On the trail of a 3.3L supercharger

[mmcdonald]

Okay, tell me if you think I am barking up the wrong tree:

Magnuson makes the blowers for TRD:
http://www.magnusonproducts.com

I looked up Magnuson's distributors in MD and am contacting a well-known speed shop in MD regarding a custom application for the 3.3 Liter.

My question regarding this application is as to the amount of boost available from this supercharger.

The compression ration on the 3.0L V6 is 10.5:1, and on the 3.3L V6 it is 10.8:1. I am not sure how much boost you can use from a supercharger based on this already high compression ratio. Most supercharged engines (street) have around 8:1 static compression ratio. Given that:

((Max Boost/14.7)+1) * Static Compression = Boosted Compression

then a 10.5:1 motor with 5psi is over 14:1 compression ratio, and 10.8:1 is around 14.5:1!

Granted, this is on max boost, and up in those revs there is not a lot of load on the motor so detonation is probably not such a large issue.

But really, 12.5:1 is like the optimum compression ratio on pump gas. I think there will be lots of retarding and extra lean fuel mixtures needed. Then more spark, and reprogrammed ECM, etc.

Do you think Toyo was going for a compression ratio already so high that no boosting is really needed? If that is the case, I don't think TRD is going to come out with this application.

Do you think (without this character in the reply: ) that this is a worthwhile pursuit?

[SC V6]

I don't know how the H*ll they would make a supercharger for a VVTi, since that means variable valve timing, its like.. they make the duration longer so the exhaust and things get out, which means that the valves overlap, like Vtech, now how would it hold the boost being boosted from a Supercharger if all it would do is go straight threw the motor?

anyone else feelin me?

[Mandarinsolara]

overlap isnt that drastic, without one it would still have to create a vacuum , robbing horsepower

[mmcdonald]

the exhaust valve eventually closes so that some fuel can get in, ya see? It closes soon enough, in fact, that sufficient vacuum is created to draw fuel into the piston chamber even without boost.

Since the exhaust valve therefore does close before the intake valve, the cylinder WILL hold an air fuel mixture, and if that mixture comes in under boost, it will hold that boosted air fuel mixture as well as it will hold the AF it drew under its own vacuum. Since the AF under boost is denser than the AF under vacuum, it will EVEN create more horsepower due to higher compression.

You have to remember that the supercharger is constantly rotating, and it is therefore constantly providing boost. It is doing this even faster than the engine is creating a vacuum, so the charge is always dense. So even though there is some valve overlap, not to worry my little friend, our supercharger will overcome the cylinder blow through caused by valve overlap.

So you see, SC V6, even though you can't understand this, it nevertheless works. Isn't that special?

[mmcdonald]

Here is what I got back from Rockville Speed:

"hello again,
sorry, but all bad news - magnacharger makes the blower itself for
toyota, but you must purchase it through toyota.
magnacharger is not marketingthe kit itself.
thanks
mike"

Dang it.

[SBCelicaGT]

Here is what I got back from Rockville Speed:

"hello again,
sorry, but all bad news - magnacharger makes the blower itself for
toyota, but you must purchase it through toyota.
magnacharger is not marketingthe kit itself.
thanks
mike"

Dang it.

Yes, this is true. Magnuson makes the kits for TRD and sells them to Toyota/TRD/ for resale. Rockville Speed probably buys these kits from Toyota/TRD.

As for your inquiry on compression versus blower pressure, keep in mind an eaton type blower is not boost regulated. In other words, it will spin the same, and push the same amount of air, no matter what the compression is on the engine if you do not change the pullies. A larger engine will require more air (volume) to fill the cylinders compared to a smaller engine. This will result in a slightly lower boost pressure reading on your boost gauge.

In short, 6psi on a 1MZ may NOT equal 6psi on a 3MZ. You also need to take into account the crank pulley diameters, head flow, etc.