Twin charging
 

So so far, the only twincharged 86 is that from the GRMN, why are the main forced induction companies focusing only on turbo and SC kits? and just out of curiosity, what would happen if you add an FBN turbo kit to the Vortech supercharger?

I dont think that setup would fit for one, the innovate twin screw would be a better fit.

The vortech kit also builds boost in a linear fashion over the rpm range so I wouldnt see much benefit to it.

Big turbo+twin screw/roots would be a better choice but you would really need a build motor to justify it IMO.

Maybe you can get FRS300 to do it, he has a built motor and a massive turbo lol.

Twin charge is cool and all, but on a 2.0L BOXER, the right size, single, turbo will net you more power, granted, there might be more lag. In that case, twin charge would make some sense. But there are ways around that. The K04 (small turbo... about the size of my fist) that was in my Cobalt SS made great power on the 2.0L Ecotec (Engine code: LNF, 260HP/260TQ from the factory at the crank) and lag was minimal.

The only twin setup that makes any sense to me is BMW style with a small turbo for quick spool shifting over to a large turbo for top end power. The higher the rev limit, the more sense it makes.

This is the only forum I have ever been on where we keep getting these twin charged questions. You can't add a Full Blown kit and a Vortech kit. I don't expect to ever see any company come out with a twin charged kit.

What about inline setups? using separate paths for each charger? root plus turbo.. I guess it wouldn't be feasible to produce this kind of kits.

Compound just doesnt make sense on this platform.

I've always wanted to build a roots/big turbo twincharged setup. This is actually probably an ideal platform given the availability of the required components (a top mount turbo is just begging to be piped into an innovate sc). Maybe when I hit the lottery...

But why? If it's for the "oh my God look what he did!" factor, put four small turbos on it. That would look insane.

Its been done twice....
yes not those exect kits but twin charged none the less.
But no i don't think it really works with this platform and a FA20.

Because there is a technical purpose to a roots/big turbo setup. The roots effectively increases the displacement of the engine, which then spools the larger turbo more easily. It could be awesome, and not only for the wow factor. Granted you can probably achieve any reasonable goal more easily with a more traditional setup, it's still a possible solution to the coupling between static displacement and turbo selection (for a given amount of acceptable lag).

So it's not entirely pointless bling.

MRT in Sydney are doing an innovate + avo twin charged 86 build.

See you're thinking in terms of the supercharger making the turbo work better, but since the Roots is the last link in the FI system, I tend to think in terms of the turbo feeding the supercharger, which feeds the engine, and try to envision how the turbo can be set up to help out the supercharger.

The problem I have always had with this kind of setup is envisioning what goes on when the blower is turning and needs lots of air, but the turbo hasn't spooled yet. What are the risks of the effective vacuum that could briefly exist between the turbo and the supercharger while the supercharger is trying to suck more air than the turbo is delivering?
There must be a reason no one does this if there is any advantage.
The proper way to do it would be to provide two parallel paths, not one feeding the other, but both feeding the manifold. But where do you put the MAF and throttle body? I think the plumbing is just too complicated.

The thinking of a twin charged, or compound charged, setup like a Twin-Screw + Turbo is the that supercharger provides a responsive throttle with mid-range grunt, filling out the torque curve of a larger turbo. As mentioned above, a supercharger (especially a PD blower) allows you to spool a larger turbo than would normally be practical for a specific engine size.

It's more about response and "area under the curve" (useable power) than maximum power. You're not getting Blower torque + Turbo torque. You're getting whichever is higher at any given moment.


An "unspooled" turbo still spins. And even if the impeller was stationary, air will still pass through it easily. There's no need for a separate intake pathway. The Supercharger will pull through the turbo without a problem.

When the Turbo begins feeding more air than the supercharger can ingest, the bypass should open to allow the excess pressure to go around the blower and into the engine.