SCT v. VEC for boost?

cyaford

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Tony: Stop screwing around and get the SCT device along with the Dealer tuning software. You should have it figured out in a short while. Once you do, give me a call so you can tune my junk. :D
 

Viper Specialty

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Dan is correct, the factory PCM can be tuned for boost with the SCT and it works quite well. We have done several. Recently we tuned our local Viper club president's Gen 3. It had an AEM before. The car runs perfect and makes 900rwhp, he drives it.


And there you have it. The SCT is filling a very large market gap these days, and is pretty much taking over Gen-2/3 builds from simple mods to the high-end of moderate builds. The upper level controllers still have their place, but are only necessary at the extreme end of things. The SCT has all but replaced the VEC's market niche and then some.
 

ViperTony

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Tony: Stop screwing around and get the SCT device along with the Dealer tuning software. You should have it figured out in a short while. Once you do, give me a call so you can tune my junk. :D

LOL...I hear you and being a IT techie I love screwing with software but time is my enemy at the moment...otherwise I'd be all over this.
 

EllowViper

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So what is the prevailing expert thoughts on the best package? SCT with a VEC doing some of the work or totally eliminate the VEC? Does keeping the VEC for injector scaling and MAP make sense and then use the SCT for modifying the required start/closed/open loop scalers/fuel and timing tables? I do not have an issue with sharing some of the work between the VEC and a SCT tune, but would like to know what the VEC does really well in combination with the SCT. Obviously the PWM outputs are a nice feature...but anything else the VEC brings to the table as a good thing to retain???
 

cyaford

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LOL...I hear you and being a IT techie I love screwing with software but time is my enemy at the moment...otherwise I'd be all over this.

:eek:

Oops! My post was meant for 1TONY1, but hey, I'll take what I can get if you want to get the programming part ironed out. :D
 

BOTTLEFED

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So what is the prevailing expert thoughts on the best package? SCT with a VEC doing some of the work or totally eliminate the VEC? Does keeping the VEC for injector scaling and MAP make sense and then use the SCT for modifying the required start/closed/open loop scalers/fuel and timing tables? I do not have an issue with sharing some of the work between the VEC and a SCT tune, but would like to know what the VEC does really well in combination with the SCT. Obviously the PWM outputs are a nice feature...but anything else the VEC brings to the table as a good thing to retain???
I think using a VEC and SCT together would be a tuning nightmare. Then you have 2 controllers making changes. I see that just being a huge game of chase your tail until you get dizzy and give up.
Not to mention, for the cost of a VEC and SCT, you could buy an AEM.
It would be a huge downfall for the SCT to need the VEC to work properly. If that's the case, then I'll wait for something that can do both of their jobs and buy that.
 

EllowViper

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I thought I had read a year or so ago that you can use the VEC to establish the basic injector offsets so you can focus the SCT on drivability across the board. I imagine much knowledge has been gained since that time regarding how to scale large injectors directly with SCT reprogramming. But at that time, that aspect of a SCT tune was the tough part with the stock PCM. Obviously DC Performance has cracked the code on doing just that with (I assume) a replacement 2 bar MAP sensor as well.
 

Viper Specialty

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You CAN use the two together successfully, but you DO NOT want the VEC to scale the injectors, that should be done by the SCT. If using them in combination, you want the SCT tuned for all vacuum conditions, and the VEC effectively doing ZERO in vacuum. The VEC should only be pulling timing and adding fuel under boost. In effect, so if you were to remove the Blower and the VEC only, the SCT's tune would be 100% correct for the engine in an N/A form, and with the fuel system being utilized.

To answer your question, no, there is no reason to retain the VEC in almost all cases, unless you need the PWM function. You can get a little more resolution by retaining it, but if you dont need the extra resolution, it wont do you any good to have it.
 

Russ M

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And there you have it. The SCT is filling a very large market gap these days, and is pretty much taking over Gen-2/3 builds from simple mods to the high-end of moderate builds. The upper level controllers still have their place, but are only necessary at the extreme end of things. The SCT has all but replaced the VEC's market niche and then some.

I totally disagree,

The SCT is still a band-aid for a permanent solution, its something I would use on a very very mild mods car and even then you get far more from an AEM which is very very cheap considering the things you get with it.

