David Shoup Tuning

01/01/2026

Thank you all for an outstanding 2025. This year brought significant achievements and record-setting results for many clients, along with the opportunity to tune a wide range of truly fun and unique vehicles.

Along the way, I had the privilege of meeting many great people, forming new friendships, and continuing to grow both professionally and personally.

I would like to sincerely thank everyone who trusted me with their vehicles and gave me the opportunity to work with you throughout 2025, as well as those who have supported me over the past year and the many years prior. I would also like to extend a special thank-you to Sebastian for his tireless efforts with scheduling, communications, builds, and—most importantly—his continued friendship.

David Shoup Tuning would not be possible without the support of this community, and I am deeply grateful for it.

Wishing everyone a happy, safe, and prosperous 2026.

10/07/2025

Hi all, fun case study of the past month with Trevor's white DAW 6969 shop car. Whenever I have a unique build or situation, I like to do a recap of the car, the setup, and performance when possible.

Over the past month Trevor and I spent some time dialing in the car at higher altitude along with some dyno time down at sea level. The goal for the car was to see how much power and torque can a "hybrid" turbo produce with all of the right modifications.

His b58 gen 1 car has his latest DAW6969 turbo and all of the supporting modifications such as a larger Dorch high pressure pump, intake manifold with ReFlex/ID1300 injectors and a custom AFS style low side system with regulator and 5 bar map sensor. Simple engine build by Barakat built with stock cams.

The day of the dyno we tested various boost levels settling on a max boost of ~45 psi. Any higher and the boost didn't result in any worthwhile gain in performance. After further Vanos, fuel, and timing adjustments, we settled at over 1000ft lbs of torque! For a bolt on turbo, this in my opinion is incredible! The best part about it is making this level of power using the factory electronic wastegate means perfect response and control.

https://www.facebook.com/share/v/1DVRC1kefG/

The only problem is 1000ft lbs of torque likes to break differentials and driveshafts as Trevor found out the hard way at the track. The good news was, the very first pull off the trailer with no ice ran a 9.2 at 150+ mph!

https://www.facebook.com/share/r/1A2PFjR6hR/ - 9.2 run

Overall, im extremely impressed with this setup and even on a stock engine B58, with a proper fuel system and parts behind it. It'll be an absolute weapon on the street!

09/04/2025

N54 friends big breakthrough today! (For me at least)

Many years ago when I started tuning big power N54 DI upgrades such as the VTT 2x shotgun pump we used to fight rail pressure oscillation. The fix back in the day was to raise rail pressure to 22mpa+ essentially forcing the closed loop pump control into a positive correction which in turn would stabilize fuel pressure. After the 2x shotgun pump was discontinued, the helix followed suit but the bandaid fix for oscillation was essentially the same.

The problem with this is 22-25 Mpa is a lot of pressure for the factory piezo injectors and can potentially contribute to early failure. Over the years the factory lowered the rail pressure from 20 Mpa at its highest down to 17 mpa in the same low load range indicating the factory even knew a drop in rail pressure was the correct choice. In the higher rpm range the stock rail pressure target was 15 Mpa so targeting 25 Mpa is a big change.

Fast forward to today, the latest DI upgrade release for the N54 is the overdrive gear/chain combo for the vacuum pump. This setup provides roughly 46% more flow from the high pressure pump so those not willing to deal with the problems of crude PI setup/control can opt for this and still make over 600whp. Its a great solution but the install is more involved than past offerings as it requires access to the timing cover.

For the first few years of tuning N54's I had limited access to the tables necessary to fine tune the high pressure pump. (Part of the tables necessary still aren't in the public definition files). Eventually tables were released for the VCV but more control was needed and the oscillation was still there in many cases.

Since I'm constantly on a quest to do things the right way, the compromise in rail pressure settings never sat well with me. With the added knowledge I've acquired over the past few years and an uptick in N54's running the overdrive gear, I dove head first into the logic to solve the oscillation issue while running a lower rail pressure target for good.

After several days of testing, im pleased to announce that the code has been broken. I can now target a flat 17mpa without any oscillation with spot on pump control. It took many hours of going though technical docs, defining tables, and testing but pump control is locked in! These changes apply to any and all N54 with heavy rail pressure oscillation even if they dont have an overdrive too!

Its never too late to continue to improve even an old platform and the N54 deserves it.

08/28/2025

Hi everyone, I'm back and working to catch up from away time. I have a lot of openings in September for same day tuning. If you're an existing client and do not want to wait for a revisions I'd love to get you on the schedule.

When you book a same day appointment the entire day is yours until your tune is complete. If you're interested, please text Sabastian 239-272-0008 or on instagram at . Let him know your name and email and what day works best for you.

Thank you and I look forward to wrapping up your calibration. 😀

08/25/2025

Hi everyone,

I'm back from Scotland. Thank you very much for your patience while I was away! I have 142 emails to review so its going to take a few days to go through all of them.

