Understanding V-Band Inlet Turbine Housings

From bolt-pattern folklore to flange reality: VB3/VB4/VB5/VB6 explained

Jump to the Flange Dimension Reference Table →

Jump to the Turbo Application Table →


Why “VB” at all? (The naming problem we’re solving)

Legacy turbo slang (e.g., “T3,” “T4,” “Sportsman,” “T6/Pro Mod”) refers to four-bolt flange families. But modern performance turbos increasingly use V-band turbine housings, which don’t match those bolt patterns. Calling a V-band housing “T3 V-band” is oxymoronic—and it creates avoidable fitment mistakes.


The VB system is a V-band-native classification that gives you the size family at a glance without dragging in four-bolt terminology:

  • VB3 → small-frame V-band family (what many people used to call “T3-ish” but V-band)
  • VB4 → mid-frame V-band family (“T4-ish” sizing, V-band)
  • VB5 → large/sportsman-equivalent V-band family
  • VB6 → T6/Pro-Mod-equivalent V-band family

What VB fixes

  • Clarity: Names align to the actual V-band families, not bolt patterns that aren’t present.
  • Cross-brand sanity: Lets you talk about Precision, Garrett, TiAL, Turbosmart, and HPT in one fitment language—then resolve the exact interface with dimensions (ID/OD/step).
  • Fewer returns: Techs and customers stop mixing housings that share a nickname (“T4”) but don’t share the same V-band geometry.
  • Catalog hygiene: Manifolds, downpipes, and adapters can be labeled by the VB family, then fine-tuned by brand-specific alignment steps.


1) VB families: how they attach

  • VB3 — small-frame; turbine housing bolts to center section
  • VB4 — mid-frame; turbine housing bolts to center section
  • VB5 — large/sportsman; housing V-band clamps to center section
  • VB6 — T6/Pro-Mod; housing V-band clamps to center section

VB is the family. Actual interchange still depends on the inlet/outlet ID/OD and alignment step per brand.



2) Dimensional quick-reference (Full Tables Below)

All dimensions shown as 99.9mm (3.93").

VB3 (bolted)

  • Inlet OD: 76.2mm (3.00") · Inlet ID: 50.0–52.0mm (1.97–2.05")
  • Inlet alignment step (by brand):
    • Precision: 57.0mm (2.24")
    • Garrett: 60.0mm (2.36")
    • Turbosmart: 60.0mm (2.36")
    • HPT: 60.0mm (2.36")
    • TiAL: 54.0mm (2.13")
  • Outlet ID: 69.85–71.12mm (2.75–2.80")
  • Outlet OD/step examples:
    • Precision / Turbosmart / HPT / TiAL: 92.1mm (3.63") OD, 78.0mm (3.07") step
    • Garrett: 90.16mm (3.55") OD, 82.0mm (3.23") step

VB4 (bolted)

  • Inlet ID: ~66.0–66.68mm (2.60–2.625") · Inlet OD/step: 92.0mm (3.62"), 78.0mm (3.07")
  • Outlet ID: ~86.0mm (3.39") · Outlet OD/step: 108.7mm (4.28"), ~96.1mm (3.78")
    • Precision often measures ~95.2mm (3.75"); many flanges use ~95.0mm (3.74") to bridge both.

VB5 (clamped)

  • Inlet (brand-specific):
    • Garrett: same as VB4 (~66.0mm (2.60") ID, 92.0mm (3.62") OD, 78.0mm (3.07") step)
    • Precision / TiAL: 69.0mm (2.72") ID, 97.0mm (3.82") OD, 74.0mm (2.91") step
  • Outlet (brand-specific):
    • Precision / TiAL: ~88.0mm (3.46") ID, 114.0mm (4.49") OD, 92.0mm (3.62") step
    • Garrett: ~88.0mm (3.46") ID, 108.7mm (4.28") OD, 95.0mm (3.74") step

VB6 (clamped)

  • Common inlet ID: ~80.0mm (3.15")
  • Inlet OD/step (brand-specific):
    • Garrett: 108.0mm (4.25"), 84.5mm (3.33")
    • Turbosmart: 108.0mm (4.25"), 84.5mm (3.33")
    • HPT: 108.0mm (4.25"), 84.5mm (3.33")
    • TiAL: 107.5mm (4.23"), 88.0mm (3.46")
    • Precision: 107.5mm (4.23"), cone seat (no step)



3) TiAL turbine housings (brand-agnostic, size-specific)

  • VB35 → VB3
  • VB3745 → VB5 (often machined to serve VB4-type turbos)
  • VB9195 → VB5
  • VB55 → VB6
    Verify wheel/backplate and step before mixing components.



