boost | 6.25 PSI |
Gasoline | 100 Octane |
ECU | Same tune I've been driving since March. |
Wheels | OZ Racing 20x10.5 Rear (54.5 lbs with tire) |
Tires | Race track shredded bone stock Michelin PS2's |
Name (DDB) | Temp(F) | RelH | Press(Hg) | DA(ft) | WHP(unc) | WTQ(unc) | WHP(djc) | WTQ(djc) | WHP(act) | WTQ(act) |
Dray_M3 | 83.3 | 22.30 | 29.85 | 1741 | 350 | 255 | 343 | 250 | 364 | 265 |
Alexshop | 81.4 | 24.30 | 29.86 | 1613 | 360 | 269 | 354 | 264 | 373 | 279 |
Z4Dave | 81.4 | 23.80 | 29.86 | 1610 | 351 | 260 | 344 | 256 | 364 | 270 |
Chris Shades | 82.9 | 23.60 | 29.86 | 1714 | 369 | 361 | 363 | 355 | 384 | 375 |
psuwcc112 | 82.0 | 23.00 | 29.87 | 1638 | 322 | 242 | 317 | 239 | 334 | 251 |
noxredna | 82.7 | 22.50 | 29.88 | 1679 | 341 | 239 | 336 | 236 | 354 | 248 |
KZ | 83.1 | 21.90 | 29.87 | 1694 | 338 | 253 | 332 | 249 | 351 | 263 |
Sleeper13 | 84.6 | 20.10 | 29.87 | 1790 | 378 | 304 | 373 | 300 | 393 | 316 |
dettinger | 84.4 | 21.20 | 29.87 | 1788 | 353 | 260 | 349 | 257 | 367 | 270 |
To see what I mean, look at the product matrix below. ESS offers three basic kits: VT1, VT2, VT3. Some of the customization hardware may be provided by ESS (such as higher boost pulley), but the customizations are not supported by ESS and at the end of the day are the customer's responsibility to install and support. Customer-installed customizations options include more boost, nitrous, stroker motors, or even a custom methanol kit. The combinations seem endless: three different kits, and many different options translates into hundreds of different possible combinations.
Custom Boost | Custom Blower | Low Compression | Stroker Motor | Nitrous | Methanol | DCT Software | |
VT1 | x | x | x | ||||
VT2 | x | x | x | x | x | x | |
VT3 | x | x | x | x | x | x | x |
There are a few items in the product matrix that need further explanation.
Even though each kit has a pre-set boost level, ESS is always willing to give
the customer a higher boost pulley (under the right circumstances). The
customer must live in an area where the appropriate gasoline is available to
meet the higher demands of the higher boost.
ESS is a reasonably large company and sells hundreds of supercharger kits. Because of their large volume, ESS has the clout to have custom-made Vortech blowers with different housing and impeller designs. I was offered a custom-made blower for a very reasonable price, but we decided that I didn't need it (yet). I didn't need it because I was not even exceeding the volume output of our existing blower. It just goes to show you: bigger is not always better (or even necessary). As far as I know, these custom-blower options are not available to any other Vortech-based kit on the market -- which means a custom-made Vortech blower for the S65 motor would only be available through ESS.
ESS does not offer a methanol injection kit nor Nitrous Oxide option. However, both are included in this product matrix to show what is possible without changing any of the ESS hardware design.
I've seen the rumors that I received my ESS kit for free as some type of quid-pro-quo. There were three people who knew beforehand exactly how much I paid for my kit (I personally told each of them) -- and these were the same three people who started this rumor. For a while, I was willing to let the rumors circulate because I wanted to see how far they would let this go. One of the guys immediately stopped his participation after I confronted him (he didn't remember discussing the price with me), but the other two never stopped in spite of being confronted. Since the rumors seemed to take hold among a select group of people, I think it's time to address them directly.
It was never really a secret how much I paid. In fact, the exact price was contained in the following statement in the opening post of my Mojave Mile thread:
I knew tuning the stroker was going to be expensive -- probably $3000 expensive. So at that point, I honestly figured I might as well spend the extra $10k and get the blower as well and be done with it.
In other words, I purchased an ESS VT2 kit for $13,000 (MSRP $13,500) -- only $500 below list price. At this point in time, the only difference between my VT2 kit and one that you can buy directly from ESS -- is the ECU tune for the Stroker+Supercharger. Everything else in the kit -- all of the components are the same ones available to any VT2 customer.
The Performance Efficiency (PE) of the ESS-46 kit is one of the highest if not THE highest on the market. The PE of this kit is between 5.41 - 5.48. The PE rates the kit's ability to produce power and factors out displacement, boost, and gasoline. This article provides a description and the formulas for calculating the PE of a supercharger kit.
While driving the car home, I began the drive rather gingerly -- trying to reacquaint myself with the car and all of its power. For the first 150-200 miles, I didn't exceed 75MPH. But after driving 200 miles towards home, 75 soon turned into 80; 80 turned into 90; 90 turned into 100; and 100 eventually turned into 105 MPH. These weren't short excursions into these speeds -- these were prolonged distances at these speeds. Luckily Interestate-5 was completely deserted that night, and I always slowed down when I approached other cars. For some reason a Lincoln Continental and Mitsubishi Mirage wanted to hang with me at these speeds. Both cars followed me all the way to Highway 101 in Gilroy California.
