going lower. . .inserts. . .

[prius70]

for those interested in lowering and mess'n with your suspension. . .

i started modifying the prius front struts to accept inserts. . .

we'll see if this works on the car. . .

some pics of the process. . .so far. . .

[Rokeby]

Prius70,

on behalf of the many members -- me most of all -- who aren't conversant
with the minutia of the suspension and other fiddley-bits under the car, could
give us a brief explanation of what benefits your mod will generate? What are
the pieces being modded, front or back? What exactly is being "inserted?'

Thanks

[galaxee]

oh my, that looks like a lot of work. so how low are you going, and what springs are you going to use?

[David Beale]

Lowering the car will reduce the "frontal area". Consider that the air -under- the car will be disturbed when you travel over it. This will drain energy from the car. Of course the air the car displaces (travels -through-) is also disturbed. Measure the frontal area by measuring the highest point of the car and measuring its' width. Multiply these two numbers together to get the area. Add in about 1 sq foot for the antenna and mirrors. Multiply this by the Cd to get the "effective frontal area". Use this number in the formula for air resistance vs speed.

So if you lower the car you will:
1. Reduce the frontal area.
2. You will also improve handling (less of a moment arm trying to pry the tires off the pavement when cornering
). But only if the lowering is done right so the suspension still works properly.
3. Some feel the car will look "better" lowered, or at least "cool" in some circles.

[prius70]

[quote=David Beale;603037]Lowering the car will reduce the "frontal area". Consider that the air -under- the car will be disturbed when you travel over it. This will drain energy from the car.

Thanx for bringing up this concept of "frontal area".

Being clueless concerning this matter, I googled it and found alot of interesting reading which gave me a better appreciation of the design that goes into race cars and cars in general: (one example)

Aerodynamics, Downforce, Ground Effects « Jim’s Garage

I guess lowering the the car or front only will reduce pressure under the vehicle and overall "drag". This is not my intension as I just like the "look" or whatever you wanna call it.

[prius70]

Originally Posted by Rokeby

Prius70,

on behalf of the many members -- me most of all --

I also am not an expert on the minutia or fiddley stuff. . .

I do have some experience lowering old VWs which have a different suspension setup alltogether.

My goal primarily is to lower the vehicle and improve stability while maintaining reasonable ride quality as I have to drive this thing to work everyday 60miles and am not interested in bouncing around the road. . .I can do that and get enough of it in my VWs.

First: I bought different springs to lower the car: different thread
"blitz springs"

To go lower I'm figured out something else to try (decided to change the location of the mount bracket on the front strut). . .which I'm still trying to figure out BTW.

I googled and found out people modify their struts and springs for many different purposes. Once modified, you can potentially adjust ride height and valving with just twist and turns of knobs and screws for whatever your purpose.

Unfortunately the prius is not too hot in the modification marketplace to gain from others experiences.

I decided to do what others have done to there struts which is to make them "servicable": I guess in the past ?80's? when your struts went out, you just replace what was broken or the "insert" and not throw the whole thing away, sounds very environmental

Servicable struts have a screw at the top of the strut body that holds an insert inside the strut body. Hopefully you can see that in my pics. . .

Todays gas struts (prius) are not servicable. There is no screw at the top or insert inside. You do not open them, HEAT them, or rebuild them which is what I needed to do to REWELD and RELOCATE the front mount.

I discovered toyota struts in the late 70's to early 90's were servicable. MR2/cressida/camry/corolla struts can be used to "steel" the large screw and threaded area from the top of the strut body. Weld this stolen area to the top of the prius strut and voila, you have a servicable strut.

Now you have the option of using different strut inserts from monroe, gabriel, koni, tokico, kyb, etc. . .some of these inserts can be adjusted with a knob!

Concerned about ride quality, I chose factory replacement Gabriels with VST technology whatever that is. Hopefully the car still rides soft.

I can say soo far that with the wheels and tires, lowered springs, and BT plate, the car is much more stable and enjoyable to drive by my "seat of your pants?" meter

[Rokeby]

Originally Posted by prius70

I also am not an expert on the minutia or fiddley stuff. . .

I do have some experience lowering old VWs which have a different
suspension setup alltogether.

My goal primarily is to lower the vehicle and improve stability while
maintaining reasonable ride quality ...

Thanks for the come-back. Now I somewhat understand what you're doing.

If it's not to much to ask, when all's put back together, could you post pix,
before/after or at max ranges of adjustability?

Go get 'em Tiger!

[prius70]

some other interesting articles about frontal area:

Ground Effects and Aerodynamics - ThirdGen.org

AutoZine Technical School - Aerodynamics

The World’s Most Fuel Efficient Car: 285 MPG, Not A Hybrid : Gas 2.0

[drees]

Great pics showing how you've hacked up and welded back together your struts.

How much lower are you looking to get your Prius?

Have you looked into any sleeve-type coil overs like the ones that Ground Control makes? That would make getting any spring rate and adjusting ride height simple - if they make a kit that is compatible.

Though if I had to guess, your choice of shortening the struts should keep the ride closer to stock which is good for your long commute. Might even improve fuel economy a bit by going lower, too.

[prius70]

Originally Posted by drees

Great pics showing how you've hacked up and welded back together your struts.

. . .sleeve-type coil overs like the ones that Ground Control makes?

. . .choice of shortening the struts should keep the ride closer to stock which is good for your long commute. Might even improve fuel economy a bit by going lower, too.

thanx drees,

had a lot of fun hacking up the struts too. . .

i figure i could only "safely" get another 1 1/2 in the front. if you go any lower the front tires will rub up against the bottom of the spring plates and the lower struts will bump up against the front axles. . .probably not a good thing. . .

i saw those spring over conversions and they look pretty straight forward to weld up and also cheap off of ebay but i don't think they're built for travel and ride quality with those short and linear springs.\

the struts are actually not shortened as i was initially planning on doing. . . either shortening the struts or lowering the bottom spring perch. they are actually the same length and travel as stock. the bottom mount is just moved up and inch and a half.

about gas mileage, another member commented about frontal area and drag coef which i found very interesting to read about. i guess by lowering the car a total of 2 1/2 inches eventually, i'll decrease the frontal area by an area equal to the part of the front tires which are no longer exposed to the wind. it will also lower the pressure under the vehicle which will creative more negative lift? in theory but neglegibe at our speeds.