The Fuel Pump Finale… (Sort Of)

How To Create The Best Pump on the Market

With our fuel pump design complete (link to fuel pump blogs 1,2,3,4), we now turned our attention to the details. We wanted a coating to protect the piston and decrease friction during operation. After testing dozens of compounds, we settled on a very strong coating that is applied with a proprietary process. This process allows for an exceptional bond with the metal, lower static friction, and increases the surface hardness. Before applying the coating however, we wanted to make sure we had the best part possible underneath it. Imagine having an orange that is covered in titanium. The surface might be incredibly hard, but with no substance to back that up you will eventually lose the shape.

After choosing a very strong alloy for our internals, we then machine their tolerances to an incredible 6 microns! To make sure the tolerances are paired for life, we serialize the parts to prevent any issues and to track the life of the pumps. We then surface treat the pumps to achieve the alloys maximum strength; only after the maximum hardness is achieved do we apply our surface treatments to bring the overall durability to an even higher level.

Numbered Fuel Pumps from CorkSport

Many companies would be finished at this point but, at CorkSport, our research has shown us that when a coating is applied it is very difficult to maintain a smooth surface. In fact, we found that the coating has many microscopic hills and valleys. There would be no reason for us to go through all the work of having incredible tolerances if we were just going to ruin them with an uneven coating. In order to correct this, the pistons are then re-machined back to their original single micron tolerance. The CorkSport Fuel Pump Internals are the lightest aftermarket kit on the market for faster response and decreased cam wear. At this point it may seem like we are flying this pump to Mars but we just wanted to make the best part on the market, and it worked.

Final CorkSport Fuel Pump Internals

Pump More Than Any Other Kit Available

All of this adds up to an improved pumping volume that is over 8% higher than all other pumps we tested and 50% larger capacity than the stock pump. When other pumps are losing efficiency because of their design or tolerances, ours is just hitting its stride.  That difference in the real world is going to be higher HP numbers, safer air/fuel ratios and the ability to go that much further without worrying about your fuel supply.

Because of the increase in fuel we highly recommend that you get a new tune for your car we have made a combo deal to save some money here.

How to Buy the Best Fuel Pump Internals

Now that the cat is out of the bag we can let you know a few more things.

Our first batch is very limited and we want to give everyone that has been waiting a fair shot at getting one. We will release these parts for Pre-Order on November 1st. The Pre-Order will be limited to the first 100 paid orders or November 14th, whichever comes first.

The CorkSport High Pressure Fuel Pump internals include a collectable aluminum box with:

  • Full color instructions
  • Stainless Steel Installation Tool (That also doubles as a keychain bottle opener!)
  • Anodized Aluminum Installation Sleeve
  • CorkSport USB drive with Installation Video, Promotional Video and Other Bonus Material
  • CorkSport Precision Fuel Pump Internals (including higher rate spring)
  • Retaining Hardware

Exploded view of CorkSport Fuel Pump Internals

The Pre-Order will go live on November 1st at 12am Pacific Standard Time and will remain up until the initial 100 orders have been placed. Unfortunately these are the only internals we will offer for 2013 so if you miss the pre-order you will have to wait until next year to get the best fuel pump upgrade on the market.

Fuel Pump Comparison Part 4 (Bombs Away!)

We know by now that adding power to your Mazda is fairly straightforward up to a certain point. However, sooner or later, that hunger for power means you’re going to need to step up to a new fuel pump that can flow more fuel. By seeing that most of the fuel pumps on the market were largely the same, we decided to see what kind of innovations we could bring to the table. At this point we had learned volumes about the pumps on the market through our research and decided to engineer a new set of pump internals that focused on everything that we had learned.

Fuel pump testing

We know this is possibly the worst kept secret since Area 51, but we started engineering fuel pump internals over 2 years ago and we aim to show you why ours is worth the wait.

We didn’t just set out to make another pump; the market has plenty of those. We set out to make the best Mazda fuel pump upgrade on the market specifically for Mazdas from a company that ONLY makes parts for Mazdas.

We started by researching many different technologies and engineering ideas in the pressure ranges experienced in these fuel pumps. We purchased every kit on the market and a brand new replacement from Mazda to test. The results from some of those tests can be found here (Link to blogs 1,2, and 3). After agreeing that 9.8mm was the maximum size we could attempt for the piston without making the sleeve wall too thin, we could start engineering the rest of the part.