4) Turbosmart

  • Current turbo families frequently referenced: sizes like 5862, 6262, 6466, 6870, 7170, 7275, 7675, 7880, 8280 across product lines (e.g., TS-1 / TS-2).
  • VB tendencies by size:
    • Smaller frames often land in VB3.
    • Middle frames often appear in VB4, with some dual-fit entries spanning VB3/VB4 depending on housing option.
  • Always verify by inlet alignment step and outlet OD/step for the exact turbo/housing you’re using.



4) HPT

  • Current frame naming commonly seen: F1, F2, F3, F5 (frames, not just single housings).
  • VB tendencies by frame:
    • F2 → VB3 (small-frame V-band)
    • F3 → VB4 (mid-frame bolted)
    • F5 → VB6 (large-frame / Pro Mod-equivalent)
  • Some HPT models appear in both VB3 and VB4 depending on the selected housing—again, confirm alignment step and OD before mixing.


Please note the information contained below may be incorrect. This is just a quick reference guide and not to be used as gospel.


Flange Dimension Reference Table

​VB Class Brand Inlet Flange ID Inlet Flange OD Inlet Flange Step Diameter Outlet Flange ID Outlet Flange OD Outlet Flange Step Diameter
VB3 Precision 50mm (1.97")–52mm (2.05") 76.2mm (3.0") 57mm (2.24") 69.85mm (2.75")–71.12mm (2.8") 92.1mm (3.63") 78mm (3.07")
VB3 Garrett 50mm (1.97")–52mm (2.05") 76.2mm (3.0") 60mm (2.36") 69.85mm (2.75")–71.12mm (2.8") 90.16mm (3.55") 82mm (3.23")
VB3 Turbosmart 50mm (1.97")–52mm (2.05") 76.2mm (3.0") 60mm (2.36") 69.85mm (2.75")–71.12mm (2.8") 92.1mm (3.63") 78mm (3.07")
VB3 HPT 50mm (1.97")–52mm (2.05") 76.2mm (3.0") 60mm (2.36") 69.85mm (2.75")–71.12mm (2.8") 92.1mm (3.63") 78mm (3.07")
VB3 Tial 50mm (1.97")–52mm (2.05") 76.2mm (3.0") 54mm (2.13") 69.85mm (2.75")–71.12mm (2.8") 92.1mm (3.63") 78mm (3.07")
VB4 All brands ~67mm (2.63") 92mm (3.62") 78mm (3.07") 86mm (3.39") 108.7mm (4.28") 96mm (3.75")
VB5 Garrett 66mm (2.6") 92mm (3.62") 78mm (3.07") 88mm (3.46") 108.7mm (4.28") 95mm (3.74")
VB5 Precision 69mm (2.72") 97mm (3.82") 74mm (2.91") 88mm (3.46") 114mm (4.49") 92mm (3.62")
VB5 Tial 69mm (2.72") 97mm (3.82") 74mm (2.91") 88mm (3.46") 114mm (4.49") 92mm (3.62")
VB6 Garrett 80mm (3.15") 108mm (4.25") 84.5mm (3.33") 80mm (3.15") 108mm (4.25") 84.5mm (3.33")
VB6 Turbosmart 80mm (3.15") 108mm (4.25") 84.5mm (3.33") 80mm (3.15") 108mm (4.25") 84.5mm (3.33")
VB6 HPT 80mm (3.15") 108mm (4.25") 84.5mm (3.33") 80mm (3.15") 108mm (4.25") 84.5mm (3.33")
VB6 Tial 80mm (3.15") 107.5mm (4.23") 88mm (3.46") 80mm (3.15") 107.5mm (4.23") 88mm (3.46")
VB6 Precision 80mm (3.15") 107.5mm (4.23") Cone seat 80mm (3.15") 107.5mm (4.23") Cone seat



Turbo Application Table

Manufacturer Turbo / Model VB3 VB4 VB5 VB6Notes / Comments
Garrett G25 X Small frame; V-band options
Garrett G30 X
Garrett G35 X
Mid frame

