Winter Mode – Rally Armor UR Mud Flaps

It’s not very often that we go out of our way to give a tip of the hat to another manufacturer’s product, but from time to time, there’s a product or service that we feel is deserving of our praise. This week, that product is from Rally Armor and it’s their model-specific urethane mud flap kits. At GrimmSpeed, we pride ourselves not only on engineering top-notch products, but also on creating an experience for the user that is second to none and that’s exactly what Rally Armor has done with these kits.

RA2

Here in Minnesota, it’s no secret that our winter months can be devastating to a car. The roads are frequently covered in snow, slush, ice or some mixture of the three and in all of those cases, there’s plenty of salt. The body shape of most Subarus is such that the front wheels, even traveling straight down the road, anything and everything at the side of the car. This leaves a nasty mess of salt across most of the car, making it look filthy and harder to clean. The best part, thought, is that they also seem to prevent the formation of large ice chunks in and behind your wheel wells, which can cause serious damage if you don’t kick them off before they freeze solid (and make a serious mess on your garage floor).

‘Winter Mode’ for most means a set of snow tires and fresh wiper blades. For most of the GrimmSpeed team, it also means mud flaps. Whether you appreciate the aesthetic or not, they make an excellently functional addition to a car that sees harsh winters, gravel, mud, etc.

RA3

Knowing that I wanted to protect my 2015 WRX as well as I could, I went ahead and ordered the black urethane kit with grey logo. They arrived quickly and were packaged very well. We take a lot of care in our packaging at GrimmSpeed and it’s easy to see that the folks at Rally Armos do the same, complete with a packaged by sticker just inside the box. Each component was nicely protected by plastic, paper or both and printed instructions were included.

RA4

Installation on the floor of the shop took 30min or so. No fancy tools, no lift, no previous experience with this kit. The brackets make perfect sense and install easily and securely. I especially appreciated how there was no modification to factory parts required. The included hardware replaced a couple of the factory clips, so I just put those in the hardware bag, labeled it and tucked it into the bottom of my toolbox. The mud flaps themselves are thick and durable, contoured perfectly for the application and feature slotted mounting holes for adjustment based on preference and precise bracket location.

RA5

In closing, I should probably note that we don’t sell Rally Armor products, nor do we have any sort of vested interest in their success. We’re simply passing along what we think is a functional and inexpensive product that meets a certain need perfectly. I’m very much a DIY person myself, and 6yrs ago, I may have attempted to hack together my own kit with cutting boards or some other nonsense, but for how quick and easy these were to install and the quality of the components, this kit is an absolute no-brainer!

RA1

If you’d like to see us review other products in a similar fashion, let us know! Cheers!

The Gift of GrimmSpeed – 2015 GrimmSpeed Gift Guide

Finding a holiday gift for the car guy or girl in your life is sometimes easier said than done. If they’re anything like us, then their automotive wish list is endless and ever-changing. Here at GrimmSpeed we hope to make things a bit easier by walking you through any product-related questions you might have, with some expert advice along the way. Give The Gift of GrimmSpeed this season and don’t hesitate to call or email us so we can help you make sure your favorite Subaru enthusiast gets exactly what they want this holiday season.

Gifts under $50

  • GrimmSpeed Apparel and Swag – A t-shirt, fitted hat, keychain or pair of license plate frames would make an excellent gift or stocking stuffer for the Subaru fan in your life!
  • Exhaust Gaskets – These might not look like fun to you, but to a Subaru owner, high quality exhaust gaskets are essential, especially if they’ll be installing new exhaust components this winter!
  • Bounty Hunter Sponsorship Kit – Challenge him or her to take part in the GrimmSpeed Bounty Program. The kit includes a shirt, sticker pack and registration to compete in fun challenges to win GrimmSpeed store credit!

Gifts $50 – 100

  • License Plate Relocation Kit – This is one of our most popular gifted products! Moves your front license plate to a less prominent location and eliminates the need for holes in your bumper.
  • Alternator Cover – An excellent GrimmSpeed-branded ‘dress up’ item that typically replaces the less attractive factory cover. Available in red, black or stainless steel.
  • Electronic Boost Control Solenoid – This is another very popular gift! Although most enthusiasts already own one, if your Subaru/Mitsubishi/Mazdaspeed nut is planning on getting tuned anytime soon, it’s a must-have!

