Performance Turbo Exhaust Manifolds – Tubular or Cast?

If you have been in the car scene for a while, you have probably seen or heard of performance exhaust manifolds.  Like any other component on the engine that affects flow, performance exhaust manifolds can have a significant improvement to the engine’s peak performance and power under the curve amongst other aspects that the exhaust manifold can affect.  

You have also probably asked the question. “What type of exhaust manifold do I need?” In this blog, we at CorkSport would like to help you better understand the differences between cast and tubular so you can make the best decision for your Mazdaspeed.  

There are two main styles on performance exhaust manifolds; tubular and cast. Both have their pros and cons to consider as an end user (that’s you the enthusiast) and as the designer/manufacturer (that’s us at CorkSport).   

First, let’s look at tubular as it’s the most common in the performance industry.  Tubular is the most popular option because of it manufacturing flexibility.  Unlike casting, tubular does not require expensive molds to develop even a single prototype. Not needing expensive molds allow great flexibility in design and manufacturing, which lends the tubular manifold as an exceptional option for one-off builds.  

To fabricate a tubular exhaust manifold you need just the raw components: flanges, tubular sections, collector and fabrication supplies, and of course the expertise to fabricate the manifold.  Let me emphasize the necessity of fabrication skills here. To produce a reliable and performance proven tubular exhaust manifold takes the correct skills, tools, and patience…it’s honestly a work of art.  

With this work of art does come some compromises.  To create the necessary runner routing, many tubular sections will need to be welded together.  This increases the chance for weld impurities and slag which can later result in cracking and poor performance.  Any reputable fabricator should be able to avoid this, but it does come at a premium due to the many man hours that must go into each and every manifold.  

Next up is cast.  Manufacturing via casting provides a different set of opportunities and difficulties to overcome.  The process of casting alone has restrictions that must be considered; such as mold design and molten flow in the casting.  Assuming these issues are overcome casting can provide unique opportunities for the design to improve reliability, performance, and packaging.  

A well-designed cast exhaust manifold can have great reliability due to its one-piece design.  There are no welded joints that can crack or fail and casting typically has a higher threshold to heat before issues arise.  The wall thickness of the casting can also be defined for the application which can improve strength if the exhaust manifold is the only part supporting the weight of the turbocharger.  

Overall performance can also be affected due to the casting design flexibility with each runner.  Unlike tubular, a cast is not restricted to standard tubular elbows and straits. The runners can bend and change profile as desired to aid in performance and packaging.  

Speaking of packaging, casting can really change the game here.  Since each runner does not have to be accessible for welding, the entire design and each runner can be tightly packaged together to reduce the overall size of the exhaust manifold and better retain heat which aids with turbocharger response.  

Lastly, comes the cost to you the enthusiast.  Although the upfront cost of a cast manifold can be high, typically the unit cost and necessary man-hours are low which helps keep cost down for you.  

As a designer and manufacturer of performance parts for you Mazdaspeed, these are all things we have to consider providing you with the best parts possible.  We’ve explored both and are happy to stick with casting as we feel it provides the best balance reliability, cost, and performance. Keep a look out for future projects and updates!

Thanks for tuning in with CorkSport.

-Barett @ CS

Versatune Packages for Mazda MX-5 Miata

Despite not being the ideal season to pull the top down, we have been busy giving the CorkSport ND Miata some love.  Unfortunately this love does not come in the form of another CorkSport Performance part, but instead better takes advantage of your CorkSport Performance parts thanks to the Versatuner Tuning Solution.  

With that, we are proud to announce our partnership with Versatuner and the ability to provide to all models supported by Versatuner.

Back to the 2016+ Mazda MX-5; working with the Versatuner Tuning Solution we setup pre-calibrated tunes that are designed to work with the CorkSport Performance Cold Air Intake System, Cat-Back Exhaust System, and the combination of the two.  

Jumping right to Power Pack 3, that combines the CorkSport Cold Air Intake and Cat-Back Exhaust; you see a power increase of 9 wTQ and 13 wHP using 92 octane fuel.  These aren’t just peak gains either, power/torque increases from 3000rpm up to redline which has been increased to 7400rpm.  If you are not ready to pull the trigger on the CorkSport CAI and CBE together, then check out Power Pack 1 and Power Pack 2.  

Power Pack 1 offers a combination of the CorkSport MX5 Cold Air Intake and Versatuner Tuning Solution with a pre-calibrated tune.

Power Pack 2 offers a combination of the CorkSport Mx-5 Cat-Back Exhaust and Versatuner Tuning Solution with a pre-calibrated tune.

What’s great about the Versatuner Tuning Solution is its flexibility to provide data logging, tune editing and diagnostics troubleshooting with any installed parts and any fuel type.  The CorkSport pre-calibrated tunes are designed for 92 octane fuel, so we do recommend having a custom tune performed for your MX-5 if 91 octane is the highest grade fuel available in your area.  Those of you with 93 octane fuel need not worry, but there could be more to ring out of your little 2.0L Sky-G with custom tuning.

