2003-04 Mach 1 Registry Owners Club - Thread for those of us who tune our own cars

2003-04 Mach 1 Registry Owners Club (http://www.mach1registry.org/forums/index.php)

- Tuning & Dyno Testing/Results (http://www.mach1registry.org/forums/forumdisplay.php?f=9)

- - Thread for those of us who tune our own cars (http://www.mach1registry.org/forums/showthread.php?t=132871)

Re: Thread for those of us who tune our own cars

Changed the IAC to a fresh OEM ford unit and no change. Has to be something with the tune. If I unplug the IAC while its doing it, the car dies. So its flowing too much air through it. I smoke tested it and couldn't find any vacuum leaks.

MAF readings are really steady, so I don't think its that because air fuel is dead on. I did just learn that you have to change all of the voltage comp and pressure adjustment tables in the fuel injector data. Noticed my timing is jumping up to 30 when it idles like that, so I'm capping low load and low rpm timing to 5.

Woooahhh! Capping the timing under 1.5k and .2 load fixed the issue. I also played with some of the dashpot and ISC functions to get it to drop to idle like a rock.

Re: Thread for those of us who tune our own cars

Congrats 828, sounds like you are really making progress on the 'ol learning curve :smokin:

Re: Thread for those of us who tune our own cars

I think so! I've come a long way so far.

Re: Thread for those of us who tune our own cars

Good job on fixing the idle issues.

I'm going to start tuning my new 5.3 BB/S tonight. I started it up yesterday and it wouldn't run without feathering the gas on the old tune. I updated the displacement and will see how it runs.

I forgot I changed to big Comp Cams so I hope I'm not battling that too much.

Re: Thread for those of us who tune our own cars

Quote:

Originally Posted by stellasmechanic (Post 1600096)

Keep up updated on how it goes! Curious what all you end up adjusting to account for the cams.

Re: Thread for those of us who tune our own cars

Did a quick test. Adjusted displacement and set idle to 950. Idled pretty well.
No need to tap the throttle or anything crazy. I'm sure I will have to do something when I lower it back down.

What is the most timing I should run on e85? I've got it at 19 above 5k and 20 below. Car runs really strong now actually get an adrenaline rush again

Re: Thread for those of us who tune our own cars

Quote:

Originally Posted by Mach828 (Post 1600536)

What is the most timing I should run on e85? I've got it at 19 above 5k and 20 below. Car runs really strong now actually get an adrenaline rush again

why are you going down in timming? if anything it should stay the same or go up with engine speed.

also you have knock sensors so log knock and add timing slowly tilll you see knock or it stops getting faster. i would think 21*or so would be ok. but monitor knock!

Re: Thread for those of us who tune our own cars

I shut the knock sensors off. They get to many false knock readings. When I ran e85 NA my tuner had to do the same thing.

I'm decreasing timing with rpm because I'm scared of how much power its making now with the stock bottom end at 115k miles. It dynod at 490 with 16 degrees of timing. Its got to be about 525 or so now. I'll put it at an even 20 and see what happens. Its roasting my 325 drag radials now from a roll with the e85 tune.

Anyone boosted with e85 and doing their own tuning? It likes to run a little lean. At low 11s on the wideband it is choppy, but likes to be at about 12. I just changed the stoich value, added timing, and adjusted the base fuel table. I don't really want to mess with the MTF since its solid.

Re: Thread for those of us who tune our own cars

You dont touch the mtf if you just changed fuels it dosnt care if your e85 or meth or gas its just reading airflow. If its good then its good!

Re: Thread for those of us who tune our own cars

with the high compression aluminator and 15 psi we peaked at 19 degrees timing on E85. I didnt discuss in depth with my tuner but at 19 we beat my power goal so we stopped there, no need to lean on it too hard. It sounded like there was a few degrees to go still had we needed it.

Re: Thread for those of us who tune our own cars

Interesting info I found on running higher octane fuels and the combustion process.

Quote:

"Lower octane gas burns more easily. It also means that the flame front moves faster. So, if you get a tank of crummy, low octane gas, you're more likely to get pinging, even though your timing and compression are the same. To compensate, you could retard the timing some amount (less advance). Likewise, the flame front moves slower in higher octane gas, which requires more ignition advance, but also allows higher compression.

If the spark plug fired exactly as the piston was at the top of its stroke (top dead center or TDC), then you're not being as efficient as possible. The instant after the spark plug fires, the piston starts moving down, and the flame front has to catch up with the piston. The distance the piston moves, after is starts moving down but before the flame front reaches it, is wasted since it's not extracting power from the process. Only after the flame front catches up does it start pushing down and giving power.

The trick is to actually have the spark happen before the piston reaches TDC. That way, when the flame front reaches the piston, it's exactly at the top of its stroke and ready to start moving down, and you'll be getting power out of the fuel's burning during the whole power stroke."

