A number of questions that have been asked via PM

[ojcool]

Quote: Originally Posted by ODHANZ

Quote: Originally Posted by ojcool

Quote: Originally Posted by ODHANZ

Quote: Originally Posted by ojcool

Quote: Originally Posted by ODHANZ

Quote: Originally Posted by ojcool

Quote: Originally Posted by ODHANZ

hey, i looked at your sig and we have a very similar setup--- i just added the jmb 4" intake w/ battery which I think you have---

how does the battery work in winter time if at all- I'm in Chicago so i'm concerned for next year-

SCT PCM flash was also on my list, but I hear that it is not as adaptive as I may need with the temperature and boost variations I may encounter.

The battery I got (kinetix 600) will not start the car in really cold weather, It got so frustrating that I finally put a trunk mounted battery in like a month ago. I kept the Kinetix in the stock location so now I really don't have a power problem
So to answer your question, yes you will need to get a full size battery and put it in your trunk. I had already run a 4 gauge for my amplifiers anyway so it was not alot of work for me.

Who told you that about SCT? Actually the exact opposite is true, anything BUT SCT will have problems with being adaptive. SCT is the best tuning solution out there. You keep all the stock functionality of the PCM and alter only the tables necessary for fuel, timing, and boost. And yes I run PCM controlled boost. I have no outboard engine managment.

hey man,

thanks for your advice here- I just ordered my SCT with 2 tunes- 1 for 93 octane at 20psi and another for 93/100 mix at 21psi- I've also noticed you are posting a lot about this PCM tuner--- any advice?

I'm not getting it tuned yet b/c I have some expensive bills to pay this year

anyways- I run all 100 octane in the summer, do not have the SCT software, and also I was curious about how to set fuel pressure (my car was running lean at high rpms 13-14 so I ordered along with the SCT, the bottleneck fix and a new pump in case mine was going out- I'm on 750cc injectors)

lemme know what you think- Thanks,
Ozzie

AGP has some pretty decent canned tunes. As far as advise there isn't a whole lot I can do for you without the software.

You cannot set fuel pressure without adding a regulator and a return line. I think PtP sells a replacement fuel filter that adds like 1 psi though. I would not suggest using it or it's going to creates some issues for the canned tunes. The bottle neck fix and pump should solve your fuel problems anyway.

I have all that but my car died today after the bottleneck install and fuel pump replacement- it did run great though for the 2-3 pulls I did at 18psi- it leaned out to 12.5 at my new 6500 redline- hope it was just the pump that was faulty- FP was set at 50 psi with my 750cc- does the SCT accomodate for FP at WOT, or is the FP used to manage A/F

Does the SCT accommodate for fuel pressure? If what you mean is does it increase the fuel pressure with boost, no. The PCM thinks the fuel pressure is static even if your using a 1:1 regulator to increase it. Are you using a 1:1 regulator?

Who did you buy your Xcal from? If it's AGP call and ask them to put some fuel into it via a table called "Power Enrichment above Stoich" this table will only fuel under boost.

Here's what I meant about the fuel pressure (I do understand how rising rate works). Say I want to run 18 psi boost right now- how does the PCM know to add enough fuel? Will it be a manual adjustment on fuel pressure if I end up lean up top? It Dosen't, you or you tuner have to tell it to, via a number of tables depending on where the problem is located. If you simply increase the fuel pressure is would be as if you, for example just put a larger injector in the car and changed nothing else. i.e. It will be rich everywhere. However this is a mute point for you b/c your problem is likely going to be richness at an acceptable fuel pressure 42psi is preferable for proper injector function. VE would be the table of choice to remove fuel to calibrate the car to an acceptable a/f ratio. Those 750cc injectors are big, IMO too big. But so many people have carried them over from the piggyback days that they are here to stay, and your tuner should have at least a ball park tune to get them to work. But I would be shocked to see a duty cycle close to 80%.

If I change the fuel pressure up to accomodate does it automatically recalibrate itself? No, it has no idea you changed the fuel pressure other than the fact that the fuel trims are all over the place and it can only correct those so far, 10% is considered max acceptable fuel trims in our shop.

If I want to up the boost to 22psi, do I need to raise the fuel pressure or will the PCM accomodate? Fuel pressure is not the way to tune the a/f ratio, it should be set at a static amount and then injector pulse width should be altered to fuel the engine. I know in the past fuel pressure was used with piggybacks, however this is NOT a experienced tuners fuel control mantra of choice. It is a "when there is nothing else we can do" solution that is used if practicable. This can be caused by a number of reasons, the most likely, too small of a fuel system, or too large of an injector choice, or no control over injector pulsewidth. Or I don't know what the hell I'm doing. (piggyback tuning) FMU's, Boost A Pumps, boost A Sparks, all come to mind as Fuel pressure related tuning, these are all ways AROUND tuning the PCM and having appropriately sized fuel system components and they are very poor solutions. However cost effective they may be, given his choice ANY tuner would LOVE to have the ability to alter PCM tables instead of use mechanical tricks

My tune was for 20 psi, but I was only running 18psi boost and noticed a/f got to 12.2-12.5 nearing redline. Did I just get lucky and hit the magic spot? If I want to go to the 20 psi for which the SCT was tuned (pwerks), will I have to manually adjust the FP? Yes, you got lucky, what static fuel pressure did Pwerks say was necessary? Were they under the impression you had a 1:1 regulator hooked up and you don't? There is likely a reason that you were seeing that a/f ratio. I can assure you Pwerks did not intend for you to be anywhere CLOSE to 12's on a canned tune. Cudo's to you for having the thought to ramp your boost up slowly instead of just set it and forget it. I would want to see a/f ratio in the very low 12's on a turbocharged car being tuned off a dyno at any RPM above 4k. It is safe to tune leaner below that for better spool.

Maybe that's the question you answered the first time around, I just didn't know what to expect with the PCM flash- I thought it was supposed to prevent the O2 sensor codes, but I may have been misinformed as I now have a p0038 code and the downstream O2 sensor is broken.

anyways- I appreciate the help, I'm glad I went with this b/c the driveability was better than dtec and it ripped on 18psi like it used to at 20 with dtec- had the car lived I would have had a few kills that weekend

I hope you don't mind but I copied this question and have posted it with an answer in the SCT forum. The reason is because it's going to be a lengthy answer and It will be helpful for you to get other forum members input as well. It really a number of questions, and it's good that your thinking this way, thats the key to learning to use PCM reflash devices, wanting to know HOW the PCM thinks is more important than what every single table does, many work together anyway so learning to reverse engineer, (and at times make educated guesses) is critical to getting anywhere...

I was going to answer more but my 2 year old son isnt' going to let me right now. There is a ton more than can be said on the subject of fueling/injector choice/ safety and how this PCM works in respect to this most critical of all parameters

stu

[2Spools]

This is a great thread with tons of info. Thanks for sharing ojcool.SCT tuning is by far the way to go and I hope more SRT owners come to see this.

[FayettevilleSleeper]

Quote: Originally Posted by 2Spools

This is a great thread with tons of info. Thanks for sharing ojcool.SCT tuning is by far the way to go and I hope more SRT owners come to see this.

i hope more and more see the light and start tuning with SCT. of course, you got those guys who are stubborn and think that an AFC NEO is THE BEST WAY of tuning. i personally have the SCT flasher, and i LOVE IT!