Making a Prius Fast?

Hey All,

I'm new to the forum, I don't own a Prius or any other hybrid. I know a bit about the PSD and can understand how the engine and motor/generators can be combined to make rear wheel torque.

My question is...do guys looking for performance from these things go straight for modifying the engine? i.e. turbo, tune, exhuast? or do you play around w/ higher voltage batt. packs?

Also, let's say I was to strap a T28 garrett onto one of these things, would I have to re-tune the computer's strategy regarding the PSD?

First, the Prius is front wheel drive. There is no rear wheel torque.

Second, guys looking for performance buy something else. The stock Prius has plenty of performance for normal driving, but it doesn't lend itself to performance tuning. It is already highly tuned and the control system is complex. It's not something that can be tinkered with without making things worse.

Tom

Yeah I wasn't too sure about the FWD/RWD thing...I'll probably say dumber things than that. I really don't know much about them.

The main reason I asked the question to begin w/, is a friend of mine told me that there is a Prius running mid to high 13 second 1/4 miles. As you said, the control system for the prius is very complex, and that is what got me wondering about how exactly he did this.

Thanks 4 the quick reply.

The stock Prius is pretty quick. The electric motors produce a lot of torque, so it's not too hard to get good times. Good tires would be one of the main modifications.

Tom

Okay, so let me try to figure this out (correct me wherever I'm completely wrong)....at max accel, the engine and mg2 contribute to total torque. the engine is able to contribute b/c of counter torque provided by mg1 through the sun gear. So in theory...if you could increase engine torque, as well as mg1 counter torque, you would increase overall torque to the wheels? Keep in mind that I'm not really considering mpg, or the most efficient way of running the vehicle the way it was intended to be ran. But if it was possible to completely re map the computers strategy, would this work?

hmmm....interesting....i really want to buy a prius just to tinker w/ things like this. i didn't even know that the prius is using the atkinson cycle. that explains alot about efficiency! but that also explains why it's not too quick.

but here's what i'm wondering....even if you had a 500 hp engine under the hood...wouldn't acceleration be limited by the amount of counter torque provided by mg1? i think i understand the way the psd works, and if i'm right, even if you had all the engine power in the world, it wouldn't matter if you couldn't produce some kind of resistance for the planetary gears. i just read something on google that said some guy bolted a turbo on his prius and didn't achieve much 0-60 times but did achieve better uphill performance.

interesting response ... could you explain this remark .... "It's not something that can be tinkered with without making things worse."

i don't think the Prius has "plenty of performance for normal driving" either.

i can see why the fuel is limited to 9-10 gallons ... weight savings, and the same for the four banger

but i would like to see the 4 banger turbocharged AT LEAST

this car has no performance whatsoever, and to drive it in a spirit fashion is rather challenging

i've taken my Prius into the Santa Monica mountains and run the same canyon and mountain roads upon which i ride my Kawasaki, and it was challenging

i'm talking Decker Canyon, Latigo Canyon, Mulholland Hwy, Westlake Blvd - really tight technical stuff

i would throw the Prius aggressively into the turns, but i could not power out of them at all, stomping the gas did nothing

couldn't power off the apex, couldn't even supply smooth consistent power into and through a turn

have to completely reinvent driving

example i couldn't power a straightaway, downshift/brake for my turn entrance, and then jump back on the gas

it's an odd sensation

plus, the motor's got NOTHING going up hill ... nothing

i think a turbo and remapping could be done to give this sucker some power and fuel economy on the inclines, and even higher freeway speeds, without adding weight (bigger motor, or a bore/stroke)

i'd be curious to hear of power mods that could give the little banger some muscle

no interest in a quarter miler, if i were, i'd drop in a stroked five liter from a mustang :thumb:

well i'll be damned...there is some1 on this forum interested in power. :rockon:

i just joined the forum today. i've been doing alot of research as to how the prius works. i'm thinking about picking up a used prius and playing around w/ some performance modifications. how much can i expect to pay for an earlier model?

