sweet99

I have a Brenspeed SCT with 3 tunes, 87, 93 and 100 octanes. This car is a convertible with an automatic. I am planning on a wideband O2 meter, a PLX devices M-300 to be precise. I have used this unit before on a Talon. I have read that with a NA motor an AFR of 12.8-13.2 is the range at WOT, can anyone confirm this? I would of course start with what I find I have and get that to the 12.8:1 and lean it until knock, hopefully near a 13:1. Then for idle of course stoich, 14.5:1 or so.
I am hopeful my SCT will log 5 parameters as that is what the software says is best to log due to speeds and quantity of possible data. I am looking at these, comments please plus fill in the blank:
1. RPM
2. Timing
3&4. Both banks O2 voltages.
5. What would be a good fifth piece of data to add to these and the wideband AFR reading?
I do not believe the 2v's have a knock sensor that would show up or pull timing, correct?
Has anyone found that the 4.6 likes less timing at higher rpm's? I have in a limited way and will try to confirm and get this data logged to share. I am talking 4K and up as that is what the SCT allows me to change. I have added 4* from idle to 2K and 2* from 2K to 4K.
Any/all advice is appreciated. Thanks, mark

czwalga00gt

2v's really dont gain as much power like the pushrod engines did by adding timing and really leaning it out. You can give it a shot; but honestly for 2-3 HP, i'd rather not push my car to the edge of it knocking.

sweet99

Well I know the 100 octane tune added power as my 60' went up a tenth but I still went into the 13.9x range with my best ever trap of 101.8 so there is something to be had. If the 60' alone was my usual 2.15 I should have gotten a 13.7x. Besides all of that unnecessary info I need to have a wideband as not knowing the AFR's is not comfortable for me. The car smells rich and even with custom tunes every car is different. My JLT CAI has the MAF outside the engine bay also, that could affect the afr's, yes?
What I really need is a confirmation of the NA AFR's at WOT and timing throughout the rpm range from those who know would be helpful. Certainly there are some guys with their dyno sheets that have the AFR on them? I may go KB SC but not until my house safety fund is back where I am comfortable! Thanks, Mark
PS: What do you run with the SC for AFR? 11:1 on 93? I could never get my Turbo Talon to run leaner than that but I ran 30psi with a large turbo. Little ricer 2 liter running 11's at 120+. Man I HATED THAT CAR!

Aixtreme89

You asking questions most people dont know... I dont think anyone in the 4.6 forum tunes there own car. How you do you plan on tuning your car? Bringing it to a dyno? Because I hope you have the SCT Pro Racer Package http://www.sctflash.com/product_racer.php or dealer custom tuning software http://www.sctflash.com/product_adv.php Because otherwise all you can do with your SCT hand held tuner is data loging and mild adjustments. If your getting a wideband o2 sensor get the pro racer software, its $300 http://www.blueovalchips.com/proracer.php Then you can buy the manual for $75 it and it will tell you everything you need to know to tune your own car. Thats the best bet for what your looking for.. Heres my dyno graph if it will help you. The dyno tuner tryed to set it for 13.0AFR but only did an hour long tune if I wanted to go for another hour he could have leveled out the fuel curve more.... There are about three dyno runs on that graph for compairison. And by the way 4.6 motors with iron blocks dont have knock sensors. I am not sure about the 03-04 cobra... All the aluminum 4.6 blocks have knock sensors.

sweet99

Thanks for the graph and other info! I tuned my last car, a '93 AWD Talon turbo, highly modified with a custom chip and a wideband, adjustable fuel regulator and a GM MAF translator with a GM MAF of course! Got into the 11's at speeds around 120+. Not being very computer literate I left at least 50HP on the table by not using DSMlink.
I plan on using my existing Brenspeed tunes if they are close enough to what I am shooting for or will get a reflash. The 4.6 does not leave much for bolt ons either and some are a waste. If anyone got the latest MM&FF at the stores it comes with na disk and mods done to a 3v 4.6, 2006 I believe. Same bolt ons that we do and not much there. They did a complete 3" exhaust with stainless sytstem headers and all the way back and I believe they picked up 10whp and the same # for torque but 14whp under the curve. That system must have cost near $1200.+ and for that little power. Even with full bolt ons and a SC they got into the low 12's, more like 12.3x's.
Nice time by the way, congrats. And thanks again, Mark

czwalga00gt

Something to note when tuning your own car... with the SCT handheld you're very limited with what you can do. To really tune your car; checking MAF voltages and data logging it against RPM is what you really want. Howevery you can not change those on the handheld without the SCT Racer package. I think its like 350$ or something.

nanaki

i leave the tuning of my car to the professionals. at least if they mess it up (hasn't happened yet *knock on wood*), it comes out of their pocket to fix it.

sweet99

Wouldn't that trick the computer as to the amount of air entering the motor so that it would then change the fuel and timing? If so that would not be the best way to go about it would it?
Remember my motor is NA and I would be using existing custom tunes from Brenseed and fine tuning them. Brent may set the tunes for a 12.8:1 to have a cushion of safety, same with timing. I am not considering major changes or starting from scratch but rather checking to see if the present tunes are as close to a 13:1 as possible, maybe a 13.1:1 without knock and perhaps juggling the timing in small increments. I believe my motor likes less timing up top. I already added 4* to the idle to 2K range as the motor is out of that range in a split second. Just some thoughts and looking for actual numbers that are working for others. Thanks for the input and advice. mark