Due to the extra ~ 170lbs added to the rear deck by my Enginer kit, my back end sags. Does anyone have any suggestions for stronger rear springs or spring/strut options for bringing it back up? Suspensions are not an area that I am adequately familiar with. I know that others have added the kit and must have dealt with the same thing, so I posted to this forum.
Not sure exactly which springs they used, but, 3 prong power put extra heavy springs in mine (note that I have a 300lb pack). What really helped the handling though, was this, much simple upgrade that I added myself: http://priuschat.com/forums/gen-ii-prius-modifications/85553-chassis-brace-prius-must-have.html Scott
I don't think there is any need to replace the rear springs. I have the Hymotion kit, which added 200 lbs. Before the kit, if I remember correctly, I measured the bumper at 12.5" from the ground with a full tank. With the kit, I think it was at 11.5" from the ground. I also removed the spare tire, which was about 25 lbs. Also, if you keep the tank around half full, you will shave another 40 lbs or so. I think that keeps the bumper around 12" from the ground. Which is still within acceptable to me. Now, if you're carrying 4 or 5 adults in the car, you do have to start thinking about reaching the weight limit, but I don't know what effect, if any, adding heavy-duty rear springs would have on that weight limit.
From the position of the bumper closest to the wheel well, mine measures ~ 8" with an empty tank and there is a definite sag to the rear end that wasn't present before. Also, I also regularly stow things in the hatch area for delivery that can add up to 100 lbs to the weight. With a full tank of fuel, this could definitely be a problem. In fact, the other day I had to drive over a chunk of concrete in the middle of the lane. It passed just fine under the car until it made contact with the underside of the back. I'll try to post a photo later as time permits, but there is definitely an angle from front to rear that is opposite of normal.
This company: Valley Spring Works 340 Industrial Way # B, Dixon, CA 95620-9206 (707) 678-3944 manufactures the beefed-up spring for the Prius. The same merchandise sold and installed by Luscious Garage and others. I always wanted to upgrade mine (2004), but never got the real incentive ($$) to purchase them. Please, share your buying experience. Horacio
Generally, with the 2kwh or 4kwh kits, there is not any noticeable sag. I put the 4 Kwh in mine and haven't noticed a problem. Of course, I also removed the spare-tire and associated tools. Perhaps your springs or struts are simply aged or otherwise malfunctioning. How old is your Prius? Mine is a 2008 with approx 50,000 miles. If yours is much older with more miles, that could be the problem.