Gifts $150 – 400

  • Catless Up-Pipe – An excellent way to free up pre-turbo exhaust flow and remove the restrictive factory cat. Also available with an external wastegate option – be sure to get the correct one!
  • Air Intake System – This seems to be at the top of everybody’s list this year. An upgraded intake system reduces restriction and allows for more power to be made during tuning. It also enhances the sound of the vehicle.
  • Air Oil Separator – Another very popular gift, available in red, blue and black. Be sure to check on which fitment is needed!

Gifts $400 and up

  • Downpipe/J-Pipe – This is the starting point for an upgraded exhaust system and is the piece that generates the greatest performance gains. Available with a number of options, you may need a couple of hints on this one!
  • Top Mount Intercooler – For that very special person in your life, a GrimmSpeed Intercooler is the cream of the crop where intercoolers are concerned. Rated to high horsepower figures, it’s an excellent fit for nearly all applications.
  • GrimmSpeed Power Packages – Available with a wide range of options, GrimmSpeed Power Packages offer a fully engineered system of modifications, designed to enhance the performance of your vehicle to a number of different degrees. A PERFECT starting point for a new enthusiast.

If you have any questions about items that are on the GrimmSpeed Gift Guide or our website, please contact us directly at sales@grimmspeed.com!

Wicked Big Meet 2015 Recap – Stafford Motor Speedway, CT

It’s been one week exactly since the GrimmSpeed team packed our rental with burgers, hotdogs and drinks for 700 people and only now are we coming down from the excitement and enthusiasm that we have for the Wicked Big Meet 2015 weekend. Held in Stafford Springs, CT, Wicked Big Meet is the largest Subaru festival in the world. In the world. In fact, it’s difficult to see just how big it is while your there, because in a single day, it’s not possible to take a look at every car on the grounds.

Our trip to Sam’s Club on Saturday morning!

As is now tradition, on the Saturday before Wicked Big Meet, the GrimmSpeed team and ECS Performance team up to host a Pre-Meet GTG where ECS opens their shop up to the public and GrimmSpeed mans the grill and provides BBQ goodies for all in attendance. This year, two of us manned a large commercial grill for 5 hours straight, grilling over 500 burgers and 300 hot dogs. This event has become a great way to kickstart the Wicked Big weekend and is a fun, relaxed atmosphere for us to shoot the breeze with our favorite people. At 7pm when the event ended, we had just run out of food and packed up out trusty tent and tables in preparation for a long day on Sunday.

grimmspeed booth wicked big meet 2015
Setting up our booth on Sunday morning – featuring Robert Champion himself.

Bright and early on Sunday morning, we arrived at Stafford Motor Speedway and began setting up our booth. Despite the already sore feet and tired voices, this is, perhaps, the most exciting part of the day. The hustle and bustle of all of the vendors settings up their tents, the rumble of Subaru engines far and wide and the growing line of show-goers, eagerly awaiting entry.

Premium ticket holders enjoyed the calm before the storm with early entry and had first crack at some crazy deals at the GrimmSpeed booth.

Folks that opted for premium tickets with early entry come pouring in at 9:00am, catching all vendors by surprise, but it’s the push we need to finish setting up and settle in for 8hrs of talking, teaching, learning and laughing. In our booth this year, we were joined by Khanh’s 2015 STI, outfitted with every GrimmSpeed product that fits and Robert’s wicked STI swapped forester. These are the men behind the madness and their cars are perfect evidence that they truly are ’bout dat life’. We were also thrilled to have Howie back with his super clean WRB GR STI. Howie also joined us at Boxerfest, earlier this year in MD and is somehow on his third set of wheels since then. Last, but certainly not least, was Caleb’s crazy BRZ. Caleb is a long time sponsored driver and those in attendance last year might recall his ‘incident’ with a track wall during the Autox event. He was back badder than ever this year in his race-prepped BRZ and booth-goers loved poking around his caged setup.

Shaded area was at a premium later in the afternoon and our tent became a popular spot for men, women, children and dogs!

