Racing Prius?

Hey, it's your car. If you're thinking of racing it, check out what modifications are allowed for whatever class the Prius fits into. Stiffening the chassis sounds like a good place to start. As for brakes, you could try stainless lines and see what fits from the Toyota or TRD catalogues in the way of bigger discs and calipers. The land speed record car used an Echo engine, so an engine swap may be the way to get more power. Adding extra batteries to the trunk shouldn't be a huge problem, though you may need to reprogram some software for everything to work smoothly. Good luck!

 

<div class='quotetop'>QUOTE(Silver Phoenix @ Jul 4 2007, 02:59 PM) [snapback]473014[/snapback]</div>

There was an article reporting the addition of a turbocharger to an early Prius. It helped and a 5 lb boost worked out (more can cause error flags). It was not an easy adaptation.

I also saw a remote install turbocharger (It can be mounted anywhere on the car) that may deal with the space limitations in your Prius engine compartment. Good luck.

JeffD

 

Endless has Prius racing calipers in development:

Tom's has performance pads for the stock calipers, I think. B)

Tom's also has a performance muffler. B)

K&N has a new replacement air filter assembly:
http://www.knfilters.com/news/news.aspx?ID=526
They say it's a lifetime washable element and that it improves performance and mpg.

After adding all the Tom's braces and the TRD Sportivo suspension kit, you'll probably want to get in ot the group-buy for the all-around skirt package. B)

For tires & wheels you may want to go more aggressive than 205's. I think a set of 235's on 17/7.5 inch rims would be minimal. 245's on 18/8's would probably require 1/2" to 1" spacers but I think would give you much better racing stability. Going to racing slicks or to UHP summer tires is a must. B)

A magnetic oilpan plug would help keep the engine clean. A thinner oil and a fast-flow oil filter would help too. Finding a ATF radiator might be a good idea, along with checking out better transmission fluids for racing type operation. :huh:

Then, of course, there's always the turbocharger - don't know who has done this - and Nitrous Oxide... :lol:

 

Unless you are wanting to start some sort of green autocross category, you are going to have to compete against MINIs. Even the N.A. MINI is going to be a serious challenge to overcome. Things like lower overall weight, multi-link rear suspension, chassis rigidity, large selection of big brake options (up to 13 inch rotor diameter), all manner of handling options (shocks, springs, sway bars, etc.) and the like are what you are up against. Horses for courses....

 

<div class='quotetop'>QUOTE(apriusfan @ Jul 4 2007, 10:35 PM) [snapback]473348[/snapback]</div>

If the prius can make it onto the track at all, it'd be a win. Once we're on the track, we can start talk of a green category... maybe requiring a PZEV emissions threshold and test pre-race... I understand other races have pre-race inspections for all sorts of things, from wing and fender positions to fuel composition to exhaust manifold volumes...
Besides, even Nascar is tipping its hat to the environment: unleaded fuel is phased in as a requirement this year.

 

<div class='quotetop'>QUOTE(bobdavisnpf @ Jul 5 2007, 08:04 AM) [snapback]473454[/snapback]</div>

That they do (have inspections for category conformance). It would be possible to tweak a Prius for competing against other Hybrids and personally, that would be an interesting race to watch. But a general autocrosser the Prius is not.

 

I autocross a Subaru Impreza that is modded to STS class. A couple of evasive highway moves in the Prius surprised me with the handling (in a good way). As for weight, the Impreza and Prius are about the same. Where the Prius has 295 ft.lbs. torque and oppressive traction control, the Impreza has 165 lbs torque and AWD. In straight line accel, I've beaten an Impreza similar to mine, at last up to legal speed limit. Off the line it's great. For autocross Prius needs more roll stiffness, less understeer, and more tire. It might be a fun project, but I wouldn't clear off the trophy case just yet. If there is enough interest for a Hybrid class, it might be worth it, but there are too many better suited cars out there now to be competitive. Don't sweat the brakes too much. I think the Prius brakes are just fine for autocross. I love my commuter Prius, and I love my autocross Impreza. Horses for courses.

 

I just recently noticed that Sigma Automotive's Prius page has a picture of a Prius labeled "Solo2 F Street." I would think running down the goods on that would be a good start. If you do, let me know - a quick google turned up nothing for me. I'd love to take a Prius (just ordered a touring model last weekend) autocrossing rather than my old '89 Porsche 944 turbo. I need all the excuses I can get...

A Honda Insight embarassed a lot of people in the SF Bay area region for a while. Very lightweight car and a good driver posted some decent times, as long as he started with a fully charged battery. It was really apparent when he ran out of amps during a run. Eventually the driver sold it and moved on, since while he did amazingly well it seemed the car couldn't crack the top ranks.

 

The Prius' simple suspension and high center of gravity will always work against you, especially in competition...I've considered going down just this road (do a search of previous topics).

Get rid of the Atkinson Cycle mill if you can. There was that turbo Classic but even the folks who built it said that it was a difficult project. There was also the Prius GT, that had more HP but, again, was an Otto. Again, I don't know how the top end of the engine was modified to work with the PSD, etc...but it was a factory effort.

Chassis-wise, there are all sorts of TOM's braces. Brake-wise, the Prius doesn't seem to use the stock brakes that much, even in aggressive driving; why you'd actually need those four-pot calipers designed to dissipate loads of additional energy, I honestly don't know.

The tires are also too small, as are the wheels; the discs are also of a small diameter...and of course, the rears are drums, so brake balance isn't so good. Then there's the feeling-less electric steering, and the traction control, which cuts engine power when a wheel even thinks about slipping...

I love my car, and I flog it at regular intervals (the TRD suspension and other things help a bit)...but it's no Porsche 993 (which I came out of) and never will be. Without its own category, I don't think it has a chance. Too many weird systems designed for economy, not performance.