My calendar for September has a lot of openings for same day tuning so if you want to book a new tune or schedule a day with me, I can finish your car in a single session instead of waiting for revision updates. I'll dedicate my entire day to your car to make sure the tune is complete.

If you need any immediate support, please send an email to [email protected]. If its an important issue and cannot wait a few days, please put "URGENT" in the subject line and Sabastian and I will check it as fast as we can.

Thanks again for all of your support and lets make some jam!

08/15/2025

Hi all, just a reminder I'm flying out to London today for Edinburgh. I'll be away for 10 days but will have my laptop for emergencies. If you need anything please drop me an email with Urgent in the subject line and Sabastian will make sure I address it as quickly as possible. [email protected]. You can also message him on Instagram

Thank you to everyone for your patience while I'm away and I look forward to catching up when I return.

-Shoup

08/11/2025

Hi everyone! Just a quick state of the union and a big update to pricing for the remainder of the year.

Since the addition of Sabastian to the team, we've both been working very hard to book clients for same day tuning. I've had the opportunity to work with so many amazing BMW owners and their amazing cars I previously wouldn't of had the bandwidth for.

We've managed to grab a few more micro records and put out some really amazing tunes. Everything from 900hp stock motor S58s, 1000+ hp B58s, 800+hp N55's, and provide really powerful bolt on hybrid tunes for N54 to S58.

This being said, its also been my busiest year to date. Since I still perform all of the tuning duties, it means I stay very busy. Over the past few months the increased workload has taken a toll on that 1 on 1 experience I like to deliver. My turn around times have slowed from 24 hours to as much as a few days and I'm unable to build personal relationships with my clients like I was before. This is unacceptable.

Since my goal is to deliver not only the best calibration but to offer more interaction, better customer service, and that true 1 on 1 experience, I need to make a change. After careful consideration Im rolling out a change to my pricing structure. The goal is to slow down the incoming workload and allow me to provide that support you chose me for. I appreciate everyone from the bottom of my heart and I'll continue to do everything in my power to give you the best tune and support!

-David

07/30/2025

07/29/2025

Hi all,

Fun case study on a stock engine B58 gen 1 with a Spool high lift exhaust cam and upgraded DI injectors. This is combined with port injection controlled via MHD+ / Motiv ReFlex integration.

The goal was to build a car that ran as much DI as possible without relying on PI which has its disadvantages. The result is more torque and improved fuel control as the DME is designed for the DI injectors. The car runs cleaner and takes more timing across the board!

In the picture below, it highlights how much of the fuel is supplied via the DI which is roughly 80% of the total fuel mass! This is the way all B58's should be built in my opinion.

07/25/2025

Hi everyone - I will be away from August 15th through the 25th. If you need anything before then, please email [email protected]

04/22/2025

Hi everyone, hope you had a great Easter/Resurrection day.

I wanted to share something I've been working on over the past month and with the help of Austin at MHD, its finally sorted.

As some of you may know, the N55 PWG can be very time consuming when it comes to tuning. Small changes can have a big affect on boost control and its very easy to rack up 10+ revisions if you're a perfectionist.

From the beginning of MHD+ I've been driving MHD crazy to release their MHD+ boost control on PWG N55 as it drastically simplifies the tuning process all while adding more accuracy and consistency to the powerband. Since its release I had identified a few concerns with the behavior of wastegate control that prevented the MHD+ logic from working as easily as the EWG N55 and other offerings.

After addressing the concern with MHD, Austin and I dove into the final wastegate duty cycle output and Austin was able to use his knowledge of the MHD+ custom code to trace the logic causing the DME to add up to 10+ % more duty cycle on top of my final output (base+PID). This has plagued the N55 PWG because the duty cycle output never matched what you expected and the car would often report a positive error but close the throttle.

With the help of one of my amazing client (Andrew H) we were able to locate the parameter adding the additional duty cycle and eliminate the cause. The end result was MHD had to update all public XDF's with this new table (which helps all tuners) and boost control with MHD+ is now an absolute breeze.

Take a look at the attached photo. you can see the WGDC base+P/D factor now follows much more closely to the final WGDC 1 output. (several small factors still apply so its not 100% exact - but now is significantly closer). In this picture, the base is slightly above final which means the car needs to remove duty. Traditionally this would create a throttle closure but now, PD can accurately control boost and maintain control.

Just because its an older N55, doesnt mean we cant improve or do it better. Im always looking for ways to improve the final product.

Again, big thanks to Austin at MHD for his time. Andrew for logging.

04/06/2025

I've been on a crusade to get bmw owners off Rotella. Especially di engine bmws. Lake does a great job explaining the science behind why... (the info really starts around 5 minutes).

Do not put diesel oil in a gas powered bmw.

Diesel oils contain more Zinc DialkylDithioPhosphate (AKA Zinc or ZDDP) than Gasoline engine oils, but does that mean Diesel oils provide better anti-wear pr...