The day was a blur and before we knew it, the crowd had migrated over to the awards and raffle. If you were part of that crowd, you probably missed the fun moments while vendors have some time to catch their breath and stumble around in a daze, wondering what had happened in the last 6hrs hours. We take stock of the product that we have left and begin tidying up the booth in preparation for the sprint to the finish. After the crowd has left, we tear down our booth area in record time, say our goodbyes and head back towards the hotel to clean up and find some dinner.

David Higgins signing Caleb’s dash!

A single blog post can’t possibly explain just how awesome this event is, so a quick list of highlights will have to do. We chatted with Hiroshi Mori (Director of Product Development with STI) as he admired the GrimmSpeed parts in Caleb’s engine bay. We saw a whopping 5800 Subaru enthusiasts come through the gate next to our booth. David Higgins, legendary rally driver, came straight from his win at STPR to give ride-alongs in the Subaru STI S206. Afterwards, he made his way to the GrimmSpeed booth to sign Khanh and Caleb’s dashboards. We saw $25k+ in raffle prizes given away. Subaru debuted the newest exciting color – Hyperblue. STI brought their 2015 24hr Nurburgring car to the states for the first time ever. The list goes on, but the only way to understand just how awesome this event is is to attend. Make it happen in 2016.

The STI 24hrs of Nurburgring car, stateside for the first time!

Finally, we owe Robert Champion, Khanh Hoon Duong and the entire WBM crew of volunteers a massive thank you. Around GrimmSpeed, WBM weekend is our Super Bowl. Although we do like to joke around and participate in the weekends shenanigans, we take the opportunity very seriously and there are no words to show the amount of appreciation that we have for what you guys put into this weekend each year. We’d also like to thank all of the other vendors and sponsors for their participation in helping make WBM the massive success that it is. Of course, WBM wouldn’t be what it is without you crazy Subaru fans (and I do mean crazy). The excitement and enthusiasm that we saw coming through the front gate all day is contagious and no amount of sales/profit/growth/etc could possibly overshadow the satisfaction that we get from seeing that. THAT is why we do what we do and you can expect to find us at Wicked Big Meet for as long as our feet and voices will allow it. See you next year!

Hiroshi Mori, David Higgins and the lucky winners of the S206 ride-along jumping for joy!

Boxerfest 2015 Recap – FedEx Field – Landover, MD

Whenever family, friends or acquaintances ask me what I do for work, I struggle to accurately explain to them just how unique and passionate our community of enthusiasts, manufacturers, shops and retailers is. They’re stunned to learn that there are enough people modifying their Subarus to support even a single person, let alone an entire industry of people developing, manufacturing, selling and installing parts. I’m sure this isn’t a uncommon conversation for people in the industry and even recall answering similarly themed questions when I was just an enthusiast myself from people that don’t ‘get it’.

If you don’t know what ‘get it’ means, you don’t ‘get it’. Keep reading.

IAG Performance TR-42 on the autocross course!

The GrimmSpeed team spent last weekend just outside of Washington DC for the second annual Boxerfest event at FedEx Field in Landover, MD. Boxerfest is one of four national events, organized by our friends at SubieEvents, that caters exclusively to the Subaru community. Manufacturers and vendors from across the country travel to take part in the festivities, meet their customers, display products and enjoy the sights and sounds that thousands of Subaru enthusiasts provide. Yes, thousands. In just it’s second year, Boxerfest 2015 attracted 2700 attendees, dwarfed only by Wicked Big Meet (held in Stafford Springs, CT), which drew nearly 5000 people in 2014. Other events include Big Northwest Meet in Portland, OR and for it’s first year ever in 2015, Rocky Mountain Subaru Festival in Denver, CO.

boxerfest 2015
GrimmSpeed donated $1000 in Gift Cards to the raffle!

Attending one of these events, or even just consuming the MASSIVE amount of media created by them, helps shed some light on just how big this ‘thing’ is. Jaws drop when I share photos of 3000 Subarus parked in the lot or of the vendor area packed wall to wall with people carrying boxes/bags/shirts/hats/etc. They begin to understand that our community is more than just a popular movie franchise from 15yrs ago.

subaru legacy gt airbags
Chuck’s Legacy GT sporting the newest GrimmSpeed TMIC.

