I have a fd with a powerfc,35r, 1300cc sec, twinpower ign, and other supporting mods. At part to almost full throttle from 6-13pis, at 5200-5300rpm its breaking up, a/f reading (9.5-10:1 just at that rpm). I began to pull fuel from the 5200rpm axis and the p13 to p16 boxes(when it was tuned after the turbo install all boxes were reset to 1.00 and I have pulled them down to .90 or so). the studder went from not pulling past 5300 to two mild studders but it will now pull past the break up point from before. I.E. pulling fuel made the studder better and somtimes not there at all, and after that the car pulles very smooth(a/f in th10.8 to 11.3 still on the rich side). I do not have any real world tunning experince, just what I have leared from this forum,and in my car. I am I going in the right direction or are there other factors I am missing? I am very weary of pulling any more fuel because of my lack of knowledge but want to learn how to do this. What do ya'll think? I would talk to the tuner who did this but he is now in jail.

 

could possibly be pri-2nd injector transiton settings

 

the lag transition on the sec. set a .02 ms. The transition occurs in the 3 to 4000rpm range depending on throttle input I believe...

 

Sometimes it is difficult to tune the AFRs around and in cells when the secondaries are coming on line. In order to determine if this is the case, check the injector duty cycles in those cells and compare those numbers with your Pri/Sec Transition (%).

 

Or maybe your plugs are just bad due to running so rich.

12psi I am running 11.5AFR.
0 - 6psi I am running 12.1AFR.

GT35R 1.06 hotside, almost stock ports.

 

Plug are cleaned and checked regulary. I have put a new set in (9's all around)and with in the time it takes to warm up and the first boost it will break up, but only at that specific rpm. every where else the car runs fine, and never had any other problems. wel my fpr line has come off to cause a chip on the apexseal . I do not have a data logger connected. I am on the interstate watchin what i can while driving in 4th gear tryn to fix this. How do I veiw the pri/sec transition?? Is there any one in the area of Slidell La that would able to lend a hand??

cewrx7r1- I as well have a 1.06 hot with stock ports, t3 flange, a-spec short runner kit.

at full throttle and 15-16 psi there is no problem but when I let the boost drop and part throttle it breaks up. I think I need to get in there and pull more fuel cause after it breaks up and I let out u always get a good back fire. What is the actual value on the inj. map?? when I go from 1.00 to .90 what am I changing as far as fuel flow?? thanx for the help,keep it coming.

 

Of course you know, you’re at quite a disadvantage without Datalogit.

You can view the injector duty on your Commander. The numerical display can indicate whether or not you are going into transition, but maybe the graph display will be more helpful.

Have you tried running just off the wastegate spring and then slowly turning up the boost in small increments?

Or try very light throttle for rpms 3,000 and up, attempting not to go in boost. This may help isolate whether it is transitional or not.

Changing from 1.0 to 0.9 results in the injector being on 10% less. 1.0 or 0.9 are just multipliers in the INJ map, meaning the corresponding cell in the Base fuel map is multiplied be the cell in the INJ map.

 

There is a large RX7 community in New Orleans that can help you!

 

I will play with the pfc tomorrow graph display tomorrow when I have some daylight. to veiw the graph go to the monitor function select inj duty and push next till I c the graph right?? thats how I was watchn the inj map and useing the map trace to c where it was breaking up on the inj. table.

Yes I have turned off the boost controller 7psi and at full throttle it breaks up 70% or so of the time, sorry I think I misinformed u earlier. it seems as the ambient air temps went up it started doing it every time.

I wish I could data log... Thats y I am so afraid to make changes cause I can't c what effects the chages are making.

from 3000 up not going into boost (-3to0 inhg)it is smooth every time, even at a 1,2,3 lbs. just gets bad under boost but at high boost (15-16psi) its ok. I have been watchin this for a while now and am just begining to make changes.

 

Ok I went out and ran from 3000 to 5300 rpm. The injector duty woul read 40 to 47 % under 10 psi, 3/4 throttle. When it would break up the duty cycle would instantly jump up into the 55-60% range from the mid 40's reading with no chage in throttle position. Is that my sec coming on out of sync.

Also the lag time on the sec's is set at +.04 not .02 as I stated before.

I ran through the same test at 0 psi or so and the duty cycle climbed smooth and no break up.

so when it would break up I could watch the duty cycle jump up 10 to 15%.

I did not run past that point so I don't know if the duty cycle would drop back down with more rpm. Does this help??

I though M-theory was the Key to the Universe??? Just pickn, I like you avatar

 

I am reluctant to advise, since you cannot log and I don't know what your base fuel map looks like. At least you have a wideband to help you out. I am running the same turbo setup as you, same injectors, and an HKS as well.

fwiw my lag is 0.14

hopefully Chuck will chime in

 

Have you tried to recal the Base Map then copying it into excel and charting it? (per Wargasm). Check at least for no crossing fuel rows. You need a Datalogit.
Barry

I will email a excel program to you.

 

Want to thank Barry 4 his help and shared information. Chuck and wargasm to the effort they put into tunning these cars. Problem solved!!! with more tunning to come.

my base map was a cluster f!@k.

 

was it too rich?

 

Barry is a good man with a wealth of knowledge who likes to extend the envelope of performance and thinking!

Now I am remembering Mark and am getting sad.

 

Chuck, it makes many of us sad but we feel privliged to have known Mark.
You are such a good person for your visits (all the way from Houston), to be with Mark.
GOD Bless You and Judy.

Mark's quote, " Life is full of trials and tribulations, misery is optional".
Barry