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I'm asking out of curiosity because on Instagram some fellow mazda owner said he would be supercharging his car and honestly I never gave it much thought, but now i'm very curious.
 

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Well, to start with, taking on such a project will not be simple or cheap to accomplish and especially not if you're set out to do it properly. Even if there was a supercharger kit available for this engine the only way to do it right is to hire someone who really knows what they are doing to do some custom fabrication to your car using a custom supercharger, tune, etc. The high compression ratio and power delivery of the 2.5L is well suited to the characteristics of a supercharger, mainly because of the NA like surge of power you get the harder you rev the engine. Superchargers don't build any power until you start passing 3000RPM or so which will work well with the strong low end this engine offers. To make matters more complex and costly, the stock differential will have to go without a doubt which, like I mentioned in a different post, (more custom work, more $$$) and obviously you will need to upgrade dampers, struts, sway bars, etc. etc. If you can find someone who really knows what they are doing in terms of ECU tuning you'll have yourself something real special. Is it worth the money - I say yes for the driving experience, but that's a subjective topic. If you are really looking to push the limits of this engine you'll need to replace the lightweight Skyactiv pistons/connecting rods with something tougher although the forged crankshaft should have no issues handling decent power levels for a 4 cylinder. Hopefully you can find someone capable of remapping the transmission for something like this to really come together.

My suggestion is to look up the previous generation 2.5L L5-VE engine for turbo/supercharger builds to inspire yourself. lol.
 

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... which will work well with the strong low end this engine offers....
Uh, not in my book. I have never felt such a weak-kneed 2.5 engine in my life, ever. This is really giving me grief... because my 2017 Mazda6 6MT feels like a really, really cammy engine... Not what I want in a pretty large four-door sedan. I feel cheated, by way of bottom-end engine power.
 

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Obviously it's possible to supercharge this engine for the right price, figure at least 5k, but you would be very limited in amount of boost to add without at least a partial engine rebuild because of the compression ration. Plus this is all assuming you can find someone to custom fabricate the the parts needed, because adding a custom turbo is actually less work than a super IMO (I've thought seriously about adding a rear mounted little turbo...).
I think with some other changes you can get enough out of this engine to be friction limited more of the time than power limited :)
I think that my 6 is much faster in reality than it seems on paper in Peak HP (should be avg HP, or some distribution of HP over rpm range...)
 

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Rear mounted? As in, under the car? WTF would you do that when Mazda makes a turbo motor that you could use pasts from and do it right.
It's a way to do it cheaper, obviously it would be better to have it part of the exhaust manifold. The stock muffler is so huge that space is adequate to put a small turbo (target maybe 5-7psi)... In the end I've let go of adding FI to this engine and focusing on squeezing the extra bits of power out of this engine that I can (intake, exhaust, tune, and eventually water/meth injection), and I recently filled the rear motor mount with polyurethane construction adhesive which really helped make the car feel faster (less latency do to engine rotation).
 

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No, its NOT a way to do it cheaper... adding the oiling, the IC piping all the way back there... who did your parts math? You can get a stock usedCX-9 turbo for under $500 with manifold. The stock SkyActive 2.5 is good for 7-9psi.
You may be right, one friend was arguing that he could help me do it cheap FWIW, and yes 7-9psi seems doable... Either way I've let go of forced induction, honestly my car feels fast now (probably 15% more power than stock) so I've shifted my limited car modding budget to focus on suspension & braking (well and water/meth injection).
 

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Obviously it's possible to supercharge this engine for the right price, figure at least 5k, but you would be very limited in amount of boost to add without at least a partial engine rebuild because of the compression ration. Plus this is all assuming you can find someone to custom fabricate the the parts needed, because adding a custom turbo is actually less work than a super IMO (I've thought seriously about adding a rear mounted little turbo...).
I think with some other changes you can get enough out of this engine to be friction limited more of the time than power limited :)
I think that my 6 is much faster in reality than it seems on paper in Peak HP (should be avg HP, or some distribution of HP over rpm range...)
I don't think the compression ratio would be much of an issue. My primary concern is the quality of the ECU tune, as this is what can easily make or break a good build and blow your motor. Now, if you're pushing higher boost, the lightweight skyactiv connecting rods and pistons aren't really up to the task but you wouldnt need to really rebuild anything else, maybe just port the heads or something.
 

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the lightweight skyactiv connecting rods and pistons aren't really up to the task but you wouldnt need to really rebuild anything else, maybe just port the heads or something.
Dude, do you know ANYTHING about cars? If you blow rods or pistons, you HAVE to rebuild the whole thing cause you have NO idea what else might have happened.
 

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Dude, do you know ANYTHING about cars? If you blow rods or pistons, you HAVE to rebuild the whole thing cause you have NO idea what else might have happened.
Dude, I don't think you understood what I said.

My goal would be to rebuild the engine BEFORE you dial up the boost like an idiot and blow something up. Even then, ill still go easy with boost unless i am more than confident with the ecu tune.

Again - the connecting rods and pistons in this engine are the weak point past a certain amount of moderate boost. The crankshaft is forged meaning it can handle a good amount of boost, and you won't need to rebuild anything else.


Unless you do end up blowing the motor... which would be a different scenario like you said. It's not that hard to understand, dude.
 

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As far as I know nobody knows what the engineering limits are on these engines. There is certainly an engineering safety margin on the design but exactly how far beyond the OE calibration it happens to be is unknown.

This much is certain -- the SkyActiv engine, being a high-compression design, is going to be very, very hard to get material boost into without severe detonation problems unless you intend to run specialty fuel all the time, which makes it completely impractical for a road vehicle.

Nobody knew on the ALH VW diesels either, originally. The OE spec is 90HP (yes, really.) Being a diesel shoving more air and fuel in becomes very easy. Just increasing the fuel (e.g. bigger injectors) provides quite a lift on its own. Recalibrate the boost and you can go a LOT further. It's not really all that hard on those engines to double their output but if you get ambitious you better be thinking about everything from engine to clutch to final drive or you're very likely to get a very expensive and unwelcome surprise, frequently involving engine and other driveline components winding up outside of where they are supposed to live.....

A few people have found the limits the hard way, and that process has led to specific recommendations beyond certain points. But you can bet VW didn't tell anyone where those limits were, and the people who found them didn't like the price associated with the discovery either. :oops:
 

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This much is certain -- the SkyActiv engine, being a high-compression design, is going to be very, very hard to get material boost into without severe detonation problems unless you intend to run specialty fuel all the time, which makes it completely impractical for a road vehicle.
100%
 
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