HiFlite999

iTrader: (2)

Application: Series I and II, with shock/spring suspension. Not for aftermarket coilovers.

Motivation: Many options exist to lower the car on its suspension. However, without going to coilovers ($$), no one AFAIK, sells taller springs or stiffer springs with the stock ride height. This can be a problem for those driving in difficult environments or for those routinely loading the car with passengers, cargo, or megaboom speakers. It is also a "quick fix" for sagging springs (like the Racing Beat springs shown).

Cautions: Not for track use. I can only vouch for this working the 2-3k miles I've run like this with mine (however, I've seen no obvious deterioration).

The main aftermarket part is a double grooved, rubber, old-style, rubber coil spring spacer. I used a Mr. Gasket #MRG-1287 sourced from Summit Racing.

Mr. Gasket Super Coil Spring Spacers 1287 - SummitRacing.com



It's designed for a 6" diameter spring, so has to be modified for this use. If you want the maximum lift, order two of them. (I didn't want this, so can't say much about that install, though I suspect that it requires removal of the spring/shock assembly from the car and disassembling to fit the spacer in the coils. You would want to cut some of the length away, so that you're not filling in coil spaces directly above each other, and may have to slice it into smaller pieces to better match the coil radius.)

Prep:
1) Cut the spacer into 6 equal length pieces. A hacksaw works fine.

2) Buy 2 nuts and 2 washers that fit your coil compresser. Flip the loose end of the compressor, and add the nut and washer as shown in the figure. The compressor is now a spreader! (I only needed to use one "spreader" but wanted to reserve the option of using both if needed).



3) Decide how high you wish to go. 2 rubber pieces on each spring will raise the height about 1 cm. 3 will raise the height about 1.5 cm. (4 I didn't try, but probably you'll get around 2 cm, and will require buying 2 of the MGH-1267s.)

4) Purchase or have on hand, 1 (or 2) small hose clamp(s) for each piece you wish to use. They should clamp neatly and tightly around the "bar" of the spring.

Procedure:

5) Lift one corner of the car and remove the wheel. Place securely on jackstands since you may have to work at times under the car.

6) Spread a coil of the spring enough to insert 2, 3, or 4 pieces of the into the space without breaking off the ridges of the groove.

7) With the RB springs at least, the spreader can be removed and still allow the pieces to be spaced symmetrically around the coil. Do so.

8) Place a hose clamp on the spring for each piece to prevent the spacer from sliding down the spring when it's uncompressed. (It might be a good idea to place one above as well but I didn't do that myself.)


Two-Piece 10mm lift:


Three-Piece 15mm lift:


9) Done! It's probably a good idea to re-tighten the hose clamps after driving around for a while. The spring flexing will "shape" them to the curve of the spring and allow further tightening.

Comments:

It works. It's cheap, but not pretty. Since the spring/shock assembly does not need to be removed from the car, they can be swapped in or out rather quickly as needed.

EricB

iTrader: (7)

it doesnt seem like a good idea, but it could be exactly what i need to stop scraping my rb midpipe on that speedbump at school.

HiFlite999

iTrader: (2)

I won't disagree with you on either point. A proper solution would be stock-length springs with a higher rate, or a machined piece to fit above or below the spring. The former has been discussed in the past, with some attempts made to get a spring shop to roll sets for a group buy, but nothing ever came of it. One could also use a model of coilover that allows ride height to be set higher, but, besides the cost, most come with vastly higher-than-stock spring rates which many are reluctant to use on the street.

TeamRX8

iTrader: (25)

they actually use them in various stiffness rubbers on racing coilover springs to tune the chassis

Longacre Coil Over Spring Rubber - RacingPlus.com

HiFlite999

iTrader: (2)

Very cool, I didn't know that.

j9fd3s

yes, we use those on the race car, much faster than changing springs!

HiFlite999

iTrader: (2)

Do you happen to know the bottom groove to top groove thickness?

They mention that the rubber for the "Swift Barrel" springs is designed for and ID of 3.5". Any idea what diameter the "Coilover" sets are designed for?

04Green

iTrader: (1)

Need help from the experts.

I have Tein H Tech, 130 pounds per inch, progressive. If I load the car, it bottoms out. Stiffening the shocks helps a bit, but not much. If I sit on the edge of the trunk, the car goes down 1.5 inches, or about right for my 200 pound butt assuming 130 or so pounds at the installed spring height. I do understand the physics is a bit off due to pushing down on the trunk, and not directly over the spring, but I cannot climb in the trunk, and measure at the same time.

I want a stiffer rear spring, but not to mess with ride height. I believe my issue is with the progressive part of the spring being very soft, and the first inch or so of suspension travel being used up by a full tank of gas and a few things in the trunk. After that, I really only have a few inches of suspension travel. I believe that the longacre spring rubbers will help me firm up the first part of the spring.

An issue is, I have no freaking idea which one to go with. Reading their guide, it looks like a 70# rubber will increase the rate of the tested spring by about 50#. I have no data on how many coils that spring has, or anything else. They are working with a 370 lb/in spring racing spring, way different from the H-Tech. So, I am not sure exactly how these compare. But, it is my only data point.

