Last summer I upgraded my fuel pump to a 255LPH. I immediately noticed a drop in performance suggesting a rich condition. Hooking up some narrowband a/f gauges only convinced me further especially at WOT (I know I need to get a WB O2). In my quest to tune this puppy, I've just purchased a spacer kit to change the FMU ratio. I've also purchased the Tweecer RT. I'm going to start by moving my FMU ratio down from 10:1 to 8:1. From that point forward I will be looking to the Tweecer to help me out. I know I need to ditch the FMU and go with the injectors and MAF. But for now it stays ($$$). Question 1: Pushing closer to 5 or 6 PSI (I'm at altitude), can I just ditch the FMU completely with my stock injectors (24#) and MAF? Or is that too much for the setup to handle. Question 2: I've heard the Tweecer and FMU combo can be a pain. Has anyone had success with this combo?
My general thoughts would be you don't have a wb and you are putting yourself in the danger zone with what you are trying to do IMHO. I feel you really are asking for trouble with only 24's and trying to remove the fmu. The Tweecer and fmu combo you speak of can be a pain from many of the comments I've seen from those who tried to make it work and work with consistent results. The problem child is the fmu ... not the Tweecer. My #1 suggestion for you would to make a wb part of your self tuning package and all the more so since you are forced. Good Luck and be careful in the area you are now starting to tread or the LEAST of your probs is gonna be looking for fresh head gaskets. Grady
Thanks for the response. I figured running just the 24's might be too risky. I'm going to keep the "band-aid" FMU for now and make the injectors/MAF my next purchase. Then the WB, I just wish the WB's weren't so pricey. Any suggestions on the size of injectors I should go with? I always hear people say go as big as possible to provide headway for future mods, especially with a Tweecer since it's tunable. But what is too big? If I had to guess I'd say 42# seem right???
My knowledge is only of a basic nature when it comes to blown applications but I feel comfortable in saying it kinda like this. 1) Your choice of blower is usually considered to be not all that aggressive and does not place the demands on the fuel system like a vortech that can move a good deal more air. 2) Like you said, you got the Tweecer to fine tune. I think if I was you, I'd get a wb first thing right off the bat get a set of 42's and matching caled maf (not C&L) ditch the fmu and tune it up real good for best results Good Luck Grady
