My friend's got a 305 v8, twin turbo, pretty much stock internals, pushing like 16PSI of boost at 4k RPMs, holley stealth ram with the commander 950, cant get the engine to run for more than a few seconds without rev'ing it....
What can you guys recomend for the fuel map? what else should we try? Changed the wires and plugs today, that didnt help much....
Thanks,
-Chris

 

Well, Holley's don't tell you what their fuel map is injecting as far as pulse width, so I'm not able to tell you a good map. I've developed a spreadsheet that'll generate a base fuel map from just the engine parameters (injectors, torque curve, bsfc, A/F) and it's proven many times to be within a few (+/- 5) percent, as long as the torque is estimated well. If you had a way of converting a pulsewidth based fuel map over to Holley, I'd be glad to help. I have the holley manual at work, and I'll see if there is some conversion in it.
It's also MANDATORY to have a wideband sensor when calibrating a fuel injection system, especially when it's a strange combination like that, and when he can't even keep the engine running (due to lack of experience I presume). Innovate sells em for $350 with a sensor, so there's no excuse.
BTW, if it won't stay running, it's usually too lean at idle (just watch where the Holley goes at idle and raise those numbers, and try to surround it with similar numbers (I forget if Holley's base fuel map is based on VE (100 at 30 kPa is 30% of 100 at 100 kPa) or some other form (like 30 at 30 kPa is 30% of 100 at 100 kPa). Also, the IAC is supposed to keep the idle good, but Holley's idle PID sucks, and you may need to open the throttle set screw some, and run with a closed IAC at warm engine. Ignition timing will also affect idle greatly, so, make sure it's timed correctly, and then throw in 16 degrees total at idle, it'll run.
SO, what size injectors is he running? What fuel pressure? Is the fuel pump big enough (pushing against another 16 psi isn't easy, and reduces the pumps flow rate)?
Did he do anything to beef up the bottom end? How about lower the compression? If he didn't he can't run 16psi, no way no how unless I'm missing something.

 

Stock internals pretty much means factory rods, crank, and pistons. 16 psi, that engine won't last too long.

 

we're just trying to find SOMETHING that will make this damn car run.....
btw we had to change the spark plugs (Brand new) and they were SOAKED with unburnt fuel....

 

The quickest way to get an injected engine up and running so tuning can start is to (aside from reading all you can before hand) is, for each Load row (i.e. 30 kPa at all RPMs) put in that much percent of the max PW required. So, if you have 8 36 lb/hr injectors and 450 ft/lbs of torque, that's approximately 9000 microseconds of batched (half injected per pulse) pulse width (18000 total). On the Holley it looks like the PW for 100 is probably 8000, so to get it to run, (with a 2 bar MAP sensor I presume), at full boost (200 kPa, or top row in Holley) put 120's. at idle (or about 38 kPa, but make sure you watch the laptop to see where it idles), put 40's. Smooth it out in between (there are 10 cells between 38 and 100%, and a change of 80, so increase by 8 for each row.

100 - 120 120 120 120
94 - 112 112 112 112
88 - 104 104 104 104
.
.
.
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For spark, put 16° at idle, at free rev put 35°, at full boost and with that engine, start low, like 12°, and at ambient (where the MAP reads at key on engine off), put a normal curve like 16 down at low RPMs, increasing to 30 by 4000 (conservative) blend everywhere.

Good luck, and hope this helps.

 

3 bar map sensor.....
Thanks for the info though!
What would i need to change as a result of the 3 bar, not 2 bar, map sensor?
thanks alot though!

 

I haven't used a Holley with other than a 1 Bar MAP, but, I'd assume that if you select 3 bar sensor on the setup page, that it would put a 300 at the top of the main fuel map. At 200 kPa, put that 120. At 100 kPa, put 60 or so, and around 30-40 kPa, put 30's. If it still isn't running, make sure all the sensors are outputting normal values, and respond properly. Idle is always a pain, most cars will idle (at least stay running, rich or lean, no matter what injectors unless completely mismatched) with an injected pulsewidth of 2500 microseconds, or 2.5 milliseconds (batch mode which means total pulsewidth for that cylinder is around 5 milliseconds which on Holley's might be right around 32 if the calculation is based on an 8 ms batch PW = 100 which is also a 16 ms single shot PW = 100).

Again, without a wideband, you'll (he'll) have to take baby steps to get it tuned. With a wideband it could be done in an hour (but a stock bottom end is asking for trouble - I can just hear the pistons cracking already - get some cold plugs in there, and put some 76cc heads on it).

Cross your fingers.

 

ok....
BTW, i just realized this, but he's got the race upgrade on the ECU as well.....from what i understand, it just has more capabilities?

 

Any ideas what size injectors he's using?

 

I've honestly got no clue.....
I assume that because he's been working with cars and working with/around turbocharged cars and custom turbo setups, he's using whatever would be best.....
Sorry, I have no clue what size injector he's running through.....I will find out asap though.....i wish i had known exactly what to ask yesterday.....but as i said, i had to leave in a bit of a hurry (My friend realized he had work later on), so i wasnt able to think about that sorta stuff.....
thanks anyway...will post when i find out more about his setup