The GrimmSpeed team flew into Reagan National Airport on Thursday night and spent the day on Friday checking out the area, visiting IAG Performance in Westminster, MD and helping pack thousands of goodie bags for Boxerfest attendees. The next morning, we were up early and and by 7am, we were at FedEx Field setting up our tent and assembling our display. At 9am when the gates opened, there was already a line of Subarus a mile long ready to rock and roll. For each event, we select a few local guys to join us at our booth and show off their cars. It’s always fun getting to know a couple of local enthusiasts a little bit better. They get top-notch parking and we always have new cars sporting our full product line to show off!

boxerfest 2015
Howie’s super clean GR STI brought a lot of attention to the GrimmSpeed booth.

We had a number of other favorites parked inside and outside of the vendor area as well. We’re car guys to core here and have no difficulty appreciating anything from a great stance on beautiful wheels to an all-out track build like the white STI gracing the IAG booth with it’s presence.

Another favorite of ours is Khanh’s 2015 STI with, literally, every single part that GrimmSpeed makes for his car. 

Enough words – I think you get the idea here. The bottom line is that the Subaru community is growing quickly and that these events are a great way to connect with fellow enthusiasts, see some cool stuff and even learn a thing or two. Nothing can describe our little piece of the automotive industry quite like a gathering this size.

Twin-turbo Subaru BRZ. Very slick setup.
Extremely well-sorted rotated EFR setup.
Super clean engine bay with a GrimmSpeed Boost Control Solenoid keeping that Precision turbo under control.
Subarus and Subaru fans as far as the eye can see. Friends, children, moms, dads, grandparents and even puppies!
subaru svx
Definitely the wildest Subaru SVX we’ve ever seen!
Of course, the event was serviced by a handful of local food trucks!

Thanks for reading! We’ll be recapping each of this years events, so keep an eye out for more! For more photos, visit the GrimmSpeed album on Facebook or visit the Boxerfest page for a number of the day’s albums.

GrimmSpeed Sponsors Dai Yoshihara’s 2015 Formula Drift BRZ

It is with an unhealthy amount of excitement that we announce GrimmSpeed’s official sponsorship of Formula Drift veteran, Dai Yoshihara’s BRZ for all seven rounds of the 2015 season. Dai’s Falken Tire x Turn 14 Distribution Subaru BRZ is sporting a new livery for the season that maintains the classic Falken Tires scallop design but integrates the corporate colors of this year’s co-title sponsor, Turn14 Distribution. When those Falkens aren’t creating a massive amount of tire smoke, you’ll find the GrimmSpeed logo anchoring the rear of the car. That may not be too often and were OK with that; we love us some tire smoke.

dai yoshihara grimmspeed

GrimmSpeed has always been a huge supporter of grassroots motorsports and up-and-coming drivers, having sponsored some of the nations fastest time attack and rally drivers ‘back in the day’. Many times, as those drivers find larger success, they also find larger sponsors. We take pride in supporting the smaller guys and are happy to ‘set them free’ as they advance, but we’re also very excited to be a part of a small group of sponsors that are supporting one of the biggest names, Dai Yoshihara, in Formula Drift this year.

Throughout the season, you can expect to see GrimmSpeed covering Dai’s season with race recaps, technical discussion and other assorted shenanigans. Let us know what else you’d like to see!

2015 Formula Drift Competition Schedule:

Streets of Long Beach (Long Beach, Calif.): April 10 – 11
Road to the Championship (Braselton, GA): May 8-9
Orlando (Orlando, FL): June 5-6
The Guantlet (Wall Township, NJ): June 26-27
Throwdown (Monroe, WA): July 24-25
Showdown (Fortworth, TX): August 21-22
Final Fight (Irwindale, Calif.): October 9-10

sponsors

Introduction: 2015 Subaru WRX 3-Port Boost Control Solenoid

If you’ve been in the Subaru game for long, you’re probably well aware that a 3-port Boost Control Solenoid (BCS) is considered my most to be a ‘must have’ improvement before having your car tuned. GrimmSpeed has become the trusted brand in the BCS market, with tens of thousands of solenoids in operation today across the globe.

The 2015 WRX offers a unique change of pace, as the factory 2-port solenoid is mounted directly to the plastic turbo inlet and interfaces with an o-ringed feature, rather than a vacuum hose. With expertise in designing machined parts and a tried and true boost control solenoid, we were excited to dig in and create a solution with an already proven pedigree of high performance and quality.

