I know somebody that picked up a holley supercharger kit for a 93-95 TBI truck. He has a 92 so it is not considered emissions legal which is not an issue. Does anybody have any experience tuning a setup like this. The kit is complete including a fuel pump and I read somewhere that you don't need a 2 bar map setup because the blower is below the TBI.

You'll need the two bar MAP as the pressure at the cylinders is what determines the required fueling. Plumb it up after the blower.

Hey just wondering if the kit for the 93-95 trucks will work on the earlier trucks?? I.E a 1990. Isnt he computer or prom different?? The kit comes with a new prom i think?? will it work with the older pcm?? Or will you have to do a custom chip tune for the blower??? Also doesnt the kit com with a 2bar map??? Sorry for all the questions and thanks for any help!!

If you were going to run 2-5 PSi you might get away with pulling that off.
HOWEVER, timing is related to load, and the best place to sense what's going into the cylinder is as close to the intake valve as possible. So you do want to run the MAP to the plenum area.

Might also remember that the TBI codes were most often used for trucks, and possibly not the best GM developed. If I were going to do anything with a blower and a TBI, it'd be with a EBL.

I'm in the process of setting up a Weiand 142 with 2" TBI and the EBL. I'll post my experience when I get that far.

Tuning a blown engine with the stock TBI ECM/PCM sounds crazy to me. I'm sure it's been done tho. I just wouldn't want to try it.

I have not talked to Holley but the info on the web page says that with carb the boost is below the carb or TBI so nothing needs to be done. They do say that you need to retard the timing. The setup came off of a wrecked truck and it was complete minus a chip. I believe that the setup is good for 100hp and it is around 5lb boost max. It does come with a bigger fuel pump also. They only recommend it for an automatic tranny but again I still wonder why they say it is not emissions legal for a earlier setup. I am not versed in the TBI setups at all and don't know the differences between the ECM's of those years other than they went to a 4l60E tranny setup.

Carbs are flow referenced, so the fueling will still be somewhat right even under boost. The stock TBI codes (early and late) and similar are all speed density, which needs to have the manifold pressure as a reference for the fueling. Both the early and late TBI systems will have similar issues with a blower, namely the fueling/timing being off.

Dimented: would the blower negate the effect of a VAFPR? something tells me the VAFPR option wont work to fuel a boosted engine. how to reference the boost to the VAFPR tables to fuel? so therfore restricted to 7.4L injectors at high FP causing a rich OL idle? another confirmation of TBI limitations as far as fueling is concerned?

I will get some pictures up shortly. I have done this and it works awsome! You want to sense boost (i.e. you want a two bar on the manifold) Trust me it makes top end tuning much much easier. If you are using the Holley 4bbl on a wieand (spl??) you need a spcer or the T blades open into the rotors of the blower.

I started out with a 749 ECM, and it worked, to many chips and I did not get anything hooked up to the GM ecm for emulation so changes on the fly were not possible. Lots of logging and chip flashing.

I spent the dough and got a C950, I was able to dial in the idle in a day, and had it running real strong in two days. The next week my dad took the car for a 700 mile round trip no problems and it got 18 MPG

https://www.thirdgen.org/forums/atta...v-dscf0080.jpg

WOW. guess you need the boost. no room for air to get passed the injectors!