Search for Replacement Heavy-Duty Rear Springs

Wonder if these would help:

http://www.jegs.com/i/Mr. Gasket/720/1285/10002/-1?CT=999

Stick them under the rear spring at the strut seat.

 

what are you putting in your trunk!?

 

wow!

 

"Air Shocks"

Least expensive way to go.

Don't forget to post pick when you're done!
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"Air Shocks"

Least expensive way to go. Try these folks, for example:
Strut Mounting Kit | Prius | FREE Shipping on Monroe

Don't forget to post pick when you're done!
.

 

Come to think of it, the rubber risers won't work in a strut -- it'll only change the preload but not ride height.

 

Interested in what you went with for the 400-500 pounds of extra batteries. I have 100 extra pounds and looking to add another 150 lbs of batteries for the Enginer PHEV kit. Thanks!

 

I searched around for upgraded prius springs and couldn't find any online. I did however find the place that seems to be supplying springs to the PHEV people. They're called Valley Spring Works, and as soon as you say "Prius" to them they ask how many pounds of batteries did you add. They're contact info is:

Valley Spring Works
340 Industrial Way # B, Dixon, CA
(707) 678-3944 ‎

For a +425lb rear spring set they quoted me $265 plus shipping. Apparently they're made to order, which is a simple process. I contacted almost all the PHEV manufacturers directly and they gave me prices from $300-500 so $265 is a good price.

Hope that helps anyone in the future who wants to beef up suspension!

 

I used to have some 4 Way Shocks. That is a brand name that no longer exists, but is a description of something different. The originals (in the 70s I think) kept the height the same as stock, but increased the spring and shock rates. I don't think you'd want to increase just the spring rates without a commiserate increase in jounce and rebound rates of the shocks. The way this worked, picture a shock with a spring around in, but NOT clamped at the top and bottom. At this time, the car sits at it's stock height due to NO additional springs. Now clamp it at the top and bottom. If the tire goes down in respect to the car it stretches THIS spring reducing rebound movement while the regular spring operates normally. Back in the relaxed position, if the wheel gets push up into the wheel well, this spring AND the normal spring compress reducing jounce movement. This operates about the same is taking the original spring out altogether and replacing it with a stouter one and hopefully replacing the shocks at the same time with increased jounce an rebound control. The clamps COULD be clamped at a higher of lower ride height is one wished, but in the case of the Prius, changing it's angle of attack would probably be detrimental to it's low CD. Maybe someone still makes a shock and spring combo that works like described, but I don't know where. I suspect a clever person could cobble something together in their garage though. Knowing the stock spring and shock rates and the target rates would help. Note: I put 4 Way Shocks as described on my wife's 1972 Toyota Mark II station wagon (In-line 6 cyl/auto tranny). The rear ones went in without a hitch, but the front ones were supposed to go inside the front coil springs through a hole in the lower A arm. I had to hog out just a tad of clearance for the clamps to fit through. The end results were great. I used it the tow a 3,500 lb sailboat/trailer combo from Long Beach to Union City (Ca, not NJ). Then all around there including a mountain lake on 152 east of Los Banos. (Further note: I immediately installed a sway brake on the hitch and it already had surge brakes, both a godsend!

Another option is those foam gizmos the thread up through the coil spring, but I am afraid that would raise the rear ride height. I raised my wife's 2011 Sienna by about an inch, but I didn't find that troubling. On the Prime it would be interesting to see if that had an impact on MPGs. Perhaps is you always had passengers of cargo it would come out just right. I am almost always solo, or on front seat passenger.

Either would be EZ on the Gen 4, as the rear coils and shocks are separate. I may just try the foam ones as they are EZ in and EZ out... and not very costly.

 

Something like this might work. The spring rates on this one might be a bit high but I thing they have the right idea. You could raise the rear of your car to the desired level the clamp it top and bottom on both sides. Maybe a few cut and tries 'til you get it perfect. If you need it one inch higher than it sits loaded as you say it is most of the time, raise it two inches and see if it sags back down to the one inch you needed. You might have to do this in one of those lifts you drive onto. Getting under the Prius in the driveway might be a bit tough. If on a frame hoist, you lose your height reference. Also note: The floor jack pylon is NOT in the center of the car, but closer to the driver's side. Two if those little hydraulic jacks under one of the pivot point of the suspension members could be used to raise each side an appropriate amount. (Bottle jack on top of the drive on lift at the proper spot to raise only the car and not the tire.

https://www.streetsideauto.com/p/superior-14-0890/?utm_source=googlepepla&utm_medium=adword&gclid=Cj0KCQjw1dDPBRC_ARIsAJZrQfp_V-ciiZSwIUBhB5-XsvchDCd5C6DsXHTx-mMXpsTl_i6f9Z07dOAaAscYEALw_wcB

Someone probably makes these with different spring rates.

Actually, in you case since you WANT to raise the car a bit is those foam gizmos I mentioned B4. I want to keep mine a stock height.

 

Another idea is that they make pads that fit into the pocket where the spring seats. Top or bottom. Just get a pair the thickness you want to raise the car by. This won't affect your spring or shock rates, just the ride height.