i hope this is in the right forum. i need some info on this FAST system that is out there. what are the pros/cons to going with this system. alittle about my setup/motor might help so here is alittle info.
383 LS6, 60# injectors, 900hp race fuel system, billet ls1 fuel rails, aeromotive eliminator pump running 50#'s at idle and cruise.
it dyno'd 682rwhp. but it runs rich ALL the time. i think the shop said that the stock computer was never meant to control or handle what it's doing right now. my a/r is 11.5 ALL the time. idle, cruise or hauling a$$.
it does load up alittle when cruising and for a sec or so when you stomp it until the computer conpensates( or whatever it has to do) has anyone had the same trouble? i'm when it comes to these things and hope so of you experts could help me out. thanks and hope i gave you enough info.

randy

 

i have FAST system on my 383 supercharged motor. easy to use easy to learn. easy to hook up ( i went with a plug and play harness). recommend the bank to bank. highly recommend the wide band option. the DFI gen 7 system. seems to be very nice but i have little exp. with it

 

I'm not familiar with the F.A.S.T. system, but I have a Gen 7 DFI set up. I'm extremely happy with this set up, as well as the great customer support from the DFI tech line. 248-380-2780

I 've heard from two very respected tuners here in town that the F.A.S.T. and DFI set ups are allmost identical as far as features an tunability are concerned. These guys claim that the F.A.S.T. set up is slightly better though, because of easier tuning. They both said that when data logging with F.A.S.T., a line is drawn across the VE table, showing which cells were active during the pull. You then just look at your air fuel ratios at each RPM, go to the cell at that RPM, and increase or decrease the pulse width accordingly.

DAMN.............I wish the DFI set up did that!

 

thanks for the info guys!!!!
randy

 

Your DFI will do this... Depending on your version of software, you may need the Pro key option to make it happen. Under the Datalog menu, select Analysis -> Fuel Analysis. It will ask you for a log file, and then overlay that over your VE, Spark, or AF table. Then you can use the Page Up/Down buttons to walk through your pull. You may also have an "overlay" button on your VE screen that will do the same thing.

Here's more info on the DFI system.

 

Maybe I missed in your post, but how are you making the 682rwHP? What is the power adder? Lot's of info about the fuel system, but not much about the engine itself. I would think that if you are running nitrous or an S/C or a turbo, it might affect your choice of aftermarket ECU.

Or is the LS6 so efficient that it can generate this kind of power NA?

 

682rwhp out of a 383ci motor NA would be kickass. I'm not sure I want to think about how street drivable it would be. I'm gonna guess this thing has a nice sized dose of boost.

 

the 682rwhp is with a ATI s/c running 17#'s and FMIC

 

The stock PCM will do just fine with your setup.... There are alot of people pushing more than 700rwhp with the stock PCM. There is a twin turbo car running 8's at 150mph running stock PCM. Just find someone who can really tune your car with LS1 Edit and save your self $2000. I wouldnt go with a stand alone system unless I want to run really large injectors (80lbs+) and making over 900rwhp. Good luck.

 

thanks for all your help. the tunning seems to be really good. i was just wondering if the FAST program would help the a/r at idle and cruise. i will ask my tuners if thy can make it alittle better this time. thanks again!

randy

 

I wouldn't exactly call Harlan's ECM "stock". It's a factory ECM, but if I'm not mistaken, there's been a few tweaks to it.

Randy, I would also look into the Big Stuff3 setup too. Kurt Urban has a lot of info on it...just check around on Tech. The system was designed by the guys who originally developed DFI and FAST (SpeedPro, SEFI8LO, whatever). Supposed to be VERY good.

 

I am using a reprogrammed stock PCM with the Acceleronics low-z impedance converter bit I do have a lot of experience with aftermarket ECU's. They have some terrific advantages. HOWEVER, anyone who implies that it is easy to get the car to run like a factory calibration is very lucky, very skilled, or blowing smoke. It can be very time consuming. The WOT part is easy though.

Rich

 

Took about 4 hours of driving around to get my FAST setup cal'd right for street driving.

 

Damn, you were taking your time then! I had a buddy drive shotgun (has gen 6 on his f-body, now works as a mech. engineer at Ford doing engine calibration), and we had my speed pro dialed in about an hour. After 15 minutes of tuning, I couldn't tell any difference in how it drove between the factory PCM and the new speed pro tune.

 

Having tuned (literally) dozens, all I can say is you two ought to be doing this as professionals!

Rich