The only way I can describe how the car ran -- was simply amazing. The sound of the motor was so intoxicating that I blame it for my upward speed ventures. Throttle response was instant and telepathic. The car knew exactly what I wanted it to do -- and was always willing to give it. The ECU tuning in the car is superb and the sound of the engine sublime. The car idles perfectly; it doesn't hunt or search for an idle speed. The car starts perfectly every time. There are never any limp modes, engine stalls, etc. It's a far cry from the problems I had with the "custom tune" I had put on the stroker. In fact, the tune on the car is night and day different -- and I think runs better than the factory ECU tune.
I am running on Michelin PS2 street tires -- nothing exotic or sticky. So at times under hard acceleration, I can feel the back-end getting a little squirrely. Recently I took my 17 year-old out for a drive (his first since the supercharger was installed). He wanted to "feel" the extra power. I told him he had better bring a diaper change -- and he informed me that he already relieved himself! Once we found our "lonely road" I opened up third gear. Within 3-4 seconds, I was already at 110 MPH. Not wanting to go any faster (with my son in the car), I slowed down -- the ride was over. I asked him if he could tell it was faster. I don't think he could get the grin off of his face -- and all he could say was "uh...yeah!"
So after seven months out of my possession, I finally had a chance to drive my car back home. I'm currently using it as my daily driver. I'm driving around with my mid-boost 613whp configuration. I get far more looks, thumbs-up, and general "atta-boys" now, than I ever did before. Maybe people are seeing the roll cage and Sparco seat in the car and realize this is one serious, mean, and nasty machine.
The car has been in two standing mile competitions, and the M-Fest track event. The first standing mile -- Mojave Mile -- we ran 181.8 MPH. In the Texas Mile, we increased the boost and ran 186.1 MPH before fouling our oxygen sensors two days before the end of the event. After changing the O2 sensors, we put our lowest (6PSI) boost pulley back on the car, drove it to Las Vegas for M-Fest and drove the track event. While at MFest, we tracked the car for six full track sesssions -- which if I (and others) counted correctly was -- exactly twice as many sessions as any other supercharged E9x M3 at the event. The car ran absolutely flawlessly while the ambient temperatures climbed to the mid to upper 80's. The motor's water temperature never exceeded 107 degrees (C). The first session was also my first time on a real track in 25 years. We were running on 20" Michelin PS2 street tires that were over pressurized by more than 10 PSI (stupid tire shop). Thankfully one of our guest driver's -- Earl -- checked the tire pressure and noticed it was way too high. He lowered the pressure and I immediately picked up 10+ seconds per lap on my next time out on the track. As the lap times below show, the performance was very consistent -- lap after lap -- usually within 1/2 second of each other.
Lap-1 | Lap-2 | Lap-3 | Lap-4 | Lap-5 | Lap-6 | Lap-7 | Lap-8 | |
Robert | 02:42.71 | 02:36.40 | 02:33.03 | 02:32.27 | 02:29.77 | 02:31.04 | 02:39.29 | 02:31.04 |
Earl | 02:13.98 | 02:12.16 | 02:09.43 | 02:19.88 | 02:09.01 | |||
Robert | 02:23.73 | 02:25.68 | 02:24.79 | |||||
Sam | 02:38.67 | 02:26.92 | 02:24.00 | |||||
Eric | 02:21.58 | 02:24.61 | 02:17.47 | 02:17.16 | 02:16.28 | |||
Robert | 02:22.06 | 02:20.72 | 02:20.84 | 02:20.46 | 02:22.10 | 02:22.55 | 02:22.83 | 02:23.24 |
By now, we've performed three different dyno runs at three different boost levels. The first dyno runs at 6PSI demonstrated 561whp (SAE corrected.) At 6.25 boost, we achieved 601whp (SAE corrected). The final results are harder to pin down. We know the final results were 50-55whp higher than our previous runs at the Arizona dyno, but we never ran this boost on our home dyno. Our home dyno has the boost gauge and is the dyno we use for published results. So if 601whp (SAE, 613whp STD) was our previous baseline, then our final results were probably somewhere around 650-655whp (SAE, 665-670whp STD). But we will never know for sure because we don't ever plan to get back to measure this configuration on our home dyno.
The large pulley (shown in the graph below) demonstrates that we are right at 6 PSI as the car was delivered from ESS. The smaller pulley was just barely smaller. As you can see from the graph, the trend line shows boost near 6.25 PSI -- again, very modest and very conservative setting.
Here are the ESS-46 vs. RS-46 vs. Stock comparison dyno charts. Unfortunately, these are the only Dynojet graphs I have of the RS-46 stroker on this same dyno. It's unfortunate because these were some of the very first dyno charts taken, when the ECU was untuned by ESS, and we still had the nasty torque dip. But nonetheless, they are good for a relative comparison.
I took some videos with the iPhone. There's not the best quality, but they are something.
Life before the stroker motor was simple. I achieved 16.5 MPG in the city, and up to 21.7 MPG on the highway. Adding the stroker motor changed all of that. I was down to 14.5 MPG in the city, and 16.5 MPG on the highway. Changing my differential increased my mileage substantially -- and adding the supercharger increased it a little more. Now, I'm back to 21-22 MPG on the highway. Since I rarely (never) have my car at home any longer, I do not have any in-city driving MPG specifications.
