Im new here, so forgive me if this has been asked already, Though I did do a search and came up with nothing. Now for the question. I wanted to know if any1 has put a turbo on only 4 of the 8 cylinders in an effort to keep it simple and if so how did that work?

 

turbocharger on 1 bank of cylinders

Basically I want to know if I could use half a twin turbo setup to achieve the same results. I was thinking that I could use a t3 turbine housing with a .63 AR with a Big enough to feed the motor 10-12 pounds of boost compressor.Any thoughts would be appreciated.

 

You can do it, but the effort you will go through to get it done will yield disappointing results. A single t-3 turbo is just too small to feed a 302+ motor.

 

definately not worth it. why not just build a single kit with a correctly sized turbo? most of the hot side would be on one side of the motor

 

Apparently Saab's doing it with one of their newer motors, but I suspect they'd have different camshaft events for the bank of cylinders with turbocharger compared to the side without.

You could do it, but it would be a real compromise unless you had some custom cam ground, IMO, and then you're sacrificing efficiency and power for packaging, which ain't an issue in our case.

 

I have a single 60mm MP w/ t-3 exhaust housing on a stock 302, and it made 478 rwhp w/ only 9#'s of boost.

 

He means the Garret T-3s like you find on turbocoupes, etc.

He isn't referring to a "t3" turbine flange

 

if you have a small turbo, just use a huge external wastegate.

As this is what a wastegate does, bleed off excess exhaust flow around the turbo instead of through it.

The problem with a turbo on one half the engine will create all kind of problems bank to bank.

Remember, each cylinder is its own engine. Coupled by a common shaft {crankshaft}

Every cylinder has its own timing and fueling needs, but most efis dont have that capacity. they tune the motor as a whole.

so if one half your engine has radically different timing and fueling needs....well you get the idea.


Nonetheless...using SAAB as an example for anything is bad. They believe themselves to be superior engineerings coming up with complex solutions to simple problems that in the end never work out. And are ALWAYS cost prohibitive. "Built from jets" lol well they went out of business in the aero industry and are about to be plowed under in the auto market too!

Anyone remember saabs variable compression compound charged engine? Yeah me either. It had a bellow for a head gasket, and the head was hinged so it could be robotically moved to lower/raise static compresison to maxmize off boost performance.

 

I've also seen old-school air compressors that are V8 or large V6 engines - one bank of cylinders provides all the power, and the other side just compresses air

 

Yea That was what came to mind for me as well reading this forum. Imo the challenge of ballancing a motor to even idle would be even a challenge. Half cylinders under boosted pressure ouch good luck.

 

Back in the 70s and 80s, SB Chevys came with a heat riser valve in the exhaust, which on cold start totally blocked the right side exhaust, forcing the exhaust through the bottom if the intake manifold. It opened up as the engine warmed up, but even fully open, it still choked the flow, enough that gutting it became popular. And you really could feel the improvement from gutting it.
I imagine the turbo would be a choke, but if that was the only way to add boost to some bizarre vehicle, then probably better that than no turbo at all. My next worry would be whether to choke the other side with smaller exhaust piping, or what. I definitely would block the crossover through the bottom of the intake manifold, the heat would cause vapor lock otherwise. Better yet would be to choose at least an intake manifold, and preferably heads also, that don't even have the exhaust crossover passages.