Nelson Performance

Nelson Performance GM LS & LT Performance, Diagnostics & Tuning LSx Performance Specialists
Trucks/cars/suv
GO FAST! In house dyno, tuning, custom wiring, installation, parts.

HPTUNERSD - FAST XFi - Holley EFI

Please contact Nelson performance at 210-626-0278 or at [email protected] for any orders or detailed pricing questions/ inquiries.

This 2008 GMC Sierra came to us after a 5.3L to 6.0L / 6L90E swap completed by another shop. Once the hard parts are ins...
05/29/2026

This 2008 GMC Sierra came to us after a 5.3L to 6.0L / 6L90E swap completed by another shop. Once the hard parts are installed, that’s where the real work begins. Proper calibration is what brings a swap together and makes it drive the way it should.

We handled the tuning side to get the combination working correctly together — engine, transmission, drivability, shift strategy, and overall performance. A swap can have all the right parts, but without the correct tune you can still end up with poor shifting, drivability issues, throttle response problems, or check engine lights.

This Sierra left running cleaner, shifting smoother, and driving the way a properly completed swap should.

At Nelson Performance we specialize in GM tuning, diagnostics, drivability, and custom combinations from mild builds to full performance setups.

📞 210-626-0278
🌐 www.nelsonperformance.com

This 2001 Escalade was towed into Nelson Performance after the customer installed a new engine and immediately ran into ...
05/28/2026

This 2001 Escalade was towed into Nelson Performance after the customer installed a new engine and immediately ran into major drivability issues. The truck was stuck in REP (Reduced Engine Power) mode and barely driveable. 🔥

Instead of guessing and throwing parts at it, we went straight into diagnostics. After testing and inspection, we traced the problem to a heavily restricted dirty injector causing poor fuel delivery. The injectors were cleaned, serviced and reinstalled, restoring proper operation and getting the Escalade back out of REP mode. 👊

While the truck was here, we also took care of several other issues to get it fully sorted out:
✔️ Replaced the brake master cylinder after the customer lost braking pressure
✔️ Installed a new belt tensioner and pulley
✔️ Replaced both drive belts
✔️ Finished everything off with a Nelson Performance tune

This build is a perfect example of why proper diagnostics matter. Even with a brand new engine, a small issue like a restricted injector can create major performance and drivability problems. Test it. Verify it. Fix it right. 💪

Now this Escalade is back on the road running strong and driving the way it should. 🚙💨

📞 210-626-0278

Customer installed headers on this 2019 Camaro SS manual transmission and brought it to us for the important part — the ...
05/27/2026

Customer installed headers on this 2019 Camaro SS manual transmission and brought it to us for the important part — the calibration. 👊

A proper tune after header installation is critical for drivability, throttle response, air/fuel correction, and getting the most out of the setup without lighting the dash up like a Christmas tree. 🔥

This Camaro left with a full custom street tune from Nelson Performance and is ready to row gears the way it should. 🏁

No dyno queen numbers. Just real-world performance, drivability, and results you can feel every time you hit the throttle. 🇺🇸

📍Nelson Performance
📞 210-626-0278
🌐 www.nelsonperformance.com

Header install created a steering shaft clearance issue on this 2017 Cadillac Escalade.The factory rag joint style shaft...
05/26/2026

Header install created a steering shaft clearance issue on this 2017 Cadillac Escalade.

The factory rag joint style shaft was making contact after the headers were installed, so we upgraded to a later style shaft for additional clearance and a cleaner fit.

Small changes like this can make a huge difference in drivability, noise prevention, and long term reliability. This is why details matter on custom performance work.

At Nelson Performance we don’t just bolt parts on — we make sure everything works together correctly. 🔥

📍 Nelson Performance
📞 210-626-0278

This Memorial Day, we pause to remember the brave men and women who made the ultimate sacrifice for our freedom. 🇺🇸Their...
05/25/2026

This Memorial Day, we pause to remember the brave men and women who made the ultimate sacrifice for our freedom. 🇺🇸

Their courage, service, and sacrifice will never be forgotten.

Nelson Performance will be closed Monday, May 25th in observance of Memorial Day as we honor those who gave everything for this country.

