turbo: blow thru vs. draw thru

bohica2xo said

The only turbochargers we used were Rajay units back then. An E flow Rajay on a 350 cid engine would push 10psi plus with a 1.0 A/R ratio on the hot side.

We ran a looser 1.3 A/R on the big blocks. Back then it was common to size a turbocharger to max out with the engine to build a system that would work without an exhaust wastegate.

Gale used a dogleg intake with a pad for the carb that put the top of the air horn below the centerline of the compressor on some truck installs. That was ok for a smallblock, but on big block it was restrictive with that short turn in to the compressor inlet. we saw icing on those manifolds, especially the one with the carb near the passenger side headlight.

Most motorhome kits had a higher carb mount. Which setup does your friend have? Which turbocharger, Garrett TO4B or Rajay E series?
B.

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A draw thru turbo NEEDS the dog leg to break up the swirl produced by the turbo and induces turbulence to keep the fuel in suspension, if it did not have the 90 degree bend, it would sling the fuel out of the air and onto the walls in the intake tract and then lean destruct by melting the pistons very very quickly as the fuel will pool up in the intake. As in the end of the driveway. It can not be a 90 degree tube or pipe, it needs to be a flat wall square 90 to stop the swirl produced by the compressor scroll as it leaves the turbo housing on a single turbo set up. TT set ups can have the compressor outlets face each other and basically blow against each others outlet to create the turbulence needed to break up the swirl. Yes these designs are restrictive for a normal NA engine, but that's not what we have or are trying to build with the draw thru system. Those restrictions mean nothing when its under pressure from boost.