I have an LBZ that I am struggling to get clean, decent driveability with. It has a 65mm wold fab turbo on it. Does anyone have any experience with this specific turbo? I've checked for boost leaks and don't have any, is it possible to have an exhaust leak that I can't hear? I haven't looked too thoroughly, but haven't seen any soot marks pointing towards an exhaust leak and definitely haven't heard any screeching. I've tried tuning the vanes all over the place and no matter what, the spool up is still smokier than I would like and is way slower than stock. I have 60 over injectors, but I'm not sure how to utilize them to help with turbo lag without just making it even smokier than it already is. I would really appreciate some help determining if it is a problem with tuning, or if it's possible that there is something wrong with the turbo? Or is it not possible with a bigger turbo to have similar spool up to stock and still being clean (1.2+ lambda/17.5:1+ AFR).
I thought maybe with the bigger injectors that I would want to lower the fuel pressure to have a longer injection pulse for the same amount of fuel and that maybe that would help with spoolup, but maybe my thinking with that is backwards because it hasn't seemed to help. I'm hoping to still have a truck with decent throttle response and ability to tow, but right now I haven't had either. EGT's have been too high and throttle response from a stop is terrible. If you don't mind taking a look, I've attached a zip file containing my most recent tune and datalog. This turbo doesn't seem to flow very much air at lower rpms and I'm thinking it may be too big for what I need and that I should just go back to a stock lbz turbo. Obviously I'd like to have the extra power potential as well, but really miss the drivability that I had before.
Another note that I feel is pretty telling that there is an issue, if I command 100% vpos on decel and downshifting, I will only see maybe 6-7 pounds of back pressure and 1 pound of boost. I thought it wasn't uncommon to see 5+ pounds of boost??
Is it possible that there is an issue with the turbo? It was brand new and have been having issues right from the get go. Could the compressor cover be over-machined for the compressor?
This has been driving me nuts and I haven't been able to enjoy my truck for like a year. Any advice would be greatly appreciated!
I thought maybe with the bigger injectors that I would want to lower the fuel pressure to have a longer injection pulse for the same amount of fuel and that maybe that would help with spoolup, but maybe my thinking with that is backwards because it hasn't seemed to help. I'm hoping to still have a truck with decent throttle response and ability to tow, but right now I haven't had either. EGT's have been too high and throttle response from a stop is terrible. If you don't mind taking a look, I've attached a zip file containing my most recent tune and datalog. This turbo doesn't seem to flow very much air at lower rpms and I'm thinking it may be too big for what I need and that I should just go back to a stock lbz turbo. Obviously I'd like to have the extra power potential as well, but really miss the drivability that I had before.
Another note that I feel is pretty telling that there is an issue, if I command 100% vpos on decel and downshifting, I will only see maybe 6-7 pounds of back pressure and 1 pound of boost. I thought it wasn't uncommon to see 5+ pounds of boost??
Is it possible that there is an issue with the turbo? It was brand new and have been having issues right from the get go. Could the compressor cover be over-machined for the compressor?
This has been driving me nuts and I haven't been able to enjoy my truck for like a year. Any advice would be greatly appreciated!