Tuning
Yes. In today’s world, Cadillac dealerships are required to perform an ECM (ECM) scan before any powertrain warranty will be honored by General Motors and this is why Tapout is careful to leave all the OEM safeguards in place including fuel trim learning, knock retard learning and boost reduction in case of intercooler failure. In order to be reimbursed for warranty work, the dealerships will need to send the logs in proving this scan was completed and the ECM has not been unlocked. All custom ECM and TCM tuning can be detected by Cadillac dealerships, and will immediately void your powertrain warranty. For this reason, it’s prudent to assume that any future powertrain repairs after your custom tune will be out of pocket expenses.
Historically, the quickest and fastest ATS-Vs have all launched between 3 and 6 pounds of boost, on drag radials or slicks. Don’t fall for the marketing hype from some tuners and believe that a ‘full boost launch’ is going to make your car any faster or more fun to drive. At least not with a stock torque converter that has stall and flash speeds between 2,500 to 3,000 rpm. However, this will all be changing soon now that we’ve introduced a higher stall torque converter. Imagine a properly engineered torque converter that allows you to sit at the starting line between 3,500 and 4,000 rpm. This will produce much more boost, and rocket launches.
The stock tune will remember if you leave the car in Touring or Sport mode. However, it will not remember Winter or Track modes. Our tune behaves in the same manner.
We can program for this if you’d like. However, all Tapout tunes retain factory idle quality and drivability. For this reason, nearly all of our customers opt for power increases in all driving modes.
Tapout tune drivability is at the same level as OEM or better, so we don’t really see any logic in having one mode with less power than the others. To us that seems like a ‘feature’ that provides no benefits.
No. And the one company that markets this feature doesn’t have it either. Check out this article for the facts: Here
No way. We maintain OEM Knock Retard operation and knock sensor sensitivity settings for all cylinders. This allows the ECM to reduce ignition timing in case of bad fuel, low octane, or other conditions where ignition timing is excessive. Some tuners completely disable Knock Retard, and this can cause catastrophic engine failure. If you have a tune from someone else and never see any knock retard in your scans, beware!
Yes, even the factory tune includes bi-directional knock retard and six zone functionality. We maintain those settings and go much farther. Most burst (predicted) knock retard learning is disabled in order to keep false knock under control. Additionally, when real knock is detected and the ECM retards ignition timing advance via knock retard, we allow the timing to return much faster (in the absence of further knock) due to increased knock retard recovery rates.
We maintain OEM fuel trim learning functionality. This will allow your ECM to use feedback from the stock narrow band oxygen sensors to automatically adjust idle, cruise and part throttle air/fuel ratio for different atmospheric conditions, brands of fuel, etc. And this is one of the reasons our tunes idle and cruise just as smoothly as stock. Leaving fuel trim learning enabled will also allow the ECM to set a CHECK ENGINE light if something is wrong with your air/fuel ratio. In fact, we set tighter limits than the factory, using boundaries in the 15 to 20% range instead of 35 to 40%. Some tuners disable fuel trim learning to mask improperly tuned mass airflow (MAF) tables.
We leave all Diagnostic Trouble Codes (DTCs) fully functional, except ones related to catalytic converters in cases where catless downpipes have been installed. This allows your CHECK ENGINE light to illuminate and make you aware of any engine, transmission and/or sensor problems. Some tuners disable specific DTCs so customers won’t see a CHECK ENGINE light when there is inherent tune problem.
We specifically leave DTC P228C enabled in all our tunes. This allows the ECM to switch to Reduced Engine Power mode in cases where fuel rail pressure is less than desired for an extended period of time, and could potentially save your engine.
We can set the electronic throttle to automatically close in case of excess boost. This is recommended for anyone who really wants to push the limits with tuning. However, during normal operation, our tunes allow the electronic throttle to remain 100% open under load.
We can set the electronic throttle to automatically close in case of excessive post intercooler temperature (typically in the range of 150 to 160° Fahrenheit). This can be used as an intercooler failure ‘circuit breaker’, and is also useful in hotter regions with drivers who thrash their cars exceptionally hard (i.e. half or standing mile racing, and/or repeated high speed floggings). If you heat soak your car at the drag strip for example, these settings will temporarily reduce boost to keep your engine safe.
- A completely stock ATS- V with A8 transmission will typically produce 425 to 435 whp on 93-octane. M6 cars are about two percent higher. 91 and 92 octane cars will be lower.
- An ATS-V with proper aftermarket tune should produce 475 to 500 whp.
- An ATS-V with exhaust, spark plugs and wideband tune can produce 500 to 525 whp.
