installed Toms front & rear lower braces- WOW

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 10:39 AM) [snapback]543607[/snapback]</div>

Glad you are liking the TOM'S braces. It still amazes me how they can transform the car's handling - each time I get a loaner Prius from the dealer, I am reminded of how much room for improvement there is.

Out of curiosity, what are you trying to achieve with the TRD Sportivo suspension and the floor stiffening plate? Hopefully, you are aware that you will have clearance issues with the floor stiffening plate and the exhaust.

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 11:39 AM) [snapback]543607[/snapback]</div>

did they have it in stock, if not how long is the wait?

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 11:39 AM) [snapback]543607[/snapback]</div>

did they have it in stock, if not how long is the wait?

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 11:39 AM) [snapback]543607[/snapback]</div>

did they have it in stock, if not how long is the wait?

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 04:27 PM) [snapback]543716[/snapback]</div>

Sharper turn in response typically doesn't come from firmer & lowered springs and shocks which is what the TRD Sportivo consists of. Your ride criteria should be addressed with the TRD Sportivo. I doubt you will see as much improvement after fitting the floor stiffening plate as you saw from the front and rear suspension braces. In the MINI community, a floor stiffener goes on when the last 5% is needed for autocrossing.

Keep us posted on the results of your journey into the modification zone.

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 11:39 AM) [snapback]543607[/snapback]</div>

did they have it in stock, if not how long is the wait?

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 07:27 PM) [snapback]543716[/snapback]</div>

I, too, have felt that white knuckle experience on freeway interchanges and agree that much can be done. But I wonder if making a Prius handle like a Civic Si or comparing it to a Cooper in a previous post is practical? They're just a different class of car. I'll admit I'm been passed by in suspension technology, so perhaps I'm underestimating what can be done.

 

Are there any efficiency gains (MPG) to be had from stiffening up the suspension? I would think that any excess bouncing (energy) due to soft suspension may reduce milage.

In drag racing any movement other than forward is wasted energy. So when you see a car doing a huge wheelstand off the line there is a ton of energy wasted in getting the front of the car off the ground.

 

<div class='quotetop'>QUOTE(RonH @ Nov 25 2007, 08:36 AM) [snapback]543945[/snapback]</div>

Trying to get even close to the handling ability of a MINI is going to require a replacement of the suspension that is in the Prius. The MINI has a multi-link suspension in the rear which is completely different than the trailing link suspension that is in the Prius. The differences between multi-link and trailing link suspension are significant; the details of which are really quite technical and beyond the scope of this thread.

That said, there is some room for improvement in the suspension of the Prius. How far you go down the path of improvement is what has recently been posted about. The front and rear suspension braces remove the 'slop' in the current suspension by tightening up all of the suspension mounting points. The floor stiffening plate similarly tightens up the connection between the front and the rear suspension. The TRD Sportivo tightens up the ride of the factory springs and shock absorbers. There is a trade-off between a tighter ride and ride harshness, which is a personal choice. Another way to get a slightly tighter ride with a minimal increase in ride harshness is to go with a Touring edition for the tighter springs and shocks. I personally dialed back the ride harshness by going with a taller tire sidewall (/60 series versus /55 series from the factory for the Touring edition) and 15 inch tires instead of the 16 inch tires of the Touring edition.

While I don't think it is financially practical to modify the Prius suspension to compete with the suspension of the MINI, it is possible to get rid of the slop that is present in the Prius suspension as it comes from the factory. Hope this helps.

 

<div class='quotetop'>QUOTE(F8L @ Nov 25 2007, 10:50 AM) [snapback]543982[/snapback]</div>

That was a dialog that I had with the owner of the SigmaAutomotive.com website when I was ordering the TOM'S bits. I personally don't see how a tighter suspension could increase mpgs. Yes, you can take turns faster than before, which would increase the regeneration from coasting. However, with a slight application of the brakes, you are triggering braking regeneration which in my experience, produces a greater amount of energy created. As an example, there is a stretch of Highway 92 between U.S. 101 and I-280 in San Mateo that drops about 200 feet in elevation (Hillsdale Blvd to El Camino Real for those of you familiar with the area). If I coast down the stretch, by the time I am at El Camino Real, I am doing something like 80 mph and the battery display is still blue (upper-most bar before turning green, but still blue). Taking the same stretch with slight application of the brakes results in a completely full green battery display.