M10,

Here is a place to start reading on perhaps the fastest Prius known:

Landspeed Prius Races Across Bonneville Salt Flats

IIRC, the car has a one-of-a-kind chip -- from TRD? -- for ICE control.
I suspect that it maxes out the top end as opposed to low/mid range.

Yes, that's right, but not only that. You would have to modify both MG1 and MG2, and the corresponding electric equipment of the car. The MG1 and MG2 always work as a pair. You need the MG1 to provide more counter torque (unless you are in heretical mode, where the situation is reversed, but the principle is the same - read here: Whats Going On As I Drive? ), but how do you achieve that? By draining more energy out of it. And what to do with that energy? Feed it to the MG2, that's the only sensible way.

So, the MG1 and MG2 pair is working as a transformer; as a parallel branch feeding energy from the ICE to the wheels. The slower you go, the more significant portion of the energy is flowing through this "electrical" channel. So, if you want to achieve anything, you need to modify *both* MG1 and MG2 to provide more power and also upgrade the inverter to handle resulting higher currents. The currents are pretty high even now and making them any higher would result in loss of efficiency. So the right answer is to go for higher voltage. This would result in a *whole* new inverter and would also require the upgrade of the traction battery pack... Of course, the software of the ECUs would have to be modified too.

So, in order to achieve anything, you would need to extensively modify the whole hybrid system; trying to tune its parts separately would bring only negligible improvements. Therefore, the right answer is: If you want more power, buy a different car... This would be a *huge* project .

OR, become a hypermiler as the rest of us . Leave the dark path of rubber burning gas-guzzlers and become a tree hugger... Buy a Prius; It will change you, you shall see...:madgrin:

It changed me!

The Prius has plenty of power for normal driving. Normal driving is what 95% of the population does. Driving around town, merging on the interstate, driving on the interstate, etc. It's totally fine.

Your post was about aggressive canyon driving or whatever. Not even remotely close to "normal driving."

In the old days automotive engineering was pretty crude. A lot of power and efficiency were left on the table; some of it low hanging fruit. It was easy to slap on a set of headers or swap in a bigger carburetor. Not so with the Prius. The Prius design is highly optimized for low emissions and efficiency. Not only did Toyota get the low hanging fruit, they plucked the tree clean right up to the top.

With such a highly optimized design, after market modifications become at best a zero-sum game. A gain in any area causes a corresponding hit somewhere else. Making matters worse, the tremendous complexity of the system increases the risk from any modification. A seemingly trivial modification can easily produce major drivability issues. Gone are the days of shade tree mechanics.

Yours is a personal opinion, to which you are entitled. My personal opinion is that almost all family cars are grossly over powered. No one needs 300 hp to drive the kids to school. We have lost our sense of perspective in this country. Automotive marketing departments have done their best to encourage this sort of lunacy, but ultimately we, as consumers, have pushed this short sighted trend.

Let's get back to your opinion, which is that the Prius is under powered. As I said above, you are entitled to that opinion, and likewise, you are under no obligation to drive a Prius. The real question, given your desire for greater power, is whether it makes sense to modify a Prius. My contention is that the Prius does not lend itself to being a tuner. You would be better suited to start with a different platform.

Tom

It's worth noting that this poster is driving a Gen II 2008 which has significantly less power and "get up and go" than the Gen III in power mode...

The Prius is not a race car, and it would make no sense to convert it to one. It is a VERY fuel efficient vehicle - in fact the MOST fuel efficient vehicle made (with the exception of all-electrics). It runs as fast as normal traffic allows, doesn't bog down, but will never spin rubber - and why would you want to do that anyway?

Jim

no, no, no.... no tree hugging for me. Wallet hugging is why I did it. I was going to spend this much ona car, so why not offset some of the cost by lowering my fuel cost.