GrimmSpeed 2015 WRX BCS

GrimmSpeed 3-port BCS 2015 WRX

GrimmSpeed 2015 WRX Solenoid

Enter the GrimmSpeed 2015 Subaru WRX 3-Port Boost Control Solenoid, the first and only of it’s kind.

We began by recreating the factory turbo inlet and solenoid in CAD to ensure a perfectly fitting system. From there, we designed a beautifully fitting machined adapter that would recreate the o-ring sealing feature that the factory solenoid uses. This bracket features 1/8 NPT threads so that both barbed fittings (included) and AN fittings can be used interchangeably, for use with the GrimmSpeed BCS, Manual Boost Controller, or other boost control solutions.

A small mounting bracket secures the solenoid to the machined adapter, to create a compact system, while still allowing those interested in running other boost control solutions the flexibility to do so. Mounting the solenoid directly in place of the stock solenoid allows for vacuum hoses of similar length and a shorter wiring harness. We contemplated the option to make a fully integrated solenoid, but decided that creating an adapter and mounting solution allowed people to use a solenoid that’s already been heavily tested and that tuners are familiar with. One possible change between now and production is to integrate the BCS mounting feature into the adapter. Cost and complexity will determine if that’s feasible shortly.

GrimmSpeed 2015 WRX BCS

2015 Subaru WRX Boost Control Solenoid

2015 wrx boost controller

Lastly, we worked to identify the exact electrical connector used on the stock solenoid so that the GrimmSpeed solution would be a true plug and play (differs slightly from the connector pictured). After that, we went ahead and built prototype and pre-production units.

2015 wrx boost control solenoid

As a brief overview of the advantages of a 3-port boost control system vs. the factory 2-port system, the 3-port systems works by interrupting the boost signal traveling from the turbo to the wastegate. That boost is redirected back into the turbo inlet (post-MAF sensor) and re-ingested by the turbo. The factory configuration simply ‘bleeds’ the signal from between the turbo and wastegate which creates a system that is a bit less complex, but reacts more slowly and with less precision.

We’re currently finalizing the detailed design and moving into production. As soon as we have an estimated release date (expected 2-3wks), we’ll begin accepting pre-orders at a discounted group buy price. We’ll start a different thread for that when the times comes, so for now, let’s keep this discussion technical.

The next step is to get a small initial batch of solenoids into the hands of your favorite local tuners. If you’re a tuner yourself or you’d like to nominate a tuner for receipt of a prototype unit, please comment below and we’ll add you to the list. From this list, we’ll select testers based on experience and geographic location.

Top Mount Intercooler Test Results – Part 1: OEM vs. GrimmSpeed

The moment many of you have been waiting for – top mount intercooler test results! In testing and developing a heat exchanger, there are countless bits of data to collect and analyze in order to facilitate the decision making process, but when it comes to evaluating the final product, performance can be quantified with relative simplicity. Everything boils down to temperature and restriction. The intercoolers primary duty is to lower and control the temperature of the hot charge air leaving the turbo and running through the intercooler. This is the first test that we performed on both the stock unit and the GrimmSpeed unit.We setup this test to simulate a real world scenario that’s typically demanding of an intercooler. The test vehicle is a 2012 WRX with a GrimmSpeed downpipe, boost control solenoid, prototype intake and tuning. On a closed course, we accelerated in 3rd gear from 3000rpm to redline repeatedly, with 5-8sec between runs. Temperature was logged via k-type thermocouples between the turbo and the intercooler and between the intercooler and the throttle body on both units. Ambient temperature here in Minnesota for both tests was between 20 and 22 degrees F.The results above speak for themselves, but here’s a breakdown. The phase differences between the runs are a result of how quickly we could safely get the car back down to speed for another run, but the important thing to notice is the magnitude of the temperature fluctuations. Predictably, both intercoolers were seeing similar Pre-IC temperatures on each run (180-190F peak), but while the GrimmSpeed TMIC kept Post-IC temperatures between 30-40F the entire time, the OEM TMIC fluctuated between 35-75F. This is the kind of consistent cooling that you should expect from a high quality TMIC and is a function of the geometry and design of the bar and plate core. Our high density core has a massive heat transfer surface area but maintains a large enough cross-sectional flow area that there’s no added restriction.

