First post here. I'm a Toyota guy and I've been driving Echos for years. However, I just picked up a 2004 Prius that was too cheap to refuse. I found it to be underpowered, so I swapped the intake cam for one from a Toyota Echo. Not sure if anyone has done this yet, but it worked flawlessly and massively increased power. I will follow up with pictures and details if anyone here is interested.
Will post pics of the car tomorrow. As most people on here probably know, the Prius runs a modified cycle, where the effective compression ratio is less than the geometric compression ratio. This is achieved by keeping the intake valves open during the beginning of the compression stroke. The result is very low compression but a high expansion ratio of 13:1. By swapping the 1nz-fe cam from the echo, the compression ratio is increased to 13:1. 13:1 is very high, so 91 octane is definitely required. This seems a very easy way to hugely increase acceleration while only mildly decreasing fuel economy.
Definitely curious! Generally the Prius' ECU won't allow additional power to be generated from mods that work on other cars (eg. turbo chargers). It will close the throttle until the same amount of power is produced.
Obviously, these engines are tuned for efficiency and lower RPM operation. Will be interesting to see how this affects overall economy and drivability. Cool experiment!
Increased compression means increased pressure on the piston rings. It's rare to increase compression on a motor without a companion upgrade of pistons and rings. Prius stock rings are not designed for that compression, It will be a lot of fun for a while though.
I can't speak to the turbo portion as I never installed it before it was totaled. However, the custom intake and full custom exhaust I had not only gave me better mpg when I kept my foot out of it, but it also charged the hybrid battery quicker and gave me a bit of an increase in power measured by my butt dyno. Never had it dynoed.. The Gen1 Prius running also a 1NZFXE that was turbocharged by Julian Edgar was able to find a way around the closing throttle.
Great to hear !! I was in communication with a user on the YarisWorld forum who had said that they had a 1NZFXE engine with a 1NZFE intake cam running on their test bench at school and had no issues and no CEL. I came close to doing the install and chickened out. Wonder how it would handle if you opened up the airways more and made it more free flowing??
I'm curious to see comparative dynos (before/after). Any other information like a/f raito, mpg, temperature related info will also be interesting.
Well it's been around 1000km now since the cam. Still no check engine light and mileage doesn't seem to be significantly reduced. It does 0-60 in very slightly under 10 seconds. That's not fast but definitely improved considering the battery has 310000km on it. The increase seems to be mostly in torque at the low end. It even starts to spin the wheels off the line but around 100km/h there doesn't seem to be much improvement. I hypermiled the last 80k and managed to pull off 3.9L/100k (60mpg). Not too bad for a $1400 car I'd say.
I also tried one more experiment with the car. Although I wouldn't claim success on this one. It is a simple modification to the inverter where I placed current shunts around the current sensors. There are 4 hall effect current sensors on the main IGBT module. All I did is bypass some current around the sensors using a few pieces of carefully measured copper wire. The idea is that the HV ecu would "see" less current flowing through MG1 and MG2 than there actually is. In theory, the HV ecu would compensate and push out a little bit of extra current. This trick worked very well for just one test run, where I clocked 0-60 in under 9 seconds. However, on the second run it tripped the over current protection on the battery and the main contactors opened. The car limped home on gas power and no damage was done. In this third picture you can see the shunt. I made these carefully with all the exact same length, so that resistance was matched. Crimps were soldered too. Perhaps this would work using a slightly thinner gauge of wire, so not to trip the battery protection.
Also, people should stop now telling me that the car is going to blow up. I don't think it will, but this is all an experiment. If the engine blows, I will swap if for one of the three others I have in the garage .
It would be interesting if you can replicate the boost converter mod that TRD did in their Landspeed Prius - going from 500v to 550.
I forgot to mention but you just reminded me, the battery does charge MUCH quicker. It goes into the green multiple times every drive just cruising on flat ground. Not sure if that is normal for a Prius but it never did it before the cam.
Never thought of that but I can definitely do that! The cap is rated 750v i think and the IGBT is 1200v max. So it should handle it. It would only involve increasing the pulse width to the boost module. I just happen to be somewhat of an expert in power electronics. This thing I'm building in the back is a big inverter, so that the Prius will double as a backup generator when the power goes out. It's not quite done yet but I was able to run a welder on it today. This will also tie in a 1.8kWh, 50s lithium pack soon. But that is for another thread lol.
This thread is blowing my mind. Fair play this experiment. I was beginning to give up dreaming that the HSD system could ever be improved, let alone touched.
That would make sense as in the PSD system, MG1 counteracts or balances against excess torque from the engine. As a result it charges the battery quicker under cruising/idling situations. At the same time under acceleration, if the engine is putting out extra torque than normal to MG1 which would drive forward MG2, MG2 (or the inverter should we say) would require less power from the battery in normal situations. If anything, beefing up the ICE makes the car work more and more like a diesel/electric loco, depending less on the HV pack, if we could imagine the results greatly amplified. With all this is mind, this is what convinced me of how performance increase was impossible for a Prius. All what these mods 'n' such, such as NOS, superchargers and kei-car turbos do is eventually keep that battery fuller. Which is good in a way, smoother driving for longer, better mpg... and then there's the emissions that are bound to've taken a hit... Anyways, the one thing you did there by messing with the inverter seems to be the most legitimate way to improve 0-60 times other than loosing weight Like, your claim how it did it in less than 9 seconds is REALLY impressive, and it's understandable too. I hope you'll find luck with the buss-bars of yours or 550V boost converter, I'm sure all the autocrossers will be over the moon for it. And here's hoping it'll give birth towards a new type or group of driver within this community.
That's cool basicly increasing current to the mgs outside of the software parameters. Do you have Toyota techstream on a laptop it would be very interesting to see the temp parameters of the mgs under load. I really like your inverter. It's hard to find a 200 volt input inverter very limited selection. I have already installed some power leads to the battery but was surprised to find 200 volt inverters not readily available. That has some marketing possibilities.
I have the software, but lack the cable. Would any USB OBD cable work? Or does it have to be some kind of can bus interface? Maybe somebody here can recommend a cable for me.
