FAST xfi tuning on a fresh startup 427 sbc

[CorvetteDave01]

Hey all,
I did get my new 427 sb motor running (barely) and need to do some tuning. I used a basemap in the software that is a 427 naturally aspirated motor with 65 lb injectors, probably a higher hp motor. Was even thinking about going with the 406NA with 36 lb injectors to see how that worked. The manual has almost no tuning info in it. It is running VERY rich at idle and dies if I don't keep the RPMs up. Runs fairly smooth with some RPM, but still very rich. I need to lean it out at idle first I think. I have no idea what table to use and what values to enter. Also, I have no IAC valve at the moment and have it blocked off. I also have not calibrated the MAP or temp sensors, how important is it to calibrate these? I did calibrate the TPS sensor.
I also need to figure out more about the wideband O2 sensor, still reading on that.
427 sb Gen1
FAST xfi with 48 lb injectors; 50 psi fpr (not adjustable)
solid roller cam 670/670; 250/258 @ .050; 111 LS
10.5:1 CR
AFR heads
Vic Jr. intake

[andrewb70]

The 406 NA map with 36 lb injectors will be WAY rich. Your 65 lb injectors are spraying way more fuel per given pulse width. I would highlight that whole map and reduce it by about 40%. That should get you close enough to start driving and tuning.

Andrew

[Blown353]

Actually the VE map should be a decent starting point as long as you remember to go into the "fuel calculations" menu and change the injector size.

If you're running your 65 lb injectors with the default tune and you still have the system setup specifying 36 lb injectors then it will indeed be VERY rich. Verify that you have the proper MAP sensor range and injector size specified before doing *anything* else or your VE table will be wrong and will not translate over properly if you change some basic components down the road.

I changed injectors on my car from 55 lb/hr to 75 lb/hr a while back; all I did was go into the fuel calculation menu and changed the injector size from 55 to 75. I did not have to retune anything.

As far as calibrating the MAP and temp sensors, you only need to verify that you have them scaled properly for the specific sensor you are using. The system software is defaulted to use the appropriate calibrations for the sensors FAST provides in the box.

[andrewb70]

oops...I forget that the FAST uses a VE table. Thanks for the reminder!

Andrew

[CorvetteDave01]

Ok thanks guys. What values should I look for in the VE table and what should I do with them if they are running the car rich?

For example my VE table reads as follows on the bottom row (7 Kpa)

39 44 44 40 51 51 51 58 57 49 49 44 44 36 36 36

[RSX302]

There are alot of parameters that you need to look at other then just changing VE. Where are you located. I tune a bunch of FAST systems for Bones Fab. in Oxnard Calif.

If you would like, email me with your phone # and I can run over a little bit with you on what you should look for. A little Tuning 101!

[CorvetteDave01]

OK thanks Ron, I'll try to give you a ring in an hour or so, need to drop the baby off first. Thanks for the offer!
Dave

[CorvetteDave01]

Oh yeah, the injectors I am running are 48 lb (@ 50 psi). The basemap I am using is for a N/A 427 with 65 lb injectors. I was THINKING about going with the 400 basemap with 36 lb injectors, but havent messed much with that one yet.

[CorvetteDave01]

Currently I do not have an IAC valve that works with this FAST ecu. The one I have is a Ford IAC (from the Edelbrock Proflo kit). It is currently blocked off. I have been told that a 'Stepper valve?' can be used on this throttle body and will work with the FAST system and that Holley sells one that does, I just don't have one yet.

Since my coolant temp and air temp sensors are not registering anything, I am going to pull them out and put in the FAST pre-calibrated sensors. After this, I'll do some more tuning, hopefully today.

[camcojb]

Currently I do not have an IAC valve that works with this FAST ecu. The one I have is a Ford IAC (from the Edelbrock Proflo kit). It is currently blocked off. I have been told that a 'Stepper valve?' can be used on this throttle body and will work with the FAST system and that Holley sells one that does, I just don't have one yet.

Since my coolant temp and air temp sensors are not registering anything, I am going to pull them out and put in the FAST pre-calibrated sensors. After this, I'll do some more tuning, hopefully today.

I've used the Ford IAC's with the FASt units, after re-pinning the wiring so it works. Not sure what IAC the Edelbrock kit uses though.

Jody

[Fuelie Nova]

Just remember the edelbrock iac is a pwm valve. You can call holley and get a conversion block with iac valve for $100.
Tg

[CorvetteDave01]

I might try to repin the Ford IAC and save $100. For now I changed the air and coolant temp sensors and am trying to get it tuned. I just need to slow down, but have gotten it to completely stop smoking.

[Fuelie Nova]

Make sure you get the correct pinout off the prints... wiring mistake on IAC = blown driver = send box back to fast :geek:
Tg

[CorvetteDave01]

I went ahead and got the stepper IA motor and the adaptor from Holley. fit and wired up fine with a new connecter, just need to know that it is a chrysler IA motor and wire it accordingly to the FAST, 4 wire setup.

[John S]

I hate to bring this back from the dead but I am just catching up on some things. Dave, how did you make out with your tuning? My engine is very close to yours except for the intake which I think I will be changing very soon.
What heads & TB are you using? IS the Vic Jr. flowing enough for your engine?