What’s Next – Pressure Drop, Aftermarket TMICs and Warm Weather Testing

The second part of our final testing will be to measure the pressure drop across each intercooler to demonstrate that the increased cooling performance comes with no sacrifice in flow rates. We’ll also run the same tests with a couple of other aftermarket TMICs. You can expect to see these results in the coming week. Lastly, in the spring, we’ll complete all of this testing again in warmer weather to show that the same effectiveness can be expected, regardless of ambient temperature. We’ll also try to find it’s limits with our 600whp STI.

Casting Intercooler End Tanks – A Day at the Pattern Shop!

Pattern Shop Newsletter 1_630

The photo above shows the machining of the TMIC outlet end tank master. The Bottom received a finishing pass and then the part was flipped so that the top could be roughed out. When all is done, this will be a flawless part. Now that the master parts for both end tanks have been completed, we’ll make a cast iron match plate from each of them. You probably noticed that it looks a lot like they’re being machined from wood and that’s because they are! These master parts will only be used a single time – to cast the real molds from, so a heavier duty material only costs more and takes longer, with no added value.

Interesting Note: The master that you see here is not dimensionally identical to our final part – it’s actually larger. Based on the foundry’s preferences, standard shrink allowances and the geometry of the model, the pattern makers job is to determine how much the cast aluminum part will shrink/contract during solidification. An easy way to cut cost, especially if you’re casting overseas, is to skip this step. Ever had an application-specific intercooler that didn’t fit quite right? There’s a decent chance that uncontrolled shrinkage was at least partially to blame.

For those unfamiliar with high end casting processes, creating the tooling and molds is the giant hurdle standing between your design in CAD and real parts. With properly designed and manufactured tooling, casting and machining the parts is relatively straight forward. One of the many benefits of casting right here in Minnesota is that we’re able to sit down with everybody involved and work through potential issues to mitigate the risk of trouble during production almost entirely. That means lower production cost for us and lower pricing for you!

GrimmSpeed Downpipe – Frequently Asked Questions

grimmspeed wrx downpipe

There’s are certain questions that we typically get from customers, regardless of the product being discussed. Instead of making you call or email for an answer, we thought we’d address a few of the heavy hitters right here so that the information is available to you 24/7.

Question: I’m planning on going Stage 2 with my car, do I really need an aftermarket downpipe to run higher boost and make more power?

Answer: Yes! The purpose of an aftermarket subaru downpipe is to remove restriction from your exhaust system. In the stock downpipe, that restriction comes in a three different forms. The first and most important is that the factory downpipe contains highly restrictive catalytic converters. Aftermarket downpipes generally either remove the catalytic converter all together or replace it with a much higher flowing unit. GrimmSpeed offers options for both. The second restriction is a result of the design of the turbine outlet flange. The OEM flange is a flat plate, obstructing exhaust flow from the IWG and forcing it to merge with exhaust from the turbine immediately. As soon as you’ve seen one, you’ll know what I mean. The third is in diameter. Stock downpipes use a smaller diameter tubing than most aftermarket downpipes. If the purpose is to remove restriction, the reason for larger tubing is clear. Even a small increase in internal diameter has a large impact on the total flow area of the tube.

grimmspeed subaru downpipe engineering

Question: Ok, so I know I need an aftermarket downpipe. There are a bunch of different styles. Do I want bellmouth or divorced?

Answer: This is where things get a little bit tricky, because you’ll get different answers depending on a person’s personal opinion regarding the proper design of a subaru downpipe. It’s important that you understand the pros and cons of each and make an educated decision for yourself. To be clear, both will do what you want, which is to unlock some serious power potential, but there are differences that can facilitate more efficient tuning and better boost control that are equally important. The reason that we’ve gone with the divorced design, despite the increased cost and complexity, is that we believe that it’s the best, plain and simple.