I was always a little disappointed with my oil consumption. Before the supercharger, my stroker motor was consuming one quart of oil per 1600-2000 miles. That is well within BMW specifications, but too much for my happiness. However, while installing the supercharger, we did perform a leakdown test on my motor -- just to be safe. All of my cylinders were well within normal leakdown ranges -- in fact the leakdown numbers were very low. Adding the supercharger has substantially decreased my oil consumption. Now I'm consuming 1-quart of oil per 3000-4000 miles. My belief is that the positive pressure inside the cylinder is not allowing the oil (under the vacuum of an NA motor) to get past the rings. Basically it's the difference between positive pressure in the cylinder (FI) versus a vacuum in the cylinder (NA).
We have been hard on O2 sensors -- VERY hard on them. In Texas, we blew through a set of O2 sensors when we ran Q16 leaded gas at some pretty high boost. After getting home, we swapped the O2 sensors, put on our lowest boost pulley, and drove the car to MFest to have some fun at the track event. However as soon as we got back, we had some unfinished business to attend to: we wanted to know exactly how much power we were making in our Texas Mile configuration. So, we put on our high boost pulley, filled her up with MS109 and started driving the car around really hard. Within 100 miles, the DME started cutting spark just like it did when we fouled the O2's with Q16. So we took her to the dyno anyways to see if we could get a better picture of what was going on.
But while at the dyno, I learned something very interesting about the MSS60 DME. When an O2 sensor fails, the DME does not reduce redline, but it does enter a safe mode of sorts. After the first run, I noticed that the car seemed to take longer to rev between 2000-8400 RPMs, and we were down 100whp on power from what I expected. Then when I looked closer, I saw the AFR and SPARK data at a constant fixed amount -- meaning it didn't change all the way from 2000-8400 RPMs. So I called Asbjorn @ ESS and told him what I saw (this was before we knew we had an O2 sensor problem). He immediately knew we had entered a special type of safe mode because he informed me that the DME will set a constant spark and AFR target without reducing the redline. So we left the dyno without any results.
Once we ran some diagnostics on the car, we discovered that we had a faulty O2 sensor on bank-1. We went to the BMW dealership to pick up another set (even though only one was malfunctioning) and asked the dealer if the O2 sensors have a warranty. We knew the standard response would be that electronic devices do not have a warranty -- and this is exactly what we were told. However, if the CAR is under warranty and a replacement O2 sensor fails -- even though it may have been replaced by a non-BMW service center -- then the part would still be covered. All we had to do was bring in the car to BMW. They would look over the car; make sure it had not been modified or raced; and then proceed to cover the warranty for the O2 sensors. At that point Sam@AutoTalent and I looked at each other and said "we're screwed." On the way out, we joked that we wouldn't even bother trying to get them replaced under warranty. But after replacing the faulty O2 sensor, the car has run absolutely flawlessly.
ESS has been amazing to work with. They have been fast and responsive with every request I've made. The car has been to their Arizona facility twice -- once for the initial kit installation, and once for an upgrade tune before heading out to Texas. Today I'm still running that same tune. ESS set me up with three different pulleys: low, low-medium, and medium-high boost. The tune they created in the ECU will accommodate all of these boost configuration without reflashing -- provided I increase the octane rating of the gasoline to match the boost level. That special ECU tune was a special request of mine -- no "map switching" required -- because I didn't want to ship the ECU back to Arizona for reflashing every time I changed pulleys. So, Asbjorn pulled the rabbit out of his hat and figured out a way to program the ECU for multiple boost levels. It's worked: the tune on the motor is amazing.
Now that I have a high performance clutch to install on the car, I plan to have the car sent back to Auto Talent in a few weeks. We'll install the clutch and figure out ways to tweak the aerodynamics of the car for our Mojave Mile and Texas Mile events. After seeing "trauma" those types of events put on the car, I'm not so sure I want to compete at Bonneville. Bonneville would certainly cause a bit more trauma to the car. I would need to install a fuel cell, fuel cut-off, electrical cut-off, and 6-point roll cage (cutting into the dash board). I'm just not willing to tear up the car to that extent.
So for now, my car has two seats: Sparco with 6-point harness in the driver's side, and OEM and seat belt on the passenger side. The car is loud inside and is unsuitable for talking on the cell phone above 45 MPH. But when I step on the gas, the roar of that motor comes to life. It is the meanest sounding beast on the road I've ever heard. While cruising around it sounds very tame -- but when you hit the gas and go through a few gears, the tame pussycat turns into a full-on beast.
]]>Here's a rundown of the various ways to measure supercharger performance -- along with some pro's and con's. In all cases, the baseline must be true and correct, and no changes are allowed between the baseline and the final results.
Method | Pro's | Con's |
MaxHP |
|
|
Percentage |
|
|
Supercharger Efficiency Formula (Version 1) |
|
|
Supercharger Efficiency Formula (Version 2) |
|
|
Supercharger Efficiency Formula (Version 3) |
|
|
One advantage of this formula is that it can't be cheated or manipulated by any
vendor. It's just a number, and the number doesn't lie. A kit's performance
efficiency will not depend on boost level, displacement, headers, exhaust, or
any bolt-on items. Simply put, the kit efficiency will determine how well the
kit performs -- and this number will remain relatively constant regardless of
any changes -- except for octane rating.
