Coilovers vs KYB AGX and springs
 

I am in a pickle. I need a suspension upgrade for my 1987 Rx7 Tii. So far I have 3 options. But first, I intend to use the car as a street car, it may not get a trackday, as there is not much option in my area. I want to lower the car about 1", have a slightly stiffer ride, but not break my back on every bump.

1. Powered by Max Coilovers. This would give me the adjustability, but I do not know about the comfort. This is the most expensive option, coming in around $1400 shipped.
2. KYB AGX struts with some sort of spring, thinking about racing beat springs. I believe my tophats on my old struts are still able to be reused. This option would be around $700 shipped.
3. Riaction coilovers, IDK, only know about them because Rob Dahm has them on his fc, but they were given to him, about $1000 shipped.

All of these options allow me to change damping, option two doesnt allow me to change the ride height.

So far I think option two is the best for my setup, also the cheapest. If anyone wants to recommend other springs or struts to use, im all ears. Most seem to be unavailable now a days though.

I can't comment on the coilovers, but I ran KYB AGX and RSR Downsprings on my old FC for awhile and had no complaints. The RSR Downs are a little softer than the Race versions and are comparable to RB stuff.
Definitely a road worthy set-up. A little stiffer than stock but livable around town.

EDIT: Here's what the drop looked like.
https://cimg9.ibsrv.net/gimg/www.rx7...085809990b.jpg

I had a similar delima a few months back so I started this thread. Any Coilovers livable on the street. - RX7Club.com - Mazda RX7 Forum It's a long read but the TLDR version is basically I increased my budget and bought these RedShift Competition Coilovers (redshiftmotorsports.com). Slipped in just before the price increase. I went pretty soft on springs 6kg. Front 4kg. Rear since mine is a streetcar. They came in last week but I think I'm still a couple weeks or so out before I get them on the car. I'll update my old thread once that happens.

KYB AGX, Tanabe GF-210, 225/45R17:

https://cimg0.ibsrv.net/gimg/www.rx7...0babc639be.jpg

If I were doing it again I might go with coils, but only because I need new top mounts and after I eventually buy them the cost will be close to a set of coils. Ride is pretty good, but since all my stock shocks were blown it isn't a fair comparison.

If you don't need new top mounts then AGX + springs is a good choice IMO.

What do you have to look for when looking at the topmounts to see if they are reusable?. Is there a rubber part on it?

The rear ones have a little rubber donut which is fairly cheap and replaceable.

The fronts have a big rubber bushing with a sleeve in the center. Obvious issues are cracking or separation of the bushing. In my case, they were original and have nearly 400k km on them.

If they look okay they should be fine, but rubber can age without cracking so it's hard to say without feeling how they ride.

plan 2.5, you can run the AGX's with a coil over kit and either the stock top hats or camber plates
the shocks work well with 350lbs/in springs in the front and 250lbs/in in the rear, 6/4.5.

Is there many other options other than the ground control kit?

Currently on Tein S-Tech springs with stock 15" wheels and tires. The front dropped lower than I expected and has quite a bit of rake. Not much gap. Looking to go with a 225/45/17 35 offset all around. Will this work?

I think it will work but you may need to run a 5mm spacer on the front. I'm going to be running a 17x8 +35 offset with a 225/45-17 tire. I have test fit the rims on the front and I think with a tire on it would be close though I think it may rub the spring. I think a 5mm spacer may be needed on the front.

The more expensive poweredbymax coilovers are much softer than their less expensive ones.

Long story short, my buddy Martin Muench was PSM’s lead designer until moving on to a new place, so he told me all the ins and outs of them years ago.

just remember these were made specifically for drifting and this is where their design concepts came from.

the less expensive ones were the original design (with multiple revisions), and were designed to be stiff since all the buzz was going low. Plus, stiffer suspension benefitted the lower hp cars for drifting.

then PSM started getting more competitive in the drift scene and they had to support high hp builds and allow for softer setups with more travel. Martin would stand in his hatch and jump up and down and I was surprised how much softer and how much more travel they were getting. How they counteracted this for Formula d level drifting was to run full custom, ridiculously rigid sway bars (literally a solid bar with splined ends which would mate to arms that would pick up on the control arms).

