1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Pinto_Girl's '06 #8+TRD Sportivo suspension

Discussion in 'Gen 2 Prius Accessories & Modifications' started by Pinto Girl, Sep 18, 2006.

  1. Pinto Girl

    Pinto Girl New Member

    Joined:
    Aug 14, 2006
    3,093
    350
    0
    Location:
    California
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    First off, I have to tell you that I'll prob'ly misuse at least one (if not many more) car-speak terms in this posting; hopefully you can get through all of that and extract any kernel(s) of information (if present) from the vast majority of chaff.

    _______________________

    I just wanted to share some observations about having 'wrung out' my '06 -- she answers to Buzz, but with this weird computer voice -- for the first time, on Highway 1, down the NorCal coast from Half Moon Bay to Santa Cruz, and back again. And how, in my opinion, she compares to before the 'change.'

    Some background: Mechanically, the car is otherwise stock, approximately 1,000 miles since new. I have removed the trim rings on the wheels (there's so much talk about unsprung weight that I wonder if anyone remembers to include the weight of the beam axle and other suspension bits, but that's another story) and "pumped up" the pressure of the much-maligned Integrity tires to 42/40, but otherwise she's as I received her new.

    My perception of the stock handling is that when she was driven smoothly and moderately, the car remained really, really composed and neutral, with only a little body lean and the feeling there was LOTS more available...but as the speed increased, she became rather more susceptible to an upset from a bump in the road or other unexpected event. And that seemed to happen a little too quickly and abruptly for my tastes...and at a lower speed than I'd like, too. I didn't want to find out how bad what I assume to be the typical front-wheel-drive terminal understeer would be, as we slid off the outside of a corner, either.

    I guess that my goal is to make this progression a little more linear, even at the expense of a bit of comfort during everyday driving. That way, I figure, I can corner faster and not be so close to the outer limits of the car's capability...or at least approach them gradually, and maybe not get in trouble too abruptly.

    I think the Sportivo suspension succeeds on this level, especially; the outer limit of the car's handling might not be that much higher than before, but I think it's lots more accessible now. The car now has a wider useable speed range.

    Also, because things are under better control, the Inegrities don't (to me) seem to be nearly as much of a problem as I've read elsewhere. They don't seem to be working nearly as hard, and I no longer see (or hear) them as a major impediment to spirited driving, at least with the new suspension pieces installed.

    I just kept telling myself to drive her I used to drive the Carrera: slower into, then accelerate out of the curves with the idea that I'd rather add power post-apex, than upset the car by braking early. Buzz generally seems to reward a smooth driving style (as did the Carrera), with gradual throttle and braking inputs, and a driver who doesn't let the car get ahead of her.

    Seems like understeer is still the order of the day, but preliminary findings indicate that she is somewhat more responsive to managing weight transfer with the throttle. I've never yet gotten into any unstable conditions intentionally or otherwise, so I can't say what happens at that point, but she feels SO much more confidence inspiring as speeds increase and the road becomes more demanding.

    As I mentioned earlier, the biggest negative issue might be that of ground clearance. I'm okay with the compromise but others may not be.

    Perhaps a good way to look at this upgrade might be as a step above the '07 touring option. I haven't yet driven one, but I suspect it will fall somewhere between a 'regular' Prius and one with the Sportivo conversion

    Regarding the Touring option, I feel like a good way to add stability to a car is not necessarily with bigger wheels and smaller tires (maintaining the same effective circumference and contact patch length) but with a tire/wheel combo that is larger overall. This way, the fore/aft length of the contact patch is increased, as is stability.

    For this reason, I fear the 55-series tires and 16" wheels on the Touring are in some ways a missed opportunity. They may stiffen the ride and make the car *feel* more responsive at slower speeds (wondering if the suspension will have softer springs and stiffer shocks vs. the American setup, as Euro cars often have). But -- with the exception of quickening turn-in -- I don't think it may really do much to increase the overall cornering limits of the car...that is, unless the tires themselves are more optimized for handling than the Integrities (not too difficult to do, I'm sure).

    Additionally, the shorter sidewalls of those 16" tires may actually make the outer limits come up even more abruptly than before...which, it seems to me, is not the best receipe for a reasonalby fast, fun to drive, predictable automobile.