My assumption is that the H-Tech is progressive, at rest the top coils are a lot closer together than the bottom ones. The range is from almost touching at the top, to over an inch spacing at the bottom at rest with half a tank of gas. I think that if I had a spring rubber in there, the boost it would give would depend on where in the stack it was located. Down low it would only help when some compression has occurred, up higher, it would boost from the start and might actually raise the car a bit (I could tolerate 1/4 inch) I think this means I can tune the rate increase (overall boost, and when in the spring compression the boost comes in) based on where in the stack I place the rubber. And, I think this means I cannot really screw up too bad if I get the firm (70#) rubber. Right? The only issues I can project occur if I put the rubber in a part of the spring too far apart to hold it or if it moves around.

I would really appreciate a second set of thoughts on this one.

Thanks,

HiFlite999

iTrader: (2)

^ In lieu of an expert chiming in: I think you're on the right track. The rubber spacer should go between an "opening" coils in the winding. It's helpful I found to inspect the spring with its normal loading vs hanging down. To do this, jack up the rear of the car and take care that the supporting jackstands are set exactly the same on both sides. Disconnect one of the sway bar links. Then, jack under the rear hub until a bubble level shows that the brake disc is perpendicular to the ground (or slightly more if you wish to show a little negative camber). Doing this I noted a huge difference between Racing Beat and MazdaSpeed spring sets. At ride height, about 3 MS coil turns are "shorted", that is, touching; the RB, not. Putting the rubber in the touching turns would boost the ride height considerably.

Cheap, narrow hose clamps on the spring wire, oriented so that the tighting screw blocks the rubber, seems to keep them in place.

ATM, I'm convinced that the D-specs lower ride height of and by themselves. Also, there seems to be some varience in both them and the springs. First pass with the D-spec and RB had the right rear corner 1 cm lower than the left. Keeping the springs in the same location, but swapping shocks side to side resulted in the car being level.

PIA isn't it?

BTW, Here are some measured stats on the spring sets I have, wire diameter, free (uninstalled) length, and number of turns:

Stock -
Front (purple dot): 0.467", 14.4", 8.5 T
Rear (pink dot): 0.428", 13 3/4", 8.5 T

MazdaSpeed -
Front (QSW 134011A): 0.5", 11 3/4", 8.5 T
Rear (QSW 128011): 0.44", 13 1/4", 9 7/8 T

Racing Beat -
Front (14026): 0.496", 13.5", 9 1/4 T
Rear (14027): 0.456", 13 1/4" (left) 13 1/8" (right), 8 7/8 T

Yes, there's a 1/8" difference in free length between the RB rear springs. And no way the MS springs are as stiff as some of the specs say.

Right now, I have MS springs on the front and RB on the rear, which gives a very level car. 4 3/4" to the ground, measured from the pinch welded piece on both sides, front and rear. (This is with no driver, 1/2 tank of gas, spare tire/kit installed, and my usual assortment of tools in the trunk amounting to about 20 lbs.)

alnielsen

iTrader: (4)

Have you thought about drilling a hole in the rubber and using a tyewrap to hold them in place, rather than the clamp?

I have Dspecs w/ H&R springs and it is far too low. I may use this to raise my ride height, instead of going to the RB springs I was contemplating.

TeamRX8

iTrader: (25)

The main issue likely is that the shocks aren't shortened to allow more compression travel

The other issue is that the race rubbers are intended for stiffer race springs with sufficient travel clearances. If the situation involves coil bind or shock bottoming then their effectiveness is out the window.

The original bumpstops are very long. If you didn't shorten those it's a good place to start on a lowered car. Ultimately the problem will be that nobody ever made any decent rate OE type springs.

HiFlite999

iTrader: (2)

I don't think the tywrap would survive. Oddly perhaps, but the rubber can move up the coil as well as down. Not sure, but it may "migrate" under repeated compression and release to a place where the coil gap is largest.

HiFlite999

iTrader: (2)

Yes, I forgot to mention that I cut the bumpstops as per Racing Beat instructions:
http://www.racingbeat.com/manuals/14026-sprg-shock.pdf
http://www.racingbeat.com/manuals/14027-sprg-shock.pdf

It's quite a substantial shortening especially considering the RB springs are only supposed to drop by 1/2".

Yeah, wish they made springs with a small drop and rates in the 250 - 300 lb range. Or "soft" coilovers.

TeamRX8

iTrader: (25)

because Mazda designed the RX8 to use the rear bump stops under hard cornering

04Green

iTrader: (1)

@ Team, thanks, I did not know that "corner on bump stops".

I ordered a pair of the 50 pound ones, so we will see. I really did not want the car lower, that is why I did the H-Tech. However the progressive part is what I think is kicking my butt. Hitting the bump stop on a turn explains why the car stops rolling so fast. I do not want to alter the track performance at all. Last trip I was re-taught about 70% of Roebling, was faster then ever, and never got into stability control. I think there is another second or two easy out there. If the rubbers screw up the track performance, they can easily come out, then go back in for the trip home.

I think a tie-wrap would survive exactly one steel on steel spring compression. Think of the springs as really dull bolt cutters. That is why the hose clamp is a good idea, if something is needed.

For those who want to inspect, you can see 80% of the spring through the gap around the exhaust exit from the rear of the car.

TeamRX8

iTrader: (25)

use tie wraps with internal wire inserts

or Lowes & Home Depot sell stainless steel tie wraps in the electrical aisle