PFC settings for 850CC primaries?
 

I am thinking about using 64.5 and 0.04 for the 850cc primaries. I tried 100/-0.04 but idled like caca.

Suggestions? Experience? TIA!

If you follow the instructions on pages 25-26 of the manual and it is too rich or turbo transition is crappy, then you will need someone with a DATALOGIT to tune the PFC. There are older post about this out there, search for them.

search on "850cc primary" and other purmutations yielded nada

I remember seeing the posts, but can't find them

Thanks Chuck. Two of the injectors are actually your olds ones!

Tony

For those that are wondering or searching in the future, here is how I got my numbers for the PFC:

550cc/min have a lag time of .73
850cc/min have a lag time of .76
Lag difference = .76-.73 = .04

Injector size adjustment = 550 / 850 = 64.5%

My search of 850 retrieved 20 posts, with about 16 being about injectors and not 850rpm.

One had these calculations for 850 primaries.
64.7 % with +.05 lag correction.

The 64.7% is mandatory with 850cc primaries. Just entering 850cc in the other box will not cut it. Now lag is a different topic all together.

Oh yeah, now I am getting alot more returns on the search. I was only getting about 6 before, and all the posts were current ones.

I am thinking someone fixed or changed something. I re-excuted the same searchs and am now getting more results.

Without adjusting any other settings (other than the 64.7 and .04) I am rock solid.

Did you enter 850 as the primary injectors? If not the then the staging of the secondaries will be off.

850 as primary. Transitions are smooth. Staging seems on.

How's it feel at throttle tip in?

Tim

Silky at tip in. No difference from the 550/850s.

My settings from ACCELERATE INJ (MS), SETTINGS 2 from the datalogit:
RPM AMT DECAY
5000 7.5 1
4000 7.5 1
3000 7.5 1.5
2000 8.0 1.8
1000 6.0 2.0

I hate the stock acc inj settings. I lean out the top end and make the curve smooth from 1000 .... ie 7.0 to 7.5 for 5000 to 1000.

Another question, what's the injector duty cycle at now with the 850's in all four at whatever boost you are running?
Thanks for the info on the 850 setup, lag time, and accel enrichment times. Good stuff to know.
Tim

I hit 70% running 1bar during some wideband tuning. That is with the 850/1300s and a walbro HIFLO in the tank. I am thinking about replacing the stock regulator with a SX 1:1 unit and adding a fuel pressure gauge. At little overkill for the stock turbos...but I am thinking of it as prep. for the a single...some day. ;)

bringing it back from the dead for people to use.

Tim

Has anyone needed to change the cold start enrichment settings?

No, but I had to play with crank time.

Can we discuss a little about the crank time and what it is actually doing? I havent messed with it but feel like I prob need to, dont really know much about it and couldnt really find any info on it though

STEPHEN

I'm running 4x 850cc with settings for primary injectors as 65.0 w/ .04 lag correction...
Car idles rich (low 11's A/F) and by changing the lag time to -.08 I was bale to lean out idle *but* accelarations were running much leaner...so I went back to .04.

Boostn7,
Have you tried just leaning out the cells at idle to help get rid of the rich idle? If so, what happened?

Tim

I'm also running a/f at idle of 11.0

Actually I've noticed that anytime I'm barely touching the throttle or sitting at idle my af is around 10.8-11.3. I thought maybe the air bleed screw was closed off so when the throttle plates were close there wasnt any air but I opened it almost completely and it didnt really help much. My idle did smooth out some but it didnt really help my af much. Its still low 11's. I've pulled out quite a lot of fuel from idle, I'm going to try pulling more just to see if it will help, but I've pulled a TON.

I'm also running the injector settings above.

Are you guys running O2 control???? I've got my O2 sensor unpluged, maybe I should plug it back in and let the PFC try and control it.

DOES ANYONE HAVE A NICE SMOOTH IDLE AND 14ISH A/F RATIO WITH 850's???? If so what is your exact set up? have you blocked off the idle control or is it still in tact?

STEPHEN

Good question Stephen, hopefully someone has some datalogit info on this or parameters for us to use.

Tim

I run both the FJO wide band and a 4-wire O2 sensor connected to the ECU.
@ idle it still runs in the low 11's so I assume the O2 sensor does not get involved with idle unless there's settings for it.
but during cruising/coasting I see A/F's in the 14's.

There is a setting concerning the O2 feedback loop, is it on for feedback or is it turned off, meaning it just reads off the maps and isn't in lean run mode at idle and low loads, part throttle driving?

Tim