My official Prius mods thread.

Well, looks like I'm not hte only one with these wheels. Here is a thread with the exact wheels that I got. Imagine it silver rather than red, and that's my car (only a little lower).

http://priuschat.com/Pics-with-17-Centerlines-t23335.html

 

OK, here are two pics of the car now with it's final (?) set of shoes. Sorry it took so long, but time is running awfully short around here...

Anyway, here they are. Enjoy.

[attachmentid=4565][attachmentid=4566]

 

Thanks for all the compliments. I'm really enjoying my Prius, and I'm glad that others are too!

It's not done yet, so stay tuned...


Anyway, a few observations now that I've put some decent miles on the new wheels/tires and suspension.

With the lightweight wheel/tire combo, some of hte twitchiness is back. The heavier wheels acted like flywheels, and helped to keep the car more stable. Now some of the wiggle is back on rough or grooved pavement. This is only at speeds above 70 mph, though, so it's not too big a deal. Still much better than stock!

THe car now feels much more responsive than ever. THe same flywheel effect that kept the car stable, kept it from being as nimble as it could be. THe lighter wheels also are quicker to repsond to steering input. I'm sure many of you have done the trick where you hold a bicycle wheel inbetween your two hands. When you spin it fast, it is hard to tilt the wheel. Same thing here. The lighter wheels respond easier to directional changes than heavier wheels.

So, if you want to eliminate any squirrliness in your Prius, go for heavier wheels. If you are a coservative drive, the hit on mpg will be minimal if any (remember, I was able to get 52 mpg with the Scion tC wheels). The lighter wheels will preserve any mileage loss at higher speeds, but will feel less stable. There is always a trade-off.

As far as traction goes, it is head and shoulders above factory. The General Exclaim UHP tires are phenomenal. The grip is great. They are a bit more prone to tramlining, but most higher performance tires are; just another trade-off. THey also make a different noise than the Bridgestones. Not louder, just different. More of a hum than a rumble. Ride is a bit more firm than the Bridgestones, but still not anywhere near uncomfortable. Even with the Sportivo suspension it is still very compliant. This setup gets two thumbs up from me. Plus the Prius looks great lowered!

So far I've found that I've gained about 4 mpg at speeds of 75-80 mph. I was averageing about 41 mpg before, and about 45 mpg now. My driving style has not changed, nor has the speeds I drive at. Mileage on short trips has not changed. If I were to drive the conservative way I did before, I might probably get a bit higher then 52 mpg. If anything has hurt my mileage, it is the speeds I drive at, not the wheels.

So, do heavier wheels and tires hurt your mileage? Seems the answer is yes AND no. It depends on many factors. You can get good mileage with heavy wheels and bad mileage with light wheels. It all depends on your driving style, traffic conditions, speed, etc...

One obvious thing I have noticed is that the best way to loose a significant amount of mileage is to use your A/C. For some of you this is not a problem, as it doesn't get very hot, but here in Florida it is an absolute need. Yes, warmer temperatures are beneficial to a Prius's mileage, but only up to a certain point, after that it's diminishing returns. When it's 95 degrees with 95% humidity, A/C use is unavoidable. I imagine when the temperatures drop down to where I don't need to use hte A/C any more, my mileage will likely go back above 50 mpg. A/C kills mileage! This has been the biggest hit to my mpg than any mod I've done. So just as the colder temps some of you experience ruin mileage, so does heat.

All in all I'm very happy with everything. The car handles great, looks great, and gives great mileage. How can you go wrong?

 

<div class='quotetop'>QUOTE(J.Wilkie @ Aug 22 2006, 10:24 AM) [snapback]307465[/snapback]</div>

Not yet. You can check post #1 of this thread to see what is and isn't installed.

 

INSTALLED
Centerline RPM Forged wheels, 17x7, 42mm offset, w/ 215/45 17 General Exclaim UHP tires
BT Tech stiffening plate
Chromed amber turn signal bulbs
Sharkfin antenna
TRD Sportivo suspension kit
Tom's strut tower brace
Tom's front suspension brace
Sherwood carbon fiber dash kit
HID fog light conversion
PIAA wipers (super-sized driver's side and rear)
Window tint
VAIS AIC-100i and iPod w/ video


STUFF I HAVE BUT NOT INSTALLED
PS2 video source
JL Audio ZR650-CSi Components (front and rear)
JL Audio 8W7 subwoofer
JL Audio CleanSweep CL441-dsp
JL Audio 300/4 Amplifier
JL Audio 250/1 Amplifier
(just waiting for JL to release the CleanSweep SSI summing module...)

FUTURE STUFF
Signal mirror housings
Kenstyle front/rear spoilers/side skirts
Touring model spoiler
Tom's floor brace
Tom's rear lower brace
Tom's exhaust system
JL Audio CleanSweep CL-SSI (already paid for but not released yet)
AV Electronic NVI nav screen interface
Alpine 6.5" Widescreen Monitors

 

<div class='quotetop'>QUOTE(Actual Mileage @ Aug 23 2006, 02:25 PM) [snapback]308344[/snapback]</div>

JL makes great stuff. I've used their gear in previous systems in other cars, and was very happy with it all. I also prefer to stick with one manufacturer whenever possible, as the parts are usually easier to integrate, and the manufacturer usually gears a piece of equipment towards it's other parts. They just tend to work better with each other.

In this case, the two Cleansweep units actually plug into each other for easier setup. I could use another manufacturer, but I'd have to splice wires and so on.

As for what the Cleansweep units do:

The 441-dsp unit takes the signal from the JBL amp and removes any factory equalization and gives as close to a flat frequency curve as possible. The ASL circuit would have to be turned off, or it woud adjust the equalizer settings as the car's speed changed. Basically rough curve in, smooth curve out.

The SSI unit takes the split signals and combines them into one signal. The front speakers have separate wires going to them from the amp. The tweeters get a partial signal and the woofers get a partial signal. Well, an aftermarket amp won't like this, and the crossover frequency the factory JBL amp uses may be different from the crossover frequency the aftermarket speakers use. THe SSI takes these two splt signals and combines them into one full range signal. The rear is a full range, so it doesn't need to be summed. The SSI also combines it in a way that the signal is smoothes out where the two signals overlap. Otherwise the level would likely jump up around the crossover frequency.

The dsp is already out, but the SSI is not. I'm going to call JL today to get an update.