Article: BoostAddict member picks up a 2016 Cadillac ATS-V and details getting tuned by Tapout Tuning - 495 rwhp

[Foagy]

Recently I pulled the trigger on the decision to start modifying my 2016 ATS-V A8 daily. I bought the car used with a buyback title back in 2018, and had since enjoyed it, but never really loved it. The car has always been fun to romp around in, but I always felt like it was missing a little bit more power. I began looking into the small pool of tuners and parts manufacturers that service the LF4, the frontrunners being Tapout Tuning, Trifecta Performance, and Renick Performance.

After some research and a recommendation from a fellow ATS-V owner and friend, I went with Tapout Tuning as my source for parts and tune. Scott with Tapout was extremely helpful from my first email and I believe his knowledge with the LF4 platform to be unrivaled. For this first phase of modifications, I went with c*tless resonated d*wnpipes, a ported throttle body, a range colder set of sparkplugs, an intercooler fill/bleed kit, a wideband O2 sensor and gauge, and an HP tuners MPVI2 to be able to log and load calibrations.

Scott had me take a log of the car with everything stock to make sure there were no issues with the hardware or stock tune. We quickly found out that intake manifold temperatures skyrocketed after only a single pull. This was due to the stock air-to-water intercooler system being perilously low on coolant. After several hours of bleeding and filling the circuit, we verified the car was healthy. Even still stock, having properly cooled charge air made a world of difference in the top end of the car. I got the car on the dyno for a baseline graph, and was surprised to see peak numbers of 420 WHP and 405 ft*lbs WTQ on 93 octane pump gas.

Given that the factory numbers were 464/445, I was surprised. I wouldn't find out until about a month later that the dyno operator ran the car in 5th gear instead of 6th gear for the baseline and initial modification runs (6th gear being 1:1). Their justification for this was understandable (no one likes being around drive-shafts when let go at 170 MPH wheel speed) but it left me without a true idea of how the car baselined.

I received an initial tune, and with some back and forth got the car dialed before throwing parts at it. Already it was noticeably faster, and the transmission tune fixed a lot of the issues with the factory calibration. Overall it drove much better as well.

All of the parts were fairly easy to get on, but I was also fortunate to have access to a lift and GM mechanic friend. The only small exception was the wideband gauge install, as routing and mounting the gauge to an inconspicuous spot in cabin turned into an all day affair. I received a new calibration now that the d*wnpipes were installed, and once again the car felt faster than before.

Now that car was in a good spot, I returned to the dyno. The car made 450/416 peak (still on 93), but I was perplexed. Even though the car felt great on the street, and had picked up over 100 ft*lbs at 3600 RPM, the numbers didn't quite match up. I got in contact with Scott, and we rescheduled another session on the dyno the following week to see if there could be an issue. We learned then about the 5th vs 6th gear issue, and came to an agreement to do the following pulls in 6th. We also discovered the dyno did not have any fans to simulate moving air, so everything going forward would pretty much be done with the car heat soaked.

5 pulls later, and we ended with some much better numbers, especially with 160 F manifold temperature. It put down 462/457, with that torque gain increasing to 150 ft*lbs low down (still on 93). For fun I had also brought some 101 octane unleaded race fuel, so we added that and retuned. On roughly 97 octane, it hit 495/471, again with the car about as hot as it could be. I knew once I had it out on the street with some moving air it would be even quicker.

Overall, I am very happy with how the car feels, and I love it now. Traction is now my biggest hindrance, even with Michelin PS4S tires. Prior to all the work, the car ran a 12.6 at 109 MPH in the quarter mile, and I cannot wait to see what it will do now. I will be back at the strip in a few weeks to find out.

This was also just the first stage of modifications, and the next round will include fuel system improvements of some sort (methanol or ethanol). Thanks so much to Scott of Tapout Tuning, and to Brett at XP Racing in Oklahoma City for use of their dyno.

[richpike]

Sweet car and great write-up! Sounds like she is moving.

-Rich

[Sticky]

Great writeup and details.

Edited a bit for formatting and promoted to the front page.

The ATS-V's are a great value. Not sure why they don't get more attention and didn't have a bigger impact. But... that just makes them even more of a value.

[Stevenh]

I was just wondering how this platform developed the other day. Thanks for the write-up. Did anyone ever push the car passed stock turbo level of power?

[Sticky]

I was just wondering how this platform developed the other day. Thanks for the write-up. Did anyone ever push the car passed stock turbo level of power?

Yeah didn't Weapon-X have some 600+ whp examples?

[Foagy]

Pure Turbos makes some upgraded stock units, but I do not think anyone has tried larger housings. I haven't had the pans/bracing off to verify, but I believe there is quite a limit on space. There seem to be plenty of examples of 600+ WHP units cars, but I have yet to see any hit the 700s. Given that there were just over 4,300 cars made, it's not surprising progress has been slow. Hopefully once the CT4 blackwing is out we will see some growth of the platform.

[7plagues]

I think this car was skipped over on the tuning scene because of its weak engine, or at least that's what stopped me from buying one when I was shopping around.

[Sticky]

I think this car was skipped over on the tuning scene because of its weak engine, or at least that's what stopped me from buying one when I was shopping around.

What makes you think the engine is weak?

[7plagues]

initially when it came out a few folks had problems with melting plugs and losing compression. not sure if it was isolated or not though.

https://www.cadillacforums.com/threa...rranty.833497/

[Foagy]

It's been almost 7 months since my original post, and much has changed with the car. As it typically happens, I got wrapped up in Black Friday sales and found myself in possession of a slew of fuel system upgrades, including an upgraded low pressure fuel pump, flex fuel sensor, and fuel cam. Once again, Scott with Tapout Tuning came through with quick delivery and an excellent deal on the parts.



A few months went by, and after much indecision, I committed to selling my E92 M3 autocross mule and getting a pickup for hauling home project (and car) stuff around. The M3 sold very quickly, and the following weekend I simultaneously collected my new truck, and dropped off the V to get everything installed. Things from here went a bit sideways.

I got a bad case of "while you're in there" and decided to also get upgraded high pressure fuel internals as to further improve the capability of the system. There were also a few hiccups with installation, which included some sheared pump bolts (apparently the bolts holding the HPFP onto the head are one time use, despite no documentation of being so). They were replaced, as were 3 of the injectors, and the car was buttoned back up.

I got the car back and after verifying all the hardware was good to go, began adding ethanol to tank. Scott had me progressively step up the E content and log at each interval until we knew everything was healthy. Of course then Scott offered a higher boost map to run E50-70, and who could say no to that. On the flexfuel tune and approximately E70, I was able to run a 7.43s 60-130.



At this point the stock tires were not going to cut, and I needed wheels and rubber for autocross. Given how few of these cars were made and the strange offsets it has, finding wheels proved difficult, but not impossible. Eventually I went with a set of Custom BC Forged RT50 wheels in brushed bronze from Modbargains. I wrapped them in Yokohama Neova AD08 tires. These weren't my first choice, but the only other tire available in the sizes I wanted (Falken RT660Rs) were backordered. The specs for the wheels and tires are below.

FRONT: 19x9.5 +28ET, 275/30/19
REAR: 19x11.0 +55ET 305/30/19



I have yet to dyno the car again or take it down the strip, but I hope to soon. I will update this thread again with those results. If I had to guess, I would say it's putting down at least 550 to the wheel. Comparing to similar 60-130 times, 600 WHP is not out of the realm of possibility. Thanks for reading

[Sticky]

On the flexfuel tune and approximately E70, I was able to run a 7.43s 60-130.

I missed this.

That's not bad... great tuning value here.