Prius Pistons

[JustDidIt]

Originally Posted by xnamerxx

Here is a cutout of a 1nz-fxe from an autoshow.

Sooo Pretty!

Originally Posted by xnamerxx

I seriously doubt that the FXE piston would have any issues in the FE engine aside from the massive increase in compression that would cause some tuning issues. The compression being close to 13:1 doesn't really scare me as long as you can control the tune, which is pretty much only possible with a aftermarket ECU. I've seen 4.6l engines running 12.6:1 on 91 octane its doable just takes more work.

Originally Posted by Viperoni

The (static) CR would be 13:1 if you use Prius (FXE) pistons.
The dynamic CR is apparently 11:1 if you use FXE pistons

To answer your question, it depends. A quick googling seems to say that there's diminishing returns, especially since you're not improving the breathing of the motor and filling the combustion chamber with more air/fuel.
One calculator said 6.5% and that's more or less what I read on another site as well... which I think is a bit low, but could be bang on. In any case, a 6.5% increase is 7hp.

Originally Posted by Viperoni

Here's another thought; since 13:1 *may* be on the high side... are there thicker head gaskets we can use?

If your original post is correct, then most I may need to change when running 11:1 compression is 91 instead of 87 pump gas, besides some EM. But even then....I run on 87 now...at the supposed static CR of 13:1 or dynamic 11:1.

Originally Posted by tooter

Sorry, I really didn't mean to come off as being negative. I was only commenting on the lack of feedback as to what happened after 13:1 pistons were installed. There's no information. I'm all for trying new things. Wait till you see what I'm cooking up...

That manifold wasn't even my idea. I can't take credit for it. The guys in Puerto Rico did it first. I just thought it looked really cool and wanted one on my engine.

If if you weren't the original.. "Imitation Is The Best Form Of Flattery"... Your idea to hack up a manifold and try something new got me thinking. The way my MG1/MG2 sits, I could never use the 1NZ-FE intake or even your 'Tooter manifold' - the throttle body would conflict with my inverter. But I was thinking of doing something with the 2AZFE intake manifold because the throttle body would come out the passenger side...problem is - the manifold is plastic.



Not sure how I could 'weld' the 1NZ flange onto the 2AZFE plastic tubing :( I may just have to make/design my own. Luckily you already have the flange I need to weld onto!

[tooter]

Originally Posted by JustDidIt

If if you weren't the original.. "Imitation Is The Best Form Of Flattery"... Your idea to hack up a manifold and try something new got me thinking. The way my MG1/MG2 sits, I could never use the 1NZ-FE intake or even your 'Tooter manifold' - the throttle body would conflict with my inverter. But I was thinking of doing something with the 2AZFE intake manifold because the throttle body would come out the passenger side...problem is - the manifold is plastic.

Is this the layout of your engine? And if it is, is your intake at the front of the engine or behind it?

Not sure how I could 'weld' the 1NZ flange onto the 2AZFE plastic tubing :(

I'm not sure, but I think that the plastic might have been ultrasonically welded. And that "snail" style manifold might still have clearance issues, but that could be easily determined simply by taking some measurements.

I may just have to make/design my own. Luckily you already have the flange I need to weld onto!

No rpoblem.
I'll always be stocking them. Since the design is finalized they can be manufactured as needed.

[JustDidIt]

Originally Posted by tooter

Is this the layout of your engine? And if it is, is your intake at the front of the engine or behind it?

My intake manifold is up front like the 1NZ-FE but the manifold is mounted/designed with the throttle body sitting directly on top in the middle of the manifold.



Picture of my front strut bar install... shows the layout better.





I really think I have the clearance to make the 2AZFE intake manifold work or something similar because I don't have much in the way if the intake was routed to the passenger side of the engine as the 2AZFE would if mounted on my 1NZ.



If the 2AZFE manifold doesn't work, My idea is to create the log style intake with fairly long intake runners. Basically the 1NZ-FE reversed. Such as examples below: