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.

Yep, the internal bypass that some blowers use to reduce parasitic loss could do something like that (I assume, obviously never tried it lol)

This part was understood. The question is how to make it work well enough to be worth the trouble and if there are any "traps" to be avoided that could cause blown motors and other unpleasant things.
I still think the whole thing is accomplished a lot easier by just using two different sized turbos.

The turbo, intercooler (I assume there will be one), piping...
I just have my doubts about how well this would work in reality. I understand the theory, but I worship at the altar of the great and powerful Murphy. This just seems too complicated to be reliable on the street.

Twin charging almost never makes sense anyways. Hellion makes a hellraiser kit to add twin turbos to the existing eaton blower on cobras and gt500's and the twins by themselves make more power.

...once they're spooled up. No denying peak power would be reduced. That's not the intention.

Twin charging is totally worth it. Only problem is it is always very custom, costs more than your car is worth + lagniappe, and isnt reliable since you will break a lot of stuff. Just look up Ronin's compound charged Exige (now called the 211 RS).

Ever been in a turbo car and watched a boost/vacuum gauge while you punch the throttle under the RPM you make boost?

I don't have a turbo on my BRZ, but in my old DSM that spooled at about 3k with a fmic etc, it would go strait to atmospheric pressure as soon as you hit the gas. Then when the turbo spooled you would hit boost of course. Regardless, I can back Draco up in that a supercharger wouldn't have an issue pulling through an unspooled turbo.

Regardless, I am sure you would get better response with a positive displacement supercharger/turbo twin charged system. What im not sure of is that it would be worth the extra weight and expense. That being said I don't have a problem dealing with a tiny bit of lag, so I may not be the best person to hear from. Id love to see someone do it though.

[ame="https://www.youtube.com/watch?v=HmscSzFurwg"]The World's Fastest Lotus? - TUNED - YouTube[/ame]

I'll just leave this here..

Ridonculous. Just put some nitrous on for a quick spool. Way cheaper. Or ignite an open exhaust port with some unburnt gas. Heck, for the cost, put an LS7 in the engine bay.

How about AVO + Votech? It would seemingly fit pretty well if it was: intake --> SC --> turbo --> intercooler --> engine. Sequentially compounded boost throughout the entire powerband of course, not bypassed in stages or w/e. Basically a sequential turbo setup except one of the turbos is powered by the belt instead of exhaust. The Vortech would have top end and helps spool the AVO turbo sooner I imagine. Keep in mind that the Vortech comes first, feeding the AVO turbo directly w/o an intercooler in between. We don't really need to worry about how much boost the Vortech is producing since thats predictably manageable via the chosen pulley size. AVO kit would have a wastegate to manage the combined total boost, but we'd prolly want to have it set to more than 7psi. The compressor in the AVO kit might not flow enough efficiently though, but I really like the placement/fitment nonetheless. A Rotrex C30-94 (or C38 even) + GTX2867 turbo would be so cool too! I know I'm about to get a ton of negative feedback, but w/e...lol