Cosmetic Tidbits: Grills and Caliper Paint

We did a couple of subtle appearance modifications on the 335i this past summer.  The first was a set of matte black kidney grills for the nose of the car.  Although it would be easy enough to paint the existing grills, from experience we know that little rock chips will immediately peck holes in our black paint, revealing the chrome underneath.  A better solution is to install grills that are black plastic all the way through.  As it happens, we sell those, so we grabbed a set off the shelf and popped them on.

Install is extremely simple -- the grills just snap into place in the bumper.  Pre-LCI (facelift) cars will have an additional "eyebrow" that attaches to the hood, but our 2009 car doesn't have that.

The other cosmetic change was to paint the brake calipers.  We didn't want anything overly flashy, but the original brake parts were looking very scabby and rusty, so we decided to freshen them up with a coat of silver paint.  Since brakes see a substantial amount of heat, we didn't want to use just any paint -- we used our brake caliper paint kit, which includes a two-part epoxy paint that cures hard, glossy, and heat-resistant.  Since we were already painting, we also painted the rotor hats.  Our silver calipers and rotor centers look a lot better than the old rust color from before.  If you don't like silver, the kit also comes in red, blue, black, yellow, and even orange.

The brake caliper paint kit comes with a handy can of non-chlorinated brake cleaner spray, which we used to soak down all the extremely dusty brake bits.  As you can see, it's still a plenty messy job; gloves would be a good call.

Tech tip: Once you mix up the epoxy paint, use it right away, because it immediately starts to thicken, and in a few hours it'll be set up.  We had one customer who didn't understand that and left it overnight... Also, hang the caliper from a coat hanger or bungie cord so it's not hanging from its brake line.

If you have the time and room, get the car off the ground on a lift or jack stands, paint all four corners, and leave it to cure overnight.  By the next morning, everything will be nice and hard, and you can assemble it all back together without worrying about leaving thumb prints in your new paint.

CP-E Intercooler Upgrade Ups Power and Torque

We installed a CP-E intercooler upgrade.  The CP-E core has a volume that's around double the volume of the stock core, and is more efficient as well.  Cast end tanks make for smooth flow in and out of the core.  The kit also comes with an additional oil cooler, which is invaluable if you're going to run the car at the road course.

We followed the instructions CP-E includes with the kit, and everything fit together nicely.  Note that plumbing clearance is very tight on a car equipped with an automatic transmission (like ours is), since there's an extra water-to-oil transmission cooler that's not present on the manual-trans cars.

You've probably noticed the CP-E logo on the intercooler core.  I wasn't super excited about the logo -- not that we don't love the guys at CP-E! -- but decided to fit the core up and see how it looked before doing anything drastic like removing the logo or spraying the core black.  It turns out that you can hardly see the core OR the logo when everything is back on the car.  If you are REALLY looking closely -- like crouching down and putting your face right at the bumper -- you can see the logo.  Otherwise, you'd never know it's there.  So it'll stay.  If anything, it's kind of nice because it's an indicator the intercooler core is not stock, if someone does end up peering in there.

We did some minor trimming of the plastic vanes on the inner bumper plastic to make installing the oil cooler easier, but we didn't have to cut or trim any of the outer bumper skin.

Once done, we strapped the car back on to the dyno and ran it.  We gained another 15 hp and 21 ft-lbs of torque.

We're very happy with the results from the intercooler upgrade, and with the fit and finish of the kit.


The massive power gains we've achieved at each stage of this project are addicting.  We're now considering a full turbo-back exhaust, despite our earlier vow to keep it stock...

In other news, the AccessPort now works on all 335i models, including 2007 model years.  We expect to hear soon about the latest maps, which will include Stage 2 maps for cars with full exhaust systems.  We also expect the release of the Cobb ProTuner software, which will allow us to develop custom maps here at Mach V Motorsports.

Wavetrac LSD: 100% More Driven Wheels!

We installed a Wavetrac limited-slip rear differential in the shop 335i, and it really changes the way the car drives.  By no means does it eliminate tire spin or slip -- it can't perform miracles -- but when the rear end does give way, both wheels are spinning, not just one.  Those annoying one-wheel burnouts, which seemed to happen every time I drove the car, have been replaced my much-less-frequent small episodes of rear-end-hip wiggling as the tires struggle a little before hooking up together.  Another benefit is the elimination of the strange left-right-left jerkiness that was the result of the stock "e-diff" braking action attempting to get control of the one-wheel tire spinning.

