All turbos come with Varying Flange dimensions, Some are universal, others are specific to the application they were intended for.
Most commonly on cummins applications we use one of the following 4 flanges.
T3:
T3 Exhaust manifold/turbo flanges are most commonly found on 5.9L Cummins from 1989-2007. This is the OEM Exhaust manifold and Turbo flange used on these year trucks. This flange typically allows for super quick spooling turbine housing options that are typically also wastegated to prevent overspeed.
A T3 Flange can either be divided or undivided (pictured above is undivided).
Divided flanges typically improve spool time due to the way they direct the airflow over the turbine.
We typically recommend a T3 Flange manifold and turbo setup for 5.9L Cummins applications wanting quick spool and less than 750HP. Although you certainly can make more than 750HP on a T3 setup, typically it is healthier and better to switch to a larger flange like the T4 flange mentioned in the next segment below.
You can find our T3 flange turbos by searching for our drop in turbos for the 2nd and 3rd gen 5.9l Ccummins
2nd Gen Drop in Turbos With T3 Flanges
3rd Gen Drop in Turbos With T3 Flanges
We do not recommend running a T3 flange on a 6.7L Cummins for any reason due to the lower flow capabilities of the T3 flange when compared to the T4 or T4-I flanges. A T3 flanged turbo on a 6.7L Cummins is at high risk of overspeed, even with a wastegate.
T4:
T4 Exhaust Manifold and Turbo flanges are not found on OEM 5.9l or 6.7L Cummins applications or any other brand pickup truck for that matter.
T4 flanges can be found on many industrial applications and larger displacement Cummins/Caterpillar/Mack engines.
T4 Exhaust manifold and Turbo flanges are probably the most universal and versatile flanges available and are commonly swapped onto 5.9l and 6.7L cummins applications as well as performance Duramax and Powerstroke turbo setups.
The T4 flange turbochargers will typically flow more than the T3 versions and allow for larger A/R housings. Many turbos that are offered in T3 are also offered in T4 flanges. Our S300 Turbos can be had in T3 or T4 flange.
A T4 Flange can either be divided or undivided (pictured above is undivided).
Divided flanges typically improve spool time due to the way they direct the airflow over the turbine.
Most T4 flanges are NOT wastegated. The larger A/R options that T4 flange turbos offer allow them to flow enough that wastegating is typically not necessary to prevent overspeed.
You can find T4 flange turbos used in many of our Custom Turbo Kits for the 5.9l and 6.7L cummins as well as for some powerstroke and duramax applications
S300 3rd gen swap for 6.7l Cummins T4
S300 T4 2nd Gen Swap Kit 5.9 and 6.7L Cummins
S400 T4 2nd Gen Swap Kit 5.9 Cummins
S400 T4 2nd Gen Swap Kit 07-09 6.7l Cummins
S400 T4 2nd Gen Swap Kit 10-12 6.7l Cummins
S400 T4 2nd Gen Swap Kit 13-18 6.7l Cummins
S400 T4 2nd Gen Swap Kit 19-22 6.7l Cummins
T4-I:
T4-I flange's are found on 6.7l Cummins applications as well as some industrial applications. This is the OEM flange for all 07-18 6.7l Cummins manifolds and turbos.
This flange is commonly confused with a T4 flange.
We currently are the ONLY manufacturer making a T4-I flange non VGT setup for the 6.7L Cummins. We make an custom T4-I exhaust housing that works on our S300 frame turbos to bolt in like stock on a 6.7L
2007.5-2018 6.7L Cummins S300 Direct Bolt In Turbocharger Non VGT
T6:
T6 Turbo flanges, The BIG boys. These flanges are typically only recommended on primary turbos in compound kits. These require another turbo to help spool them or a lot of fuel/displacement/rpm to spool them as a single turbo.
These turbos on any pickup application we reserve for compounds as mentioned above, or as single turbos for 1000+HP applications.
You can find our T6 Turbos in our compound kits (paired with a T3 or T4 turbo to spool it) or individually as single turbos.