Imagine that your downpipe is a freeway, your turbo is a tunnel and your internal wastegate is traffic trying to enter the freeway. On a typical freeway, a car would use an on-ramp to get up to a proper speed and direction before merging with traffic in a controlled manner. That is exactly what a divorced subaru downpipe, like the GrimmSpeed unit, facilitates. Our divorced tube is the perfect length for the exhaust gases from your IWG to merge with the rest of your exhaust with minimal turbulence. Any shorter, and the exhaust from your turbine is still recovering from leaving the turbo, expanding into a larger tube and making a turn down towards the ground. Any longer and you’re simply adding unnecessary cost, material, weight and complexity to the assembly. Now, imagine that the traffic entering the freeway simply enters from a stop sign. We’ve all had to make that nasty right-hand turn during rush hour, don’t make your exhaust do the same. Good, predictable exhaust flow for your internal wastegate will ensure that you are also able to create good, predictable boost control.

grimmspeed sti downpipe faro arm

Question: I have X downpipe right now and i didn’t have any trouble installing it, but I just can’t get rid of my exhaust leaks now.

Answer: This is something that we hear very often. Persistent exhaust leaks of this kind often come from flanges that are severely warped or from parts that don’t fit properly. Creating exhaust components that fit perfectly is more complex than most people (and other manufacturers, it seems) realize. Designing a part that installs easily is one thing. Engineering a part that installs easily, has appropriate clearances from other components and has nice, relatively flat flanges that are are at exactly the right angle to create a perfect seal is a bit more difficult.

Here’s where GrimmSpeed’s engineering process emerges miles ahead. Other manufacturers create their welding fixtures from an OEM downpipe to match it exactly. Sounds great, right? Wrong. We’ve been engineering top of the line exhaust components for a while now and we’re going to let you in on a little secret – Subaru isn’t perfect. In the design of this downpipe, we used our FARO Arm to 3D scan a handful of OEM downpipes and saw that from pipe to pipe, there was a significant amount of variation. We bring all of this data in CAD, overlay the scans, and then find the average of each flange location. We then design our pipe and build our fixtures to that average, instead of a single downpipe. This ensures that our tolerance range is at least as tight as the OEM, with no GrimmSpeed downpipe ever fitting worse than an OEM part. On top of that, we also use our FARO Arm to 3D scan the areas of each test vehicle affected by the downpipe. This ensures that we have proper clearances for the firewall, O2 sensors, transmission bracket, subframe and so on.

Question: So what sets the GrimmSpeed Subaru Downpipe apart from other downpipes that get decent reviews but are a little bit less expensive?

Answer: This is where you’ll have to use the information that we’ve shared to make an educated decision for yourself! If you’ve made it this far, you already understand the care that we take in our design and manufacturing processes. Now, we’ll overlook fitment and design and consider just build quality. All of our materials are top-quality, Made in the USA stuff. Aside from the obvious benefits of supporting local and domestic business, this means that we know exactly what we’re using to build these downpipes. All “Stainless Steel” downpipes are not created equal. Our 3″, 16ga tubing is beefy and our 1/2″ 304 stainless flanges are the thickest and flattest around. Thick flanges help us avoid warping during the welding process and ensure a fantastic seal to your turbo.

We periodically check our fixtures for accuracy using our 3D scanning equipment, to ensure that over time, it hasn’t pushed or pulled from the heat cycling. Each downpipe is welded by hand just feet (literally) from where they were designed and developed. Robotic welding looks great, but in an application like this, nothing can replace the skilled hand of a true craftsman. This type of welding requires that changes be made on the fly to ensure not only a cosmetically excellent weld, but more importantly, a structurally flawless one.

grimmspeed exhaust welding tig

The bottom line is that we’re all Subaru enthusiasts here. We get it. We’ve all had the ‘budget’ downpipes at some point and while some of us have had fine experiences with them, others of us have not. We take pride in developing and manufacturing products that we know won’t let you down in 5 days, 5 months or 5 years from now. A GrimmSpeed downpipe will outlast your car and we stand behind each one that leaves the shop 100%.

Need help with which GrimmSpeed Subaru Downpipe will work best for you? Check out the links below for more information on each fitment.

http://www.grimmspeed.com/downpipe-02-07-wrx-sti-fxt/

http://www.grimmspeed.com/downpipe-catted-02-07-wrx-sti-fxt/

http://www.grimmspeed.com/downpipe-08-wrx-sti-fxt-lgt/

http://www.grimmspeed.com/downpipe-catted-08-wrx-sti-fxt-lgt/

Restriction in the Stock BRZ/FR-S Intake – Results

Procedure:

We wanted this testing to be performed on the road to obtain real world data, as opposed to on a dyno. This method would allow the air dam to obtain actual flow to be received from moving at realistic speeds on the street. The conditions were less than ideal for tire grip (28 degrees F), so tests with tire spin were immediately thrown out and retested. However, since we’re measuring differential pressure the high density of the air due to the low temperatures has no effect on the overall pressure reading.