We then built all the internals available in SolidWorks and tested the efficiency of them all for flow design and volume. This was merely the beginning of our design phase but helped us realize many great ideas (as well as a few not so great ones). We ended up with a design unlike any other on the market that, according to the data, would be more efficient than anything on the market.

Fuel pump piston

With the increase in flow and efficiency we knew that our design could also benefit from a stiffer spring rate for the pump. That would enable higher RPM’s and improved cam wear over the life of the pump. Since we would be flowing more, the pressure on the pump would be greater than ever, the stiffer spring was just good insurance to get the power we needed even past the stock redline.

CorkSport Fuel Pump Internals

During our testing we also discovered the keeper assembly used by the factory is no accident. Many of the other pumps on the market use a keeper system similar to an intake or exhaust valve. This style does a fantastic job of locking the piston in place, but creates a few issues of its own. Because of the flow of fuel, the piston rides one side of the sleeve more than the other; over time, this will wear more into the piston which will affect clearances and efficiency. To prevent this, the factory style keeper allows the piston to spin as the spring moves up and down. That led us to choose the factory style retainer. We didn’t want to guess on either design without proof of our theory so we produced samples of both styles to prove wear differences and address installation challenges related to both styles.

Now that the cat is out of the bag, we’ll have just one more fuel pump blog next week with a very exciting limited offer. Stay tuned as CorkSport is about to take Mazda performance one step higher!

Fuel Pump Comparison Part 3

Welcome back to the Fuel Pump Comparison, Part 3. If you haven’t been following along with us feel free to read Part 1 and Part 2

Corksport dyno testing of fuel pumps for Mazdaspeed 3

Now that we have a good understanding of the basics for these high pressure fuel pumps we can start to really dig deeper into the specifications. One of the items we were really curious about were the materials used in the construction of these pumps. We decided to have the hardness tested and ascertain the materials used. The factory pump internals do not use any coating, the hardness test showed us that the internals went through a hardening process as the core was significantly softer than the surface. Because of these hardness requirements, many other aftermarket internals use a coating of some sort to decrease friction between the piston and the sleeve. As for what the stock internals are made from, we answered that. Except for the hardening procedure, according to their chemical breakdown, they match a common die steel, so nothing too fancy.




We now understand why it is so common to hear that the factory pumps are machined to such tight tolerances. At high rates of speed and pressure with a hardened material, you could easily have failures if tolerances were not correct.

When testing the fuel pumps on the dyno, we chose a Mazdaspeed 3 (2nd gen) with bolt-ons and a stock turbo. The factory boost levels we maintained 1700psi all the way to redline with no issues. As soon as we raised the boost slightly, the fuel pump began to drop pressure. With a Cobb AccessPort and a stage 2 reflash, the pressure of the pump would drop under 1000psi by 5000rpms. If you’re going to turn up the boost or run a reflash, an upgraded fuel pump is a must.

dyno results for different fuel pumps on mazdaspeed 3

Our dyno is able to adjust load, so in our testing we chose a load value typical of 4th gear on the street and tested all pumps with the same load on the same day, only hours apart from each other. All the pumps tested performed very similar for power but the stock pump actually ran a lower air/fuel ratio. This is because all of the pumps were tested with no tune. When we changed to the Cobb stage 2 map, the power levels increased but we could not complete the test with the stock pump as it just could not keep up with the demand. With the stage 2 tune, we found the air/fuel ratios to be very, very rich and had a very real possibility for causing high load misfires. We actually experienced that several times on colder days. With no tune, this does not happen but the car did still run very rich in boost with all the aftermarket fuel pumps. With a custom tune though, there should be no difference between the pumps and you can raise the boost without worry of running low on pressure.

Now that you have read Part 3, see Part 1 and Part 2.

Stay tuned for part 4 in our fuel pump comparison series, things are about to really heat up!!!

Fuel Pump Comparison Part 2

In part 1 we discussed fuel pumps, their uses and what’s inside them. Now we can talk a little about what goes into making them and what the differences are.