"So where does the knock suppression of richer mixtures come from?

If the mixture gets ignited by the spark, a flame front spreads out from the spark plug. This burning mixture increases the pressure and temperature in the cylinder. At some time in the process the pressures and temperatures peak. The speed of the flame front is dependent on mixture density and AFR. A richer or leaner AFR than about 12-13 AFR burns slower. A denser mixture burns faster.

So with a turbo under boost the mixture density raises and results in a faster burning mixture. The closer the peak pressure is to TDC, the higher that peak pressure is, resulting in a high knock probability. Also there is less leverage on the crankshaft for the pressure to produce torque, and, therefore, less power.

Richening up the mixture results in a slower burn, moving the pressure peak later where there is more leverage, hence more torque. Also the pressure peak is lower at a later crank angle and the knock probability is reduced. The same effect can be achieved with an optimum power mixture and more ignition retard.

Optimum mix with “later” ignition can produce more power because more energy is released from the combustion of gasoline. Here’s why: When hydrocarbons like gasoline combust, the burn process actually happens in multiple stages. First the gasoline molecules are broken up into hydrogen and carbon. The hydrogen combines with oxygen from the air to form H2O (water) and the carbon molecules form CO. This process happens very fast at the front edge of the flame front. The second stage converts CO to CO2. This process is relatively slow and requires water molecules (from the first stage) for completion. If there is no more oxygen available (most of it consumed in the first stage), the second stage can't happen. But about 2/3 of the energy released from the burning of the carbon is released in the second stage. Therefore a richer mixture releases less energy, lowering peak pressures and temperatures, and produces less power. A secondary side effect is of course also a lowering of knock probability. It's like closing the throttle a little. A typical engine does not knock when running on part throttle because less energy and therefore lower pressures and temperatures are in the cylinder.

This is why running overly-rich mixtures can not only increase fuel consumption, but also cost power. "

Re: Thread for those of us who tune our own cars

That is interesting.

Re: Thread for those of us who tune our own cars

good post... the slower moving flame front is why if you run high octane fuel in something designed for low octane you can get an incomplete burn that results in carbon buildup in the cylinder over time. Eventually itll raise compression a bit and then when you try to go back to low octane itll ping.

Re: Thread for those of us who tune our own cars

Latest tuning info to share:

The importance of the fuel pump voltage table. After the new walbro 465 fuel pump my table was way off, causing pressure 20psi spikes that could be seen by datalogging the pressure drop across the injectors, causing momentarily rich conditions and hesitation. The 340 pump I ran needed 13.5 volts up top but this walbro is only seeing 8.6 volts. I used a histogram data logging pressure drop across the injectors, actual fuel pump voltage, and fuel pump flow to populate the table.

Next is to clip the pressure sensor transfer function. You want to clip it something close to the fuel pressure you want and then add your max boost. Many say to default to 60. The purpose of this is to keep the pcm from seeing random spikes and making drastic adjustments. It is located in the returnless fuel pump section in Advantage.

Re: Thread for those of us who tune our own cars

Results are in from my e85 tune. Hit about 8.5lbs of boost vs the 9lbs it saw on the 91 oct run below it. 50hp bump. 17 degrees of timing to 23 degrees.

http://i182.photobucket.com/albums/x...ps9enof9dl.png

Re: Thread for those of us who tune our own cars

Is that 17* timing max on 91 ans 23* max on e85?
are u raping up spark or just locking in 17/23 on the hit?

Re: Thread for those of us who tune our own cars

Increased it with rpm. Here is my BLK table.

http://i182.photobucket.com/albums/x...psuunjsnwt.png

Re: Thread for those of us who tune our own cars

Hey guys quick question.

How the hell do I shut off the knock sensors? I thought I did it but started the car and still getting codes for them. Such a big learning curve here

Re: Thread for those of us who tune our own cars

You have to deactivate the code to keep the light off.

Quote:

Originally Posted by SLOWHITE (Post 1601269)

Hey guys quick question.

How the hell do I shut off the knock sensors? I thought I did it but started the car and still getting codes for them. Such a big learning curve here

There is a spot where it says knock sensor retard. And then it shows the degrees of timing they are allowed to pull based on load I think. I just zerod them all out where i didnt want them doing anything and I didn't have to mess with the codes. I did it this way so they can still adjust timing during cruise if knock isn't detected but they don't do anything for wot.

Re: Thread for those of us who tune our own cars

Any tips for tuning idle on a car with stage 3 comp cams?

The car runs but it won't idle. STFT's are between .98 and 1.02 so the MAF transfer is good.

Re: Thread for those of us who tune our own cars

What is your idle rpm set to?

Won't idle as in it starts but dies? Flow more air through the IAC valve.