    The Sportivo suspension is a great way to increase the limits of your Prius -- not to mention, give it that mysterious 'what looks different?' look -- but the ground clearance issues and cost of the kit and installation seem to take it sufficiently out of the mainstream.

    And, honestly, that's just the way I like it!
    [big smile, and thanks to Priuschat for turning me onto this in the first place]

    yours in the generation of high g-forces,
    --Pinto_Girl
     
    #1 Pinto Girl, Sep 18, 2006
  2. brasche

    brasche Member

    Joined:
    Jan 14, 2006
    156
    1
    0
    Location:
    Orlando, FL
    Vehicle:
    2008 Prius
    Model:
    N/A
    Thanks Pinto_Girl.

    It's nice reading a fellow track driver's opinion.

    You might want to consider Tom's lower front suspension brace to help with the understeer. It improves turn-in at low speeds and stability in the high speed sweepers. It also greatly shortens the time needed for the Prius to regain it's composure, plus it eliminated most of the tramlining too. Well worth the $250.

    Brian
    '06 #8, BT and Tom's lower braces (otherwise stock)
     
    #2 brasche, Sep 18, 2006
  3. DocVijay

    DocVijay Active Member

    Joined:
    Sep 15, 2005
    1,455
    2
    0
    Location:
    Tampa, FL
    <div class='quotetop'>QUOTE(Pinto Girl @ Sep 18 2006, 04:26 PM) [snapback]321289[/snapback]</div>
    Not forgotten, but those are all parts that are not so easily changed. If you find a company that can make me some titanium replacements for all those bits, then I'd be happy to replace them.

    Wheels and tires are the easiest (and arguably the only) bits to replace on the Prius to reduce unsprung weight.
     
    #3 DocVijay, Sep 18, 2006
  4. NuShrike

    NuShrike Active Member

    Joined:
    Feb 21, 2005
    1,378
    7
    0
    Vehicle:
    2005 Prius
    Model:
    Five
    Adding some parallel comments to your review and as a topic bump:

    So today, I joined you guys as I finally got mine installed on a 2005 #6 with 53K+ miles, Yokohama AVID H4S tires, otherwise stock.

    The 2005 predates any Toyota "improvements" to the shocks/springs handling, so it's probably less neutral compared to the 2006 stock. The 2005 likes to roll and lean (which could be a good thing on turns balancing lean/weight against traction), but the handling was otherwise fairly spongy/springy, and tended to really bounce back and forth on bumps such as speed bumps, driving up into a driveway, or backing out of one, for instances.

    At this point, my driving had adjusted to the Prius's bicycle-like steering including automatically counter-steering for the weight rollback after turns and lane changes. This heavy rolling was certainly initially quite a surprise compared to my '96 Civic.

    So on the way home after install, I tried out a familiar left-turn and surprised myself with traction control kicking in a 2-3 times on this turn I did every day with the grippy Yokohamas. Usually, I just chirp the tires without TC kicking in. Probably, the usual body-roll feedback is now missing so I misjudged how hard I was pushing the turn, or I need a LSD now. :) I'll have to check the instrumentation over a week or so to see if I was pulling different Gs and anything else.

    Like Pinto Girl says, slow down enough for a turn, accelerate smoothly right after the apex to shift the weight evenly and constantly onto the outer tires and toward the back. It's just a different beast with the Sportivo now. Can't say much about understeer yet, as I've previously adjusted by oversteering on turns, and letting the car straighten itself out.

    No new problems with clearance nor bottoming out yet, as it clears all the speed bumps and dips I was previously was already taking at speed.

    If there's one thing to be said, it's the much, much, improved damping that rids the bouncy spongy feel of the stock suspension and less likely to scrape/bottom out while still slightly lowered.

    It's not yet noticeable harsher nor noisier, as the Yokohamas were already pretty firm compared to the Integrities. If anything, everything seems more smooth and soft now because of the improved dampening. I guess the word for it is firm?

    I think the stock's bicycle-steer is good training if one wanted to be a more precise driver by understanding, anticipating, and countering the Prius rocking and weight-transfers, but now I can be more lazy and sloppy. :) I'll probably have a better summary of things after a few weeks of retuning my driving technique.
     
