no, that is too long. remember total stroke is different than bump travel at the ride height you'll be at. Your coilover has 5.4 inches of travel fully extended, but it isn't fully extended when it's on the car. You can use some math to figure out how much bump travel you'll have with the spring rates you want and with the lower spring set where you want it.
Thanks andyroo. I plan on sticking with the same spring rates, about 225 lb/in. I found this article on calculating bump travel, so I'm assuming this is what you're talking about.
Except once I figure out bump travel, how will that help me determine the correct spring length I'll need? I guess I'd look at the springs "usable stroke" again.
Off the top of my head I'm thinking a 7" spring would do it.
Yup, that's the way to calculate bump travel. With the ride height where you want it, you then need to make sure the spring has more stroke than the damper has bump travel. Otherwise the spring will fully bind/close which is pretty unpleasant. A 7 inch spring sounds about right.
Thanks again. I'm pretty low on these, so the travel is minimal already. In that case, I'm thinking an 8" spring would probably work as well. Does anyone know the length of the front springs that come on vmaxx/kw v1's? That would be really helpful.
If you know your existing spring rate, and you have the ride heights adjusted to where you want them to be. Measure the length of the compressed spring. Jack up the car and take all the weight off the springs. If your existing springs are compressed at all, you will need to do more work. With the spring in the fully extended position measure the length. If the spring is still compressed when the car is jacked up, do what you need to do to uncompress the spring. This might be screwing the spring perch down on the shock, or removing the strut. I am not familiar with the coilovers you have. You said your existing springs are 225 lbs/in. If the spring was compressed three inches, then the amount of preload would be 3*225 or 675 lbs. The spring you would need would be long enough to compress to the desired ride height plus the remaining suspension travel of the strut without coil bind. This assumes you know the spring rate. Do you know if the spring lost any ride height after it was installed? Good springs do not loose ride height. If the springs have lost ride height you need to rate the springs.
You could also do it by knowing your corner weights. If you have the corner rates, and the spring extended length, measure the spring length at ride height. The spring you would need would be one long enough not to bind and provide the preload plus remaining strut travel.
complicating this though is that the springs he has are progressive, and likely not very good quality so a little inconsistent even beyond that (vmaxx isn't known for high quality springs or damping).
Oh and lastly, I've looked around and found some "formulas" for calculating spring length. When swift states 7", are they using a specific formula or is that just from the top to the bottom?
Ok, so I did a little measuring this morning. The springs on the front struts of the vmaxx are roughly 8 1/8" measuring from the end of the coil at the top to the end of the coil at the bottom. So lets say about 8".
I also have about 1" of threads left above the collars. In that case, I'm pretty sure an 8" spring would be my best bet.
