Garrett Performance Turbochargers are at the forefront of engine boosting technology, offering a vast selection of Turbo Car Parts designed for racing and performance enthusiasts. With a wide array of over 35 different turbochargers available, choosing the ideal turbo car part for your engine’s performance can feel overwhelming. This guide will demystify the principles and basics of turbo matching, ensuring you select the right component for optimal results. For those seeking advanced technical insights, explore our expert resources here.
Garrett performance turbo car parts are engineered to support engine displacements from 0.4L to a massive 12.0L, and deliver horsepower ranging from 140 to an astounding 3000 per turbocharger at the crank! It’s crucial to remember that Garrett’s horsepower ratings are contingent on vehicle modifications and precise tuning. These ratings are calculated based on the compressor map’s choke flow, representing the turbo’s maximum capability and potential flywheel horsepower. Selecting the correct turbo car part for your specific application is paramount. An oversized turbo can lead to turbo lag, hindering responsiveness. Conversely, a turbo that’s too small may not achieve your desired horsepower and risks overspeeding, potentially causing turbo failure and costly engine damage. Forget the notion that bigger is always better. Turbo technology is constantly evolving, and Garrett engineers are dedicated to developing more powerful, efficient, and compact turbo car parts.
Understanding Crank Horsepower vs. Wheel Horsepower and Parasitic Loss
When discussing target horsepower, we’re referring to the peak power output you aim for your car to achieve at maximum engine RPM, measured at the crankshaft. It’s important to differentiate between crank horsepower and wheel horsepower. Wheel horsepower is the power actually delivered to the wheels after accounting for parasitic loss, also known as drivetrain loss. This loss represents the power consumed as it travels from the engine through the transmission, driveline, and axles to the wheels. The extent of drivetrain loss is influenced by the transmission type (FWD, RWD, AWD), with automatic transmissions typically exhibiting higher losses. Estimating drivetrain loss early in your project is crucial to manage expectations when your car is dyno-tested.
Tuner Tip From Mike Mcginnis- Innovative Tuning: Innovative Tuning points out that larger brakes and heavier wheels and tires also contribute to drivetrain loss. Some dynamometers can conduct a parasitic loss or coast-down test, so consult with your tuner.
If your target is wheel horsepower, use these guidelines to calculate the required crank horsepower. Automakers also typically rate vehicle horsepower at the crank.
For example, let’s aim for 600 wheel horsepower in a rear-wheel-drive vehicle. To determine the necessary crank horsepower for turbo selection, we must factor in drivetrain loss: 600 * 1.15 = 690 crank horsepower.
- Front Wheel Drive: Wheel Horsepower * 1.1 = Crank Horsepower (10% loss)
- Rear Wheel Drive: Wheel Horsepower * 1.15 = Crank Horsepower (15% loss)
- All-Wheel Drive: Wheel Horsepower * 1.2 = Crank Horsepower (20% loss)
With our crank horsepower target of 690, we can now utilize the Garrett Performance turbo product selector to filter suitable turbo car parts. Each turbocharger is defined by its operating range in crank horsepower and engine displacement (liters). Inputting these values into the performance turbo product page allows you to refine your search. Located at the top of the product page are input boxes for horsepower and displacement. For our example, we’ll use 690 horsepower and 4.0 Liter Displacement.
The search yields numerous results. We counted 24 options, including reverse rotation configurations of the GTX3582R Gen II, GTX3576R Gen II, and the G Series G35-900.
Turbo Car Part Selection Based on Vehicle Application
Vehicle application and intended use are vital considerations when choosing turbo car parts. For autocross, rapid boost response is paramount. A smaller turbo or a turbine housing with a smaller A/R (Area/Radius) ratio would be advantageous. This configuration prioritizes quick spool-up and responsiveness, potentially sacrificing maximum top-end power. Conversely, for drag racing, where maximum power and top speed are the goals, a larger turbo and a turbine housing with a larger A/R are typically preferred to maximize airflow to the turbine stage. These are fundamental steps in turbo matching, but crucial in narrowing your search for the ideal turbo car part.