Just my opinion, but I think the main benefit of the suspension improvements is more of a safety item (the car is less likely to spin (or it will spin at a higher g-force) than as it comes from the factory). But the increase in 'quality' of the ride - priceless.

 

<div class='quotetop'>QUOTE(F8L @ Nov 25 2007, 01:50 PM) [snapback]543982[/snapback]</div>

Yes and no. The real job of the suspension is to keep the wheels on the ground. Can't go if they're in the air! While its obvious in turns, its a factor in straight-aways, also, especially for front wheel drives. Accelerating shifts the weight back, but too much and you're using your torque to lift the front end as you pointed out in dragsters. Too loose and your wheels are bouncing off the pavement. Too stiff and the body's center of mass is coupled to the wheels and tipping occurs. That's why active transmissions have been such a revelation in non-NASCAR racing where the suspensions tuning can be adjusted dynamically as the situation demands. I seem to remember F1 was going to ban them. Did that occur? Another example is mountain bike suspensions and I suppose motorcycle suspension, although I'm not as familiar with them. Too loose and you're wasting your energy pogoing the rear wheel up and down. Too stiff and your back wheel is hopping over every little bump.

 

<div class='quotetop'>QUOTE(sc_trojan @ Nov 24 2007, 07:27 PM) [snapback]543716[/snapback]</div>

Watch it, this sort of thing will get you into *big trouble* here on PC!!
[smile]

So...how much overpressure will those Integrities tolerate, anyway...? In Prius-land, THAT'S performance!!
[laughing]

<div class='quotetop'>QUOTE(apriusfan @ Nov 25 2007, 02:39 PM) [snapback]544001[/snapback]</div>

Again, it's impossible to put a number --any number-- on "improvements" (if we can even agree to call them this) to the car...except, of course, the price.

I think, if you're happy with the way yours is, you should definitely keep it that way.

If others prefer to modify their cars, that's okay too, as long as one does not increase the ride-height or other things which might (if you'll pardon the expression) impact me in an accident.

But, debating whether or not it's worthwhile to alter the car, seems a bit like debating how many angels can dance on the head of a pin.

-------------

Years ago, I was involved in a study, which examined the feasibility of uniform placement of controls in all passenger cars sold in the USA. In other words, no matter what brand of car you drove, the controls would look, feel, operate, and be placed in the same location, across the board. Wondering, how you'd feel about THAT...?
;-)

 

<div class='quotetop'>QUOTE(Pinto Girl @ Nov 28 2007, 01:38 PM) [snapback]545406[/snapback]</div>

I would be the last person to debate the merits of modifying one's car - I seem unable to resist the temptation to do 'something' to each of the cars I buy (whether it is to replace s/c reduction pulley, wheels & tires and shocks on my MINI or the DICE iPod controller, brake pads, wheels & tires and front and rear suspension braces on the Prius; if there is an improved aftermarket product, I want it). My only point is to be honest with yourself, don't use mpg improvement as a means to rationalize the effort (and expense) if improvement in mpgs is going to be doubtful at best.

 

I disagree. In all my previous cars, springs and shocks make a very significant difference in turn-in repsonse compared to things like strut-tower braces. The only thing that helped turn-in response more than stiffer springs was a large front sway bar.

 

Wait till you make mods to the Prius. There are differences in the body stiffness that are not present in other cars. The Prius has been engineered for economy before all else. Body stiffeners add weight and weight reduces mpgs. Also, there is slop in the suspension from the rubber mounts that are fitted. The TOM'S Rear Suspension braces (there are two braces in the TOM's rear kit) compensate for slop in the rear suspension that springs and shocks do not.

It is also possible that the wider tires that I have fitted contribute to improved turn-in.