To account for octane rating, I relied extensively on the Dyno Database. Using the results I had at my disposal, I calculated that each AKI point above 91, accounts for approximately 7.15whp of gain. Therefore, a 91 octane motor is the baseline, and anything above it will be adjusted by 7.15whp per AKI rating. There seems to be a ceiling on AKI rating. Tests have demonstrated that the MSS60 DME does not continue to increase performance above (approximately) 96 AKI octane gasoline. This was predicted by some M3Post forum members and then demonstrated in later tests.
Now that I know how much whp each point of octane adds or subtracts from performance, I can come up with a unified formula that accounts for baseline performance, displacement, boost, and gasoline. Here's what I came up with (version 3):
Efc = (Gain - (7.15*(Gas_AKI - 91)) / Displacement / Boost
Here's how it works:
Example-1:
Efc = ((517-357) - 7.15*(91 - 91)) / 3.996 / 8.0
= 150 - (7.15 * 0) / 3.996 / 8.0
= 150 / 3.996 / 8.0
= 4.69 Efficiency
Example-2:
Efc = ((601 - 409) - 7.15*(96-91)) / 4.619 / 6.25
= 192 - (7.15*5) / 4.619 / 6.25
= 192 - 35.75 / 4.619 / 6.25
= 156.25 / 4.619 / 6.25
= 5.41 Efficiency
Real World Examples
Now let's look at some more real world examples. The results below were taken from the Dyno Database -- all from independent dyno results. Not a single vendor dyno was used to compile the results below. You will quickly notice from these examples that the efficiency does not deviate very much for each vendor. There are no real statistical "outliers" here -- because all of the results regardless of the displacement, boost, or gasoline produce an efficiency in the same ballpark as each other (on a per-vendor basis). Without any "outliers" -- the results are very good proof that this formula works.
Description | Before | After | Gain | Octane | Displ. | Boost | Efc. |
ESS-46 | 409 | 561 | 152 | 91 | 4.619 | 6.0 | 5.48 |
ESS-46 | 409 | 601 | 192 | 96 | 4.619 | 6.25 | 5.41 |
ESS VT2 | 329 | 468 | 139 | 91 | 3.996 | 6.5 | 5.39 |
ESS VT1 | 338 | 441 | 103 | 92 | 3.996 | 4.5 | 5.33 |
G-Power SK2 | 338 | 457 | 119 | 91 | 3.996 | 6.0 | 4.92 |
G-Power SK2 | 319 | 437 | 118 | 91 | 3.996 | 6.0 | 4.92 |
G-Power SK2 | 346 | 545 | 199 | 94.5 | 3.996 | 9.0 | 4.83 |
Gintani Stage-2+Meth | 367 | 517 | 150 | 91 | 3.996 | 8.0 | 4.69 |
Gintani | 330 | 461 | 131 | 91 | 3.996 | 7.0 | 4.68 |
Applications
There are a few applications for this formula above. Primarily, it can be used to cross-check a vendor. If a vendor's kit produces an efficiency factor of 7.80, but the kit efficiency with verifiable dynos has demonstrated an Efc=4.92, then it would be a clear sign that the baseline was not correct, the boost was not being reported accurately, the gasoline was not the octane rating claimed...or many of these factors combined. The bottom line is that this number does not lie -- whereas vendors might. I've already used this formula to sniff out multiple instances where the baseline dyno was not taken from the same car.
I've also used this formula for another very important purpose as well. If you know the baseline of the car and the final result -- this formula can be used to cross-check a vendor to prove how much boost they were running. The G-Power 9.0 PSI entry above was a great example. I knew the baseline, final result, gasoline octane -- but I didn't know the boost. Using this formula, I calculated the boost as 9.0 PSI and then wrote the vendor to ask. I didn't realize the vendor was a mathematician -- and he was impressed with the formula I presented. The vendor did confirm that the car was running 9.0 PSI -- and that my formula was used correctly to figure this out.
Finally, the efficiency factor can be used to rate a vendor's product. It's very clear from the table above which vendor creates a product with greater efficiency than the other. Whereas vendors are very emphatic about their products and always claiming to be better than their competitors -- this efficiency factor is a non-biased way to rate the products and compare the results. As more vendor products come to market (AA, VF, etc.), it will be interesting to see how they stack up against the vendors already established in the market.
Low Compression and Custom-Built Motors
Since there is no baseline with a custom-built or low-compression motor, the efficiency formula can be slightly modified. This is a case where MaxHP can be used instead of HP gain. This method comes with a negative side-effect: Now, the results are dependent on the dyno -- whereas the above method is relatively immune to dyno brands.
Efc = (MaxHP - (7.15*(Gas_AKI - 91)) / Displacement / Boost
Example-1:
Efc = (517 - 7.15*(91 - 91)) / 3.996 / 8.0
= 517 - (7.15 * 0) / 3.996 / 8.0
= 517 / 3.996 / 8.0
= 16.17 Efficiency
Example-2:
Efc = (601 - 7.15*(96-91)) / 4.619 / 6.25
= 601 - (7.15*5) / 4.619 / 6.25
= 601 - 35.75 / 4.619 / 6.25
= 156.25 / 4.619 / 6.25
= 19.57 Efficiency
Using the same exact DynoDB entries as above, but using MaxHP instead of "Gain" -- the results would be as follows. There's a few things of importance to point out from the results below. For the most part, the relative order of the entries did not change. Only the items highlighted in red have change their relative positions. Secondly, the method below shows the superiority of measuring against the baseline. In Efc-v3 the efficiency coefficients were all within a few percent of each other, whereas ignoring the baseline tends to spread out the results differently and with less accuracy. The G-Power SK2 kit at the bottom (listed in blue) because it shows the effects of a different dyno brand. All of the other entries were gathered using a Dynojet -- whereas the last entry was gathered with a Dyno Dynamics -- which definitely have a lower measuring scale than Dynojet.
