1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Needs more low

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Old 11-29-14 | 09:55 AM
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Needs more low

Just wondering if any suspension gurus or racers have any tips or tricks on getting a bit more low out of my front coilovers. Im running...

-T3 camber plates
-Eibach 8" x 2.5" 200 lbs
-Ground Control weld on perch and sleeve
-KYB GR2 inserts (the best I could find for SA) unless you know of any better?
-Panasport 15x7 +10 Kumho 205-50-15

I just want to narrow out the gap between the tire and fender lip. Theres about 1.5 inches between them. Id like to lower the car another 1/2"-1". Right now I'm maxed out on low... I welded the perch to where the top of the GC sleeve was flush with the top of the strut tube. I have 2" of strut travel.

I have 2 options in my head of how to solve this. Order a 7" spring in a sightly stiffer rate (250 lbs would be the max for GR2s) and lower it 1/2". OR, play with mounting the camber plate ABOVE the strut tower... Safety concerns? Can it be reinforced? Is there a kit for this? FYI Ive played with - camber and find that the car does best at full positive on the plate markings. Not sure what the translates to in degrees. Looks stock to me. From the fender lip to the ground the ride height measure 23.9 inches. How tall is stock? Id guess close to 26".

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Old 11-29-14 | 10:26 AM
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I would think the only way to get lower now is to cut and weld the top of the strut tower an inch higher than stock position.
Old 11-29-14 | 11:48 AM
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That would do it. I did this almost twenty years ago with the old Racing Beat kit and have been really happy. Just takes some commitment to cut the tops out of the towers is all.

However, I have read of people mounting the camber plate on top of the strut tower without any other mods.

In either case your handling will suffer as you go lower, unless you add spacers between the bottom of the struts and the ball joint. I have tried mine with and without the spacers and the handling really sucks without em.
Old 11-29-14 | 02:08 PM
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It rides and handles fine now. I just wanted another 1/2" of adjust-ability. The control arms seem to have the proper angle to them.
Old 11-30-14 | 02:38 PM
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From: https://www2.mazda.com/en/100th/
you have a few choices:

the proper way would be to just order the shorter spring. the GC collars are 4 turns per inch, so you can sort of figure out if that will get you to the right place (1" at the spring isn't 1" of ride height).

you can raise the shock towers, however since you can't buy anything off the shelf, its custom, and way more work than its worth, just to lower the car 1/2".

i think i would try removing the coil over collars altogether, and see where it ends up.

putting the camber plates on top is possible, but it isn't the safest thing. if you think about it, when you have the plate under the strut tower, the plate is held in by the strut tower. when you put the plate on top, it is only held by the 4 bolts. so you have much less margin.
Old 11-30-14 | 04:00 PM
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The stress and weight of the car is entirely supported by the bolt heads on the camber plates... i figure this the least desirable approach. I figure a 7 inch spring will feel stiffer, but have more tension, therefore maintaning the same ride height. Maybe 1\3". My experienses with cutting dead coils has shown the shorter speings can maintain the same height. Untill you cut too much that is.
Old 11-30-14 | 04:10 PM
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From: https://www2.mazda.com/en/100th/
Originally Posted by NCross
The stress and weight of the car is entirely supported by the bolt heads on the camber plates... i figure this the least desirable approach. I figure a 7 inch spring will feel stiffer, but have more tension, therefore maintaning the same ride height. Maybe 1\3". My experienses with cutting dead coils has shown the shorter speings can maintain the same height. Untill you cut too much that is.
a 7" 200lbs spring will feel exactly the same as an 8" 200lbs spring, as they are both made to be the same rate, just different lengths.

the 2.5" springs in different lengths are not in any way like cutting the coil from a regular spring, as that is not how they change the length
Old 12-01-14 | 10:28 AM
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My other thought was to cut and re-weld the perch a couple inches lower, but I have maybe 1/2" of clearance between the tire as is. Id have to measure and see if the spring would hit...
Old 12-01-14 | 10:33 AM
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From: https://www2.mazda.com/en/100th/
Originally Posted by NCross
My other thought was to cut and re-weld the perch a couple inches lower, but I have maybe 1/2" of clearance between the tire as is. Id have to measure and see if the spring would hit...
you could do that. try removing the threaded adjusters, it would probably get you where you wanted to be
Old 12-01-14 | 10:58 AM
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Actually, scrap what I said about 1/2" of clearance. Its more like 3mm! I wonder if they make thinner threaded perches with a tapered bottom?

