We’ve been working on our twin turbo LS3 Corvette for a while. Using the APS base kit, we have been limited by the original T25 turbines for a while, even with a great engine combination. Stuck making around 660-680rwhp, we were left explaining a bit.

Until now.

Nick over at Turbo Concepts helped execute the upgrade we’ve needed for a while. Machining the housings for larger 60m turbines and filling them with modern “5-blade” wheels uncorked a major restriction point. Our older setup was seeing 24psi of backpressure to the engine at 660rwhp. These have only about 17psi of backpressure at that same flow point.

Even better, flow was able to jump MUCH higher with the turbo upgrade. We now see over 77#/min of airflow through the engine, while lambda stays right on target at 0.78 for safety. E80 fuel lets us add more oxygen and knock resistance to the party. The results were nothing short of surprising. So much so that we didn’t initially believe out eyes and ran it again:

We seem to have channeled our inner Bob Ross with this happy little accident. The weird part was that reported MAP was much lower than we expected. We’ll tackle that in more detail later, but let’s just say the the Brian Tooley Racing stage 1 cam is certainly breathing better now. THIS is what most of us expect when we hear “twin turbo LS3 with a decent cam and E85”.  Over 100rwhp increase from changing turbos was an absolute eye opener for sure. Making over 800rwhp (on a Mustang Dyno!) through a set of GESI Cats is the icing on the cake. This wall done using the same calibration techniques we teach over at our STREAMING SITE and use with our clients in person. No black magic, just solid fundamentals and a clean tailpipe.

Now we just need to clean her up and get ready for HOT ROD Power Tour. Look for us anywhere along the long haul and say hello. We might even get to the HPTuners midway booth if we can make it on time.

ICYMI – Flyin’ Miata NC Turbo Kits are a Thing Now

One of our favorite clients, Flyin’ Miata, has released their all new NC turbo kit. If you’ve been following us, you saw the work we did a while ago on Mike’s white Miata. The test vehicle even made it to a few local Detroit area events as we were polishing the tune on it. After a bunch of behind the scenes work, we’re proud to announce that our client has the right CARB emissions testing completed. The FM guys have finally ironed out all the supply chain bugs and have kits on the shelf ready to ship now.

Of course, we can get you one here and even install it too, since we’re the FM Michigan outlet. Kits currently start UNDER $5k – an incredible bargain considering how many smiles per gallon one gets from this hardware. We tested with the smaller turbine housing, but the larger .86 A/R gets our recommendation in such an already responsive car like the NC Miata. This kit has everything you need in one package. There is no need to go shopping separately for fittings, fuel system, or tuning. Even better, they released the new turbo kit at 11psi instead of the older kit’s 8psi. Don’t worry, it’s still plenty safe on your stock hardware. Better flowing exhaust will only make it that much more impressive though, and the kit will just keep going. FM has also taken this kit to the road course to prove out durability. It just works everywhere.

Lots more info HERE. You can also order one from us directly. On site installation is also available.

The guys from the Minnoxide podcast stopped by the Calibrated Success Tech Center to record an episode with Greg. Tons of great questions from the hosts, so we just kept going for a while here. Topics ranged from OEM testing and prototype builds to tuning strategy and internet arguments.

It’s no secret that one of my other hobbies is audio. Car audio, home theater, reference stereo, live music, it all ties in. I was actually more interested in car audio than engines when I first got to engineering school. My Big Brother in my fraternity was an electrical engineer who had been playing with crossovers and speaker enclosure design for years when I met him. He taught me a lot about how the physics tied in to what we hear (and feel), along with how best to start making adjustments to correct what we hear. Fast forward a few more decades and I still play with sound. Sometimes I’m making it (playing music or movies) and sometimes I’m helping mitigate it (dyno cells, listening rooms). The science behind it is the same either way.

We’ll start with my recent project: a reference quality 2-channel audio setup in my listening room at home. While the Digital Signal Processor allows us to flatten the frequency response and align the flight time of music from each driver to the listener’s head at the optimum seating position, there are some things it cannot do. The DSP can’t fix diffraction caused by early reflections from the speaker baffle. These speakers were designed with minimum surrounding area to create that unwanted interference similar to the Bowers and Wilkins 801, which were my inspiration ever since I heard a pair back in the 90’s.

But great drivers will only get you so far. The room itself can color the sound with reflections and standing waves. What you can’t see in the photo above is the foam panels on the walls directly opposite the speakers. These help tame the primary reflection off the back wall, but looking deeper at the measurements, we’ll see that something is missing. Even with careful measurements and recalibration of the DSP, the room still sounds very “lively” compared to what I know is recorded in some tracks. Time to go back and look at the measurements taken with our calibrated microphone using the Room EQ Wizard (REW) software. This is starting to feel a lot like comparing ECU datalogs and calibration files now.

Yes, that looks like a lot of noise. The truth is that moving the mic (or your head) just an inch or two can significantly change the frequency response at the new position as some reflections become either constructive or interfering. That’s why we take multiple recordings from multiple positions and average them before making decisions. With an 18′ sub and over 1kW of power, I can make all the low end bass I want, but the room seems to over-deliver around 50Hz no matter what I do. Looking at the RT60 plot shows how various frequencies decay in the room. The low end clearly likes to hang around for longer than the speakers dictate.

Digging deeper, we look at the Waterfall plot and find something interesting. I saw peaks around 50, 100, 150, 200, 300Hz. This can’t be a coincidence. These are all multiples of the same fundamental frequency (~50Hz) with diminishing intensity as the order is increased.