Description | Before | After | Gain | Octane | Displ. | Boost | Efc. |
ESS VT1 | 338 | 441 | 103 | 92 | 3.996 | 4.5 | 24.13 |
ESS-46 | 409 | 561 | 152 | 91 | 4.619 | 6.0 | 20.24 |
ESS-46 | 409 | 601 | 192 | 96 | 4.619 | 6.25 | 19.57 |
G-Power SK2 | 338 | 457 | 119 | 91 | 3.996 | 6.0 | 19.06 |
G-Power SK2 | 319 | 437 | 118 | 91 | 3.996 | 6.0 | 18.22 |
ESS VT2 | 329 | 468 | 139 | 91 | 3.996 | 6.5 | 18.01 |
Gintani | 330 | 461 | 131 | 91 | 3.996 | 7.0 | 16.48 |
Gintani Stage-2+Meth | 367 | 517 | 150 | 91 | 3.996 | 8.0 | 16.17 |
G-Power SK2 | 346 | 545 | 199 | 94.5 | 3.996 | 9.0 | 14.59 |
The prototype (pictured below) was made for my car in preparation to the Texas Mile. Unfortunately, the clutch arrived the day after we left, so we never had a chance to install it or test it.
The factory BMW clutch weighs just above 45 pounds, whereas the ACT clutch weighs a scant 27.6 pounds.
Specifications:
Manufacturer | ACT (Advanced Clutch Technology) |
Retailer | Auto Talent |
Construction | Twin disc, carbon-carbon |
Flywheel | Lightened Steel |
Weight | 27.6 pounds. |
Use | Combination Street/Race applications |
Contact information | Sam@AutoTalent |
I believed we fouled our O2 sensors -- but others disagreed. The VP Racing representative happened to come by when we were working on the car -- and he too opined that we fouled our O2 sensors. Yet others believed we fouled the plugs. One thing we all seemed to agree upon: the source of the problem was the Q16 race gas.
We gambled that we could simply change the gasoline from Q16 to MS109 and the problems would go away. It was a gamble that didn't pay off. After changing the gas, the "misfire" still occurred. To diagnose the problem, I attached the BT tool, read the codes -- and it was blank -- not a single code in the DME. All misfires store codes in the DME, but fouled O2 sensors do not. By this time it was too late to travel to Houston to pick up a pair of O2 sensors -- so our venture at the Texas Mile was over on the first day.
To be safe, we changed the plugs and O2 sensors. When we pulled out the O2 sensors -- a look of horror came across eveybody's face...when this is what they saw:
Clearly, we screwed up the O2 sensors. But we're not out of the woods yet. We
started driving the car -- and found out the problem didn't go away -- in fact
it's now worse! Now the "fouling" is down to 6000 RPMs -- and it's happening in
2nd gear as well! But on the good side, the ESS guys have been looking into this
and made some interesting discoveries.
AJ @ ESS looked into the DME code and discovered that the ECU constantly
sanity checks the O2 sensors. If the DME sees something it doesn't like in a
certain gear, it "installs" an RPM limiter. If the problem persists, then the
RPM limiter gets lower and lower. This is exactly what was happening to us. As
we continued to drive the car with the Q16, the RPM limiter kept getting lower
and lower -- because we had fouled the O2 sensors. There's only two ways to fix
it (assuming you've replaced the O2 sensors): 1) clear the adaptations in the
DME; 2) drive it out. Since we had no way to clear the adaptations ourselves, we
had to do the latter -- drive it out.
The DME goes through an adaptation cycle about every 50 miles. So after
replacing the O2 sensors, about every 50 miles our rev limiter would increase
another 500 RPMs. After 200 miles, the car was back to normal.
It was a hard lesson to learn. As we've seen others running C16 without "any"
problems, we figured running an oxygenated version of the same fuel wouldn't be
such a bad thing. We were sorely mistaken. In fact, in Texas, the racing team
servicing the 250 MPH Ford GT told us that Q16 is so nasty, they literally
change the plugs after every run and then tow the car out to the starting line
-- just so the car doesn't idle with Q16.
So how much gas did it take to screw up my O2 sensors that bad? How many
tankfuls did it take? It was much less than you think: it only took about 15
gallons to screw it up that badly. So think twice before using C16, Q16, or any
other leaded race gas in your S65 motor. Within a short amount of time, you can
foul your O2 sensors and ruin your performance.
You knuckleheads at SS-Post had better pay attention for three minutes (if you don't all have ADHD). If you look at the data below, you might learn something. For some of you (JM), it might be the first thing you ever learned in your lives.
