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I would think that the variable is the weight of your engine + flywheel and clutch compared to a 12A + flywheel and clutch. Everything else is a constant. I mean you and your passenger were going to ride in the car no matter what.
Spring rates are a function more that just weight. Beyond keeping the car from dragging on the ground, they are a function of what is being done with the car - its intended purpose. The intended purpose drives the kind of tires being used and in my mind, tires determine allot of other things. Like suspension improvements, sway bars, shocks/struts and finally spring rates. Running all season or even summer only street tires shouldn't require extreme spring rates. R Comps or 200 wear tires up the ante.
I would think that the variable is the weight of your engine + flywheel and clutch compared to a 12A + flywheel and clutch. Everything else is a constant. I mean you and your passenger were going to ride in the car no matter what.
Spring rates are a function more that just weight. Beyond keeping the car from dragging on the ground, they are a function of what is being done with the car - its intended purpose. The intended purpose drives the kind of tires being used and in my mind, tires determine allot of other things. Like suspension improvements, sway bars, shocks/struts and finally spring rates. Running all season or even summer only street tires shouldn't require extreme spring rates. R Comps or 200 wear tires up the ante.
agreed. its like available traction vs how many degrees in roll you can accept with your suspension geometry.
the trouble with the street car is that we don't really know, and we might want it to roll a little more (Mazda uses body roll to let the driver know they just turned, so the ND miata rolls like a big sailboat...)
"Ironically, many find that the best solution to many of these problems has been to raise the car back up to its designed ride height! While this definitely eliminates geometry problems and reduces binding somewhat, rear cornering capability is still sacrificed because lateral weight transfer is increased."
It appears lowering the car amplify's handling issues....that is short of a major rear end reworking!
It won't hurt my feelings if those springs raise it a hair...and I always have the rubber spring inserts that would help if needed.
"Ironically, many find that the best solution to many of these problems has been to raise the car back up to its designed ride height! While this definitely eliminates geometry problems and reduces binding somewhat, rear cornering capability is still sacrificed because lateral weight transfer is increased."
It appears lowering the car amplify's handling issues....that is short of a major rear end reworking!
It won't hurt my feelings if those springs raise it a hair...and I always have the rubber spring inserts that would help if needed.
for the first race we had the lemons car low, and it would understeer really bad coming out of corners. race 3 it was on the RB springs, which are higher, but softer, and didn't understeer nearly as badly.
you can see its like a truck....
A 3 link Panhard setup really is a lot better than the stock 4 link and Watts linkage. I watched a video of a friend of mines car going through turn 9 at Road Atlanta which is a long high-speed sweeper. 4 times the car snapped out and caught as the rear suspension was binding. My car on the other hand is rock solid in the rear.
If you can weld it is really not that expensive to create the 3 link and Panhard system, its mostly angle iron, some tubing, and a few rod ends. It would be terrible in a streetcar though, it creaks and pops when driving around slowly in a parking lot, and acts weird when reversing. But once up to speed it is fantastic, we could make up time even on more modern cars with more elaborate independent suspensions in the uphill esses at VIR.
If nothing else I am learning how not to kill myself in this car :-) I did stand my hair up once on a sweeper going north of 100 and have not done it again...nor do I plan to. no cage in this tin can.
A person could fab up a three link that uses Rubber, Urethane or Polyurethane bushings in place of the rod ends. This could be done on the third link arm as well as on the panhard bar. Here are some examples that Summit Racing sells: https://www.summitracing.com/search/...cending&page=4
My 2012 Mustang came from the factory with a 3 link with a panhard bar and it worked really well. It was the best stick axle a Mustang ever came with. It used a stubby little third link that could replicated in an RX7 easily without needing a huge box like my install. You would have to heavily reinforce the car where ever you intend to mount the chassis side of the third link. Which would be a good excuse for a 4 point roll bar.
I would also employ the T-3 drop brackets or fab something up that lowers the lower control arm mount on the axle housing. This would allow you to lower the car and keep everything in geometry. As an example, I moved my lower control arms down 3 inches from stock.
