Prius Tuning - More HP (200-300 whp)

I don't know how many horsepower this guy is making but here's a thread for a modded 1.5 liter Prius motor swapped into another car.

 

You will need the entire Prime electrical system including inverter

 

Pretty much any engine ever made can be over bored and assembled with a slightly larger diameter piston to match. Often, for minor changes and stock use, rebalancing isn't required. Different desired results need different solutions. There are many thin wall castings that can still handle a 0.060" over bore and be perfectly fine for everyday use, but be a "grenade in waiting" in most other applications. If you were to get a rebuilt 1.8 from an aftermarket rebuilder, I would guess it would likely have a 0.020 or better overbore, depending on condition of the cylinder walls and availability of pistons. Piston/rings availability definitely depends on demand, otherwise custom pistons needed at twice the price. It's not rocket science.

Going from a 1.8 to a 1.9 isn't like 1.8 to 2.3 or something. It's adding 6 cubic inches (~5.5% volume). Let's say the car makes 1 hp per CI. It will likely make 5-8 additional ft-lbs on the bottom from the increase in displacement. Assuming the intake and exhaust can handle additional airflow, the engine could make 6ish hp additional at the top. If the intake/exhaust can't handle it, then you'll end up with more torque down low, but a loss of hp at the top. More torque at the bottom is always more fun than more hp at the top in a daily driver, since that's where you spend 95% of your time. It's just the way the world works.

The real question is whether doing this modification would be worth the cost. I certainly wouldn't do it if I had a properly functioning car, but if I had the blown head gasket problem, I would certainly be looking at it as a viable option for a stock replacement, if the price was right and it was guaranteed the additional 5.5% flow wouldn't jack with the electronics.

 

You would have to pull the engine where a hg alone can be done in car. So its a rebuild versus a head gasket which is my recommended path anyway.

 

to this day I don't know why no one has made a rebuild kit, well one will hopefully be available in 2022

I've gone down this route, even had the 1.8 scanned to determine how much bore the block can handle. What It can handle out of the box isn't enough to gain for me. So, once I get the M20A-FXS working in my car the plan is to clean my block, fill the gap in the block then have that block bored to more than 2.0, not settling for the 1.9cc. Also, the max can go without ecu work... from all of the people I've talked to, the general consensus is the Prius ecu's should adapt and "learn" to use the bored motor but since this hasn't been done at all, its hypothetical.

Weiso will be making the pistons, we just need to get them the final specs and measurements once the block is made. From there the block is going to be replicated... so everything you just said we are already on and have a plan for.

Now say you needed to mess with ecu, how do you feel about that? In a perfect world a obd2 dongle comes with the kit and you leave it in to keep the proper maps in place. So far that's more cot effective than setting up some ecu hardware and you upload a file to us then we send one back for you to load. Hoping there is no wiring piggyback that'll be needed but still working through it all.

no, I have the plugin, just swap the battery.

 

@black_jmyntrn

Sry about that. My post #83 was more for AZ, as he's acting like that engine from his favorite shop is some kind of black magic deal. I did notice in his "email" from them that they clearly state "we're working on....". Personally, I think BFD, because I could take a 1.5 engine out of a Gen 2, put a small overbore on it, custom pistons and rings and balance if needed and I'm confident it would fire right up and run just fine. So I'm not impressed with a shop doing it on a 1.8. Any rebuilder shop could do it. It's just not getting done because there's just no large scale demand for a stockish+ engine replacement for $$$ when someone that needs an engine replaced can get a salvage for a few hundred. For those more performance oriented, it can start getting a bit more challenging with major and minor thrust wall thickness (more of a V engine thing, I guess, than an inline style thing), deck height, balancing etc become much more important. I'm pretty sure a minor OB on a stock engine would be manageable by the OEM electronics, but you're certainly right that going above and beyond "minor" are likely to create issues with strictly oem.

 

@tmr understood. The thing about this Prius ECU, IMO it's smarter than we give it credit for, and since no one has yet to try to push past things the performance aspect has been at a standstill. I'm like, on the edge of the bridge about to jump off into the ECU world... right there... lately I've been glad I have the Plugin, the extra ECU and electronics make performance upgrades from the electric side a lot easier. Looking for a Prime Prius Battery now, it'll give me the juice to run the electric rear motor, and versus an 80hp motor readily available motor, Im going with a ~130hp motor that's new but you can't get any more after the two handfuls in stock anywhere(weighs on me because I'm hoping what I do can be replicated). My car is going to be HEAVY... If I can disperse the prime battery along the floor with the inverter for the rear motor and not need to cut the ninth wheel well for the rear awd subframe and electric motor, ill be very happy! the cooling strips in the prime battery and the position the internals sits is in there with that concern.

when I think of the power the low-cost Tesla has, if I can find a 200hp+ electric motor that is relatively small, I would try to embarrass every tesla at a light that I come across. get a sticker made that says "Tesla Eater" or "Powered by Eating Teslas"