Lastly, you might be wondering why the Power Packs have any significance to you? Well along with power, aesthetics, and glorious noises, we are able to cut you deal when you get the combination of CorkSport Performance parts and Versatuner Tuning Solution.  We’re here to make modifying your Miata easy and fun.

Thanks for tuning in with CorkSport Performance.

-Barett @ CS

New Year, New Gains

As the New Year rolls around, most people are looking for a change for the better in their lives.

At CorkSport we think one of the best changes you can make is more power for your Mazdaspeed. We have all the parts you need to liven up your Mazdaspeed3 or Mazdaspeed6 in 2018.

Safety First

One of the first things to consider when modifying your Speed is the health of its engine. Performing maintenance is very important but it only gets you so far. When adding power, one of the first modifications on your list should be the CorkSport Max Flow Fuel Pump Internals.

These pump internals allow you to maximize your stock fuel system for optimum power capabilities and safer than OE A/R ratios. This means you can add the power you want and have peace of mind that your engine will get the fuel it needs.

Put the Power Down

Like the CS fuel pump internals, the CorkSport Stage 2 RMM for Mazdaspeed 3 will not directly increase the power levels of your car; however, it helps you put all that hard-earned power down. By decreasing the amount the engine can rotate, the Rear Motor Mount allows for reduced wheel hop and torque steer while providing faster throttle response and crisper shift feel.

Even we are surprised how much this engine mount changes how a Mazdaspeed 3 feels. Don’t worry Mazdaspeed 6 guys and gals, we have an RMM for you too.

 

Improving Airflow

Engines in an extremely simple sense are air pumps; so the faster you can get air in and out of the system, the better. That being said, some of the simplest and easiest power gains you can get from your Mazdaspeed are from upgrading the intake and exhaust. We have seen peak gains of 25ft-lbs and 33WHP from only the CorkSport Stage 2 Intake and a CorkSport Racepipe.

Checkout the dyno sheet below.

Power and torque levels will be further increased if you install a full CorkSport Turbo Back Exhaust instead of just the race pipe section.

The catback exhaust section has proven to gain up to 14WHP while the downpipe section alone has proven to gain up to 21WHP. In the dyno graph below, the downpipe car had a CorkSport Intake installed at the same time as the downpipe (hence the 50hp gain).

If that wasn’t enough flow for you, we also offer 3” and 3.5” intakes for even more airflow into your turbo. Keep in mind though, once you get into those you will need to use a new tune to ensure your car runs optimally. But check out the extra flow you get!

Turbo Upgrade

The CorkSport Drop-In Turbo is a fantastic upgrade to the stock K04 turbo that allows your car to make more power on an equivalent boost pressure. It will work with any mods you already had on your OE turbo as the CS turbo is truly a drop in upgrade. With supplemental tuning, fueling, and supporting parts, you can push your Speed to its limits.

The Next Level

CorkSport also manufactures parts that can take your Speed beyond the parts discussed above. A short list of the parts with the best power gains can be seen below:

  • CorkSport Intake Manifold: A higher flowing IM can support much more power than the relatively restrictive OE unit. Best when paired with a larger throttle body.
  • CorkSport Camshafts: Replacement cams with extra lift to provide increased power and torque across the entire RPM range.
  • Bigger CorkSport Turbo? Yes, there is one in development. See this blog post for details.

No matter what your goals are for 2018, CorkSport is here to help you achieve them. Whether you just picked up a Mazdaspeed and are unsure where to start, or have been driving one for years and want the excitement you once had back, CorkSport has a part for you.

 

Daniel

CorkSport Engineer

25 hours of Thunderhill

25 hours of 69

For many people across the USA, the days after Thanksgiving means one thing. To them, it’s the start of the Christmas season. The beginning of holiday shopping, pumpkin spice lattes, and the best home cooked meals you can’t wait to dive into.

However, for a small select few group of individuals and teams, it’s a time for something completely different. It’s a time to see what you are made of, a time to put it all out on the table. A time where you know if the past year of planning, testing, and preparation are about to reward you greatly or tear you down completely. It’s the time where you hope to be able to stand up on a Sunday at noon and can say proudly “I survived the 25.”

For those lucky few (some call them crazy or stupid) the weekend after the Thanksgiving Holiday is what you might call a different type of holiday.

For the past 15 years, the 1st weekend of December is when some of the worlds best pro and amateur drivers descend upon a small city in Northern California known as Willows. Just on the outskirts of this quaint little city lies a little well-known road course titled merely “Thunderhill.” Now what makes Thunderhill so unique, well it’s probably the fact that this venue host the longest and most extreme endurance race in all of North America. For 25 hours straight; teams, coaches, drivers, and fans endure the rain, cold, dark, lack of sleep and more to try and make a name for themselves, and this year CorkSport did just that. Made History…

 

 

While attending the 25 Hours of Thunderhill is nothing new for CorkSport as we have spent the past several years supporting Mazda North America and their racing efforts with logistics, crew, and parts. This year was the first year where we entered a new team ourselves and brought our car, crew, trailer, and everything else you need to try and survive 25 hours of racing.

