Protomotive Protomotive Tech Tips January 30, 2023

Introducing VGTs

When it comes to turbocharging your engine, there are several options available to you. One of the most popular types of turbochargers on the market today are Variable Geometry Turbochargers (VGT). These turbochargers are designed to provide the benefits of both low-end and high-end turbochargers, making them a versatile choice for many drivers.

However, some people question the quality and effectiveness of VGT turbochargers, leading to the question, “Do VGT turbochargers suck or blow?” In this comprehensive guide, we will explore the pros and cons of VGT turbochargers and answer this question once and for all.

What is a Variable Geometry Turbocharger (VGT)?

A Variable Geometry Turbocharger (VGT) is a type of turbocharger that is designed to adjust the size of the turbocharger’s compressor wheel to match the engine’s needs. The VGT system uses a series of vanes that can be adjusted to control the size of the turbocharger’s compressor wheel, allowing for improved performance at low RPMs and higher boost pressures at high RPMs.

Pros of VGT Turbochargers

There are several benefits to using a VGT turbocharger in your engine, including:

Improved Low-End Torque

One of the biggest benefits of VGT turbochargers is improved low-end torque. Unlike traditional turbochargers, which can experience lag at low RPMs, VGT turbochargers can adjust the size of their compressor wheel to provide quick and responsive boost, improving low-end torque and acceleration.

Better High-End Power

In addition to improved low-end torque, VGT turbochargers can also provide better high-end power than a non-vgt equivalent due to the ability to have a larger turbine housing a/r with nozzles to also make it drive like a smaller a/r. As the engine RPMs increase, the VGT system can adjust the vanes to allow for lower backpressure, increasing the exhaust flow and backpressure, thus providing additional horsepower.

Improved Fuel Efficiency

VGT turbochargers also have the potential to improve fuel efficiency. The ability to adjust the size of the compressor wheel based on engine needs means that the engine can operate more efficiently, using less fuel and reducing emissions.

Cons of VGT Turbochargers

While there are several benefits to using a VGT turbocharger, there are also some drawbacks, including:

Complex Design

VGT turbochargers are more complex than traditional turbochargers, and their design can make them more prone to failures and more difficult to repair. The additional moving parts and complex control systems can also make maintenance more difficult and more expensive.

Increased Cost

Due to their complex design, VGT turbochargers are generally more expensive than traditional turbochargers. This can make them a less attractive option for some drivers, especially if they are working on a tight budget.

Restrictive Turbine Wheel

Even though the variable a/r ratio of the VGT turbo has many advantages, the small diameter of the turbine wheel still causes problems. To spool quickly, these usually have very small turbine wheels. And even though the a/r is variable you still need to get the exhaust out! The ultimate flow of the engine is limited by this. You will see this effect commonly on 997.1TT’s that hit a wall just over 700whp levels. Larger compressor wheels don’t help here either. They simply increase the backpressure more due to the huge difference in overall diameter of the wheels.

Final Thoughts

In conclusion, the answer to the question “Do VGT turbochargers suck or blow?” is a bit more nuanced than a simple yes or no answer. While VGT turbochargers have several benefits, including improved low-end torque and better high-end power, they also have some drawbacks, including a complex design, restrictive turbine wheels and increased cost.

Ultimately, the decision of whether to use a VGT turbocharger in your engine will depend on your individual needs and preferences. If you are looking for improved performance and are willing to pay the increased cost, a VGT turbocharger may be the right choice for you.

Looking for Upgrades?

Even with their cons, VGT’s are hard to beat on the street up to 700whp levels. A 997.1TT with 1100cc injectors, an E85 tune, Billet VGT turbo upgrade and a Protomotive X-pipe has brought many smiles to the drivers.

Protomotive Inc.