]]> I'd have to say that using actual dyno results and plugging them into CarTest simulator has proven more accurate than any prediction pulled out of thin air. A lot of people mocked my approach. The results now unequivocally speak for themselves. CarTest smulations have proven practically dead accurate for 60-130 (within 0.13 seconds), 1/4 mile trap (within 1MPH), and now 1-mile trap (within 3MPH).Once I returned from the Mojave Mile, I modified the CarTest data with the actual car and atmospheric specifications and re-ran CarTest:
Curb Weight | 3295 lbs (actual vehicle weight) |
Driver weight | My actual weight (not saying) |
Weight of fuel | 0 (already included in vehicle weight) |
Temperature | 55.6 degrees (from national weather service) |
Humidiry | 30% (from national weather service) |
Altitude | 2700 feet (actual altitude) |
Headwind | 10 MPH |
Slope | +0.85% |
The Results
These are just a few things to consider when looking at our incredible results:
Based on what we learned, we plan to make some changes for the Texas Mile. I'm hopeful we'll break 190 at Texas.
When looking at the vBox data, it appears the braking distance is 4025 feet -- just over 3/4 of a mile. That should be plenty of distance to slow down after 180+.
Here's the vBox graphs.
Run-3 (181.8 MPH):
Run-4 (178.9 MPH):
Download the vBox files HERE.
We had a simple idea: get enough horsepower to hit 200MPH in the standing mile. Thank goodness, things never work out exactly as you plan. In this case, that's a good thing because we wanted to break this project up into two phases (maybe more). Phase-1, go to the Mojave Mile and see what we can learn, apply any changes, and go compete at the Texas Mile. As we found out, it's a good thing we decided to "learn" locally -- because many things went wrong.
]]> After a week of intense preparation, we showed up in Mojave at 6PM the night before the Mojave Mile. Our goal: get the car tech inspected so we can fix any last-minute problems if necessary. Tech inspection was supposed to last until 8PM and we arrived at 6PM. Upon arrival we asked the event coordinators if they wanted our car on/off the trailer for tech inspection. That's when the tech inspector pointed to this gorgeous Mercedes Red-colored Black Series and said "that's the last car for the day, we're closing tech inspection." For some reason an 8PM deadline to those guys was a 6PM deadline to us -- and we're already too late. The only thing we can do is show up at 7AM the following morning and get in line with the hoards of other late-comers.The paddock was supposed to open at 5:30 AM so people could get their own work areas. With the M3 off of the trailer, I arrive at 5:30 AM and wait until about 5:45 when the same tech inspector shows up and says "no racers allowed this early -- don't come back until 7AM." I return to the hotel, waste some time, then show back up at 6:45 AM. When I arrive, not only are the gates already open, but the paddock area is pretty full as well.
The first order of business is tech inspection. The tech inspectors look over the car and conclude that everything is perfect... But wait, they start talking among themselves, pointing, and come back to me and say "your fire extinguisher isn't up to code. You need a metal bracket, not plastic. Inspection failed." Our bracket for the roll cage was a very well fitted Sparco aluminum bracket, but the fire extinguisher bracket itself (supplied with the fire extinguisher) was plastic. We look around in the paddock for a team that might have an extra: nothing. I go into Mojave at all of the gas stations: nothing. I call my wife -- who is on her way from San Jose -- and tell her to stand by because I may need her to pick something up along the way. As soon as I return, a guy who was in the same situation as us had just returned from Lancaster (30 miles away) and handed me his receipt and said "Auto Zone" has them in stock...you better hurry." As I hop in the Durango, I call my wife back and tell her "never mind" right before calling Auto Zone to confirm that they will set aside an extinguisher. On the phone, Auto Zone informs me that they are now sold out. Knowing that my wife is just approaching Tehachapi mountains, I call Auto Zone in that city. Luckily they have the extinguisher in stock and set it aside for my wife who literally arrived five minutes later. Tehachapi is only 20 miles away, so within 45 minutes we were back in the tech inspection line and passed. The car is now qualified up to 205 MPH. The only thing left is for us -- the drivers -- to qualify for 205 MPH as well.
Driver qualification is simple: on your first run, don't exceed 150MPH. They do allow you some margin for overshooting, but they're really looking to see if you're the type of person who follows instructions. When it's my turn to go, I launch into 1st, short shift into 2nd, then accelerate hard into 3rd and 4th. I have the video vBox hooked up with a digital oLED display in place of my speedometer. I accelerated so fast that I looked down and made the mistake of looking at the digital speedometer: 155MPH. Until that moment, I was pretty calm. When I realized I was going 155 MPH and I couldn't see the end of the track, I got scared and slowed down. I was looking for the finish line and it wasn't anywhere in sight. After looking over the vBox data, I realized I was only at the 1/2 mile mark -- and already travelling 155 MPH. For the remainder of the run, I stayed in 4th gear and just cruised around at 150 (or so).
Upon my return, I talked to Sam and told him how the car handled. We were pushing real hard to the left, slowing from 150 is no problem, the brakes are fine. During my run, I also noticed that the only timing device (or radar) was at the very end. This allowed Sam to take a different approach during his qualifying run: go as fast as you can, then slow down to 150 before crossing the finish line. So that's exactly what Sam did. He accelerated up to 165 MPH -- in a scant 3400 feet -- before slowing and finishing his qualifying run at 154 MPH.
Top speed runs -- and more drama
Now we're both qualified to 205MPH, the car is qualified to 205 MPH, all
that's left is to get back in line and make a speed run. But now, it's time for
the second surprise of the day: we need arm restraints and didn't have any.
During my qualifying run, the inspectors at the grid said I would be limited to 165 unless I had arm restraints. This was another huge surprise to us. We looked over the rule book at least 5 or 6 times and didn't see anything about metal brackets on fire extinguishers, or arm restraints for runs above 165 MPH. After searching for nearly 30 minutes, we found a woman with an extra set who was willing to loan them to us. This was great news because only 5 minutes later my line of cars was taken to the grid.
