Hyperco 5.5" single pigtail rear spring test

[kngrsll]

Alright, i got one of the two sets of springs i ordered today. This pair of springs is the 275 lb rated, 5.5" diameter, 12" free length, single pigtail rear spring. When i first got them, i thought, damn these things are big!! Then i thought, shit, they don't compress at ALL!! Only one of these would actually become an issue. Feel free to speculate :)

Ok, so in review, i measured the rear spring on the car (Tanabe DF210) to be about 12" free length and 5.5" in diameter with a spring rate of 123 lbs. I thought with the rubber on each end of the spring out, they may just fit. I ordered both rates bc i thought that the 175 lb would have a much better chance of fitting, but i don't know this as they are not here!

So first i measured the height of the rear wheel well stock:




looks to me to be about 24.5" roughly...

So then i jacked the car up and pulled out the rear springs. Before putting in the new ones, i took a picture of them in comparison.




So, as you can see, they are nearly the exact same free length. Which is good that i guessed it right, but bad that it wasn't good for the rear height when it was installed! Also, the diameter of the Tanabe spring is probably closer to 5" rather than 5.5", and in fact, i think they sell a 5" spring just like these, so that may be a better option.

I went ahead and installed them, they just slid in and i lowered the car. The rear of the car was pretty high. I didn't go drive around on them, but i put the shocks in, and the droop length kept the springs in fine. So here are two pics, one of the height and one of the measurement of the height.




I see that as 27 1/4", so nearly 3" higher. Now, one could just trim 3" off the spring, but then i think you will have issues of losing the spring if you were to lift a rear wheel. That no good. What you could do is use the rubber hats and leave it in for another inch or so and they mostly compress. Another idea was to weld in a short metal tube that is about 2.5 or 3" in diameter on the spring seat to keep the spring in place if it were to come off the lower seat (and that would be REALLY bad. Another option would be to reduce the droop length, which is possible with some simple straps.

Anyways, thought i would share. Hope it helps, I will try the 175 lb springs when i get them. If Loren or largeorangefont wants to do some math, feel free! :D I think the lighter springs will fit perfect, but we will see.

Oh, i got another nice package today too!



15x7 +25mm 13 lb Team Dynamic Spec Miata wheels!! :D so much win!!

HA!! IT WORKED!!! I cant believe it!!

Ok, so i took the springs to a random muffler shop, i approached one of the workers outside with my springs and asked if they could do a cut on them. He said no problem, got his torch out, and cut where i measured! So that was way easy, i thought it would be alot harder to get someone to do that lol.

Ok, so i didnt get pics of that stuff, i should have. I measured from the very bottom of the spring when it was sitting level, and i rotated the spring until the bottom part of the coil got to 2.5". So i made a line there and had it cut. The free length of the spring now was 9.5".

I went home and jacked the car up. I didnt have to unbolt anything now lol, i just used a wrenched and popped the springs out! So once they were out,i installed the rubber hat on top, and i put the new ones in, and lowered the car. This was tricky, you lower it a little and make sure its in place, and then go all the way. Well here are the pics:


Before


After

Can you tell a difference? I can't!! and if you dont believe me, look behind the car, black springs in the first pic, red springs in the second!

So then the problem of the springs staying in came up. So i drove the car around, and i had no problems. I drove about 30 miles. I went to an empty parking lot and did donuts, and slides, and anything to try to make something bad happen and nothing did. The problem will really come with large pot holes or something like that so that may have just been for fun! :) So i visited a few places and such, and couldnt really think of how to do the strap thing yet. I figured, why not use the spring as the strap? So my temporary solution is these hardcore zipties. they are metal and are made to support 100 lbs of weight themselves. There are 6 on there, so that splits the load up pretty good. Anyone know the weight of the rear subframe? They came from Advance Auto in the Performance Parts section.

So how did i do that? Well there is a hole in the top spring perch, you can slide the tie wrap in it, over the spring, and tighten it. For the bottom, there are holes all over in the perch. So do the same, around the spring and tighten to the perch. There are two on the bottom and one on the top.

Next, to test this, i jacked up each side individually. The spring stayed in place, the zip ties held it in!



So this is the amount the car is off the ground right before the tire comes up (and the spring and straps carry that corner load.)



This is a terrible pic, but you can see the straps (untrimmed!)



The same picture with the spring loaded instead.



See? Its normally really hard to get the rear tire off the ground!!

I even stood on the wheel and jumped up and down on it to test the straps, they work!! im only 165 lbs but, it passed my test. I think i will make straps later, but now i can really do them right and not in a hurry.

So how does the car drive?? FANTASTIC!! Loren is so right about this chassis, it really wants more rear spring!! so now it has 175 lb springs in the front and 275 lb springs in the rear. The car is so much more agile. I had to really bump the shock settings up to make up the difference, so i am glad i had that adjustability. For anyone with blues, i would suggest upgrading the rears to either the blue xD shock or just get the HTSs. You may be able to just do the rear HTS and keep the blues up front if money is an issue, but the front adjustability is nice. I have not played with shock settings much yet, i think i will only play with the rears once i get the settings i like.

So I have an autox tomorrow, lets see how this set up works!!

A big thanks to everyone who helped and had some input/ideas for this!! You know who you are!! (and if you guys dont: Loren, Tamago, and largeorangefont)