- An ATS-V with exhaust, spark plugs, methanol injection/ethanol fuel blends and tune might make anywhere from 535 to 600 whp, depending on how much methanol you spray and how much risk you’re willing to take.
ECM = engine control module (2016 through 2019 ATS-V engine settings)
TCM = transmission control module (2016 through 2019 ATS-V A8 automatic transmission settings)
CCM = chassis control module (2017 through 2019 ATS-V active exhaust settings)
Each of these takes a different number of credits to tune. Refer to our credit chart to see the right amount.
The E78 controller was introduced in 2011 and used a new torque based control structure. To get an idea how this system functions, take a look at the following report from HP Tuners.
HP Tuners How to tune the E78 and E39 ECM
Yes. We spend countless hours on the dyno studying the hundreds of calibration tables found in the LF4 ECM calibration. We dig deeper than others and often uncover hidden tables that others do not have knowledge or and/or access to. We lock all tunes in order to protect our intellectual property. Our calibration files may only be viewed and/or edited by Tapout Tuning, L.L.C.
HP Tuners MPVI2 / VCM Suite includes two Universal Credits when purchased from us. You will need two credits to license your 2016 ATS-V or four if you have a 2017, 2018 or 2019 ATS-V. We will also need to license your vehicle in order to write your calibration. Our cost for acquiring these credits is included in the Tuning prices. For a complete list of how many credits are required for your year and control module check our table.
HP Tuners VCM Suite has been designed to work with Microsoft Windows® 7 or newer. Windows® 10 is the recommended operating system.
Minimum system requirements:
- 2 GHz CPU
- 4 GB RAM
- Microsoft Windows® 7 or newer
- Microsoft .NET Framework 4.6.1 or higher
- USB Port
Of course. We start with a scan of how your car is currently working with the parts and mods that are already on your car. Then we create a custom calibration specifically for your car. In fact, if make additional modes mods within 30 days of our tune we will retune and optimize it for free.
It depends. For cars that are still running catalytic converters, emissions testing should be no problem. For cars with the cats removed, our tune won’t keep you from passing an emissions test, but your lack of cats will.
When you purchase our tune, we typically cover any and edits you may want or need for the first 30 days. After that, you can sign up for any of our monthly tuning subscriptions if you still want to continue with tuning edits. This would cover things like new mods, different octane fuels, race track specific tunes, remote dyno tuning, etc. Any of these subscriptions may be cancelled at any time, but many customers enjoy having me at their beck and call 365 days per year.
Yes, we can add burble/crackle to your tune. However, this is not safe for your OEM catalytic converters. Once you upgrade to catless downpipes, it should be safe to move in this direction if this is your sort of thing.
No. You will want to order an HP Tuners VCM Suite, plus however many licensing credits your car requires. Then just sign up for any of our monthly tuning subscriptions and we will continue updating and/or editing your tune as required for new modifications, different fuel octane, etc.. If you received the HP Tuners when you bought the car you would only need the subscription.
Our preference is to always tune these cars when they're stock, before any modifications are installed. This gives us the opportunity to find and fix pre-existing problems. Then we can update the tune each time you add new mods. If you just start installing mods and there is a problem, it's sometimes tough to tell whether it was a pre-existing problem with the car, an installation issue or a tuning error. We're then forced to try to solve an equation with three variables.
The factory ATS-V fuel system is designed to safely accommodate ethanol blends up to E10. With proper fuel system modifications (i.e. LPFP and fuel cam, or methanol injection, plus wideband oxygen sensor), we can get you a beautiful flex fuel tune that will support E0 to E55.
Engine
On LF4 engines, the right/passenger side bank is the farthest forward. That's what makes the right side of the engine 'bank 1'. The right front cylinder, closest to the coolant bottle, is cylinder one (1). On the right/passenger side, the cylinders are numbered 1-3-5, from front to rear. On the left/driver side they are numbered 2-4-6.
- Engine oil: ACDelco dexos1 full synthetic, 5w30 (7.0 quarts with filter)
- Engine coolant: 50/50 mixture of DEX-COOL with clean drinkable water (12.3 quarts for engine, plus 3.3 quarts for intercooler)
- Mobil 1 Synthetic LV ATF HP transmission fluid, GM part number 19417577 and its blue colored label. Do not use the black bottles or grey labeled HP fluids as those contain earlier formulations that cause TCC shudder in some cases.
- M6 manual transmission fluid: manual transmission fluid, GM part number 88861800, 88861801 in Canada
- Rear axle and limited slip differential (driver’s side): DEXRON LS gear, 75w90, GM part number 88862624, 88862625 in Canada (1.6 quarts)
- Electronic limited slip differential (passenger’s side): DEXRON-VI automatic transmission fluid (0.149 quart)
- Hydraulic brake and clutch system: DOT 3 hydraulic brake fluid


Stock LF4 spark plugs are AC Delco 41-147, 12662396, iridium, gapped between .030 and .035″.