I knew from my practice run that the car was pulling rather hard to the left. There was a 15-20 MPH head/cross wind that was also throwing the car around quite a bit. During my first run, I got scared -- so I knew I had to work through my nerves. I decided that I wouldn't look at the digital speedometer and instead I would hit the pedal to the metal and concentrate on the run. My strategy all along was to short-shift first because the tires were going to spin anyways, drop into 2nd and modulate the throttle into hard acceleration. At the top of 2nd, I got some wheel spin, dropped it into 3rd, 4th, and then 5th. At the end of the run after taking my foot off of the gas, I looked down at the speedometer and saw "181.7" -- that was when I knew I had a really good speed. I left the track and picked up my time slip on my return to the paddock. The timekeeper looks at the slip, hands it to me and says "that's a really good speed!" Thanks!
Next was Sam's turn at top speed. Luck wasn't so kind to Sam as it was to me. After my run, we inspected the car and noticed the driver's side inner wheel liner was rubbing against the wheel. It seems that the high speeds were taking its toll on the car. When Sam left the starting line, I could hear him spinning tires in 1st and 2nd. When he reached approximately 150 MPH, the wheel liner departed the vehicle and took along with it any sensors attached to it. We heard the PA announcer say they were closing the track because the BMW shredded a tire. We already knew it didn't shred a tire because Sam finished his run and posted 178.9 MPH. We also saw him driving back, so I immediately knew the wheel liner dislocated itself from the car. Within five minutes, the fire inspectors came to me and handed me the BMW temperature sensor they found on the track. I was impressed: they found a 2" x 2" piece of plastic and returned it, along with all of the pieces of the wheel liner.
Fixing the car damage
At this point, the car is black flagged unless we can fix it. We take it to the
paddock, jack it up, and begin to work on removing the remainder of the wheel
liner. After its removal and a few zip ties later to secure the supercharger air
filter and oil drain line, we go back through tech inspection and back into
line. By this time it was nearly 4PM and little did we know the next run would
be our last. Sam asked who was going to drive, and assuming we had two runs
left, I said I would drive. We discovered again that the event coordinators had
a slightly different definition of "run until 6PM" than we did. Had I known the
next run would be our last, I definitely would have let Sam have it -- to
complete his unfinished business.
On the last run, it's clear that the car is pulling harder and harder to the
left. The missing wheel liner helps the aerodynamics of the car by keeping the
wind away from the tire. Now, there's nothing stopping all of that wind from
hitting the tire and screwing up our time. Between runs I analyzed the vBox data
and noticed that I short-shifted 4th-5th. I shifted at 155 MPH, when I could
have gone above 170. I figured this affected my time somewhat, and was hopeful
that I could break my earlier 181.8. But there was no such luck. With the wind
getting nastier and nastier, the car struggled to break through and topped out
at 175.6 MPH on our last run of the day.
Conclusions
A lot of people might find it totally surprising that we are just two amateurs
with a goal of hitting 200 MPH. Many people doubted us, called us liars, and
said prove it at the Mojave Mile. Well, we proved it. We ran faster than 60-70
other cars. There were only a very small handful of cars that even came close to
180 MPH, let lone cracked above it. Best of all, we did it on stock wheels, and
stock tires. That's right, we didn't have any racing wheels, nor racing tires.
We did all of this on bone stock 19" BMW wheels and tires!
Final pictures of the car:
More Notes
In the picture above of the starting lines, you can see the Red-colored
"Black Series" Mercedes. The owner says there are only ten red-colored Black
Series Mercedes in the country. His best time was 161 MPH. There were about 10
Ford GT's at the event. I asked two drivers their times, and it was the mid-high
170's. Another GT driver posted a 188.
Sam did tell me that a few cars broke into the 190's. Maybe he can fill in
details because I didn't recall hearing any 190's, except "Big Red" (see below).
The fastest car at the event was "Big Red" -- a nitrous breathing old-school
Camero with 1100 horsepower. He posted 200.07 MPH.
I was the only BMW at the event. I found that a bit surprising considering what
I thought were commitments from others to run their cars at the event. In the
final analysis, we were the 9th fasted car overall at the entire event.
Here's the pictures of my three time slips. I don't have Sam's...maybe he can
post them if he has time.