I had the RESpeed street kit on my 79 with Rota RB 15x7 +20 and 205-50-15. Seemed like I had more clearance with that setup and had it about 1 inch lower. What size spring came with the street kit? I'm thinking it must have been 7". I remember I specified 200 Lbs and just cut a couple coils off a pair of Racing Beat rear springs. Ride was good. I used the same GR2 struts all around, but no camber plate. I doubt the camber plate raises the car that much?
Old 12-03-14 | 03:31 PM
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A. can you remove that gold nut and let the spring sit on the perch?
B. if you add spacers to the wheels you would have more clearance to lower the perch.
Old 12-03-14 | 07:25 PM
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I dont think the perch is wide enough to hold the spring. The threaded gold nut is maybe 2mm wider than the spring and the lower perch is about 1/4 smaller on each side. I dont like the idea of spacers on a street car without them being the "double bolted" hub style ones. Those would stick the wheels way out as they are already flush. I dont think I want to drill into this clean original paint for flares either.

I think Ill just try some 7" springs. Other than that Ill just live with it. Its only 1/2" that I want. I'm just too picky.
Old 12-03-14 | 08:34 PM
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Looks like shorter spring, and raise the perch roughly half the difference.
Old 12-03-14 | 10:57 PM
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First I think your car looks great just as it sits but a 7" springs would do what you want. I would never cut a coil over spring. They are designed with two flat ends for a reason and really don't have any dead coils.


The Ground Control camber plates you have are not designed to sit on top of the strut tower. I have custom made camber plates on my race car that are mounted on top of the strut towers. They are made out of 5/16 cold rolled steel and have 8 mounting bolts. So it can be done but not with what you have.


You didn't mention whether or not you have ball joint spacers installed. These allow you to maintain front end geometry when you lower an RX7. Not sure if you have lowered the car enough for that to be an issue.
Old 12-04-14 | 03:53 AM
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RCA? No, but it seems to be fine looking under the car. It may be a future upgrade.
Old 12-04-14 | 06:02 AM
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weird... im running GC in the fronts and they're almost as high as they can go bc im TOO low hahaha
Old 12-04-14 | 09:06 AM
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Yeah 7 inch springs would do 2 good things for you, it would allow you to get the car lower, and when you adjust the lock ring up from the very bottom of the adjuster it would give you more clearance to the tire. If you are happy with the 200lb 8 inch springs just get some 2000lb 7 inch springs and call it a day. I run 7 inch 400lb springs on the chumpcar with cheap ebay threaded sleeves and it works fine.
Old 12-04-14 | 09:23 AM
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Pics.

I wanna say I'm on 5 or 6" springs but can't remember exactly
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Old 12-04-14 | 11:49 AM
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Quick question N Cross, Im about to do the same thing as you in the front. but what are you running in the rear ?
Old 12-04-14 | 04:37 PM
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I have the same rear springs as in this auction. Front springs are obviously different.

Ground Control coilover Conversion Kit 1979 1985 Mazda RX 7 SA FB | eBay

Its basically like installing 150 lbs RB springs in the rear, but you can cut a couple dead cols to get your desired height. I managed to win a NOS NLA GC kit for 79-85 a while back on ebay. Basically these rear springs with T3 style GC kit.
Old 12-04-14 | 04:54 PM
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Dont mind the dirt. I had to put wheel bearing grease on the dead coils to keep them from creaking constantly.

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Old 12-04-14 | 07:55 PM
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Ohhh hell yeah. I was set in buying strange engineering coilovers for the rear but this seems alot easier, which i like. I just built one of my front coilovers like you did with a 7 1/2" spring
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Old 12-05-14 | 09:43 PM
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Finished my fronts today and installed them. Rear is sitting on chopped springs just to get an idea.

I welded perch so the sleeve top was 1/2" below the top of the strut. Using 7 1/2" 200lb springs. I still have maybe a 1/2" adjustment lower. But this is where I want it.

Old 12-06-14 | 10:14 AM
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Just make sure you have enough travel. FYI fb shock is a hair shorter so you get more travel when lowering.
Old 12-06-14 | 10:35 AM
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Im thinking about trying a 7 inch 300lbs spring. Under heavy braking the top hat claps against the bump stop.A stiffer spring should help.


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