If you get an SCT and a good dual bank air fuel analyzer with 2 good sensors you are into it for almost the price of the AEM. And that does not even begin to cover all the other features built in to the AEM.

What people in the viper world need to start realizing is your fuel/ignition control is far more important and necessary than getting any other mods if you want reliable and maximum power from your mods.
 

SquadX

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...and the debate conts.

so for a supercharged viper...and AEM over the SCT and factory PCM?
 

Russ M

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Factory PCM is not bad, it seems to have the ability to handle forced induction and considerable power mods.

But at the same time you have to be near someone that has the ability to tune it, and if you do then it can do the trick well enough.

However there is nothing short of spending 10k+ on engine management that will give you the capabilities and flexibility of the AEM.
 

Viper Specialty

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I totally disagree,

The SCT is still a band-aid for a permanent solution, its something I would use on a very very mild mods car and even then you get far more from an AEM which is very very cheap considering the things you get with it.

If you get an SCT and a good dual bank air fuel analyzer with 2 good sensors you are into it for almost the price of the AEM. And that does not even begin to cover all the other features built in to the AEM.

What people in the viper world need to start realizing is your fuel/ignition control is far more important and necessary than getting any other mods if you want reliable and maximum power from your mods.


I am sorry, but you are absolutely wrong here. The SCT is NOT a band-aid. Are you forgetting that the Viper's JTEC PCM is nothing more than an OEM-produced narrow-band STANDALONE COMPUTER just like the AEM is? Both a tunable JTEC and an AEM have very similar abilities. Of course, the AEM is Wideband, and the JTEC is narrowband, and the AEM has extra inputs and outputs. But otherwise, they function very much the same. If your build does not have a need for some of the AEM's extra features, why would you bother? The AEM is a far LESS reliable system than the JTEC is! Which system has millions of dollars in R&D and a near 100% reliability rating? Not the AEM, that I can tell you!

The Narrow-Band functionality of the JTEC is not something to be afraid of so long as you use it correctly. You don't need to monitor both banks on a moderate build- if the car was running right when tuned, and your trims are not all over the place, you will be alerted to an impending problem 99/100 times, as any problem that would severly impact a single bank would have popped a CEL in most cases alerting you to check the other bank as opposed to the one you ARE monitoring. And the same goes for WideBand at all- while it certainly is a useful tool, so long as it was used while tuning the car, the tune should NOT be changing, and anything that had changed drastically would alert you via a CEL that something is not right. Closed Loop in a narrow band form DOES work.

I sell ALL of these controllers, up to and including the controllers that make the AEM look like a tinker-toy. However, these controllers are all used based on what the build requires, unless the extra features are needed, absolute reliability is needed, or engine safety is paramount due to power demands. However, in many cases, the AEM+ controllers are NOT needed these days.

Otherwise, you are preaching to the choir here. I have run my previous engine design with a VEC2, a VEC3, and SCT after that, and currently run a ridiculous SQ6M12 with all the bells and whistles. But, I NEEDED to do so on the build I am putting together, it was not much of a "choice". The same engine design I had before was run successfully with a JTEC as well for a while last year, just to prove it COULD be done. I have even removed a few AEM's and put the cars back to SCT/JTEC for simplicity and reliability.
 
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Viper Specialty

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Factory PCM is not bad, it seems to have the ability to handle forced induction and considerable power mods.

But at the same time you have to be near someone that has the ability to tune it, and if you do then it can do the trick well enough.

However there is nothing short of spending 10k+ on engine management that will give you the capabilities and flexibility of the AEM.


Am I losing my mind or did you just contradict yourself in the post that I just answered 17 seconds ago?

No one is saying that the AEM cant do the job, or that its not a hell of a deal, or any of the AEM+ controllers dont have more abilities and are a better tuning system than the JTEC. However, cost is a factor here, and if you dont need more than JTEC level capabilities, why in the world would you spend 3500-15000 on a controller that you absolutely do not need? That seems like an awful waste of money to me, and a lot of added complications that you didnt have to have. What about all of us in Plug-In states that require OBD-II functionality? AEM is one hell of a headache for us... and if you plan on putting one in, it better be worth the effort!


And while we are on the topic.... why in the world are we arguing about the AEM? That was not even a topic in this thread.
 
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