The test was performed the same each time, on the same stretch of road. The road was uphill, which is beneficial to increase the time of each pull in order to have a better chance of obtaining accurate sample data to combat the low sample rate of the manometer’s datalogging capabilities. We started off in first gear, rolling into the pedal to wide open throttle to avoid wheel spin, shifting at 7300rpm into second gear, straight into wide open throttle, shifting again at 7300rpm, and immediately into wide open throttle through all of third gear. Each run took approximately 14 seconds to complete. We performed this test 3 times for each configuration, measuring pressure drop from:

  1. Snorkel inlet to airbox inlet
  2. Front of airbox to rear of airbox (filter)
  3. Rear of airbox to entry of intake elbow (MAF housing)
  4. Entry of intake elbow to throttle body
  5. Snorkel inlet to throttle body

These runs were performed back to back on the same day, stopping each time briefly (less than 5 minutes) to save the datalog file to the computer, and/or to change pressure test locations on the intake tract.

Results:

grimmspeed stock airbox testing

This graph shows what happens across first through third gear, which is clearly shown by the fact that all five components have three clear humps, each with longer durations. These occur during wide open throttle, and the dips show the pressure approaching 0 between shifts. This graph also shows why having such a low sample rate makes for poor data, but we’ve made up for it by increasing the amount of trials. The fact that the graph maxes out for the overall system at about 9.5in of H2O in all three gears shows that that value is most likely correct for the overall system. Same goes for each of the individual components of the system; in each gear they seem to have the same maximum value. The graph also shows that restriction increases as RPMs increase, because as RPMs increase so does the required flow rate. The short duration of first gear shows the weakness of the sample rate, as the peak numbers of the individual components do not exactly match the peak numbers of each component in second and third gear. For this reason, the graph is most accurate for the third gear section (approximately 9 through 14 seconds), and shows a nice curve instead of a quick peak. However, for illustration purposes, showing all three gears shows that the pressure drop is RPM dependent and not speed dependent as would be initially expected. One would expect more air in the front air dam from the increase in speed to change the results in each gear, but clearly it does not.

This graph also does a good job of “double checking our data.” Remember that the orange line (Snorkel to Throttle Body) is the overall restriction of the system, and that it is the sum of the individual components. The graph of this curve is real world data, and is not simply the overall curves added together in Excel. However, if one were to measure the peaks of each gear for each individual component, and add them up, they would find that they total up to about 9.5in of H2O, which is what is shown to be the peaks of the overall system.

The effect the snorkel had on the system was very interesting. The snorkel showed a consistent pressure gain of about 3in H2O. The fact that the inlet is smaller than the outlet lends that the decrease in velocity of the air as it passes through should increase the pressure. However, the fact that this number is nearly high enough to cancel out any one other component’s restriction shows that in stock for the intake is very well designed. Each other component seems to have a restriction of about 4in H2O (air filter, MAF housing, intake elbow).

Conclusion:

This answers a lot about the perceived weakness and the performance of the stock intake. It also goes to show that since the pressure drop doesn’t seem to be dependent on vehicle speed that all of this testing could have been performed stationary while strapped to a dyno. Removing the snorkel should yield no performance gain, but leaving it in could be compared to removing the air filter, or the MAF housing, or having a lossless intake elbow. However, all of these perceived restrictions really are not that bad. Each component having a restriction of 4in of H2O is really only equivalent to about 0.144psi, with the total intake’s restriction being equivalent to about 0.342psi. If I were to perform some completely fake equivalency math, and say that this car makes about 165whp in stock form, and at one atmosphere (14.7psi), a restriction of this size would be equivalent to about 3.84whp. So we would expect to see a gain of only about 3.84whp if we were to create a completely lossless intake system that acted at the exact same air to fuel ratio. However, luckily that math is completely fake, and just for illustrative purposes as there have proven to be larger gains than that achieved without creating a theoretical “lossless intake.” This is true because there are so many more contributing factors than just reducing pressure drop on an intake that is already well designed.

Chase – Engineering