Finally got around to ordering my intake and TB for my vortec SFI setup that Im putting together. I decided to go with a victor E and 1000 CFM TB from edelbrock w/ 36 PPH trickflow injectors. One of the nice things about the TB is that its progressive linkage like a carb with the secondaries closed until around 60% throttle. It also uses the later hi-resolution delphi IAC that has 0-320 steps from closed to open instead of the usual 0-160 that the older IACs have. Its going on top of my new 350 with an XE270HR and trickflow 195 heads. Ill miss the TBI, but itll be cool to have a new OBD-II EFI setup.

BTW, has anyone run one of these yet? Im curious how the throttle response is in the lower RPM range. Edelbrock rates them as being for use from 4500-8500 RPM, which is a bit higher than I intend to use the motor.

 

what vendor did you order from?

Does your ECU have the resolution to use 320 steps? I recently added IAC control to my 7.4L TBI successfully after a year of swapping wires.. I believe 0-80 steps was adequate to give me a cold coolant idle at 1200rpms.

I was contemplating using my 7.4L when I convert to port but that sequential TB seems to be a great idea on a dry manifold. I hear a dry manifold is tempermental? Maybe I sell the TBI unit complete with inj's.

 

I ordered from Summit. I will be using a vortec PCM, which has a 32-bit MCU. The stock IAC for the vortec trucks is the same as whats used on the edelbrock TB. The linearizing IAC flow table in the vortec PCM calibration goes from 0-320 steps, while the same table in the $0D TBI PCM only goes from 0-160 steps for a small block TBI.

As far as dry flow manifolds go, they should actually be easier to tune than a wetflow because there is no fuel dynamics. The steady state tuning was always easy with TBI, but the dynamic tuning always took a long time, and required me to add additional code to my $0D PCM to provide teh correct fueling model for estimating the AE requirements, which change dramatically with temperature and pressure. With a cold manifold, you need LOTS of AE, but once its hot, no AE is needed. On top of this, the manifold temperature constantly changes due to the fuel absorbing heat as it vaporizes. With a dry flow manifold and SFI PCM, the dynamic tuning is basically limited to adding additional cylinder airmass with the dynamic fueling routines to compensate for lag. Its still complicated, but it should be less fickle than the wetflow TBI.

 

Just wondering what your intake/throttle body/injectors/rails are going to run you? Im looking at doing a similiar upgrade but not DFI just MPFI with The Flash EBL and a single plane setup. I was hoping in the range of $1000/$1200 including the ebl and injectors etc. Any thoughts? Let us know how the tuning goes!!

 

You gonna bring this new setup down by e-town this coming March....?

 

The parts shown in the pic where ~$1100. If you have an old TBI, you can slum it by just taking the injector pod off and using the TBI base + carb adaptor as the throttle body.

 

Id like to, but Im sort of back to square one as I took my retro-roller setup out of my motor (long story...), so its basically just a bare short block now. That, and the car is still an empty, rusty shell with no interior, wiring, or front end.

In place of the roller, I have an isky single pattern flat tappet with decent duration to match the intake and heads. 221/221 .465/.465 with a 108 LSA. Should be interesting to see how the PCM handles the overlap

 

$0D is flash, no?

What is the max CFM the MAF can read?

-- Joe

 

The $0D actually used a standard 27C512 UV erase EPROM w/ memcal like the TPI ECMs.

The max airflow the MAF can read (from the MAF table in the vortec ECM) is 400 g/sec, which is roughly 700 CFM at 70 deg F.

 

Oh.. Stinker..

I'd switch to a late model maf system if it could read around 1200cfm. (blower).

Thanks!

-- Joe