SCT - Hands On

[Jack B]

I have been playing with the SCT Racer package for about a month prior to actually reflashing the PCM. I did find some software issues, but, SCT did get them straightened out. I have the same problem that many of the modded vipers have, after changing heads and injectors, that nasty low/mid power hesitation appeared. i tried for years with the VEC to fix it, it ain't happening.

I finally reflashed the car today. I changed the fan on, set point, the idle and the delays for acceleration enrichment (AE). The results were fairly interesting:

1. I set the low fan point to under 180 and the high speed point a few degrees higher. This is a race tune so i do not care about fan longevity. The temperature was 85 degrees today and the temp gauge looked like it was broken, it stayed right at 180, no matter if it was idling or moving. I will verify the interaction of the two fans in the future. It wasn't exactly that simple, but, not difficult.

2. I set the idle at 800 and that is exactly were it now runs.

3. Lowering the AE delays eliminated the hesitation. I believe the large injectors merely react slower than the oem injectors. The factory throttle position delay for AE seemed too great, I changed it and the map delay and the hesitation is gone.

This is just a start and maybe not the exact same problem that everyone else is having, but, it sure felt good to see technology work. The next step is to start removing the VEC power enrichment values and replacing them with SCT power enrichment.

The header/title was suppsed to be "Hands On", but I couldn't change it afte i saw the mistake.

 

[Simms]

Good info Jack. I've been thinking about going the SCT route and removing my AEM.

 

[EllowViper]

I know the cost of the SCT through the various vendors, but what is the total cost including the Racer tuning package if you can legally post it?

 

[ViperTony]

The header/title was suppsed to be "Hands On", but I couldn't change it afte i saw the mistake.

Fixed the title for you. Thanks for posting the info on the SCT. While I don't have the extent of mods you have, I have been using a Vec3 and just sold it in favor of an SCT tuner. I'm going in for a SCT dyno tune next week and will report my results and differences between the SCT/VEC3. I considered running them both but it's overkill for my needs.

Question: Jack how are you logging, still through the Vec3 or are you using something like Ease or PCMSCAN? Any recommendations?

 

[Viper Specialty]

We always recommend PCMSCAN, as it is the only datalogging software I have seen that actually allows recording in tables, which is a god-send for building base fuel maps from scratch.

PS- Jack, what is the exact name of the AE tables you changed, and on what processor code? I have never seen an AE delay timer anywhere I have looked. PE sure, but not AE.

Also, if you dont feel you are up-to-***** on the software enough yet to build a good base prograg to start tuning [IE, set everything up properly for different injectors, etc, etc, etc] let me know and we can build you the base file to tune on top of. Otherwise, going back and editing those items later will screw everything up.

 

[Jack B]

Fixed the title for you. Thanks for posting the info on the SCT. While I don't have the extent of mods you have, I have been using a Vec3 and just sold it in favor of an SCT tuner. I'm going in for a SCT dyno tune next week and will report my results and differences between the SCT/VEC3. I considered running them both but it's overkill for my needs.

Question: Jack how are you logging, still through the Vec3 or are you using something like Ease or PCMSCAN? Any recommendations?

I have a Innovate DL32 for use as a permanent logger. I have the (2)widebands, intake air, coolant, spark advance, fuel pressure, rpm and throttle position being monitored. The DL32 is nice because it records to a SD card and is controlled by the Innovate O2 gauge (it has an integral log button).

For more detailed logging I am using the EASE package, the current version is much better than it has been in the past. They also have a wireless option. The cost of the SCT package was approximately $900.

I just came back from a ride in the viper and I cannot believe I had that hesitation for so long, it is absolutely gone. I do not consider that tuning, the tuning comes next. When i log with the DL32 the slope of the rpm curve gives you your hp. Just find a safe level spot and consistently log the rpm slope at WOT. I use the 3000 to 5500 rpm range in 3rd gear. When you compare the slope of two different rpm curves, this will show any improvements in your tune.

 

[EllowViper]

Yea baby. Now we are getting somewhere!! I think a SCT with RACER tuning package and PCMSCAN would be a killer set-up. I'll watch this thread like a hawk.

 

[Viper Specialty]

Yea baby. Now we are getting somewhere!! I think a SCT with RACER tuning package and PCMSCAN would be a killer set-up. I'll watch this thread like a hawk.

Thats the same setup we usually sell to our customers...

995.00 ALL IN.

 

[cyaford]

Do any supporting vendors sell the tuning software? I have the SCT, but I am far from a good tune, which I feel that mail order tunes can't provide.

 

[EllowViper]

VECs are not going to be worth too much in the near future I fear...if I'm reading the tea leaves correctly. Dont' get me wrong I love the VEC capabilities and ease of tuning (within its inherent limits), but I have to believe a properly set-up PCM will respond faster and more effectively than having to go through a piggyback controller. It would be interesting to hear about processor delays and all that jazz when it comes to using the straight PCM vs. a PCM running in conjunction with a VEC.