    #4 NuShrike, Oct 18, 2006
  5. Pinto Girl

    Pinto Girl New Member

    Joined:
    Aug 14, 2006
    3,093
    350
    0
    Location:
    California
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Cool; thanks...it's great to read your comments. I agree, the better damping really seems to keep things under control and lets the poor, overworked Integrity tires take a bit of a break sometimes.

    I'm beginning to think that Buzz has gone from somewhat under-suspensioned, to somewhat underpowered now...

    hmmmmmmm....
     
    #5 Pinto Girl, Oct 20, 2006
  6. NuShrike

    NuShrike Active Member

    Joined:
    Feb 21, 2005
    1,378
    7
    0
    Vehicle:
    2005 Prius
    Model:
    Five
    <div class='quotetop'>QUOTE(Pinto Girl @ Oct 20 2006, 11:04 AM) [snapback]335655[/snapback]</div>
    I concur.. Now that I'm not particularly fighting the vehicle to get around a turn, it's now why isn't it pulling out of the turn.. :)

    I also concur on the "hardness" of the ride. It's not significantly harder nor jarring than before because of the nice seat cushioning, but one can sure hear each one much louder and more significantly. If the road had a series of bumps parallel to your tires, be ready for a percussion band. I wonder if more sound dampening in the doors would help.
     
    #6 NuShrike, Oct 20, 2006
  7. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    45,024
    16,244
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I'm wondering if larger tyres would help negate the ½" drop of the Sportivos. In other words, it can help those who upgraded to 17s to fill in the gap even more.
     
    #7 Tideland Prius, Oct 20, 2006
  8. PRIUS13

    PRIUS13 New Member

    Joined:
    Oct 8, 2006
    5
    0
    0
    I still have not heard of anybody mentioning 18" wheels on there prius. I had them installed as soon as I left the dealership. Nothing but compliments! I also ordered my sportivo kit about 3 weeks ago and was told it should arrive the second week of January. What the xxxx? :angry: Anyways, Do any of you think I will have a problem with the wheels 215/40/R18 fitting with the suspension kit combo. I hope not since I cannot cancel my order. There does look to be enough room from where the tire sits now and the top portion of the shock tower.
     
    #8 PRIUS13, Oct 22, 2006
  9. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    45,024
    16,244
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Most of us do a +2 which would be 17s if we were upgrading from 15s.
     
    #9 Tideland Prius, Oct 22, 2006
  10. NuShrike

    NuShrike Active Member

    Joined:
    Feb 21, 2005
    1,378
    7
    0
    Vehicle:
    2005 Prius
    Model:
    Five
    [reply moved into another thread]
     
    #10 NuShrike, Oct 22, 2006
  11. GreenSpeed

    GreenSpeed New Member

    Joined:
    Jul 31, 2006
    201
    0
    0
    Vehicle:
    2006 Prius
    <div class='quotetop'>QUOTE(Tideland Prius @ Oct 20 2006, 07:42 PM) [snapback]335997[/snapback]</div>
    OOO!! Wicked thought! I have 17s... Hrm. BT Tech Plate plus Sportivo Struts and Springs = $2000+ (total plus installation)?

    <div class='quotetop'>QUOTE(PRIUS13 @ Oct 22 2006, 01:47 AM) [snapback]336334[/snapback]</div>
    There's a few of us with 17's and i happened to pull up to a Prius with 18's when i was at the Marina they look pretty spiffy.

    <div class='quotetop'>QUOTE(Tideland Prius @ Oct 22 2006, 08:26 AM) [snapback]336396[/snapback]</div>
    What's +2 Tideland?
     
    #11 GreenSpeed, Nov 3, 2006
  12. adamorzol

    adamorzol New Member

    Joined:
    Apr 17, 2007
    65
    0
    0
    <div class='quotetop'>QUOTE(PRIUS13 @ Oct 22 2006, 02:47 AM) [snapback]336334[/snapback]</div>
    How did the 18s work out with the TRD Sportivo suspenstion kit? I had 225/45/17 tires and they rubbed and had to go with 205/50/17 to fix the issue.
     
    #12 adamorzol, Apr 18, 2007
(You must log in or sign up to post here.)