Turbo sizing is the highest-leverage decision in a build: too small and you cap your power ceiling, too big and you spend every stoplight waiting for boost. The True North Turbos TNTSF series — four ball bearing, drop-in replacements for the Garrett® G30/G35 footprint — spans 615WHP to 950WHP (roughly 720 to 1,110 hp at the crank, using WHP × 1.17). Here's how to pick.

The Golden Rule

Buy the smallest turbo that meets your power goal. Peak numbers are for dyno day; response is what you live with every day. A ball bearing centre cartridge already buys you quicker spool than a journal bearing unit — don't give it back with an oversized compressor you'll never fully use.

TNTSF54 — The Response King (615+WHP / 720+ HP)

54mm (2.13") inducer flowing 69 lbs/min over a 60x55mm turbine. The TNTSF54 is for drivers who want boost now: street WRX/STI (proven 615+WHP on EJ25), Evo 4G63 beyond 500 hp, 400–500 hp 2JZ street cars, and N54/N55 BMWs around 450+. Twins on a Coyote or LS push past 1,000 hp.

TNTSF58 — The Sweet Spot (745WHP / 870 HP)

58mm (2.28") inducer flowing 78 lbs/min. The TNTSF58 is the do-everything street/strip choice: 600+ hp on EJ25, 4G63, 2JZ, and N54/N55 platforms, and 1,100+ hp in twin V8 configurations. Same inducer size as a G30-770 — with a rating a full 100 hp higher.

TNTSF62 — Serious Single Power (800WHP / 935 HP)

62mm (2.44") inducer with an oversized 82mm exducer, 91 lbs/min. The TNTSF62 suits 700+ hp singles on 2JZ, EJ25, and 4G63 builds that still see the street, and 1,300–1,400 hp twin-turbo V8s. This is G30-900/G35-900 territory with more flow.

TNTSF68 — The Flow King (950WHP / 1,110 HP)

68mm (2.68") compressor over the full 68x62mm G35-size turbine. The TNTSF68 is for full-send singles and monster twin combinations — G35-1050 territory and beyond. Accept a little more lag; collect a lot more top-end.

Turbine Wheels and Housings

The TNTSF58 and TNTSF62 offer both turbine wheels — 60x55mm (G30 size) for response or 68x62mm (G35 size) for flow. Every model takes a T3 0.83 A/R housing or dual V-band in 0.61, 0.83, 1.01, or 1.21 A/R. Smaller A/R spools faster; larger A/R breathes better up top. Street singles usually land at 0.83–1.01; twins can run smaller.

Quick Reference

Power goal (crank)	Single turbo	Twin V8 setup
Up to ~720 hp	TNTSF54	—
~720–870 hp	TNTSF58	—
~870–935 hp	TNTSF62	—
~935–1,110 hp	TNTSF68	—
1,000–1,400+ hp	—	Twin TNTSF54/58/62

Still on the fence between sizes? That's what the Turbo Spec Form is for — send your combo and we'll spec it with you. For the full G30/G35 comparison story, see the TNTSF Turbo Guide or shop the TNTSF collection.

FAQ

What size turbo do I need for 600 hp?

On most four- and six-cylinder platforms, the TNTSF54 — rated 615+WHP (roughly 720+ hp at the crank) — covers a 600 hp goal with response to spare; step to the TNTSF58 for headroom toward 870 hp.

Should I pick the 60x55mm or 68x62mm turbine?

60x55mm (G30 size) for faster spool and street response; 68x62mm (G35 size) for higher flow and top-end power on bigger builds.

Are all TNTSF sizes direct G30/G35 drop-ins?

Yes — all four install in an existing G30/G35 location without custom fabrication.

True North Turbos TNTSF turbochargers are not manufactured by, affiliated with, or endorsed by Garrett Motion Inc. "Garrett", "G30", and "G35" are referenced solely to identify fitment compatibility.