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RacePrius competes 14 hrs event, now driving Coast-to-Coast

Discussion in 'Gen 2 Prius Main Forum' started by EKIM, Mar 27, 2014.

  1. EKIM

    EKIM Junior Member

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    342,000 mile car, all stock right down to the batteries and the interior reinstalled.

    We raced it at 24 Hours of LeMons at Sonoma Raceway (after driving it from San Diego straight up to and onto the track).

    Articles relating to the race here:
    LeMons Sears Pointless Inspections: Diesel Porsche 911 Set To Battle The Homer | Car and Driver Blog
    LeMons Sears Pointless Day One: 5-Series, Fiero, Luv Lead Classes | Car and Driver Blog
    24 Hours of LeMons Sears Pointless: The Winners | Car and Driver Blog


    And one of the drivers of it decided to buy it and had the BRILLIANT idea to drive it home.
    To South Carolina.
    Starting from San Francisco.

    Follow him on his journey here:
    Race Prius | Facebook
     
    Cristino, Patrick Wong and tanglefoot like this.
  2. tanglefoot

    tanglefoot Whee!

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    Congrats on the "Most Marin County" award.

    How did the Toyohog do? That's an interesting creation.
     
  3. EKIM

    EKIM Junior Member

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    Let's just say it's done better at previous events it's attended.

    The clutch, the stock Harley unit, is a little weak when asked to haul around ~1800 lbs of "racecar" and when pulling up the hill between turn 1 and 2, if traffic is stopped, it needs to be pushed to get going again. We had to push it up a few times under yellow flag conditions-- once with the Hybrid and once with the Toronado that we brought.
    Here's a video of the Toronado trying to push it uphill in the dirt.


    Eventually, the clutch that we put in last year at Sonoma at the track had to replaced this year. We did this Saturday night.

    Then starter issues plagued us at driver change time.

    Finally we discovered that the motor had some "interference issues" about 4 hours to go on Sunday so we just left it parked/broken. We suspect we lost some crank roller bearings while push starting it in the paddock with the hybrid.

    It's slow, though. About 15-20 seconds a lap slower than the hybrid, which is about 25 seconds slower than the front-runners.

    The fun thing is the ToyoHog is street registered because a Prius doesn't have to (yet) be smogged so they renewed the tags! I drove it to cruise nights/car shows a few times.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Nice work... What was the mpg logged during the race? :cool:

    I read the list of LeMons rules: the $500 limit on vehicle investment (not counting "safety" equipment) is pretty amazing.

    How many labor hours did you invest in each Prius that was raced?
     
  5. EKIM

    EKIM Junior Member

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    We also
    We did 29mpg on the drive up to the track from San Diego 70-80ish mph for ~500 miles

    On Saturday, on track, we averaged 16.8mpg for the day. We were driving in "B" mode to maximize regen, but the battery was put on empty pretty quickly. During full-course-yellow laps, we'd get the battery charged back up but one full-throttle acceleration and it was back to 1 or 2 bars by turn 4. I'm not sure what the mpgs were for Sunday when there were fewer full-course yellows.

    Hours to build the ToyoHog? Oh geeze I couldn't even fathom a guess. I missed the first 2 races I'd planned to debut it at because I kept running in to hurdles.

    For the hybrid, it wasn't a whole lot, comparatively: the learning curve on working on a hybrid and trolling this site was a lot. Swapping out the brake actuator pump assembly thingie took a day. Stripping the interior and reinstalling all of it was a bunch but so was cycling the modules and trying to get some life back in them. at 341,500 miles, this motor was in far better shape than the one in the car that had 240,000 on it. It sounded worse when I took possession of it, but turns out it may have just been because of some broken spark plugs (why they broke is still a mystery but likely due to detonation).

    FWIW: I emailed the organizer of the event and asked how he'd feel about a stock 340K mi prius that had been left for dead racing in his series. He said to "Bring it!" My response

    Nobody asked for budget documentation. Nobody cared.

    It's not like we would contend for any wins. And it was sporting full interior, no aftermarket cheaty anything, and low friction/high treadwear tires. Now if we had a lightened E30 or a turbocharged miata it would be a different story.

    And our good theme helped.
    We (organizers included) all fully expected it to blow up. I was kinda hoping to be able to say I threw a rod in a Prius on a racetrack, and we had the 240K motor as backup. But rods all stayed inside and the spare stayed in the truck.
     
    Patrick Wong likes this.
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Thanks for providing more info about your race prep.

    BTW, driving in B mode worsens fuel consumption and reduces regen, because more energy is spent on keeping engine RPM higher than is required for a given vehicle speed.

    I would be interested in seeing more photos of the Prius with the motorcycle engine: how did you provide engine and transmission controls at the driver's seat, did you totally gut the Prius drivetrain and electronics, how the transmission was connected to the front axle, etc.
     
  7. EKIM

    EKIM Junior Member

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    Well, there ya go! More genius resulting from me listening to the wrong "Prius Expert". The added (perceived?) engine braking did seem to help, though.

    Here are some build photos of the ToyoHog.(there are some issues with the site periodically)
    http://www.hubgarage.com/mygarage/Spank226/vehicles/71076
    It is just a Prius shell and suspension at this point. Chain drive via the stock Prius differential that was removed from trans, lathed down and then drilled/tapped to take the chainwheel from the donor Harley rear wheel. Pillow Block bearings support the trans bearing snouts and they slide a little to tension the chain and get the angle right. Differential cage has plates welded over it and it is pumped full of moly grease to lube the spider gears.

    The entire engine support/mount is bolt-in using the stock mounting locations of the Prius drivetrain. It is completely removable and bolt-in capable to another Prius. And the ToyoHog is in fact for sale if anyone is interested. Comes with a spare 1200 5-speed sportster motor circa '94

    here's an in-car video of it's first outing. Handling improved some since that vid.
     
    Patrick Wong likes this.
  8. EKIM

    EKIM Junior Member

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    Just an update for anyone with half a care.

    Here's a video wrapup of the event back in March
    RacePrius made it to South Carolina with no issues that some zip ties or a trash bag couldn't fix.

    The proud owner is preparing it to race May 3-May 4 at Carolina Motorsports Park in Kershaw, SC and then again on July 5-July 6 at Sebring International Raceway in Sebring, FL

    (and in other news, the ToyoHog was listed on ebay but didn't meet reserve. I still think the listing writeup-- and especially the questions-- are worth a read)

    Oh, and please don't think I'm a Prius-hater. I'm not. But I am an equal-opportunity offender
     
    dorunron likes this.