Guys based on many different peoples opinions I have built a 408, FI (F1R). I have invested quite alot of time and money and I am nearing completion. I was told not to skimp on the fuel system so I ensured that it was up to spec, that is it will support 800+RWHP. I went with Acceleronics 96# low imp injectors.... along with their converter box. The car runs. We seem to be having trouble tuning the car ...... running to fat on bottom, we have the pulse width nearly cut in half... and we are afraid if we go any lower we will burn out the injectors. I don't have a BS3, noe do I really want to invest in one. I know others that ran/running low imps with no probs, if there is any help ya'll can offer I would deeply appreciate it. I am not a tuner and I'm trying to get this right. I use HP Tuners.



Thanx in advance.

 

Where is your fuel pressure? You can always lower the fuel pressure and see where that gets you for part-throttle and idle. I am assuming that you are using a 1:1 regulator?

 

What is your inj pulse width? You should be able to get down to around 1.2 ms but lower then that you will probably get an erratic idle because the inj does not have enough time to fully open and close. Also, in your PCM's program there usually is a table for "minimum inj pulse width", that will not allow you to go below approx 1.2-1.3 ms. You might try to lower that a little if your already there. I've never heard of burning out an injector with too low of a pulse width.

 

that converter box may be limited in its ability to produce low injector pulse widths. Call Acceleronics ask them what the minimum pw that the converter box is good too. If your pushing it see if you can get the fuel pressure down furthur.

or

sell the converter box. And run the injectors natively on megasquirt id talk to dieselgeek or Parish (single turbo truck with 1000rwhp) he can tell you how to set up a fuel only megasquirt system. Dont buy the two bar system for HPT if you decide to go this route. msefi.com