 

[ViperTony]

Do any supporting vendors sell the tuning software? I have the SCT, but I am far from a good tune, which I feel that mail order tunes can't provide.

Yes, ViperSpecialty sells the software, $449 I believe but check their website.

 

[Simms]

VECs are not going to be worth too much in the near future I fear...if I'm reading the tea leaves correctly. Dont' get me wrong I love the VEC capabilities and ease of tuning (within its inherent limits), but I have to believe a properly set-up PCM will respond faster and more effectively than having to go through a piggyback controller. It would be interesting to hear about processor delays and all that jazz when it comes to using the straight PCM vs. a PCM running in conjunction with a VEC.

I think the AEM sales will decrease as well.

 

[Viper Specialty]

Do any supporting vendors sell the tuning software? I have the SCT, but I am far from a good tune, which I feel that mail order tunes can't provide.

Look one post above yours

 

[cyaford]

Here's a friendly tip. Do not leave your SCT Tuner in the garage when the bug guy, or anyone else for that matter, comes out to do some work. I've looked everywhere for 2 solid days, and can't find it. Last time I saw it, it was by the car in the garage. No big deal, as the SCT was no better than the stock(or modified??) tune it replaced, so I had put the factory tune back on. Any discount for buying the tuning software along with the SCT device? Will I really need logging software, or will a few hours on a dyno with A/F readings suffice?

 

[Purdue_Boiler_Viper]

VECs are not going to be worth too much in the near future I fear...if I'm reading the tea leaves correctly. Dont' get me wrong I love the VEC capabilities and ease of tuning (within its inherent limits), but I have to believe a properly set-up PCM will respond faster and more effectively than having to go through a piggyback controller. It would be interesting to hear about processor delays and all that jazz when it comes to using the straight PCM vs. a PCM running in conjunction with a VEC.

I won't profess to have studied this in any detail, but my guess is that any delays are similar to those "sold" by the stereo music business, i.e. that you need equal length wires to your speakers in order to prevent the delay over the longer wires from corrupting the sound. While true, the ear could not possibly hear the nanoseconds of delay. Since we are dealing again with an extremely fast electronic system coupled to an extremely slow mechanical system, I see a parallel.

I'm sure you guys will let me know if I am full of it.

 

[Jack B]

We always recommend PCMSCAN, as it is the only datalogging software I have seen that actually allows recording in tables, which is a god-send for building base fuel maps from scratch.

PS- Jack, what is the exact name of the AE tables you changed, and on what processor code? I have never seen an AE delay timer anywhere I have looked. PE sure, but not AE.

Also, if you dont feel you are up-to-***** on the software enough yet to build a good base prograg to start tuning [IE, set everything up properly for different injectors, etc, etc, etc] let me know and we can build you the base file to tune on top of. Otherwise, going back and editing those items later will screw everything up.

"Min Delta TP for AE"

That seems to be the one that cleaned up the hesitation. That is a 25% change in TP before the enrichment can take place.

Innovate Logworks can also build tables.

 

[Jack B]

I won't profess to have studied this in any detail, but my guess is that any delays are similar to those "sold" by the stereo music business, i.e. that you need equal length wires to your speakers in order to prevent the delay over the longer wires from corrupting the sound. While true, the ear could not possibly hear the nanoseconds of delay. Since we are dealing again with an extremely fast electronic system coupled to an extremely slow mechanical system, I see a parallel.

I'm sure you guys will let me know if I am full of it.

The delay that i was talking about was a criteria built into the PCM. The PCM does not allow enrichment till the throttle moves over 25%. That must be OK with oem injectors, but, some larger/slower injectors seem to have a need for earlier enrichment.

 

[Jack B]

Dan:

I looked at the PCMSCAN website, the choices are a bit confusing. What is the best set-up and do you sell the product?

I guess the question is what interface do you use, it looks like it is not compatible with any of my interfaces.

 

[Viper Specialty]

Here's a friendly tip. Do not leave your SCT Tuner in the garage when the bug guy, or anyone else for that matter, comes out to do some work. I've looked everywhere for 2 solid days, and can't find it. Last time I saw it, it was by the car in the garage. No big deal, as the SCT was no better than the stock(or modified??) tune it replaced, so I had put the factory tune back on. Any discount for buying the tuning software along with the SCT device? Will I really need logging software, or will a few hours on a dyno with A/F readings suffice?

Yes, the price above, 995.00, includes the Pro-Racer [449.00], SCT [499.00] and PCMSCAN [200.00]... as you can see, add them together and its 150 bucks off!

And sorry, there is ABSOLUTELY NO REPLACEMENT for the logging software. If you require ANY edits to the base maps, there is NO way around needing it. The Dyno is *ONLY* for tuning Wide Open, it is useless for anything else without logging software.

