BADSZ28

iTrader: (39)

I just put in a cam and headers and a borrowed tune. After some logging my O2s seem OK (880-930) and my LTFTs are not perfect but it is a working progress. Any how duty cycle is 125% at WOT at higher RPMs. I have read that people have gotten has much as 460rwhp out of these without problems, well I do not think I am anywhere near there. What am I missing in the tune? Where can I get more out of the injectors so the duty cycle is not so high? Is this even possible or do I really need injectors? I am trying to get a WB on it once I find someone to borrow from. I do get codes. P0300 and some O2 codes. Have not figured out how to eliminate them yet. I am a novice. Car feels strong and has no KR at WOT. Any sugestions?

SSDION

Hi,

I'm in the same situation as you (120% duty cycle at 6000rpm) but I have a wideband to check my AFR. My wideband says 12.85:1 AFR at 6000 rpm and my O2 are 880-890 mV so you are probably too rich at 930 mV. Get a wideband to make sure your AFR is good and not too rich. Probably that this is the reason why you get 125% duty cycle. By the way, I bought the dynojet wideband commander kit and it's working very good and easy to install.

First of all, you have to put your car in open loop all the time to get rid of your fuel trim that can modify your WOT tuning (Be carefull not to melt your engine in open loop, it can be dangerous if your tuning is not good!!). Set your EQ ratio over 1.0 (1.13) and your PE vs rpm to 1.2 for safety. There are a few threads on LS1tech and HPTuners site who explain how to do it. Also unplug the MAF to get into Speed density tuning. If you don't plan to buy a wideband, stay in closed loop and try to get your LTFT in the -4-0% range and after that do your WOT tuning and try to get 880-890 mV from your NB O2.

Dial your VE table so your commanded ARF is the same as your wideband reading. After that, you can calibrate your MAF if you want to put it back and If you want(prefered for the street), you can put back the car in closed loop.

On my side, I'll have to buy bigger injectors and a racing fuel pump. My engine is a LS1 383 with TSP giant cam, ported heads and headers with full bolt-ons. 1st, 2nd and 3rd gear are like trying to drag race on ice My 285 tires are not good enough now Make sure your car is not too rich before investing in new injectors and pump. Also check your fuel pressure at WOT to make sure it doesn't drop under 58 psi.

Also, you will have to increase your timing in the WOT region until you get Knock retard and backoff a little. Best thing is to check your torque and HP curve on the dyno or check your 1/4 mile mph. For my car, 28 degree of advance is good at WOT.

After tuning, You will see a huge power difference if your car is not tuned properly right now. Be patient and careful with tuning, It's not a 1-day job

Hope this will help you with your tuning

SSDION
Quebec, Canada

BADSZ28

iTrader: (39)

Thanks for your help. My timing when the SES light is on hits 29.5* with no KR. This table is conservative compared to my high octane table. This leads me to believe I can give it more timing. So just by looking at my O2s I may actually be rich. I feel better now. I was worried I was way lean. My VE table and MAF table are pretty good. Needs work but the O2 readings stay in line. I am just trying to keep it alive till I can get a pro to tune it.

Also Bank 2 seems to be much leaner. What can I do about that?

SMOKINV8

iTrader: (6)

Save your money and buy some bigger injectors. Think about that for a minute and it might make sense. 120% duty cycle is NOT a matter of running a little rich on the fuel mixture.

