Hey Guys,

I am new to this site and have a desire to add a Whipple supercharger to my 1995 Chevy Tahoe 5.7 TBI. I have looked around the country in attempt to find a good serviceable unit that is mostly complete. I have a gentleman that has a complete kit he purchased new a few years back. It is designed for a 1996-1999 Tahoe 5.7 TBI as well.

My memory leads me to beleive that the 1996 and up units are OBD11 computer controlled ECUs. My Tahoe on the other hand I beleive to be a OBD1 system.

The fitment of the throttle body from what I can see on older apps is a bit different than the 1996 -1999 app. Is there any way the primary supercharger unit will work if a bottom plate is exchanged out to mount on the top of the TBI assy with the 93-95 configuration?

What about fuel management and the timing retard? What would be required to get approx 18 degrees advance under boost? I read somewhere that the earlier units used a MSD retard system, is this something that we can apply to my vehicle with a boost sensor in line?

The info off the supercharger and the packaging is a follows:

on the top was written (96 350 SC) (DIS CHARGE) (I B S)
on the bottom was written (96 350 SC) MAN INTAKE
on the fuel management computer was written (Whipple Electronic Fuel Injection)
on the instruction papers was witten (1996-1999)

Ok guys let me hear from someone in the know!


Thanks,

Vann (Newby to the site)

There really isn't anything at all compatible between a kit made for a L05 (TBI 350) and one made for an L31 (Vortec 350)

The bracket for the Vortec 350 kit is designed to mount to the driver-side air conditioner bracket. On your engine the alternator is there and totally different. In theory you could swap out all your accessories to the Vortec type and change your A/C lines, but that doesn't solve the rest of the problems...

On a TBI kit the actual TBI unit gets moved to the intake side of the supercharger and air with fuel is drawn through the supercharger. This is necessary because on a Twin-Screw or Roots supercharger the throttle body must be on the intake side of the supercharger, not after it. With the Vortec 350 kit the throttle body is moved to the supercharger inlet elbow and the stock CPI injectors stay in their OEM location in the manifold. In early kits pressure to the stock injectors is increased with the same type of FMU used on the TBI kits. On later model Vortec 350 Whipple kits two auxiliary injectors are connected to an auxiliary PCM that monitors intake air temperature and intersects mass air flow. There's no MAF sensor on a TBI system, the Vortec kit needs the OBD-II PCM and its sensors.

I guess the bottom line to using the Vortec kit would be dumping the Vortec-specific auxiliary injectors and PCM in favor of a simple FMU and a boost-a-pump. You'll need the Vortec accessory drive. It's a bolt-on swap but you'll need to get the A/C lines to go with it and change the alternator hook-ups. (Make sure you get a power-steering pump without the electrical connector on it (EVO). Then, you'll need to fabricate a tube that goes from the supercharger discharge to the intake manifold where it will bolt on in place of the TBI. Next you'll need to fabricate an adapter to mount the TBI to the intake elbow of the supercharger. You'll need some type of filter so get a filter box off a Vortec truck and plumb that in.

Is this all worth it? Hell no it isn't... Keep looking for the right kit.

__________________
"James B." '99LT_Tahoe4Dr2WD, Tuned L29 Vortec 454, 62#Injectors, Cutouts, 4L80-E 10.5"14bolt ,EatonPosi-4.56:1, Gear_Vendors, HydroBoost, (NEXT: Brodix heads, 230/240 cam, SS roller rockers, longtubes, THEN: Intercooled W200R-8psi in the future...)