 

[Viper Specialty]

"Min Delta TP for AE"

That seems to be the one that cleaned up the hesitation. That is a 25% change in TP before the enrichment can take place.

Innovate Logworks can also build tables.

Hi Jack,

That table is not a delay, that table is the minimum change in TP before the PCM adds an amount of fuel in uS added to the pulsewidth at at instantaneous time based on the rate of change in Thottle Position. Basically, it is designed to "cover up" the lean-dip you would get on tapping the pedal since the computer cant react instantaneously to a change, it takes a moment to register a change and respond- so this table "pre-empts" the change by dropping extra fuel to burn immediately. It really should be labeled "Tip-In Fuel"... not so much AE fuel, as it is not constant. [See Next Post Too]

I suspect you already know this, but its for the good of anyone who wants to use it. However, you have covered up your problem- not eliminated it... but I am not sure what your original problem was to begin with.

LogWorks may be able to build tables, but I have not been successful in getting any of that system to work correctly when I tried it, short of the widebands themselves. Their integration sucked IMHO.

 

[Viper Specialty]

The delay that i was talking about was a criteria built into the PCM. The PCM does not allow enrichment till the throttle moves over 25%. That must be OK with oem injectors, but, some larger/slower injectors seem to have a need for earlier enrichment.

The table you are actually looking for is called "Part Thottle Enrichment", that is what REALLY controls mid-throttle fuel before WOT. What you appear to have done is just covered up the injector change hiccups with extra tip-in fuel, masking the actual issue effectively. In general, larger injectors will require LESS AE fuel uS for the same tip-in effect, but only if everything else has been corrected first. After base-maps are set up, the proper way to set up Tip-In is to log with a wideband, and "stab" the gas while logging. keep adding fuel or lower delta TP until you no longer see a lean shift, and it tips rich instead.

 

[Viper Specialty]

Dan:

I looked at the PCMSCAN website, the choices are a bit confusing. What is the best set-up and do you sell the product?

I guess the question is what interface do you use, it looks like it is not compatible with any of my interfaces.

Use This Package: PPE Online Store

 

[whitebluevipe]

Use This Package: PPE Online Store

stupid question but can this package give you detailed info. like running engine temperature or any other info?

 

[Viper Specialty]

stupid question but can this package give you detailed info. like running engine temperature or any other info?

Yes, it can display and log any OBD-2 PID supported or any combination of them.

 

[Jack B]

Dan:

I have to mildly disagree with you. I know it is not a true delay, but, ultimately it does delay the enrichment. That voltage delta value is almost 30%. In other words the throttle has to be moved 30% before the tip-in can initiate.

My issue is very similar to many on this board, a low/mid range hesitation when going to wot. This is not a maybe, the hesitation is gone. Look at it this way, I am now reducing the time the engine sees with air entering (throttle opening) the cylinder and no tip-in fuel.

Let me ask you again, PCMSCAN, it does not appear to come with any interface cable and none of my scan tool interfaces are listed as compatible. What do you do for the interface.

 

[Viper Specialty]

Dan:

I have to mildly disagree with you. I know it is not a true delay, but, ultimately it does delay the enrichment. That voltage delta value is almost 30%. In other words the throttle has to be moved 30% before the tip-in can initiate.

My issue is very similar to many on this board, a low/mid range hesitation when going to wot. This is not a maybe, the hesitation is gone. Look at it this way, I am now reducing the time the engine sees with air entering (throttle opening) the cylinder and no tip-in fuel.

Let me ask you again, PCMSCAN, it does not appear to come with any interface cable and none of my scan tool interfaces are listed as compatible. What do you do for the interface.

I think we are on different "problem pages" here... I thought you were talking about a mid-RPM range hesitation in the map, while you appear to be talking about a response issue type hesitation. Is your VEC still scaling your injectors? If so, that is the source of your hesitation, and yes, its no wonder that your issue was solved by adding more tip-in fuel. The VEC falls on its face on tip-in response time.

-The PCMSCAN software I linked to above INCLUDES a USB interface, as it says right on the page...

 

[Dom426h]

Dan, is it true that the "LiveLink" software available on the SCT website to be used in conjunction with the SCT for live dataloging Only works with Fords & GM's ?

 

[Viper Specialty]

Dan, is it true that the "LiveLink" software available on the SCT website to be used in conjunction with the SCT for live dataloging Only works with Fords & GM's ?

YEs, thats true. LiveLink for DCX does not currently work.

 

[cyaford]

YEs, thats true. LiveLink for DCX does not currently work.

Are plans underway to make it work?

 

[Jack B]

Use This Package: PPE Online Store

Dan:

thanks - one more question, in their description/list of parameters I do not see the ability to call up the adaptive cells.