I have the stiffer less expensive ones. Are those too much for you? Yes. Did I use to daily on them being 18YO until 27YO? Yes. Would I have them now on a fc daily? No, get into that in a moment. Do I like them? Yes. Does they suit my driving style? Yes, car is now a dedicated drift car with ~320whp. But man do I get tired after driving that thing for 30 minutes now. But they offer brand new replacement dampeners for $100-150 a piece. I put 50k on my original psm dampeners then replaced all 4 and it’s back to new. Also changed spring rate from original 10/8kg/mm to 8/6kg/mm with the 6k being their newer swift springs.

Now i daily a 06 Subaru sti. Stiffest whiteline sway bars I could get paired with soft twin flex z coilovers. Do I like this for my daily setup? Surprisingly yes. You can see I kinda copied what the formula d guys were doing.

I used to daily a Lexus sc400 with the stiffer PSM coilovers but it rode like a boat anyways since it was so heavy it was similar to my sti now.

what would I do if I have a got a second fc to daily or even if I upgrade to a new turbo on my current fc? I’d run the PSM softer coilovers.

You should also factor in little things like “do you mind three wheeling to get up/down driveways?” Due to the reduced travel coilovers have compared to strut/springs.

I’ve ran kyb agx back in 2007 with racing beat springs and the car was a fun canyon cruiser. Didn’t have any complaints about them. But now I’ve just had a trend of going to coilovers for all my cars and not looking back. The key is finding the correct ones in terms of ride quality, servicibility, longevity.

just my .02.

Got them on the car, I like how they fit. For some reason the rear tophats were loose, and not compressed all the way. Ended up raising my car .5", which means my stock suspension sagged 1.5".

what setup did you go with? Forgive me if you listed it above.

Kyb Agx with racing beat springs. Used my OEM tophats.

Cool. I had the same setup and loved it, especially for canyon carving.

next play with the alignment! rear toe in makes a HUGE difference.
on an NA i'd start with zero in the rear, and then start adding toe in (the bolts have marks so you can DIY, just move it the same on both sides), until you like it.
at zero toe the turn in is really aggressive, and it wants you to be on the gas before the apex, which is not always possible on the street. the stock toe setting trades the turn in for stability.

in the front i like zero toe also, it had the best steering feel. you want to run as much camber as the front parts will let you, should be -0.5 or so, and this is plenty on the street.
camber in the rear is kind of what it is, and you can buy stuff and take a little out, but its optional.

and get a good tire pressure gauge, and set the pressures when the tire is cold :) or tires...

That's the next step! What would you keep the same settings on a turbo?

with a turbo you probably want more toe in for the rear to start with. its a higher power car and you want it to be a little more stable, and then don't need to be on the gas as early, its got power, lol

I posted the paragraph below in the Tech section. It's not too active though. I'll probably get more feedback here since it is more active and related.

Looking for a wheel tire setup for my 1990 Vert. I'm on Tein S-Tech Springs with stock alignment and don't plan on changing. Will also leave my fenders untouched. My goal is to have the most grip possible without overkill. For instance, if I won't benefit from a tire wider than 225, then I'll just stick to 225. I am also willing to sacrifice the cool stretched setup look for a narrower wheel if it offers more grip. For now, I am thinking 17x8 35 Front 215/45 and 17x9 25 245/40 Rear. Future mods will probably be a RB catback, test pipe, and LSD if I can find one. Nothing crazy, just for spirit driving. Any input is appreciated.

the NA cars really benefit from short tires, 205/50/15 is way better than the stock 205/60/15. not the best looking setup though...

the Mazdaspeed fitment was 17x8 35 in the front and 17x9 30 in the rear, and give or take that is probably pretty good. you'd want a 225 on the 8" wheel and 245 on the 9"
you could also do 17x8 35 all the way around and run a 5mm spacer in the rear, or something, or skip the spacer... its just for looks

Met my goal of having a functional wheel tire setup on Tein S-Tech springs, with stock alignment specs, no fender modifications, and no spacers. Front wheels are 17x8 38 offset with 215/45/17. Rear wheels are 17x9 25 offset with 245/40/17. Huge plus the overall height of this setup is very close to stock height. I don't believe I could've gone any wider without rolling the fenders or a spacer on the front.

https://cimg5.ibsrv.net/gimg/www.rx7...3a1ba67e10.jpg
https://cimg0.ibsrv.net/gimg/www.rx7...9c4f8455f3.jpg

Thanks for the info. I have been running 215/50r16's and I liked that setup a lot. Unfortunately the tire industry stopped making that size tire.

This would be an ideal setup for me using AGX's and a Tein spring setup.. ..

I'm 4 lug, but I'm sure something out there would work if I go with the same widths and offset .

Thanks. .