Here's the car's vital statistics for the Mojave Mile:
Description | Data |
Vehicle | 2008 BMW M3 |
Motor | RD Sport RS-46 4.6L "Stroker" V8 |
Supercharger | ESS VT2 for ESS46 |
Horsepower | 613 whp |
Torque | 429 wtq |
Boost | 6.5 PSI |
Fuel | 50:50 mix of 91 Octane / Q16 |
Wheel | Bone STOCK 19" BMW factory wheels |
Tires | Bone STOCK 19" BMW factory tires (Conti Sports) |
Curb Weight | 3295 pounds (1/2 tank of gas) |
Acceleration Data:
Description | Run-1 Est. Time |
Run-1 Tr. Speed |
Run-2 Est. Time |
Run-2 Tr. Speed |
Run-3 Est. Time |
Run-3 Tr. Speed |
Run-4 Est. Time |
Run-4 Tr. Speed |
Run-5 Est. Time |
Run-5 Tr. Speed |
0-60 | 8.04 | 8.01 | 6.08 | 7.13 | 6.54 | |||||
60-130 | 10.22 | 9.23 | 9.07 | 9.26 | 9.36 | |||||
1/8 Mile | 11.08 | 85.16 | 11.12 | 87.52 | 9.49 | 92.48 | 10.37 | 90.02 | 9.82 | 90.53 |
1/4 Mile | 15.47 | 115.16 | 15.38 | 122.88 | 13.61 | 125.29 | 14.58 | 122.57 | 14.02 | 122.64 |
1/2 Mile | 22.28 | 147.18 | 21.94 | 153.37 | 20.09 | 153.18 | 21.16 | 151.55 | 20.62 | 150.01 |
3/4 Mile | 28.23 | 156.15 | 27.60 | 149.97 | 25.73 | 168.58 | 26.74 | 168.25 | 26.30 | 164.66 |
1-Mile | 34.15 | 151.48 | 33.64 | 152.26 | 30.84 | 182.47 | 31.91 | 179.51 | 31.57 | 176.27 |
Time/Distance-to-speed Data:
Speed | Run-1 Time (Secs) |
Run-1 Distance (ft) |
Run-2 Time (Secs) |
Run-2 Distance (ft) |
Run-3 Time (Secs) |
Run-3 Distance (ft) |
Run-4 Time (Secs) |
Run-4 Distance (ft) |
Run-5 Time (Secs) |
Run-5 Distance (ft) |
10 MPH | 1.48 | 11.64 | 1.55 | 13.13 | 1.06 | 9.17 | 1.72 | 12.51 | 1.17 | 8.71 |
20 MPH | 3.47 | 57.95 | 3.40 | 52.56 | 1.98 | 29.07 | 2.63 | 32.40 | 2.19 | 30.42 |
30 MPH | 4.62 | 99.50 | 4.49 | 92.44 | 3.05 | 68.25 | 3.80 | 75.08 | 3.16 | 66.42 |
40 MPH | 5.51 | 145.18 | 5.86 | 65.98 | 3.92 | 112.76 | 4.82 | 127.17 | 4.09 | 114.28 |
50 MPH | 6.39 | 203.77 | 7.21 | 254.44 | 5.19 | 196.60 | 6.13 | 215.90 | 5.58 | 210.31 |
60 MPH | 8.04 | 337.06 | 8.01 | 318.79 | 6.08 | 268.18 | 7.13 | 296.10 | 6.54 | 287.66 |
70 MPH | 9.28 | 454.88 | 8.79 | 393.58 | 6.92 | 348.32 | 8.04 | 382.75 | 7.42 | 371.37 |
80 MPH | 10.47 | 586.32 | 10.27 | 554.97 | 7.75 | 439.71 | 8.92 | 479.79 | 8.31 | 469.41 |
90 MPH | 11.66 | 734.94 | 11.41 | 698.10 | 9.20 | 620.41 | 10.36 | 659.60 | 9.75 | 650.18 |
100 MPH | 12.86 | 902.29 | 12.57 | 859.16 | 10.39 | 786.32 | 11.60 | 831.81 | 11.02 | 826.80 |
110 MPH | 14.11 | 1093.65 | 13.76 | 1042.15 | 11.61 | 974.22 | 12.88 | 1028.38 | 12.30 | 1024.78 |
120 MPH | 16.37 | 1474.16 | 15.00 | 1252.55 | 12.88 | 1189.36 | 14.22 | 1255.65 | 13.65 | 1252.80 |
130 MPH | 18.26 | 1821.30 | 17.24 | 1660.75 | 15.15 | 1606.60 | 16.39 | 1653.25 | 15.90 | 1667.29 |
140 MPH | 20.45 | 2253.93 | 19.19 | 2047.06 | 17.10 | 1993.53 | 18.56 | 2083.28 | 18.15 | 2113.64 |
150 MPH | 23.06 | 2810.72 | 21.24 | 2483.23 | 19.08 | 2414.95 | 20.78 | 2556.73 | 20.62 | 2639.15 |
160 MPH | 23.47 | 2991.75 | 23.07 | 3320.41 | 23.30 | 3130.51 | 23.51 | 3295.92 | ||
170 MPH | 26.23 | 4085.98 | 27.49 | 4146.48 | 28.60 | 4525.19 | ||||
180 MPH | 29.81 | 5005.16 |
Gear Shifting Data:
Gear | Run-1 Speed (MPH) |
Run-1 Distance (ft) |
Run-2 Speed (MPH) |
Run-2 Distance (ft) |
Run-3 Speed (MPH) |
Run-3 Distance (ft) |
Run-4 Speed (MPH) |
Run-4 Distance (ft) |
Run-5 Speed (MPH) |
Run-5 Distance (ft) |
Shift 1st | 18.59 | 28.25 | 38.64 | 130.78 | 42.73 | 127.19 | 45.62 | 155.97 | 39.38 | 110.42 |
Shift 2nd | 55.27 | 240.55 | 72.85 | 421.88 | 82.75 | 467.65 | 81.79 | 497.23 | 84.50 | 516.43 |
Shift 3rd | 112.21 | 1139.27 | 122.41 | 1308.65 | 125.64 | 1329.37 | 124.21 | 1361.62 | 127.03 | 1437.63 |
Shift 4th | 153.38 | 2575.80 | 164.38 | 3400.47 | 162.31 | 3461.60 |
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