Pre-Production Update: New CorkSport 72mm Throttle Body

CorkSport continues to strive for new and innovative products to elevate the Mazdaspeed platform, even as many in the community have fallen away from it. For the past year, weโ€™ve been steadily working on a throttle body upgrade for the DISI MZR that doesnโ€™t force you to compromise between performance and drivability.

GEN-6-497 72mm Throttle Body Pre-Production

Our initial design process started with simulating various inner diameter sizes to see where maximum gains could be achieved with both 2.5-inch and 3-inch IC piping. The resulting best compromise for both piping was 72mm ID versus the OE 60mm ID. The 72mm ID also allowed us to retain the OE bolt pattern for a painless installation utilizing an O-ring for sealing between the throttle body and intake manifold.

Once the prototype was produced, we began the validation process. To prove and measure the true increase in airflow, we flow-benched both the OE and CorkSport throttle bodies. To reduce variables in testing, both throttle bodies were equipped with 3D-printed velocity stacks with a 0.5-inch radius.

GEN-6-497 72mm Throttle Body Pre-Production Testing

The flow bench testing showed impressive gains at 28-inch H20 with a 12mm larger ID. Testing was performed at 25 percent, 50 percent, and 75 percent throttle plate open. We attempted 100 percent, but the flow bench we used could not support that high an airflow. At 75 percent throttle open there was an increase of 131cfm.

GEN-6-497 Flowbench Testing

With the flow bench showing impressive improvements, it was time to put it on a car and see how it responded. Installation was straightforward, only requiring a new 3-inch silicone couple and T-bolt clamp. The first drive with the new 72mm throttle body was quite undramatic โ€” I consider this a great thing because the car drove great. There were no odd throttle surges, no choppiness, and no unpredictability. Throttle response felt a bit more crisp and alert in a predictable way.

The first dyno testing was performed on a CorkSport turbo-equipped car with CorkSport camshafts and intake manifold. Dyno testing showed about 100rpm decrease in spool and inconclusive peak power gains. This may be due to the lower volume of airflow moving through the engine. However, driving the car felt better.

Next, we wanted to see how the 72mm throttle body would react with a larger turbo setup. We sent the prototype to a beta tester running a GT3582R at 34psi with a built and PI-equipped engine. This is where the CorkSport throttle body woke up. Check out the graph below. The green graph represents the OE throttle body, and the blue graph represents the CorkSport prototype 72mm throttle body.

GEN-6-497 Throttle Body Dynojet Research

Again, the results are impressive with a 16wHp/20wTq increase at peak power, but whatโ€™s even more impressive is the power under the curve. There are consistent gains from spool to redline. Spool was about 100rpm sooner, followed by a substantial gain from 4,000rpm to 5,000rpm and more conservative gains from 5,000rpm to redline. Both of these dynographs were produced on the same day within a few hours of each other due to the installation time.

So, youโ€™ve got the info. Now tell us what you think of the new CorkSport 72mm Throttle Body. Comment below, or reach reach out on Facebook or Twitter.

36 Replies to “Pre-Production Update: New CorkSport 72mm Throttle Body”

  1. We do not have plans to test all of the spacers on the market to see which ones work and do not. The throttle body works with the OEM manifold and opening so there is probably a good chance it will work with model spacers.

  2. if you need a tester for the St manifold hit me up also the coolant ports that are on the tb, any chance you would release an option having them deleted?

  3. No, it is a PNP but you can make more power with a tune to take advantage of the extra volume.

  4. This is made for the Mazdaspeed 3/Mazdaspeed6 and Cx7 turbo models. We have not tried it on a Mazda 3 and we are unsure if it would fit or operate properly.

  5. Awesome, love for the MZR is forever! Now if we could just get a CorkSport steering wheel for the Speed6! ?

  6. This is going well! We are still working on it, but should be able to release it to the market soon….ish.

  7. This looks like the shit, my throttle body has been having the little noise coming from it after shut off and i believe its going to take a crap, so id like to replace it and if corksport has one, well thats whats going on my speed6.

  8. Need any testers for a stock turbo? Would love to help the brand, as I love my corksport parts already

  9. Need any testers? I need a new TB, I did mention in July my TB failed already. Running a Full Race EM + GTX3071R & CP-E IM + custom FMIC (TRV185 IC)

  10. I am also running a corksport turbo, corksport hpfp internals, corksport ends, corksport injector seals, corksport map sensor, and their 3inch intake, do you guys need anymore testers for final betas or finalized product? My throttle body has continually buzzed for a while now, like a long time and am looking to replace it. My second question is did you get any updated numbers on your corksport turbo tested car, and did these cars require tuning I didn’t see any mentioning of it.

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