By now we're getting pretty good at the differential swaps on these cars.  Give us a call and we can put one in for you. It takes about a day.

Note that there are two types of differentials on these cars.  Most of the automatic-equipped cars have bolt-in differentials, and some of the early manual-transmission cars do, too.  Replacing the differential on those cars is a straightforward affair.  Other cars have weld-in diffs, and that requires a bit more work and cost, since we have to have ring gear machined off the old differential.


In my next post, I'll talk about a CP-E front-mounted intercooler upgrade.  Check back in a few days.

Summer Tires! New Wheels, Too

Betting there won't be any more snow storms this year, we took off the Continental all-seasons and the OEM BMW wheels they were sitting on, and we bolted up a set of Hankook Ventus Evo V12 tires, with some VMR V701 wheels.  The wheels are 19x8.5" in the front, 19x9.5" in the back.  The tires are 235/35R19 front, 275/30R19 rear.


The visual difference is striking.  The large wheel diameter combined with the spoke profile of the wheels gives a nice sense of depth, and the 20mm wider rear tire fills out the wheel wells.  The V701 style seems like a good visual match for the car.

As you might expect, ride comfort is reduced.  The thinner and stiffer sidewalls transmit more harshness into the car, and sharp expansion-joint style bumps make themselves known more than the softer 18" Continentals.  I thought I might sense an increase in steering feel, but it doesn't feel that different.  The car does tend to tramline a little more, following troughs or grooves in the pavement more than before.

Weight-wise, the new setup is actually lighter than the old, despite being both wider and larger in diameter.  The stock wheels with 225/40R18 Contis on the front were 50.5 pounds for the package.  The new fronts are 49.5.  The stock rears with 255/35R18 Contis were 55 pounds even, while the new ones weigh in at only 51.5.  I didn't get a chance to weigh all this hardware separated from each other, so I'm not sure how much of the difference is wheel and how much is tire.  Still, it's nice to know the new rollers are actually saving weight.

On the ECU front, we're continuing to test new maps from Cobb tuning.  I should have some updates on that in the near future.

A desperately-needed limited-slip differential from Wavetrac is on the way, and should be installed in the car in the next couple of weeks.  Stay tuned.

Downpipes Yield Still More Power; Winter Tires Handle the Weather

We picked up some take-off catless downpipes from a customers, and decided to put those on the car.  The install is a little tedious because of the tight work space, but it's straightforward other than that.  If you do it yourself, plan to replace the rear gaskets.  The front gaskets are a hard ceramic type that can be re-used.

The rest of the exhaust is still stock, including the remaining main catalytic converters.  The car picked up still more power -- another 12+ hp and 10 ft-lbs, with no change in the ECU mapping.

After showing the "uncorrected" numbers in my last post, I have switched back to "SAE" correction on this one.  I figured I'd have to list out the weather conditions if I did uncorrected numbers, and with three different runs it's starting to get complicated to list all that out.  So...SAE correction just takes care of that, attempting to normalize over the different weather conditions.

In the near future Cobb Tuning will have "Stage 2" ECU mapping intended for cars with modified exhaust systems.  At that time we'll re-flash the car and get the car back on the dyno with the new ECU logic.  We expect still more power from that change, and more when we upgrade the intercooler further down the road.

If you were looking closely at the picture of our shop staff working on the 335i above, you'd see the new Continental ExtremeContact DWS tires (in stock Sport Package fitment of 225/40R18 and 255/35R18) we put on earlier this winter.  As you probably know, the Bridgestone RE050A Sport Package tires are...downright hazardous in cold weather.  The Continentals were a HUGE improvement in the snowy weather we had, with decent grip in sub-freezing temps and snow or slush.  They're fairly quiet, and they have a very comfortable ride.  The price isn't bad, either.  The one trade-off is that they are not run-flat tires, so in that sense we're flying without a net -- the 335i does not include a spare tire.  We carry a small air pump and tire plug kit, although depending on where/when we broke down we might just call for a tow if it comes to that.

AccessPort Installed!

