2005 Prius engine into 1986 MR2: mk1 1nzfxe Prius swap (gas only)

[cRiPpLe_rOoStEr]

Originally Posted by kameleon

They were talking about putting the 1nzfe cams from a yaris/echo/xA/xB in a prius and running E85 with 25% larger injectors.

Now that is figuring with E85 and 25% larger injectors but in all honesty running 93 octane on E10 (what I have easily available) and the 13:1 compression ratio it should be very close if not over.

I wouldn't be so sure about the effort to run ethanol in a Prius. At least for me it seems that CNG is more suitable to the operating pattern of a hybrid car's engine than ethanol due to the idle shut-off. And the cams swap would eliminate the perceived advantage of the power stroke becoming effectively longer than the compression stroke. Trust me, I'm from Brazil and very used to ethanol-fueled cars.

[serialk11r]

Wait, was he running a 7000rpm rev limit on a Prius engine?

You shouldn't swap the non-Prius cams into a Prius, because the connecting rods are not meant for a 7000rpm limit. They made the connecting rods thinner on the Prius.

What you want is the Prius pistons in a normal 1NZ. A slightly different grind on the 1NZ cams might be desirable. Supposedly the 1NZ rods and valves can go over 7000rpm easily without modification (MR2 Spyder 1NZ swap guy had been running it at 8000 with a turbo).

Actually I don't even think that's a good idea, because it's a lot of effort for miniscule gain. I would just shave the head a little and slap on a supercharger if a stock 1NZ's power doesn't suit your taste.

[BLSTIC]

Thread Revival!

Train of thought:
I currently have a 2NZ powered Echo.
I was looking at the 1NZ-FXE as a replacement, or a camshaft donor for a regular 1NZ.
I found this power graph for the 1NZ-FXE http://www.autospeed.com/cms/gallery...=0&a=1450&i=14

Note that the peak torque is 115Nm @ 4200 rpm, with peak power of 53kw @ the 4500rpm limit. This implies that could the 1NZ rev harder, it would make more power. With the peak torque being so-much-lower than a 1NZ-FE (141Nm) it also implies that the cylinders are being nowhere near filled.

The FXE inlet manifold is... well it makes me cry. I haven't seen the exhaust manifold but it's probably the same. Simply putting on the FE manifolds should yield a major improvement in mid-high rpm power, which given mr220's anecdote appears to be the case. The usual intake/header/exhaust mods should improve this further.

I have no simulation data (I haven't paid to have my copy of engine analyser unlocked), but I assume that the FXE cam, properly timed, will improve the already 80kw 1NZ-FE at the top end. It might even get to 100kw with appropriate exhaust & intake mods.

Another thought is that with the super-late valve closing, you may want to run very small (filled) inlet ports. If the cam is timed correctly a high velocity port can get to 115% volumetric efficiency at peak torque, which in this case would be at high rpm.

It's important to note that even with all of these ostensibly horsepower oriented mods on the intake side of the engine, as long as you have a mild exhaust cam it's not going to suffer the usual low-rpm efficiency loss (even though low-end torque would suffer)

As an added bonus, the completed 850kg Echo would have a power-weight ratio approaching early WRX's. Which is just cruel and unusual.

[samwichse]

Photobucket is the one making me cry on this thread.

All those pictures hidden...

At least you can right-click open them in a new tab like so:
Photobucket

[deejaaa]

OMG. PB sucks! they should be treated the same
as hijackers.