A person could fab up a three link that uses Rubber, Urethane or Polyurethane bushings in place of the rod ends. This could be done on the third link arm as well as on the panhard bar. Here are some examples that Summit Racing sells: https://www.summitracing.com/search/...cending&page=4
My 2012 Mustang came from the factory with a 3 link with a panhard bar and it worked really well. It was the best stick axle a Mustang ever came with. It used a stubby little third link that could replicated in an RX7 easily without needing a huge box like my install. You would have to heavily reinforce the car where ever you intend to mount the chassis side of the third link. Which would be a good excuse for a 4 point roll bar.
I would also employ the T-3 drop brackets or fab something up that lowers the lower control arm mount on the axle housing. This would allow you to lower the car and keep everything in geometry. As an example, I moved my lower control arms down 3 inches from stock.
Yes, dropping the lower control arm mounts is high on my list for next steps. Since I don't need the stock upper arm mounts on my housing I can cut them off and weld to the lower mounts and call it repurposed material to fit the wacky rules.
If nothing else I am learning how not to kill myself in this car :-) I did stand my hair up once on a sweeper going north of 100 and have not done it again...nor do I plan to. no cage in this tin can.
Not necessarily an SA housing, I believe all years had a rear drum brake version. I have used both a disk brake and a drum brake housing and for my setup I much prefer the drum brake design. The caliper bracket ends up being a nice 3/8 thick bearing retainer
It comes with everything including camber plates, so it should be easier than guessing and buying parts on my own. Also got the hybrid perch upgrade, whatever that is. Ordered it with the MR2 stut inserts and 400lb springs.....hopefully they send me the right struts. Probably be a while waiting on parts and getting it together but at least I'm committed now. :-)
@ 650 I have a 1980 rear housing sitting in my garage if I ever needed it or someone needs one. I'd need to make new adapter plates for my brakes If I used it though... and thats assuming the 83 GSL SE stuff would slip right in
It's crazy how many original parts I tossed from this car, only to see what people charge for them on ebay, ah well.
EDIT:
I should also add that I can see signs up rubbing on the outer edge of my drivers side rear tire, but the passenger one has none, nor do the fender wells show anything. Almost like that might be the rub when I hit bumps.
Could it be that when I hit a bump going straight it pushed the rear to the drivers side just a bit?
Good choice. That is a modern version of the old Pro7 spec kit except that the Tokiko adj. whites are NLA. There will be a template and directions for notching the top of your strut tower to get castor adjustment. Rear ride height is created by cutting dead coils. Put weight in the car when measuring.
If you want wider track on the front, just drill new holes in the crossmember. I put my crossmember in a mill and moved the holes out a half inch each side, once I drilled the new holes I welded hardened washers on both sides for good measure.
I needed the extra track width since I couldn’t get enough camber even with the camber plates adjusted all the way in, to the point the 2.5-inch springs were almost rubbing on the strut towers.
Here's my crossmemeber. It looks like moving it out 1/2 inch would be right where a maind support is. Is your's the same? please advise if anyone else has done this.
if you bought camber plates and stuff there isn't really a need to move the control arm anymore
I think he's looking to widen the front track. Not sure why, but the simplest way would be some wheel spacers. I'm using 10mm spacers with my Enkei rims, to push them out from 38 ET to something more like a 28 ET would ride (on GSL-SE suspension). Otherwise my tires rub on my coilovers.
I forgot about my wheel spacers. You guys are probably right. no need to do it with spacers and coil overs. too much work that is probably not needed on a street car.
So GC is going to get back with me on recommendations, spring rates etc, but I had to tear stuff apart.
The tires do touch BEFORE the bumpstop hits. After removing the shocks, springs etc... I jacked it up w/o tires from the center until it hit bumpstops and did not see any binding issues. Also did that just raising one side and did not see evidence of binding (it never tried to lift that side until it hit the bump stop. All the bushings in the trailing arms and watts link are new rubber.
edit: there is probably 1/4-3/8 left before hitting bumbstops in this picture.
You'll notice with the tires on and hanging the passenger side is off the ground about 1/4 inch more than the drivers side.