Most people tuned for higher boost are running one or two heat ranges colder than stock, gapped a little tighter.
We recommend Brisk Silver Racing Plugs that come pre-gapped.
When you replace the spark plugs, always apply dielectric grease (included with our Brisk plugs) on the inside of the coil pack connector boots. This will displace the air and prevent carbon tracking.
Recommended torque value when installing in aluminum cylinder heads is 8 to 14 foot-pounds.
You can buy them here
- 13 to 15 psi is stock for lower altitudes. Those at higher elevations will likely see less.
- 17 to 20 psi is what you can expect with most aftermarket tunes.
- 18 to 20 psi can be run with intake, exhaust, spark plugs and tune.
- 18 to 23 psi may be run with intake, exhaust, spark plugs, and methanol injection or ethanol fuel blends. That’s the practical limit for stock LF4 turbochargers.
If you’re using a sniffer and going to put the wideband sensor in one of the tailpipes, use an inner one with the exhaust valves open. You can also install your wideband in place of one of the rear narrow band sensors if you are running catless downpipes and already have the related rear oxygen sensor DTCs disabled in your tune. The best solution of all is to have an exhaust shop weld an additional bung in place for the wideband.

The stock intercooler works very well when the it is properly filled and bled. We always check intercooler performance before adding boost on every car we tune. We have found that approximately 25% of ATS-Vs have a completely non-functional intercooler, and another 25% have intercoolers that seem to work fine at stock boost levels but need bled and filled in order to keep up with higher boost levels.
Our intercoolers only hold 3.3 quarts of fluid. If they're more than a few ounces low, an air pocket can reach the pump. When this occurs, the pump will turn off after five seconds, on order to protect itself. When the pump is off, manifold air temperature (MAT) skyrockets under boost. The ECM will respond by reducing target boost, pulling ignition timing advance and closing the throttle.
Fortunately, there is a simple and inexpensive to make sure your intercooler is topped off and function fine. The Tapout ATS-V Intercooler Fill/Bleed Kit.
General
140 foot-pounds or 190 Nm
Yes. You will actually have cooler exhaust gas temperatures while running water/methanol injection. This is because the water draws heat out and the methanol burns cooler than gasoline.
If you have run your car in the eighth mile and want to know how it will perform in the quarter mile, simply multiply your time by 1.555. All the ATS-V time slips we have data for show a ratio between 1.530 and 1.560. Ratios on the lower end of that range normally indicate a front half problem such as starting line traction or a missed 1-2 or 2-3 shift in the case of a manual transmission. Ratios on the upper end of that range tend to imply a back half problem such as knock retard, boost drop-off or a missed 3-4 shift in the case on an M6 car.
According to the BOOSTane™ website, there are a lot of additives that make claims about what they can do for your performance. However, BOOSTane™ is not your average octane boosting product. Utilizing a proprietary, patent pending blend, BOOSTane™ Professional effectively raises your fuel octane as much as 23 points, up to 116, if you want!
We took a 2018 ATS-V A8 with intake, spark plugs, exhaust and tune and filled the tank with 93-octane Sunoco fuel before strapping down on our local dyno. Baseline was a solid 499 whp using SAE correction factor and smoothing = 5. We performed all pulls in sixth gear with the torque converter locked up to ensure we gathered the best possible data. This method shows the lowest numbers, but we prefer it since it’s the most reliable, consistent and repeatable from dyno to dyno.
One 32 ounce can of BOOSTane™ Professional was poured into the tank. Based off of the BOOSTane Mixing Chart , the resulting octane was around 102. We were able to add a few minor tuning edits due to this higher octane and the result was 521 whp. We then added a second can to the tank (resulting in an octane of 104), made a couple more tweaks and found ourselves at 549 whp. Peak boost remained the same at 20 psi. Ignition timing advance was increased from ~ 8 to ~ 13° BTDC on the top end. Net gains were an astonishing 50 whp at the top of the powerband with solid gains throughout. Also notice that the power delivery became noticeably smoother with the increased fuel octane.
Total ATS-Vs produced: 4,442
Year
Model
Coupe
Sedan
A8
M6
2016
ATS-V
1,379
1,498
2,363
512
2017
ATS-V
310
579
676
213
2018
ATS-V
213
344
441
116
2019
ATS-V
121
0
100
21
2021
CT4-V Blackwing
2,023
2,419
3,580
862
46%
54%
81%
19%
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