Does anyone know is the VEC II is the right program to use when useing a turbo..to get the fuel mapping right? ... or would i be better off useing the SCt tuner and having it dyno tuned? will the sct allow me to change the fuel mapping? not looking for anything insane.... looking into a single turbo set up with an H pipe with a collector for the turbo to mount on...turbo will be a T4 looking for 7-8 PSI of boost...nothing crazy i'v been talking with a local shop...says he can do the system just unsure about the tuning........ anythoughts or places to look to get the info i need?
**********WARNING************ you might also want to read thru this thread: http://www.srt10forum.com/forums/showthread.php?t=13707&highlight=tuning+turbo
i'v read that thread....an have...talked to a number of people 1 guy with the same setup i'm talking about.........and it runs flawless...they say twins are way better..... which is on the option on the list.... but i'm just gathering info..right now nothing set in stone... just been throwing around ideas.....blowers are fine an dandy..but i want to pop the hood and nobody know it's there....an yes i'v heard very bad things about STS an the viper motor.... but a custom app works alot better for some reason..than their kit.... it will be alot ofmoney in tuning but the guys i'v talked to at PSi said they can get the tuning part done ..... but again nothings set in stone.. i might just stick to tring to hit 650RWHP on motor just getting allthe info i can and learning some Edit heres some stuff i pulled out of that post you posted wade A few things that may help. Re-plumb the system, so that it reads boost that is actually present. Some of the booms were a result of over boost due to a bad reference point. Get rid of the STS version of the computer control and fuel augmentation. Get bigger fuel injectors. Get VEC 3 or the AEM computer system for the truck. Get it tuned by a truly gifted tuner. The tuner can build a fuel map that will keep the air:fuel in a nice safe area. Using the larger injectors will allow the fuel to be added at the cylinder instead of in the intake. i'm just hoping from.. getting a boost reading from the right point with the right tuning it should work fine.....as stated above tuning will be the big issue
(This is general, not speaking directly about STS- and all of this is assuming you arent using some type of additional injector setup) Short Answer in your case: BOTH. (General) You need to answer a key question first; 1. Has the engine or fuel system been changed, or are they stock? The VEC-2/3 does a nice job for boosted applications on stock engine/stock fuel system cars. However, it is not good at and not capable of some things. The one thing it is not capable of doing is tuning Closed Loop, which must be done at the PCM Cal level. It is also not good at scaling large injectors. Have a set of "72-96s"? That right there is "Tough-Impossible". This is where the SCT comes in. The VEC is not efficient at scaling, and the larger the injector, the less efficient it becomes. The SCT on the other hand can scale (and tune base tables) at the PCM cal level, eliminating all scaling from the VEC's duties. Of course, there are also dozens of other things the SCT can do, from OBD-2 control to Fan temps to Idle which the VEC cannot. On the other hand, the VEC will handle boost internally, the SCT will not do that easily. SRT-10 Only; The OEM PCM contains what is called a "closed loop timer". In a nutshell, this parameter keeps your car at 14.7:1 AFR (Very Lean for accelleration, Dangerously lean for boosting) for a set time (~3 sec part throttle, ~1.5 sec WOT) regardless of how hard your Fuel Management Unit tries to add fuel to it. This parameter has caused more engine damage as a whole on boosted cars than any other thing to date on these cars. Its a ticking time bomb... and sooner or later it will catch up to you. In this case, reflashing the PCM is your ONLY option to turn this off, which is why it is required in my opinion for any SRT-10, even stock-engined/fuel system cars, if a blower is installed. Gen-1 & 2 cars dont have this, and can get away without the SCT as long as the engine is close enough to stock not to run into closed loop issues or scaling problems. I should also mention that turning this timer off even on stock cars nets a NICE increase in throttle response and tip-in torque. FMU/SplitSec cars (Paxton): No need to use a VEC, the SCT can handle all tuning parameters, even under boost, due to the Mechanical FMU and SplitSec functions. Of course, these systems have their limitations to the stock fuel system capability. All things aside, a car tuned at the base level with SCT will be MUCH smoother than anything with a piggyback. The VEC does one thing well by design & program, and that is add fuel and pull timing under boost. Anything else, SHOULD be done at the base level if at all possible. Basically, they work very well together- one picks up where the other leaves off. Both the VEC-3 and the SCT tool, as well as custom tunes and software are available through us.