Good luck to you. I think (but hope I'm wrong) that you'll find that this project will turn out to be more expensive than you'd suspect, and the returns might not be as substantial as you'd like.

Let us know how you do...at this point, I'd like to find a salvaged Pri, fire up the torch, and drop in a smallblock V8...

 

You wanted specs on that FSP Prius, you got it:

http://blog.myspace.com/index.cfm?fuseacti...blogID=44975985

I showed this to my wife and she said "NO!, You already have a race toy." I guess I will just have to "borrow" her car for a Sunday drive. B)

 

Has anyone thought about fitting a second standard battery pack for more hybrid oomph? Isn't it one of the highest energy density batteries around? Safer and lighter than lead acid. If it's purely for racing remove the back seat and put extra batteries in that space. For a standard look put the seat cover back over tha battery. Will another hybrid battery like from a Camry or the SUV version sold in USA fit in place of the back seat.
Not cheap but nothing is in racing.

Change the head on the Atkinson cycle engine, there is nothing wrong with the Atkinson cycle crank position, it's the late closing inlet valves that reduce power. Will the Yaris head fit? You need to remap the VVTi, EFI, and ignition as well.

 

<div class='quotetop'>QUOTE(patsparks @ Jul 27 2007, 09:02 PM) [snapback]486479[/snapback]</div>

Um,

The thing that makes it an Atkinson cycle is the late intake valve closing. The offset crank position is done to reduce friction; the Otto cycle Yaris engine does the same thing.

So, I guess I don't quite understand your point. Could you clarify?

 

you could go from atkinson to otto.. get everything trd offers.. and toms...
then there is not much going on for the engine performance but you could try and fit a cold air intake even if its a custom built one (but thats when you go to the otto cycle).. then you should go lighter... a lot...
get rid of everything... the seats, the dash, the speakers.... then maybe just maybe you're getting somewhere...

if you succeed in the otto conversion and get something like a yaris engine you may find a few stuff to pump up power...

and most of all some $$$ and some luck and some good connections or convincing attitude to get some sponsorship its not an easy task but good luck

 

I've been thinking about this one for a while.

A couple years back, I went to the autocross in oakland.... er... i think it's oakland. ( i don't cruise there often )

I believe there is a hybrid category. The people were excited to see me. several people commented that they wanted to see a prius try it. I was told i did pretty good. I was not the lowest time. ( i can't recall the numbers )

my tips: make your car a semi plug in. this way your main battery will always be full. ( at the end of the race my battery was dead. I had to force charge it. ) Don't force charge. it's bad on performance. ( this is why i say phev ) stiffen the entire car with all the braces you can. replace the suspension. Don't increase the brakes. you'll wreck the whole point of the car. If you want to brake faster, just hit them harder ( it's not all that bad )
Turbo charge it. Pay a shop to pick one out and install it. try to make them give you a warranty on their work, the unit, and the stability of the prius. ( good luck on that one. i wouldn't try it.) Leave the exhaust alone. Leave the intake alone. ( changing those would kill the purpose of the car )

Have fun. take as many pics as you can. post them all. start a webpage. share it here. Let me drive your car ( last one optional of course)

I side on the opinion of not destroying the car. It's a clean hybrid. Leave it as a clean hybrid. Make it an awsome racing... clean hybrid.

just my $0.02 cents..... sorry.. that's my fee. i don't like donating ( just kidding)

 

It's nice to show the world that you can have fun too autocrossing a Prius on weekends.

 

There are a lot of good ideas on this forum. In fact, there are enough to start someone tinkering who has the time and car.

But you guys are NOT thinking about how to really optimize the car; we should be playing into its strengths and compensating for weaknesses.

(1) Manual control over the CVT ratio range. Give me a lever like any stickshift, with a short throw and the ability to move in two directions smoothly: toward me (higher gears; higher speed) and away from me (lower gears; higher acceleration). And it needs to have much faster reflexes.

(2) Don't commit suicide replacing the weird ICE. Play to its low-RPM strengths. It works, therefore it is ready to be improved upon. More aggressive fuelling with computer-controlled NO2 injection, alongside a more open exhaust system, should get you an easy 20-40 safe horsepower; probably substantially more if you're willing to start taking risks or having parts machined in more exotic materials. This is a very good route, though!

(3) You don't want to upgrade the batteries until you're absolutely sure you need to. Remember, gas mileage isn't a problem, so running the engine constantly to keep the batteries charged is also not a problem, especially considering the nitrous oxide power boost.

(4) If you DO think you need a battery upgrade, it's because you're right and you've taken the wisest of all electric drivetrain upgrade decisions: in-hub rear-wheel motors calibrated to throttle computer to match the front-end drivetrain.

It needs to be reclassified after these alterations as a "multiply parallel hybrid electric" vehicle, but so what? You have a synthetic all wheel drive system that has flexibilities unheard-of up to now - before that the slowest relative speed you could apply at one tire was zero. Now one wheel can turn backwards to change the drift pattern or automatically help recover from a spin.

Dot, dot, dot...

~ dan ~

And yes, I know it would require infinite money, infinite monkeys, and infinite typewriters... But if I had anywhere near infinite money I'd already be making my race Prius

 

I completely agree... could not say it any better... than what you just did Fruzzetti

 

Imagine using that CVT for a drag racing car. The engine could be tuned totally differently than usual. Instead of trying to have a reasonably high, mostly level power curve, you could align freakishly steep torque and power curves with enormously high, but short, peaks; then you use the CVT to just keep the engine in the high-power range for the whole trip. You could shave half a second off any car's ET and it frees you to develop an engine with a less balanced design which also means less cost.

~ dan ~