Sadly MNAO did not attend this year so it was up to us to make sure that the brand and name would make a forceful showing at the event and that is precisely what we did.

 

 

To start this whole thing off, we brought out our 2016 Mazda 3 GT. You guys are more than familiar with this car as Co-owner, and founder of CS Derrick Ambrose has been piloting this ride for two race seasons now in SCCA racing. We spent several weeks leading up to the event preparing the CorkSport Mazda3 for this daunting task.

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We got extra safety equipment installed, upgraded our data acquisition package, optimized and engine tune for the  2.5L engine, and even installed some upgrade prototype pieces to have the car suited for the race.

Some of the CS goodies that were on the car during the run where our SRI, Cat-back exhaust, RMM, sway bar, and some prototype pieces like our aluminum skid tray and upgraded transmission engine mount. We needed the best parts we could get in there if we wanted to be competitive and make history.

No one has ever raced the 3rd generation Mazda 3 for this long in any endurance race. This car started off just like any other Mazda 3 and still retained a full OEM chassis, transmission, and engine. The engine internals where untouched and the transmission received a CorkSport LSD.

 

The team showed up on a brisk and cold Thursday morning, and we went to work. We immediately set up and got the drivers briefed. We got some practice in on Thursday followed with some qualifying on Friday all to be prepared to push this car to the limit for 25 hours. The team grabbed the pole position, and we were 1.5 seconds ahead of the next car which was fantastic. It showed we had the pace and ultimately the faster car. Fast forward to Saturday, and the flag drops green.

We had a great start and excellent drivers in the car. We struggled a bit through the night with consuming tires at a rate faster than we had anticipated and also had a few issues with how quickly we could get fuel into the car, despite the problems the team and the car pushed through the night. With just a brake change and tweak to the exhaust through the night, we maintained a good pace that ultimately got unwound due to the fuel issue mentioned above.
There was a Miata in our class that could get better fuel economy and tire consumption and slowly crawled there way up to lead during the night.

As the sunlight begins to break through, we are in a healthy 2nd place but a bit far off the leader, however, it does not worry us too much as we still have a shot at a win. Things were looking good till right about hour 22. One of our driver’s radio’s in and let us know he lost 4th gear (that’s not good). None the less we keep pushing knowing we have a spare transmission should we need to swap.

 

Now at hour 23 we get another message. “I lost 2nd gear” The transmission has now lost two gears, and we get a bit nervous. The car is still going and driving strong but our lap times do suffer from not being able to use all of the gears. After a quick powwow with the team, the decision is made to leave the car out on track and finish the race between 3rd and 5th gear.

With only 2.5 hours to go swapping out the transmission did not make sense as we were very secured in 2nd place. So we did just that and pushed on through, and you know what happened? We did it. While we didn’t get the P1 spot like we had wanted we did what no other SKYACTIV-G Mazda3 had done before.

We survived the 25. We proved the chassis and the platform, we pushed harder, longer, and further than absolutely anyone else has. The car was relatively unscathed, and minus the transmission, the vehicle performed excellently. All of the CorkSport parts did precisely what they needed to and outperformed all expectations.

We took the 3rd gen platform and solidified it as a competitive car and chassis that can be used and used well at all levels of motorsports.

So, what happens next?

The Mazda 3 made it back home and now lay dormant inside of HQ. We will be spending the next few weeks going through a ton of data and running through the car with a fine tooth comb.

We’ll take the transmission apart and see what her demise was. We’ll likely strip the SKYACTIV 2.5L down as well to check out what two years of racing looks like on her. The oil is already out of the car and on its way to the lab so be sure to stick around and see what we find out there.

Now one of the great things about this is what our success brings to the community. Everything we learned here can and will be applied to all of our parts and products moving forward. When we win, you guys all win. So, celebrate our accolades with us and wish us luck as we begin to prepare for the 2018 race season.

 

Do we tackle the 25 hours again next year? Do we show up with a turbocharger and more aero? And do we fight our ways to a P1 finish? You better believe I am going to try.

 

-Vincent  

My CorkSport Mods: Keith’s Mazda 3 Sport

I’ve met a lot of amazing people thanks to my Mazda 3 Sport, but Yolanda Sampson (Instagram: @bluehalogirl) is the one I blame for this addiction we call “modding.” When we met, I hadn’t done much to my car yet, just a couple minor things like tinted windows and tinted taillights. She had a feeling I’d be into meeting some more like-minded locals and invited me to a meet. We got along like only two Mazda nuts could, and it was game over for me.

Mazda 3 Sport

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