We hope everyone has a safe weekend with family, friends, and the people who matter most.

🇺🇸 Land of the free because of the brave. 🇺🇸

📍 Nelson Performance
📞 210-626-0278

Classic OBS style with modern LS power. 🔥This clean 1997 C1500 came through Nelson Performance for an LS setup featuring...
05/24/2026

Classic OBS style with modern LS power. 🔥

This clean 1997 C1500 came through Nelson Performance for an LS setup featuring a 6L80E transmission, NP engine harness, and custom tuning to bring everything together the right way.

Clean drivability. Modern transmission control. Reliable swap integration.

Whether you’re building a street truck, weekend cruiser, or full performance setup, proper wiring and calibration make all the difference. 👊

📞 210-626-0278
🌐 Nelson Performance

This 2024 Colorado ZR2 stopped by Nelson Performance for a little turbo truck attitude 😎✔️ Boomba BOV Adapter✔️ Aluminum...
05/23/2026

This 2024 Colorado ZR2 stopped by Nelson Performance for a little turbo truck attitude 😎

✔️ Boomba BOV Adapter
✔️ Aluminum Cold Pipes
✔️ Full Nelson Performance Tune

Better throttle response, improved drivability, and now you can actually HEAR that turbo working 👀🔥

These new Colorado platforms respond great to tuning and airflow upgrades.

Ready to wake your truck up?
📞 210-626-0278
🌐 Nelson Performance

2000 Silverado came in with a parasitic battery draw that would kill the battery overnight.The obvious suspect? The afte...
05/22/2026

2000 Silverado came in with a parasitic battery draw that would kill the battery overnight.

The obvious suspect? The aftermarket radio.
Nope. 👀

We pulled the truck apart, traced wiring, tested circuits, and dug deep into the electrical system. After a lot of diagnostic time, we found the real issue — the ignition switch was stuck in accessory mode causing a constant power draw.

Removed the switch, retimed the gear, verified repair… and the draw is gone. ✅

This type of work is extremely time consuming, but real diagnostics matter. You can’t replace good diagnostic work with guesswork or parts swapping. That’s what Nelson Performance is known for.

📞 210-626-0278
Nelson Performance

05/21/2026

“2024 Colorado in for a Boomba BOV adapter install!

This modification vents boost pressure differently so you can actually HEAR the turbo every time you let off the throttle. 👀🔥

Does it add huge horsepower? No.
Does it make the truck way more fun to drive? Absolutely. 😎

That signature turbo ‘PSSSHH’ never gets old.

📍 Nelson Performance
📞 210-626-0278
🌐 www.nelsonperformance.com”

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A 2005 GTO came into Nelson Performance running hot and ready for answers. After diagnostics, we found the cooling fans ...
05/20/2026

A 2005 GTO came into Nelson Performance running hot and ready for answers. After diagnostics, we found the cooling fans had failed. We replaced the fans, installed a 160° thermostat, replaced the upper radiator hose and serpentine belt, topped off the cooling system with fresh coolant, and got this GTO back on track.

Cooling system issues can turn into major engine problems fast if ignored. Proper diagnostics matter. 🔥🏁

Nelson Performance
210-626-0278

LS swapped builds can create some of the toughest diagnostic problems out there.This LX450 came in with a random no star...
05/19/2026

LS swapped builds can create some of the toughest diagnostic problems out there.

This LX450 came in with a random no start and extended crank issue that wasn’t going to be solved by just throwing parts at it. Time to slow down, dig into the wiring, verify signals, and diagnose it the right way.

That’s the difference real diagnostic work makes. Anyone can guess. Not everyone can troubleshoot.

At Nelson Performance we specialize in solving the problems other shops can’t figure out — especially custom builds, swaps, drivability issues, electrical problems, and performance diagnostics.

📍 Nelson Performance
📞 210-626-0278

Address

10034 Roosevelt Avenue
San Antonio, TX
78214

Opening Hours

Monday 9am - 5:30pm
Tuesday 9am - 5:30pm
Wednesday 9am - 5:30pm
Thursday 9am - 5:30pm
Friday 9am - 5:30pm

Telephone

+12106260278

Website

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