I've got Auto Custom Carpets for my Fury as well - I hope I get it installed in the next few months...
And somehow it hasn't sunk in until now that you've got a T-5 in this thing... WOW, this is such a great real-world build! No super exotic parts, but lots of readily-available and affordable upgrades that come together in the best possible way. Outstanding!
Joined: Sun May 04 2014, 04:47PM
Location: Missouri
Posts: 75
Hey guys, little update for you. I took the fury to my local track just to see what it would do. My best run of the night was 14.2 with a 1.93 60ft. I did expect a little faster than that but I didn't break anything so I guess that's a win! Here are a couple pictures my nephew took at the track.
An added note, I now have almost 4,000 miles since the swap and I'm still loving it. It's reliable and gets low 20mpg on the highway. I get stares and questions about it everywhere I go! The only issue I have is that I can't seem to find anyone to get the motor to idle right with the megasquirt. I have the comp cam in it and the idle wont stay. One of the tuners I took it to said that the surging idle (300rpm to 1500rpm) is the best they could do. It only does this after it warms up. Before then it idles at about 1k rpm and has a good (yet too high) idle. Any guidance would be great!!
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
If your tuner has some experience with MS, and/or custom tunes on OEM ECUs, let's presume they are reviewing tables and finding things look as they should, but the problem persists. The larger cam might be a difficulty, but they should know how to account for that (same as for how a carb would be set up for a large cam).
With that said, to increase/decrease engine speed you supply more air** and the fueling system (whether carb or EFI) should respond to give it the fuel for that amount of air. With EFI, you have the IAC responding also, adding/reducing air, trying to maintain a set speed. (** or ignition timing)
Your tuner should've been able to make sure the hysteresis (the damping) in the IAC and idle speed is suitable, but maybe they didn't.
But - I would make sure you don't have a vacuum leak, that you're not running your IAC too high/low on it's step-range, and that you're not using too much (or too little) ignition advance to bring the falling idle up. The fastest way to correct engine speed is with an increase in ign advance, because that happens on the next cylinder fire. Trying to bring up engine speed via more airflow takes a bit longer. With that said, you don't want 'too much' advance at idle, because that leaves no margin for some extra advance to catch the engine speed drop.
As time goes on, people (tuners and technicians, that is) are going to focus on electronics to solve problems, and will ignore old-school mechanical basics in diagnosis.
Are you using Tuner Studio or another MS tool to monitor what is happening? I would be curious what the IAC, timing, TPS and wideband are doing when all this is happening.
Joined: Sun May 04 2014, 04:47PM
Location: Missouri
Posts: 75
Thank you! I'll talk to the tuner and see what he says. I'll see if I can get more info on that too. I am not very good when it comes to the tuning, hence why I took it to someone! I did test for vacuum leaks and did not find any. I replaced the iac twice as well.i will talk to the tuner and see if he can send me a copy of the file, he is using tuner studio. The last time I took it to him, he said that the tune looks perfect and that something is wrong mechanically, causing the idle issue. I was unable to find anything mechanically wrong with it and I even took it to my buddies shop to let him have a look. He told me it was definitely the tune.
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
Ah, it's the tune. No, it's mechanical. Gotta love getting opposite opinions! And your tuner will love to hear someone on the internet is 'helping'!
FWIW, from everything I've read, getting the airflow modeled correctly is critical (so your cam is making that more difficult) and the idle (and transition from it) are the hardest thing to tune.
I would recommend getting these 2 books by Greg Banish, read them, go thru with a highlighter, too. If you only want to invest the time in 1 book, get the 2nd one.
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
From my experience, in the speed density world: warm it up good watch the corrections it's making for O2 readings let it self learn or adjust the VE table manually if needed to narrow the correction hunting at idle like you describe is a lean condition. Add a 1/2 point a/f ratio to it to see if it stops. If so, and since warm up is ok, you'll then need to back off your warm up fueling. I don't use timing correction to maintain idle, i turn that off. I'm more interested in being able to tell something isn't right than have the ecu mask it for a smooth idle The rate and amount your IAC corrects can be important. On my classic fast with a GM style IAC sticking out the back of the elbow I had to set it to be much faster acting than the defaults
Joined: Thu May 01 2008, 11:15AM
Location: Chicago,IL
Posts: 2868
so all the old photos are gone again. What year of hemi did you use and truck or car? Got any photos of the engine accessories, oil filter relocation, manifolds to fenderwells?