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Trevor Morris

2024-04-22

Todd is the ultimate godfather of Porcshe! His knowledge and informative videos have been invaluable to me as a Porsche enthusiast. I'm incredibly grateful for his expertise and guidance. I had an intermittent problem with my 996tt that has plagued the car for 6 years, no shops were able to figure out the problem. I emailed Todd and he narrowed it down within a couple emails, and sure enough he guided me to the problem and it was a simple fix in the end. Not to mention Todd's tuning skills are off the charts, as the car also traps 144mph in the 1/4 mile. Keep up the fantastic work, Todd!

Chris Roundtree

2024-02-19

I wanted to thank Todd at Protomotive Motorsports for going above and beyond when he helped me sort out a problem with a product that I had purchased from another vendor. Todd seems to always have the knowledge to put together the best combination of parts to make any model Porsche not only go fast or handle better, but do it reliably. He always answers the phone. In the rare event he doesn’t pick up he gets back to you within twenty four hours. Emails get responded to just as quick. I really appreciate having some like Todd available when working on any Porsche as you know he has a proven setup to satisfy any goal. Thx Chris

Antreas Smilas

2024-01-22

Super in every way..2 years now in ecu and tcu perfect power delivery ,reliable,and fast as mr Todd promise in number...i can say even i draggy was the same numbers as promise to achieve with this set up.

Taylor Berg-Kirkpatrick

2024-01-04

Todd has got to be the world's expert in forced induction Mezger Porsche engines. I've worked with a bunch of mechanics, tuners, engine builders across multiple Porsches over multiple decades... and Todd has been the most helpful and knowledgeable of the bunch. And this has even been true while working with him remotely! (I'm in CA and he's in AR.) Just by looking at my logs and hearing about my engine rebuild, he's been able to diagnose stuff that in-person mechanics have not been able to. For example, Todd was the only person looking at my car to suggest a problem with a BRV could explain some of the weird behavior... following his advice, I dug in myself... lo and behold, torn BRV diaphragm on bank 1! Wow! Further, Todd has the most experience tuning these cars of any tuner I've worked with. Tune is absolutely solid and safe. Very very confident in his work!!! Absolute strongest possible recommendation!!

N K

2024-01-04

Todd and his team are true professionals and they always provide excellent customer service, quality parts they sell and very reliable engine builds. This is very rare in our industry today. Great job Protomotive!

raphael wirth

2023-05-29

Todd est l homme de la situation…. Des difficultés ou des problèmes pour régler le problème? Todd trouve la solution malgré la distance ( je suis français) Merci à lui et son équipe pour leurs conseils … Maintenant mon 997 turbo fonctionne à merveille et est un véritable avion de chasse! Je recommande a 1000% !!! À bientôt pour d autres évolutions !!!

Adam McGregor

2023-04-05

I don’t think there is a better shop to shop entrust your Porsche to then Protomotive and the Knighton’s. Just search there name with 993 and you can start to get an idea of their storied history of building monster but reliable 911 Turbos! I have over 12 years and 30k miles (street, autox & track) on the Protomotive set up on my 997tt and it has never skipped a beat!

Piotr L. Pawlak

2023-04-05

Unfortunately they could not resolve my issue, but Todd tried very hard to find some other resolutions. He was very helpful and responsive.

B W

2023-03-23

Todd is by far the most professional and knowledgeable Porsche person I have ever worked with in my life and I have had many cars and have been doing this for over 20 years. He not only knows how to overcome every single problem, but also knows how to explain exactly what he is doing and brings the car to a point where it feels like stock even though it has double or triple the power. If you go anywhere else you would be making a mistake

Alex May

2023-02-20

The engineers at Protomotive are absolutely the best. They performed extensive work on my Porsche GT2 and I literally could not be happier. Their work, attention to detail, problem solving and communication with me were all next level. Customer service is remarkable. I had a question while at the track, on a Saturday, and Todd immediately responded to my questions. Class act.

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Do VGT Turbochargers Suck or Blow? A Comprehensive Guide