Quote Originally Posted by aznevo8
ok you guys are forgetting. correct me if im wrong. i dont think its fuel. but i do think its the ratio. i say its not fuel because yeah hes pumping 255 lph out of his tank but its not being shot into the motor anyfaster with stock injectors and rail. so i dont think the pump is hardly doing anything for him. but everyone is right he has no engine management and u cannot correct the a/f. ur throwing in a lot of air and your running almost stock fuel if its not stock period. so he would be detonating. hense the choking. and i was the same as u, run it til it breaks and replace it with better parts. that will not work the way you did it. whatever breaks and you replace with better parts will put stress on other parts your not replacing. SUPPORTING MODS is a must. esp in dsm's.
No, he's not running lean, infact, he's probably running rich. I'd say he'd probably fuel foul the plugs if anything. The high flow pump will bump his base fuel pressure up, effectively "increasing" the size of the injectors loosely speaking. There are a number of things wrong with his setup that I've already discussed with him, all of which I'll address within the next week or so. If you log the stock injectors with a 255 pump, at the boost level he's talking about, you'd see that the injector on time is probably well within its limitations, as they are good for well past the 230whp he's making right now. As far as the rail, well I've got the stock fuel rail in my 650hp race car, so that's not an issue either. The way the DSM fuel system works is when you increase fuel pressure, there's a "drop" as the fuel moves from cylinder 4 to cylinder 1 (#1 being the leanest). There is actual data from a liquid flow bench I can post if you're interested to see, but this is one of the reasons I "trim" each cylinder when I tune stock fuel system cars. The DSM fuel system does have it's limits, but to be honest, it's one of the best stock running fuel setups I've seen. I've made well over 600whp with just a walbro, afpr, ems, and some larger injectors. Infact, the 580whp in my sig was made with 650cc injectors, and stock fuel sytem, which leads me to believe that his problem exists somewhere else.