Hello all, I recently replaced my stock turbo because i noticed it was leaking some oil by and it had some end play. It just so happens I came into a sweet deal on a slightly used BD super B. This turbo is for a 2003 cummins but the only difference I could find for install was changing the exhaust downpipe. So the problem is now I'm down about 2-3 mpg. There is a noticable power gain and broader torque curve but peak power seems to be at about the same RPM as it was before. I am not having much luck finding specs. for this turbo but everything I've read says its not much bigger than stock other than the exhaust housing is quite a bit larger. Any input would be appreciated on how to get my MPG back.

Maybe a set of 7x.009 injectors?HX35 = 56/60/12Super B = 57/65/14

I agree on bigger injectors, either RV 275 or 40 - 50 hp aftermarket.

Check boost leaks too

Thanks for the input guys. So I'm thinking injectors/programmer and seeing how long the stock Trans. with 180k on it will last.

  Buzzinhalfdozen said:

Thanks for the input guys. So I'm thinking injectors/programmer and seeing how long the stock Trans. with 180k on it will last.

Nothing like backing into performance...............always start with the weakest link and progress from there.

VB and converters always first mod on autos in 2nd gens and better clutch on manuals. Then we go to gauges and then engine mods.

I am a driveline bullet proofing junky, engines are always second in my book.

Ya I know I'm the same way. That's why I'm leaving it alone for now, but it would be a fun experiment if time and money want a factor