This last week was awesome, I was able to dyno 600HP and everything looked PERFECT. We figured we'd go out and do some street tuning just to verify. As soon as we get the car off the dyno and started driving around we were hitting lean cut. After a couple of hours of trying to dial in the tune and still hitting lean cut one of us (3 guys in the car) finally looked down and saw at WOT we went from 80psi down to 28PSI via my fuel pressure gauge in the center console, only during WOT however.
Yesterday I drove down to the shop and met up with Geno and one of his guys Shawn, they helped me go through the vehicle and we thought I had a bad fuel pump (DW 300) so we slapped in 2 new Walbro 255. Nope, still having problems.... After some more testing we found the car would run on one pump but would die after a little bit on the other. Kept troubleshooting to find that one of the power leads from the front relay to the rear was shorted so we put both pumps on one power lead. This fixed the problem and the car would go up to around 80psi then drop down to around 50psi at WOB but would still hold fueling.
Geno and some guys from Full-Race, my wife and I all piled into my wife's truck, my Flex and Geno's truck pulling a trailer in case of mishap with the Flex to head down to Tucson SIR (120+ miles away). We got to the track around 9pm and jumped in line, on the way down Jeremy and I street tuned the car and scared the crap out of my wife (car in 4th gear goes from 60-100++ real fast now). Car seemed fine on the road.
First pass, car lean cuts in 2nd gear then is so rich at 5K++ that it chokes and throws a service engine light due to too much fuel.
We tried to dial it back but 2nd pass was the same problem so no good runs last night. We made 2 passes from 9pm until 1am due to some fast cars breaking every 2 or 3 passes at the track.
Game plan:
1. Run new power leads to replace old ones, need larger gauges (previous was 8, probably going with 6 now)
2. Throw the old DW300 back in but long term need to swap to Walbro 420's for power levels I'm at.
I'm at a crossroads long term on how to tune the car, I have three options:
1. ProEFI to control aux injectors, boost (min boost = 500HP can't get lower than that and car won't hook on street tires at 500HP), timing and use their awesome traction control via rev limiter to get some decent street launches. I can also get boost per gear, timing/boost based off of ethanol content etc.
2. Follow Ford Racing's dual DI pump (I was told it's a dual pump) and install a 2nd DI pump on the other valve cover, this will require a custom valve cover, custom cam and control of dual spill valves. I might have to make an electronic box to take the ECU to split to both spill valves and not fry it from the new load.
3. This is very small chance - put the car back to stock and trade it in on a Tremor and go nuts on that. It weighs about the same but the transmission is the same as Mustang so lots of parts, more room for BIGGER turbos and larger support. I could probably have a 1K HP Ecoboosted truck within a year, I'd still be fighting fuel control so I'd probably get to the same place I'm at now very quickly.
The trials and tribulations of being FIRST suck, especially when I don't have anybody to talk to about what to do next. I'll keep banging away though!
BTW, getting home at 3:30 am after getting up at 5:30 am makes me groggy....