CorkSport Fuel Pump Comparison

CorkSport Fuel Pump Comparison


Does size matter? When looking at the stock piston on the factory fuel pump you can sure say that it does matter. If you increase the piston diameter you increase the flow of the pump. We have decided to compare the similar internals first and then compare the APR pump afterwards. The Autotech/KMD internals use the same diameter piston head. At 9.8mm compared to the factory 8.0mm. When comparing the volume area they are both about 50% improvement with the KMD edging out the Autotech by a  marginal amount. This slight edge comes from the shape of the end of the shaft being slightly different. The Autotech looks more like a piston from an internal combustion engine where the KMD is very similar to the factory design at the end. Because these are the older version of the KMD internals they are coated differently. They look to be a TiCN coating but we can’t say for sure. The Autotech internals are listed as a DLC coating which stands for Diamond Like Carbon. The newer KMDs are now PVD coated (Physical Vapor Deposition).


CorkSport Fuel Pump Comparison


When we start comparing the sleeves that the piston rides in we notice they are all similar in shape and size. The Autotech has a coated sleeve that appears to be some sort of tool steel. The factory is uncoated and appears to be tool steel. The KMD is uncoated and appears to be stainless of some variety. Internally there is a relief cut that is ~3 times larger on the aftermarket internals which should help with the 50% improvement in flow. The sleeve shows the constraints for why you can not go much larger than the 9.8mm piston. The end that fits in the factory pump can only be so large and the wall thickness must maintain a certain size or failure will be imminent.


CorkSport Fuel Pump Comparison


For a long time the CP-E pump was rumored to be made by APR. The CP-E pump we ordered actually came with an APR sticker on the side of it. Oops. We quickly disassembled it and documented the findings. The pump uses a 9.5mm piston which is smaller then the two internal only options. APR claims 40% improvement and we calculated about a 41% improvement so no issues there. They also chose a Stainless steel sleeve and DLC coating on the piston. The big difference comes when you look in the cap. They machine in an extra Seal to help with the oil deposit issue. Is this needed?  We aren’t sure yet but it is an interesting addition.


CorkSport Fuel Pump Comparison


Now for the one big addition that only one manufacturer saw fit to think about. APR added a spring that increases the ability to return the piston. This can be very important for wear on the cam shaft if you get any float from the spring at higher RPM’s; the more the pump worked, the more important this would be. Remember that the cam has three lobes on it so even though the cams spin at half the speed of the crank the pump spins at three times that of the cam. This makes a 1.5 times the crank difference. So what ever the RPM you are at the pump is at 1.5 times that. At a 8000rpm redline the pump is going 12000rpms.  The pump also has to draw in 40-50% more fluid so a return spring plays apart in that as well.


CorkSport Fuel Pump Comparison


Next time we will get these pumps on the dyno and check out how the hold pressures at the same load. Luckily we have an in house dyno that can vary load and the ability to log pressures.

Fuel Pump Comparison Part 1

Adding power to your Mazdaspeed 3 and Mazdaspeed can be amazing and very rewarding. One of the most important decisions you can make when tuning these cars is which fuel pump to use. Since we have never seen a proper comparison of the currently available models we decided to test them for the Mazda community. In this multi-part series, we will talk about the basics, the differences and the advantages with all of the available options.

Most aftermarket fuel pump upgrades consist of changing the internal parts of the factory pump with an enlarged piston and sleeve. By enlarging the piston, you increase the volume of the pump; thus creating more flow and the ability to maintain pressure at higher power levels.

Black residue on Fuel pump internals

When you first start taking the fuel pump apart, the first thing you are met with is the sight of a strange black deposit in the cap of the pump. Shown above are the deposits common to most caps. The bottom is a machined surface that should be clear of debris. In order for us to more clearly understand the situation we sent the cap out to undergo chemical analysis.

Chart of analysis for black residue in fuel pump

The spectrum analysis shows that the buildup is made of motor oil and defoaming agents that are added to motor oil. The oil in the cap is from the camshaft case that drives the pump, a slight amount leaks by the seal and into the pump. When installing new internals it would be a very good time to clean that area as best as you can and possibly replace the O-ring that seals the area inside the cap.

Once we understood what the substance was we then set out to see the options available. We purchased a CP-E pump (APR), Autotech internals and KMD internals to compare and test. Next time we will be measuring all the internals and comparing expected increases while determining what the real differences were. If you already have a pump, are thinking about getting one or are still scared, you’re going to want to see the next blog in this series.