My Complete Review of H&R Lowering Springs

Strut and chassis braces are installed to maintain the wheel geometry when the suspension is under more strain: they work to keep more of the tire planted to the ground. The lower CG & brace mods are not exclusive; one does not choose one or the other. A properly sorted car would have both installed for best performance.

Drag coefficient is determined in part by the frontal area of the vehicle. Unless you physically modified the body, you did nothing to change the drag coefficient.

See above.

The suspension does not drive the car. Unless you have problems with tires skipping on acceleration (not an issue in a Prius), there is no suspension mod you can do to make a car accelerate faster.

 

I beg to differ...

RWYB - Technical Features

"When you watch a car launch, you can see that the back end squats down and the front end rises up. What is really happening is the car’s body is rotating about its centre of gravity and this is dynamic weight transfer. Effectively there is more load on the back and less on the front. Great for a RWD car, not so good on FWD as grip is reduced under launch.

...

For a front wheel drive car or a rear wheel drive car, the key is the stiffer rear springs and also the lower centre of gravity. On FWD cars, a stiffer rear spring and the lower centre of gravity will reduce the change in body angle during acceleration (squat) and therefore reduce the amount of load that is taken from the front axle, thus preserving grip."

besides wheel hop...'squatting' does take energy away from acceleration.. Look at the mods in the rear suspension of most FWD drag racers.

 

The article you've linked is specific to drag racing, a sport in which every car begins by expelling a huge cloud of burnt rubber. Perhaps my Prius is broken, I don't know what the prior owner did to it, but I've yet to be able to sustain any sort of wheel spin...

Let's pretend wheel spin is a problem in a Prius so Justdidit doesn't feel so foolish.

The equation that determines F_s,max (the maximum amount of force one can apply before breaking traction) has two factors: the coefficient of friction and the normal force. (for more info see Friction)

When the engine produces more force than the wheels can transmit to the road, the driver has a few things he can do to limit wheel slip: change his tires (to increase the coefficient of friction), mod his suspension (to maintain the normal force), and simply not mashing the gas as hard (to decrease applied force).


When we're not talking about drag racing, where WOT is the rule and not the exception, you're not going to get any more acceleration out of a suspension mod, because you're already under the limit of F_s,max. You're already applying all forces to the ground... more force does not magically appear.

Call me a heretic for not believing in magic. You can disagree all you like...

FWD drag racing... what next, mini-van autocross? Sorry, I just find the phrase humorous.


To the first order, any energy that is consumed by a spring is eventually returned to the system. Just as the suspension does not produce acceleration, it also does not consume acceleration. But that's not what you meant, right?

What you probably meant to say was that the momentary reduction in normal force on the drive wheels during acceleration results in a momentary reduction of F_s,max. Hence, the "grip" of the drive wheels is reduced from "squatting". Again, something a stock Prius owner will never experience... but I could be totally wrong.

Please introduce me to these drag racing Prius owners of which you speak! Is there an entirely separate forum for these fellows?

 

If you are lifting the car then you are wasting energy that could be used for forward momentum instead of upward.

FWD race cars haven been around for quite some time and many are actually quite fast.

 

I've got a Dodge Neon ACR for tracking... but FWD drag racing...

 

You should visit a track sometime.

 

Never underestimate wagons. LOL

 

Regardless of wheel spin (which I've never known a have prius to have during a straight line launch) Suspension does play a part in acceleration. Torque is wasted lifting the front end, rather than moving the vehicle forward. For someone who spouts so much knowledge about cars and all about drag racing, you fail to appear to know anything about FWD

"This is interesting because it seems to demonstrate horsepower governs maximum speed (circular track), but torque influences acceleration (drag racing)."

Enzo Ferrari was once quoted as saying "Horsepower sells cars, Torque wins races..."

Let me introduce you to World-Racing.com below is Chris Rado's Pro Drag 1,200 HP and somewhere over 1,000 lbs of TQ - FWD Scion TC...

Now... don't you feel like such a foolish person for making such a condescending know-it all comment? Do some more research. I'm done here.

 

CLEARLY you need a huge splitter on the front lip .

 

So there's a modified Honda Civic EX with a 6.525 1/4 mile ET. Is that fast enough?
Fast Honda Civics 1/4 Mile 0-60 Drag Racing - DragTimes.com

 

I still don't see how all of this nonsense means macmaster05's Prius should have accelerated faster with his new springs... but you guys keep on with your FWD show and tell. It's cute!

 

It's a Prius. virtually no suspension upgrades will yield any increases straight line performance. Hell, virtually no upgrades will improve straight line performance save removing huge amounts of weight out of the car.

 

Whoa there, be careful with your logical, rational statements. Justdidit is gonna have a field day with that... see what I got?

 

I see I overestimated my audience. Let me try again...

 

And people will always post about stuff they don't understand.

 

I'll give macmaster05 and others the benefit of the doubt... physics is a difficult subject to master. H&R has to have a good advertising campaign to give so many the belief that they get an HP gain from installing their springs!

 

What I don't understand is how there was any confusion as to anyone mentioning a belief in HP gain with suspension mods? HP isn't the only thing that effects acceleration...but you probably already knew that. Maybe the 'cute' pictures you posted help your irrelevant argument be more irrelevant to the topic and show how your mind minders and your maturity.

Even your idea that drag coefficient isn't changed by changing the height of the front end of a car to the back end unless you physically modified the body is completely wrong.

Please, for the sake of others receiving more incorrect information, do more research.

 

Idk justdidit i added a sticker to my car which easily gave me about 5-10 hp