Tuner Tip From Mike Mcginnis- Innovative Tuning: Innovative Tuning emphasizes, “Fuel type is a critical factor in turbo matching. For instance, achieving 500 whp on pump gas versus E85 may necessitate different turbo specifications. To make the desired power on pump gas without excessively high compressor outlet temperatures and to manage exhaust temperatures for knock safety, oversizing the compressor might be advisable.”
Single Turbo vs. Twin Turbo Car Part Setups
Once your target horsepower is established, the next decision involves choosing between a single turbo or twin turbo setup. Both configurations can deliver power efficiently with excellent response. Space constraints in the engine bay might dictate a twin turbo setup with smaller turbo car parts. Alternatively, your chosen manifold might only accommodate a single turbo. The choice depends on your analysis of factors like budget and component availability. For a twin turbo configuration, consider this additional calculation: if you have a 4-liter engine and aim for 690 crank horsepower with twin turbos, divide both your target horsepower and engine displacement by two. In our example, a 4.0L engine and 690hp target become a 2.0L and 345hp target per turbo.
Using the performance product page sorting tool, input 345 horsepower and 2.0L displacement to see twin turbo car part options. The results will differ significantly from the single turbo search. Remember that these results represent turbo car parts within Garrett’s product line that fall within your specified horsepower and displacement ranges. Further research is essential to find the perfect turbo match. This online tool serves as an excellent starting point for turbo selection.
Standard and Reverse Rotation Turbo Car Part Configurations
Garrett offers turbochargers in both standard and reverse rotation configurations. Often called mirrored or mirror image turbos, these options allow for symmetrical turbo system designs. A reverse rotation compressor wheel spins counterclockwise, featuring a compressor housing outlet pointing left. Compressor wheel rotation dictates the airflow path. Standard rotation turbochargers spin clockwise with a right-pointing compressor outlet. The images below illustrate various engine configurations and turbo setups.
Quad turbo V12 LS utilizing two sets of GTX3582R Gen II mirrored turbochargers in a build by Haltech.
Twin GTX5533R Gen II standard rotation drag race setup for Mark Micke.
Mirror image GTX3076R Gen II turbo system by Schmuck Built LLC.
Single turbo G Series G42 in a R34 GTR.
Refining Your Turbo Car Part Search
With these considerations, we can further refine our turbo car part search. For our example, we’ve chosen a twin turbo setup. Next, examine each turbo product page to identify available turbine kit options and review the horsepower and displacement range of each turbo. A general guideline: if your engine horsepower and displacement targets (345hp / 2.0L) are near the lower or upper limits of a turbo’s range, it may operate inefficiently and might not be the optimal choice. A well-matched turbo provides the necessary power and responsiveness within an efficient portion of its compressor map, typically closer to the middle of its specified horsepower and displacement ranges.
Remember: Our target is 345 horsepower for a 2.0L engine (per turbo) in a twin turbo application, aiming for a total of 690hp from a 4.0L engine.
GTX3071R Gen II: Rated for 340-650 Horsepower & 1.8L – 3.0L Displacement. Turbine housing inlets are available in T3 and V-band with V-band outlets. Our target horsepower (345hp) is just slightly above the turbo’s lower limit (340hp). At lower engine RPMs, power output will be even less. This turbo car part might not be the most efficient choice, so we continue our search.
G Series G25-550: Rated for 300-550 horsepower and 1.4L- 3.0L displacement. Turbine housing inlet options are primarily V-band with one T25 option. Our horsepower and displacement requirements fall comfortably within this turbo’s range. The G25-550 is available in standard and reverse rotation for mirrored setups. This turbo car part appears to be a significantly better match than the GTX3071R Gen II.
Conclusion
These are the essential steps for turbo matching and selecting the right turbo car part. You should now be equipped to calculate your target crank horsepower, accounting for drivetrain loss. After deciding on a single or twin turbo configuration, you can use these figures to effectively utilize the performance product page’s turbo sorting feature and refine your options. You also now understand key considerations when reviewing individual turbo specifications. This guide is just one tool to enhance your understanding of turbocharger systems. Numerous other factors influence turbo selection, which we will explore in part 2.
If turbo matching still seems complex, Garrett has developed another tool, Boost Adviser, to automate the sorting process based on your inputs. Access Boost Adviser here. It’s a free resource, accessible by clicking the image below.
Learn more about different turbo types from Garrett Motion and their distinctions.
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