We've now installed the Cobb AccessPort on our 335i project car.  As with other AccessPort installs, it couldn't be easier.  We plugged the AccessPort up to the car's OBD-II port (it's by the driver's left ankle), and selected "Install."  Fifteen or so minutes later, it was all done.  We pulled the car back on to the dyno and observed a substantial gain in power, and even more in torque.  We picked up 49 hp at the wheels, and a whopping 72 ft-lbs of torque.

Note that the graph here shows uncorrected numbers, and my previous graph was using SAE correction.  I posted the uncorrected number here because although the ambient temperatures were the same, the relative humidity levels were different by 4%, and I think the SAE correction was too heavily weighting the humidity difference.  But corrected or not, the gains are pretty impressive, especially considering how easy the install is.

Here's another graph.  This one shows our 335i with the Stage 1 AccessPort program, graphed against a stock E90 M3 that we dyno'ed a few weeks ago.  The M3 has a smidge more horsepower up towards that stratospheric 8400 RPM redline, but the 335i has as much as 113 ft-lbs (!) more torque to the wheels.

Speaking of torque, the additional grunt really points up the 335i's lack of a mechanical limited-slip rear differential.  While the "electronic differential" does work, the car has a hard time coping with so much torque, and the feeling as the power gets shuffled back and forth (as the car grabs first one rear brake caliper and then the other) is unnatural and disconcerting.  We're looking into fitting our car with a mechanical  limited-slip differential.

Tint Installed, and Dyno Baseline

As I mentioned previously in my mods plan post, window tint is one of the first modifications on my list.  It looks good, keeps the interior cooler in the summer, and makes items inside the car less obvious to snooping thieves.  We had our friends from TNT Tint come and tint the windows of our 335i.  We've used TNT for many years, and have always been happy with the work.  The tint material is charcoal non-metallic film from Madico.  The result is shown here.

In anticipation of getting a dyno result for the Cobb AccessPort, we strapped the 335i to the Dynojet chassis dyno for some baseline (pre-modifications) numbers.  The car put down 266 whp and 278 ft-lbs of torque to the rear wheels.  That's pretty standard for a 335i, but a little higher than we'd expect for a car with 300 crank horsepower.  Our usual rule of thumb is a 15% drivetrain loss for a 2WD car, so most cars with 300 crank hp would put down about 255 to the wheels.

When we tried to apply the AccessPort tune, we were denied -- the AccessPort wasn't yet programmed with our car's particular ROM, so we have to wait until the engineers at Cobb Tuning update the AccessPort so it can work with our vehicle.

Turns out the AccessPort has a handy utility built-in to make it easy to send your ROM file back to Cobb Tuning.  If the AccessPort does not recognize your ECU, it'll pop up an option to download the ROM to the AccessPort.  Select that, wait a few minutes, and then hook the AccessPort up to your PC.  The ROM file can be downloaded and sent off to Cobb's tuners.

Once the file is back here we'll reflash the car and get some revised dyno numbers.  Watch this space.

Cobb AccessPort for 335i Announced!

The Cobb AccessPort is a tuning device that I've been using for many years.  It was first released in 2004 for the Subaru WRX, and I've been conducting custom dyno-tuning sessions using the AccessPort since that time.  Even though there are other tuning tools for the Subaru, the AccessPort is my preferred tuning suite.

Last week Cobb Tuning announced an AccessPort for BMW N54-engine cars.  It will come with maps for a couple of different combinations of hardware modifications, and will also allow for custom tuning.  Here at Mach V Motorsports we intend to use the N54 AccessPort on our own car, and will take advantage of it to develop our own calibrations for the car.

The AccessPort has several advantages compared to many of the other tuning solutions that are available for the 335i.  Since it uses the original ECU, there are no wires to hook up other than a single OBD-II port plug.  Once the reprogramming is complete the AccessPort can be removed from the car.  The AccessPort programming retains all the car's factory safety features and limiters -- they are adjusted as appropriate, without having to fool or "trick" the ECU by editing the sensor signals.  The AccessPort can be easily removed and the car reverted to stock at any time, again without doing any physical modification of the car.

This definitely changes the marketplace in terms of tuning tools for the turbo BMWs.  I'm very excited about the AccessPort.  Stay tuned for real-world dyno results!