APEXi AVCR Question

[Pstl_pete]

Should injector duty cycle read 100% during deceleration at times? It does it for a split second and then goes to back to 0%. When you shut the car off it also shows 100%. I have doubled checked the wire it is hooked up correctly to the No. 1 injector wire on the ECU.

This relates back to the first question, at 9psi I was seeing only 53% duty cycle. That seems a little low for WOT with such small injectors. I do have pulled 25% fuel out though.

[420sx]

what turbo? t25? t28? t3?

[fliprayzin240sx]

If this is on a SR...the duty cycle option on it is crap. It wont show you anything close to wut ur duty cycle really is.

[Pstl_pete]

Sorry its a S14 T28.

So I shouldnt rely on the AVCR for duty cycle at all? Everyone has told me to use it as a gauge.

[420sx]

If this is on a SR...the duty cycle option on it is crap. It wont show you anything close to wut ur duty cycle really is.

i beg to differ. i seen work just fine and tells you when ur maxing out your injectors.
do you have first hand experience? or is it just something "you heard"? :ugh:

[420sx]

Sorry its a S14 T28.

So I shouldnt rely on the AVCR for duty cycle at all? Everyone has told me to use it as a gauge.

stock sr injectors running on t28 max out at 9-10 psi. let me check with Muzzy he has t28

[Muzzy]

yea ho....my injector duty does go to 100% when i stop at a light or somethin sometimes. mostly when i have my AC on it will do that.
the duty only hit 53% at 9psi at WOT because u prolly didnt hit 6k-7k rpm. i have a T28 and when im at .8 bar (about 12psi) i max my injectors out at about 98% at 6k-7k rpm(WOT). daily i run .6 bar ( about 9psi) i hit about 85% at 6k-7k rpm (WOT). its a wise idea to look at the duty to maek sure u dont lean out and blow up. Plus u can get a better idea of exactly when the duty is at a certain percentage during the run by using the graph recording function so u can review it.

fliprayzin240sx- i doubt this...everything else that the AVCR monitors is correct based on all my other gauges and stuff. i've never heard of anyone sayin its crap. only bad thing i have heard about is its hard to set up...which it is not.

[Pstl_pete]

Did some more testing.

Hit 75% IDC at 9psi. Tried to add more boost but my AVCR wont hit the target boost I set now! Still getting used to all the settings, ie duty cycle.

FYI - I have pulled out about 20-25% fuel on my safc so that may have lowered my IDC?

[DTS]

the avcr duty cycle is definatly fairly accurate untill the 99-100% area

also you cant just set your target boost and expect to hit it, you have to tune the solonoid duty cycle to match it.

[JDMs13]

Sounds like its confusing to set up? To those of you who own this, would you say it was worth 4 beans? I guess being able to monitor your injector duty cycle would make it hella worth it.

FLIPANZE......what makes you say this feature is bunk?"

[DTS]

its the best boost controler i have ever used. definatly worth every penny IMO.

and it isnt hard to setup it just takes a hour of reading the manual and playing with it to understand it and once you understand it you will understand that the amount of tuneability and customization of the boost is amazing.

[Muzzy]

yea its great! worth every penny. if it were not 4 that i could have blown my motor by now cuz i wouldnt know my injector duty. its also great of your speedo or tach is broken.
yea its a bit tricky to set up at first. but u set the solenoid duty to reach the target boost.....thas how i set it up.

Pstl_pete to answer your last questoin u posted in regard to the SAFC......are u using larger injectors???

[Pstl_pete]

Nope, stock injectors. I have a wideband and had to pull out about 20% to get it to down to about an 11:1 ratio.

I have read the entire manual and I thought I understood duty cycle but if someone is so inclined to explain it again, Im all ears.

What duty cycle are most of you set at?

[Muzzy]

well...at .6 bar i hit 78% ID at .8 bar i hit 92% ID
u may have lower IDs because u are runnin a T25..im runnin a T28 so my duty will be higher at the same boost level.

to achieve those boost i set mine at .6 bar @ 40% SD and .8 bar @ 50% SD

[Happy240sx]

Nope, stock injectors. I have a wideband and had to pull out about 20% to get it to down to about an 11:1 ratio.

I have read the entire manual and I thought I understood duty cycle but if someone is so inclined to explain it again, Im all ears.

What duty cycle are most of you set at?

Something doesn't seem right to me here. I've seen dyno's and afr's of stock turbo, stock boost, stock tune sr's running 12:1 afr. You had to take OUT 20% fuel to get it to 11.1:1. Why are you running so rich if still on 370's? Are you on a stock ecu?

Also, if all is well, why stop at 11.1:1 -- aim for 11.8

[fliprayzin240sx]

well explain to me how the fook im running 100% duty cycle on my 740cc injectors but only 70% on my stock 370cc???

[Muzzy]

well when u let off after a hard run at full boost and depress the clutch the rpms drop so low that it cut soff 4 a sceond and the ecu dumps fuel in it like its trying to start itself. hard to explain but my car does it all the time when i run A/C. i'll drop it out of third and coast or drop it out of second to the red light and it will shutter or cut off because of the load of my AC compressor and it will read 100%

[Pstl_pete]

Something doesn't seem right to me here. I've seen dyno's and afr's of stock turbo, stock boost, stock tune sr's running 12:1 afr. You had to take OUT 20% fuel to get it to 11.1:1. Why are you running so rich if still on 370's? Are you on a stock ecu?

Also, if all is well, why stop at 11.1:1 -- aim for 11.8

Im just as confused as you are. Everyone is telling me that I should be maxing out my injectors but Im not. I am thinking this has to do with my Z32 MAF. I had to push it to - 25% in some spots just to see an AFR reading of around 11:1. The car runs PIG rich and is dog slow with the SAFC zero'd. I have all the right setting for the Z32MAF but I just think the SAFC computer doesnt do a great job converting the signal at WOT.

As for my AFR, this was after one tuning session, I was able to get it down to 11ish:1. The problem is the powerband is so patchy where the car feels sluggish down low and when you rev it out it picks up then again falls out a bit at 6K+ but the AFR up there shows full rich on my AEM. I just grew tired of trying to tune the flat spots out knowing I should be maxing my injectors. I will be switching back to the SR MAF that will hopefully alleviate the problem for the timing being until I upgrade the injectors and reflash the ECU.

Oh and I am on a stock ECU, T28 turbo.

[Muzzy]

u will max your injectors at about 13 psi....i did