Is this because the pivot point on the watts is on the passenger side?
I know I have another set of spacers laying around and may use the front spacers for trial and error looking to move the rear tires inward probably about 5mm. hopefully I have a set laying around.....
This would also help the offset from the rear and front tires.
moving slow on this, but want to get it as good as I can.
If you have spacers on the rears I would lose them…unless the inner tire wall rubs. You have 245 tires on 16” wheels, that’s a lot to ask of the stock fender/wheel well. I am assuming going to smaller wheels is not a consideration. Maybe time to consider flaring the fender or get some aftermarket flares if you still need the spacers.
I wouldn’t worry too much about how it hangs unloaded.
parts arrived. too early to give you my take, but looks good short of not including bump stops and I have not begun to evaluated install. 440lb front spring 200 rear.
here's a good way to spend a couple hundred bucks, and yeah....the havier flywheel, clutch and throwout bearing will be done while it's in the air.
also, I hate the RB bushings and have opted for rubber and drilling a hole for mounting w/o compromising OEM if needed. (the RB ones are much thinner, poly and stuckier allowing less movement of the sway bar)
my front strut housinging are getting ready for welding and supports
soo.... you're going to run poly bushings in all 4 rear arms???
no, those are rubber in the lower arms. I just left em on when I painted the arms. The upper arms are rubber original but in good comditioni i,e not cracked all to hell and still flexible. removing the original rubber from the lowers was a PITA and I realised it was still pliable and not brittle. putting rubber bushings on front sway bar at all connecting points as well. I swapped out the rear wheel spacer from 20mm to 5 mm and am changing the front from 20 to 15mm for a net gain of 10mm on each side when comparing front to rear width. The rear actually goes all the way up into the well now with no rub.....
I'll updatre my findings on this as long as there's interest.
1st picture is RB rear springs vs. the eibachi from GC. The RB (right) are thicker so they do look stronger, but the eibachi's are definitely stronger when on the car based on just jacking the rearend from the center and comparing ride heights.
now the shocks. these are the agx adjustable vs. the koni oranges for a fox body. (the koni's have been painted red. part # 8050 1033
HUGE difference in compressed height. about 1 1/2 inches. The agx bottoms too soon and doesn't get close to the rear end bump stops when jacking up until the shock bottoms. I will roll with the koni oranges, as the agx's I think would have very limited travel short of having a lowering bracket on the axle.
lesson learned.
1st picture is with both shocks fully compressed. 1nd picture is fully extended-and you can see, I already cut more than an inch off of the agx bumpstop.
I haven't messed with shocks too much; went from 34yo stock to Koni Sports and haven't looked back.
But yes, the rear Eibach springs are 200# and have dead coils so you can lower the car without affecting the spring rate. Plus they're about an inch or so lower than stock. The RB are 112# and "supposedly" lower the car 1". They actually raised my rear almost an inch, so I guess they need a few thousand miles to break-in and soften. They are designed for "sporty comfort".
The eibachi's seem to ride (what I can tell just from jacking) about an inch higher than the RB. that's with the technical how "many fingers fit between tire and wheel well analysis"
I'm cool with the Koni oranges, as when I was talking to Jay at RB he mentioned using Koni's, and I could hear the ugh in his voice when I told him I just bought agx. I beleive his comment was that the damping is different from the konis I will be running up front and the agx's. I'm just trying to "give back" to the forum on my findings as there looks to be a big difference in "yeah they fit/bolt up" and are they functional. With the agx's there is still about 3 inches left before the factory indie the spring bump stop hits. so even if I cut the springs the shock would be bottoming way before it ever had a chance to hit te bump stop. I should make up at least 1.5-2" depending on thickness of strut bumpstops I use. that should get me closer to having the factory bumpstops (inside springs) functional/ability to bottom before the shock. Perhaps when I jack up just one side and the rear end pivots a little it will get me there...either way the koni have more travel. weird because both are for the foxbody's.
either way, I won't be cutting the dead coils until I finish front as well and get it on the ground.......
01-27-22, 05:48 PM