THIS is something our brain will recognize, and should be addressed. But why is it there? Knowing that sound waves have a predictable length based on their frequency, it was time to break out the tape measure and look at the listening room again. This room is a bit irregular, so I took a bunch of measurements and looked up what frequency each measurement would correlate to for wavelength. The results jumped right out at me:

Seeing peaks at multiples of 46-50Hz is NOT a surprise in this room. Now we’re getting somewhere. We have definitive proof that our room contributes to 50Hz (and multiples thereof) noise. We just need to treat it. Treating low frequencies largely depends upon absorbing energy as the waves approach the walls. Bass Traps can be used to great effect here. After doing lots of reading, the biggest lesson I can transfer to you about bass trap effectiveness is the equivalent of “no replacement for displacement”. Studies have been done on various designs, shapes, densities, and placements. The biggest influence on low frequency attenuation is the thickness of the element. 2″ panels do just about nothing this low, 4″ panels are marginal, and 6″ really starts to work well. This means that either a substantially thick panel on one of the walls, or a bunch of corner elements could be used to have an impact upon the waves in question here.

The easiest is to add are corner traps. We can always stack additional panels in front of these or along the walls later, too. We’ll start with these corner traps that are up to 7″ deep and put them on some of the surfaces touching our 50Hz waves. Do we expect this to cure the problem? Probably not completely, but it should make a dent. We’ll take some more measurements after they’re in and see how we did. Since this is a reference listening room, I’m fully expecting to get or make some larger 4-6″ panels for some of the offending walls too.

So how does this relate to your dyno cell?

I’ve helped many shops reduce unwanted noise in their dyno rooms. Ideally, I can get involved before the room is made to help create a room with favorable geometry. This can avoid standing waves in the first place, and has the biggest impact. After that, we look at where we can either absorb reflected sounds, or break them up to reduce their intensity. Properly done, we can have a significant impact on noise emitted from the dyno room, even if the car is incredibly loud. Reducing the impact on your hearing, or neighbor complaints is a nice benefit too.

Motor Trend and HOT ROD Magazines recently shared an article I wrote talking about the new twin turbo LT7 engine in the 2025 Corvette ZR1.

GM recently dropped the details on the new 2025 C8 ZR1. As an engineer who has worked in both OEM development and aftermarket performance, I’m nothing short of impressed. I spent the last quarter-century bouncing between walking the aisles of the Performance Racing Industry show and releasing engine calibrations that have been driven by millions of unsuspecting users around the world. I have seen lots of 1,000-hp engines. I have had lots of engines go to production after passing emissions, durability, NVH, and safety standards. I haven’t seen very many that did both. Sure, there’s the Bugatti ($3 million and 1,200 hp), the Aston Martin Valkyrie ($3 million and 1,000 hp), and the Ferrari SF90 ($540,000 and 986 hp, combined), but all of these are about as available as unicorn tears to mere mortals. Engines like the Hellephant make over 1,000 hp but have zero chance of passing emissions, so they’ll never be offered in legal roadgoing cars. What we have in the ZR1 is a real accomplishment, and a point where my two worlds seem to have collided…

Read the whole article HERE.

We recently helped a shop with a handful of remote calibrations…

If I’m honest, my brain still hurts a little. I was humbled to spend the last week listening to and speaking with some of the brightest minds on the planet regarding mobile emissions. The CRC and OSAR conferences bring together experts from academia, agencies, and private industry to discuss a wide range of topics regarding real world emissions and how we measure them. Topics ranged from large marine diesels to lawnmowers and everything in between.

While I am admittedly nowhere near an expert in two-stroke diesels that get measured in megawatts, much of the diesel research was still applicable to my work on light duty spark ignited engines. In depth discussion of NOx sensor technology, the formation of ammonia, particulates, and various oxides of nitrogen definitely crosses over. A representative from the EPA had a very eye opening review of just how many defeat device equipped diesels they found at a recent heavy duty equipment and vehicle auction. (It was almost 30% of vehicles sampled!) They are most certainly aware of what these look like and how they are being employed. On the other end of the spectrum, data was also presented from field measurements of high mileage gasoline powered cars in Nigeria. Again, truly some eye-watering levels of pollutants were found where the vehicles are well beyond their planned compliance life and fed with poor quality fuel.

For my part, I was able to present some of the in-use testing I have been doing using our in house Mini-PEMs and the VMAS units. The emphasis here was to show a cost effective way to knock off the first layers of emissions testing prior to running expensive 1065 laboratory tests when the expected result isn’t going to be within 3% of an already tight standard. The reality is that data that is within even 10% can be extremely useful when the larger real world noise factors are taken into account. Companies looking to perform early product development and agencies testing likely dirty vehicles can both same time and money with these simpler measurements.

To cap the week off, I went straight to the SEMA Garage from the airport to help with the ETTN Student Career Fair held in conjunction with the Detroit section of SAE. Turnout here was impressive with so many dedicated students showing such interest for jobs in the performance industry. These are our future, and we couldn’t be happier.

Tuesday, February 20th, 2024, SEMA will be hosting “Bridging the Gap from Runs Good to Emissions Compliance” on their virtual education channel SIGN UP HERE. Greg will be discussing how to make the transition from traditional performance tuning to the more involved emissions compliance work needed to obtain a CARB EO or SEMA Certified emissions status. It will also include helpful hints for tuners and shops to avoid costly interactions with enforcement personnel while improving the overall quality of their calibration work.