RedHardSupra

iTrader: (1)

safe limit is 80%, you're at 120+. so you need 40% more fuelflow. sounds like svo 42s are in order (42@3bar is 48.5@4bar, so sqrt(48.5/28.8)= 1.3) that should get you right in the ballpark

soundengineer

iTrader: (16)

couple of corrections....
set your open loop EQ ratio to 1.0 not to 1.13
then set your PE to match your dsired AFR....at WOT PE/OLFA tables... it will command whatever is the richest of the 2..so if you command 1.13 in OLFA and PE is less..its always going to be 1.13

next fuel trims are a joke with any cammed car..if you are stock..no issues..as soon as you change anythig...evenexhaust or a lid..you can consider the o2 narrowband readings to be not as accurate...
save yourself soe headaches...get a wideband...tune the entire thing with the wideband in a bung pre catalytic converters and it will be much easier...and much more accurate

definately step up to a bigger injector..at a minimum you want 30# SVO's..and I would probably consider 42# lucas injectors but you will probably find the 30SVO's faster and cheaper.

and as far as seeing 460 with stock injectors....
not happening..atleast not with safe and proper A/F...
and I'd be willing to bet that the guys making 460 on 28# stock injectors are also at 120% and a higher fuel pressure than 58psi and they will gain HP from stepping up to a bigger injector

you can find out that your car is best torue and power anywhere from 12.3 up to 13.1 ish on an ls1 engine...
adn its not usually a flat value.... different rpm's and different amounts of torque require more or less fuel to make torque and power....same with timing..a little less timing at peak torque wil help it a lot.

you can tune a car in 1 day..I do it in about 4-6 hours..but I've also been doing it for quite some time and I already know what I'm doing and know what works and what dosnt..so I have a foot ahead there...
but definately take your time and get it right..

SSDION

Thank you scott for your advice

I put the OLFA back to 1.0 to get 14.7 AFR at part throttle after dialing my VE table at 1.13 OLFA. The 1.13 OLFA and 1.2 PE were just to be safe at first because my VE table was way off.

The only problem I have is that when I use the AFR% error histogram with copy paste and multiply to dial VE table at part throttle, it's like the corrections are not high enough to get the proper AFR. I used 25 cell counts to get accurate data but..??

I'll probably invest in 42's injector to lower my duty cycle and play with timing for peak torque and HP.

Thank you again

SSDION

BADSZ28

iTrader: (39)

So is the idea to tune the VE so you never need PE? What should I set the delay RPM to for PE? I have it at 5500. Do I make the whole OLFA table 1.0? What should PE be set at? Mine is at 1.25. I know I need a WB and injectors but no money for another month so I want to make it safe till then. If I do injectors do I need a pump at the same time?

RedHardSupra

iTrader: (1)

leave OLFA alone. set PE to 1.15 (12.7 AFR, good 'all around' number), and just don't go WOT until you get new injectors. you dont need a pump, unless you're going with huge injectors. svo 42s are good on a stock pump.

soundengineer

iTrader: (16)

most guys set th entire OLFA to 1.0 to tune..which is bad in practice..LOL
I personally just set the temperature row that I am in under fully warmed up conditions to all 1.0..then set PE accordingly
at colder temps and hotter temps you will need different values then 1.0...you can work on that later...its a wierd thing to do and I can explain it all someday..just not right now...

technical

Yeah, but setting the lower temp rows to 1.0 makes the car sound sound really cooooool.... blop blop blop. until it warms up.

BADSZ28

iTrader: (39)

OK I will do this. What RPM for the VE though? I have an M6 car. I read that you want it set to your launch RPM. Is thus correct?

RedHardSupra

iTrader: (1)

for trex go 1050rpm, that should keep it out of trouble. once you change it, make sure you redo your RAF so it doesn't have idle issues

BADSZ28

iTrader: (39)

So I want to set my PE just off idle? Idle is only about 900-950. Gotcha on the RAF after changing injectors.

RedHardSupra

iTrader: (1)

huh? what does idle have to do with PE?

BADSZ28

iTrader: (39)

You said to set my PE RPM to 1050. This is practically off idle. I know it does not kick in till WOT but why so low? Is it suposed to be used durring full rpm swing? Or are you telling me to set it low as a safety precaution till I get the injectors?

technical

You originally state VE in the earlier post. That's the confusion.

RedHardSupra

iTrader: (1)

idle rpm to 1050, PE is for WOT

BADSZ28

iTrader: (39)

Woops. I meant PE. So to clearify, what do I set my PE delay RPM at?