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SCT Tuners

Lordgufi

Well-Known Member
How many of you actually use the logging features of the SCT software?

I know many of you use it for tuning and such but do any of you Log with it?

if so i'd like to try to start getting some logs from random people and labeling the accordingly so that people have something to look at for comparason. A log will tell you if your car is running correctly, give you a base comparason for what your car needs to be doing.

Basically for logs to be compared of course you would need similar modifications. This being said you would also need similar cars, EG: a stock 1998 gt will not log the same as a 99, we all know why.

I'm going to try to start getting my car loged a bit in 3rd gear, 4th is impractical and we only have 1/8th mile tracks around here so its near pointless.

Format for posts would be:

Car: 1998 Mustang GT
Modifications: Stock ( be detailed please )
Transmission: Manual 5
Type of log: 3rd gear pull ( EG: 1/8th mile pull )
Where: ( if you preferr not to disclose, just put something generic )
Other info: Barometric pressure, temp, humidity, altitude all go here.

Some of this info i know will not be readily available but be descriptive as possible.

If any of you need a place to store logs I will be making a FTP site on my website for saving these if you guys need.

if you make a pass... make a log. what good is a Dyno pull reading for a log if the track is totally in different weather/altitude even with zero modifications to the car.

Well Hopefully this catches on.
 

smashedheadcat

Well-Known Member
I log my car all of the time but I guess I don't understand what you're asking. Do you want me to send you my datalogs so everyone can see them and use them for... whatever?

The dyno vs the track log isn't as different it's hyped up to be. Mass air cars are a good thing. A 4th gear pull on a dyno shows rpms, load, air to fuel, and MAF counts over a broader spectrum than the track does. On a dyno you get to monitor in real time so you can abort if something doesn't look right. At the track or on the street, you have to "hope" everything is doing well enough to complete the pass and capture the data.

Instead of comparing logs with everyone, IMO, it may be better to teach people how to read them on their own. But, if they aren't tuning the car themselves, then they don't really have to know how to read them either as a tuner will tell them to log "this, this and this" and send it to him etc.
 

Lordgufi

Well-Known Member
i whole heartedly agree that a dyno pull is a much better Standard than a track.

the logs for comparason on a dyno would be fantastic even with seperate modifications you would be able to see small differences in where the tune was causing the ecu to pull timing/add fuel or even see where the ecu overracted and be able to figure out why.

however on the track is near the same kind of story while a dyno will give you the broader more exact log, it doesn't give you what your going to see on the track.
 

smashedheadcat

Well-Known Member
I agree 100%.

There are a lot of variables that can cause the tune to be somewhat different each pass. I have all the fuel modifiers shut off in my tune so my air to fuel in open loop is commanded based on rpm and throttle position only. Once the maf curve is dialed in then it continues to give me the air to fuel ratio that I expect. I have a few tunes that I use but they all share the same maf curve with slight changes to the base fuel table. The timing curves are shaped the same but obviously much lower on my street tunes vs my race tune. I have it setup with all the spark modifiers to only pull timing. It either goes to the spark I tell it to go to, or a modifier will pull timing. I'm fortunate enough to have one of those setups that hits 200% load by the 60ft mark and stay there the entire time. So barametric pressure changes, density alititude changes and all that really don't mess with LOAD too much on my car which helps keep the timing curve where I want it.

One big difference I noticed from the dyno to the track is this. My setup at 17psi on the dyno made just shy of 700rwhp at 97.X& duty cycle on my fuel pumps. This was at 6500rpms. On the track with the exact same tank of fuel, same tune, same week, I hit 100% duty cycle on my pumps at just over 5000rpms. My fuel rail pressure dropped enough to max out the injector pulse-width and the car started to drift lean. I had to take a half pound of boost out of the car to keep it from drifting lean on the top end of the track. My wideband probably saved my engine as I was able to see something was happening, and used my datalogger to find what that something was.
 
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