07/23/2026
Auxjection Review & Results: Wicked Performance
Everyone keeps asking if the Wisher Performance Auxjection actually works. We spent a full day on the dyno to answer that question. Our result? 1,003 WHP on E85.
Over the past few months, weāve seen the buzz surrounding the Auxjection system. How much power can it actually support? Is it worth the money? Does it really work? We decided to spend some time answering those questions ourselves.
Before diving into the results, it's important to understand what this system was designed for. Auxjection was never intended to replace a properly designed port injection system. For the price, you could have the Auxjection or the Atlas controller. Instead, it was created to bridge the gap for those guys in the 750-900 WHP range who don't want to run methanol injection or convert to a return-style fuel system, but still want the ability to run full E85.
I stand by my rule of thumb that when you get into the 950 WHP or higher range, you need to move to either a return style fuel system, or one of the in-tank bucketed systems from DSX Tuning, paired with a full port system such as the Atlas. If you are still in Aux Pump HP territory, this will work for you. With that said, letās dive into the test.
For this test, we used a 2019 Camaro ZL1 1LE equipped with a 377ci LT4 built by our friends at Atlanta Speed Shop, stock LT4 heads, a Brian Tooley Racing camshaft, Magnuson 2650 supercharger (complete with worn-out bearings and peeling rotor coating...), a 103mm inlet and throttle body, an LPE Big Bore high-pressure fuel pump, and FIC 30% DI injectors, backed by a McLeod Clutches RXT Hybrid Ceramic Twin Disc clutch. The goal wasn't to make a 1,000 WHP car. It was simply to see if the Auxjection system became the limiting factor.
We started with an 80mm upper pulley and a 9.45" lower. The car made 18.5-19 psi of boost and produced 929 WHP on 23Ā° of timing (Keep in mind these are bone stock LT4 heads). We were short of our goal, so we swapped to a Griptec 2.90" upper pulley. While that should have given bigger results, boost only increased by 1-1.5 psi, ultimately yielding 957 WHP on the same timing. At that point we noticed supercharger inlet pressure dropping. While we didnāt anticipate any restriction in the beginning, we decided we needed a bigger intake.
We replaced the Roto-Fab Big Gulp with the Clegg Performance Designs 6" intake and Green filter that we had on the shelf. After making the necessary fueling adjustments for the larger intake, the results were immediate. On the very next pull, boost increased by 2 psi, inlet pressure stayed within 1-2 kPa at 7,000-7,200 RPM, and we made 971 WHP on only 20Ā° of timing.
Now having the 21.5-22 psi of boost we were looking for, things got easier. At 22Ā° the car made 991 WHP. Just a few numbers short of that 4-digit number everyone wants. After cleaning up the fueling on the Auxjection and doing a plug reading, I decided with another degree of timing in the upper RPM band, we should reach our goal. On the next pull, the car made 1,003 WHP / 914 lb-ft of torque, at 245 kPa (21.8 psi). Auxjection peaked at only 65% utilization, with ethanol content at 73%, so there is certainly more on the table for the system. However, having reached our goal (and being 2:30am), we decided to stop there. This was never about max power, but rather seeing whether Auxjection would become the limiting factor.
While I have tuned this system multiple times on 750-900 WHP builds, and it has worked well, making the Auxjection system perform at this level does require quite a bit of manipulation of injection timing, outside of the standard parameters provided in the user-defined file. If you have any thoughts on purchasing this kit with the intent on leaning on it, I highly recommend you do so carefully and understand that proper calibration is critical. Not every tuner thoroughly understands injection timing and duration (which is a large contributor to how this system operates). Getting it wrong could be catastrophic.
I'd like to give a shoutout to Caleb at Wisher Performance for taking the time to answer questions and help troubleshoot late into the night. When you start leaning on this system, the tuning approach changes completely, and having that kind of support while we were working through the testing was greatly appreciated.
In closing, these results should not be considered the norm purely for the sake that your results will vary based on your combination and your tuner. But when setup properly, the Auxjection system came online exactly when it needed to and delivered the fuel required to stay on target.
Final thoughts: Truthfully, I was skeptical about cylinder distribution when the system came out, and the reality is that 2650ās are the worst in that aspect. For a 2650 application at this power level, a complete port system is the better option. As mentioned previously, the purpose of this test was simply to explore the upper limits of the system and see what it was capable of. Itās more than just a few injectors spraying through a plate. It's about the engineering happening behind the scenes, and whether the coding for the fuel strategy can keep up with the engine's fuel demand. Most people using Auxjection aren't chasing four-digit power numbers, and that's okay, because I don't believe that's what the system was originally intended for. For the right application, though, we came away impressed with what we were able to accomplish and will continue to consider Auxjection an option on our mid-range powered builds.
TLDR: 1000whp with auxjection.