Garrett

G40


X




Garrett

G42 Compact


X




Garrett G42 X Large frame
Garrett G45 X
Very 
Garrett G47 XVery Large Frame

Garrett

G50




X


Garrett

G55




X


Garrett G57 X
Garrett GTX2860R X GTX small frame
Garrett GTX2867R X
Garrett GTX3071R X X
Garrett GTX3076R X X
Garrett GTX3582R X X
Garrett GTX3584RS X X
Garrett GT2554R X Legacy GT small frame
Garrett GT2860RS X
Garrett GT2871R X
Garrett GT2876R X
HPT F2 5562 X F2 frame (VB3 per guidance)
HPT F2 5862 X F2 frame (VB3 per guidance)
HPT F2 6062 X F2 frame (VB3 per guidance)
HPT F2 6262 X F2 frame (VB3 per guidance)
HPT F2 6264 X F2 frame (VB3 per guidance)
HPT F2 6266 X F2 frame (VB3 per guidance)
HPT F2 6466 X F2 frame (VB3 per guidance)
HPT F2 6870 X F2 frame (VB3 per guidance)
HPT F2 7170 X F2 frame (VB3 per guidance)
HPT F3 6466 X F3 frame (VB4 per guidance)
HPT F3 6870 X F3 frame (VB4 per guidance)
HPT F3 7170 X F3 frame (VB4 per guidance)
HPT F3 7275 X F3 frame (VB4 per guidance)
HPT F3 7675 X F3 frame (VB4 per guidance)
HPT F5 8280 XF5 frame (VB6 per guidance)
HPT F5 8884 XF5 frame (VB6 per guidance)
HPT F5 8891 XF5 frame (VB6 per guidance)
HPT F5 94MM XF5 frame (VB6 per guidance)
Precision 5658 X
Precision 5662 X
Precision 6062 X
Precision 6262 X
Precision 6266 X
Precision 6466 X
Precision 6670 X
Precision 6870 X

Precision

6875 H-Cover


X




Precision 7275 H-Cover X
Precision 7675 H-Cover X
Precision 6875 Sportsman X

Precision

6880 Sportsman



X



Precision

6885 Sportsman



X



Precision 7175 Sportsman X

Precision

7180 Sportsman



X



Precision

7475 Sportsman



X



Precision

7480 Sportsman



X



Precision 7485 Sportsman X

Precision

7680 Sportsman



X



Precision

7685 Sportsman



X



Precision

8080 Sportsman



X



Precision

8085 Sportsman



X



Precision 8385 Sportsman X
Precision 8685 Sportsman X

Precision

8891



X



Precision

XPR 8803




X


Precision

XPR 8805




X


Precision

XPR 8808




X


Precision

XPR 9103




X


Precision

XPR 9105




X


Precision

XPR 9108




X


Precision

XPR 9403




X


Precision

XPR 9405




X


Precision

XPR 9408




X


Precision

XPR 9803




X


Precision

XPR 9805




X


Precision XPR 9808
X
TiAL VB28 X Housing
TiAL VB30 X Housing
TiAL VB35 X Housing
TiAL VB35 REV X Housing
TiAL VB3745 X Housing
TiAL VB9195 X Housing
TiAL VB55 X Housing
Turbosmart TS-1 5862 X TS-1 smaller frame (inference)
Turbosmart TS-2 5862 X X TS-2 available VB3/VB4 (inference)
Turbosmart TS-1 6262 X TS-1 smaller frame (inference)
Turbosmart TS-2 6262 X X TS-2 available VB3/VB4 (inference)
Turbosmart TS-1 6466 X TS-1 smaller frame (inference)
Turbosmart TS-2 6466 X X TS-2 available VB3/VB4 (inference)
Turbosmart TS-1 6870 X TS-1 smaller frame (inference)
Turbosmart TS-2 6870 X X TS-2 available VB3/VB4 (inference)
Turbosmart TS-1 7170 X TS-1 smaller frame (inference)
Turbosmart TS-2 7170 X TS-2 mid frame (inference)
Turbosmart TS-1 7275 X TS-1 smaller frame (inference)
Turbosmart TS-2 7275 X TS-2 mid frame (inference)
Turbosmart TS-1 7675 X TS-1 smaller frame (inference)
Turbosmart TS-2 7675 X TS-2 mid frame (inference)
Turbosmart TS-1 7880 X TS-1 smaller frame (inference)
Turbosmart TS-2 7880 X TS-2 mid frame (inference)
Turbosmart TS-1 8280 X TS-1 smaller frame (inference)
Turbosmart TS-2 8280 X TS-2 mid frame (inference)

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