Do the T3 need mods to fit on a 13bt manifold ? How's the availbility of this turbo, who made this turbo ? Which one is the best between the CT26 and the T3 ? Any lag on the T3 ?
Thanks for answering to my many question.
The T3 is not a single turbo, rather it's a family of turbos. They were originally made by Garrett but have since been discontinued. That family has become the mainstay of aftermarket turbo makers due to the large range of wheels and housings that will interchange onto the same core.
Lag is an often misused term with turbos. Each turbo and engine combination has a certain rpm and fuel level needed to deliver a certain amount of boost. This is your boost threshold.
Lag is the time that it takes to build boost from no load when you're already above this rpm.
The bigger turbo you fit, the higher your boost threshold which means for a bigger proportion of your rev range you have no boost and it will take higher rpm to build to your maximum boost.
Otterav has wound his fuel right up to be able to spool his large CT26 turbo, others who didn't wind the fuel up couldn't get decent boost until 3000rpm with the same engine/turbo combination.
He seems a little sore on this point, to the stage of insulting people who point it out.
The turbo I recommend is the T25 (also superseded, but the current equivalent is the garrett GT2052). On my 3.8 litre Isuzu diesel with the T25 turbol I have 16psi boost at 1400rpm and 20psi boost before the 2000rpm cruising speed. I have 100hp at the wheels at 2000rpm, that's approx 520Nm at the crank.
A 3B would be short lived at this output, but it shows you what the turbo is capable of.
I have turbo adapter designs to fit the T25, T28, T3 and GT2052 to the CT26 manifolds. Most of these adapters are 14mm thick. The GT2052 conversion has been done by Diesel42 on this board, but I don't know if his truck is on the road yet.